HomeMy WebLinkAboutAPA3486. I.: ; ·~
l , H
t · I
. ~ ~
' i l' !
I l
.I 1
I; \ r r . I .
·: r.·
\, 'I
·I! '· '
' i
: lt.
'I
'!l
I
. I
' ( .
J. 1\,,
:
I! I I [': l\ I ' I
J
.. !11 ~.
l
Ill
.I I
It i
I 1"-...-I ..
!: 'II l
i ' !'
!
I
'I
-d
·. . . . ~ .
<\,.:_~'\ ....... ! \. f.
. ; '' '; ~. :~-'il
__ i. ; ... ' ~J"'.!\.1
VA D wp.L<7.t:!~.'JJ.t 0~ Lbc l n!A$
..
IK
~~~s
-~~~
Merged Wi{jj
· -. · _ . . . -A.R.L.I.s.
A~-z,
. r\v ;)4 ~4'-
. .
. . .; .. $,~V s I T N A. . . . . . .. . ·. M'C!10~GE, AL ASKA .
r•~ · · · ' .-~ 1~7 .. ·r~i~t .. R.ANSMISSlON . SYSTEM .
· i'EHVIRON _M .ENTA .L
. .
.. '
ASSESSMENT
DRA·E;T
..
UNI TED STATES D~PARTMENT OF :Tl-fE INTERIOR
Alaska Power Administratio11
Environmental Assess.ment for
Transmission Systems for
Devil Canyon and other
Potential Units qf
The Uppe.r Susitna
River Project
September 19.75
... ------··-·--·----------.. ---~-~ ---·---~------------~-~~-----------_____ ...__
Preface
The Alaska Power Administration is cooperating with the Corps of Engineers
in their evaluation of Devil Canyon and other potential units of the Upper
Susilna River Project under the January, 1972, study resolution by the
U.S. Senate Public Works Committee. As requested by the Corps, and
consistant with APA's planning and power market responsibilities, AP A
is providing the transmission system and power market analyses for
the Corps studies.
Authorities for this work include Section 5 of the Flood Control Act of
1944 concerning transmission and marketing of power from Corps of
Engineers Projects, and the Act of August 9, 1955, concerning Interior
Department investigations of Alaska water and power development potential.
This report is a preliminary environmental assessment for the project
transmission facilities. It is being circulated in preliminary draft for
informal comments; based on comments received, the draft will be
modified and forwarded to the Corps for their use in preparation of the
draft Environmental Impact Statement for the project.
This draft addresses only the proposed transmission facilities; it does
not cover environmental impacts of the hydroelectric development and
alternatives to hydroelectric development.
A.R.L.I.S.
~\~:CHORAGE, ALASKA
Est. 1997
ARLIS
Alaska Resources
Library & Infonnation Services
Anchorage, Alaska
Title
Preface .
Contents
INTRODUCTION
Contents
DESCRIPTION OF THE PROPOSED ACTION
THE CORRIDORS
Susitna Corridor
Nenana Corridor
Delta Corridor
Matanuska Corridor
ENVIRONMENTAL ASSESSMENT OF CORRIDORS .
Summary Matrixes .
Susitna-1
Nenana-1
Susitna-2
Susitna-3
Susitna-4
Nenana-2
Nenana-3
Nenana-4
Nenana-5
Matanuska-1
Matanuska-2
Delta . . •.
ENVIRONMENTAL IMPACTS OF CORRIDORS
Summary Matrixes .
Susitna-1
Nenana-1
Susitna-2
Susitna-3
Susitna-4
Nenana-2
Nenana-3
Nenana-4
Nenana-5
Matanuska-1
Matanuska-2
Delta . . . .
ii
Page No.
i
ii
1
5
11
12
12
15
15
18
19
23
24
26
26
27
27
27
28
28
29
30
31
33
34
38
42
47
50
53
56
59
61
63
66
71
75
MITIGATION OF IMPACTS
Soils . . .
Vegetation
Wildlife . .
Existing Developments
Scenic Quality-Recreation
ADVERSE ENVIRONMENTAL IMPACTS
RELATIONSHIP BETWEEN SHORT-TERM USES OF THE
ENVIRONMENT AND LONG-TERM PRODUCTIVITY . .
IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF
RESOURCES .......... .
79
80
82
83
84
84
86
91
94
OTHER ALTERNATIVES TO THE PROPOSED ACTION 97
Sharing of Rights-of-Way . . . . . 98
Underground Transmission Systems 100
Direct Current Transmission . . . . 104
Alternative System Plans . . . . . 105
Alternative Methods of Construction and Maintenance 105
Alternative Endpoints . . . . 108
No Action (non-construction) 109
ACKNOWLEDGEMENTS . . . . . . 111
APPENDIXES I, II, III
iii
Table of Figures
Page No.
1. The Railbelt 2
2. Alternative Transmission Line Structures 8
3. Alternative Transmission Line Structures 9
4. Alternative System Plans 13
5. Alternative Transmission Corridors 14
6 Transmission Corridor Segments 16
iv
INTRODUCTION
;
i
j
;
Figure I
,. '
' UNITED STATES DEPARTMENT OF THE INTERIOR
ALASKA POWER ADMINISTRATION
THE RAILBELT
J Scolt -Mile\
25 75
2
J
INTRODUCTION
The transmission system studies for; the Upper SusitnaRiver P:i:-oject are
of pre-authorization or fea.Sibilitf grade. They consist of'evalui.:tion of
alternative corridor locations from the viewpoints of engineering, costs,
and environment; reconnaissance studies of transmission systems needed
for alternative project development plans for use in overall project
formulation studies; consideration o'f alternative transmission technologies;
and feasibility grade designs and cost estimates for the preferred transmission
plan. These studies deal with general corridor location; the ~ore 'detirlled
studies following project authorization would include final, fri the ground
route location.
The purpose of a preliminary transmission corridor survey is to eliminate
those which do not appear to be feasible, whether for technical, economic,
or environmental reasons. The preliminary su1·vey then analyzes
those remaining corridors and presents the data on the various alternative
corridors in such a way so that comparisons can be made. At this
point, it is not within the scope of the preliminary survey to show
preference for some corridors over others , only to reject obviously
unfeasible ones and to analyze the feasible ones. Further analysis
then provides the basis for the selection of the preferred system
plan.
Basically, the selection of corridors devolves on the need to transmit
pb, ,,r from a generation site --~e;Devil Canyon-Watana damsites --
tr two load centers, Anchorage and Fairbanks (See Figure 1). The
load centers are almost equally to the north and south of the Upper
Susitna complex, and are connected to each other by two basic corridors --
the Anchorage-Fairbanks Highway/ Alaska Railroad and the Glenn/Richardson
Highway, The alternatives are all variations upon these two basic
corridors, which are dictated by the topography and climate of the
Railbelt area.
Although the most economical transmission corridor is theoretically
a straight line joining generation site and load center, physical and
social factors force deviations from this shortest-distance ideal. Thus,
it can often happen that physical and social factors are in opposition
to .economic factors, and a balance has to be found. This striving
for a balance results in alternatives; from which, eventually a most
desirable corridor has to be chosen;
3
The method of analysis for the altematives uses the shortest segments
between intersections of altemative corridors as the units of evaluations;
these may vary in length from 15 to over 100 miles. These segments
were evaluated on a set of physical and social criteria, but are not
to be compared to each other. These evaluations are shown in the
matrixes on pages 19-22 and pages 34-37.
Using these segments as basic units in combination, several alternative
corridors can be devised and can then be compared. To save repetition,
segments common to altemative corridors being compared can be omitted
from the comparison. The corridor presented in the Description of
the Proposed Action is that route which produces the minimum adverse
impacts consistent with economic feasibility.
4
DESCRIPTION OF THE PROPOSED ACTION
DESCRIPTION OF THE PROPOSED ACTION
The proposed action includes the.construction and operation of a transmis-
sion system to deliver power generated by dams and powerplants
on the Upper Susitna to the two primary load centers of Anchorage
and Fairbanks, and perhaps other load centers that may prove feasible.
The design and location of this line will provide for the mast .economical
construction and reliable operation consistent with minimal damage
to the environment. If approved, construction would begin in 1986.
A subsidiary purpose in the construction of this line will be the inter-
connection of the two largest electric power distribution grids in the
State of Alaska; this will result in increased reliability of service
and lower cost of power generation.
The proposed corridor runs from the Devil Canyon powerhouse west
\c. Gold Creek, then southwest along the Susitna River and the Alaska
Railroad to Talkeetna. From Talkeetna the corridor follows the east
bank of the Susitna River to the Nancy Lake area and then due south
to Point MacKenzie. The second half of the corridor runs from Gold
Creek north to Chulitna and then parallels the Anchorage-Fairbanks
Highway and the Alaska Railroad through Broad Pass, the Nenana
Canyon, and to Healy. From Healy the corridor will follow the existing
GVEA 138 kv transmission line to the existing substation at Gold Hill
:r· 'Cster, although the existing right-of-way may not necessarily be
uc.ccl. The section of corridor from Devil Canyon to Point MacKenzie
., about 140 miles; fromDevilCanyon to Ester is about 200 miles.
The voltage of the section from Devil Canyon to Anchorage is 345 kv
and that of the section from Devil Canyon to Fairbanks is 230 kv.
Both sections are double circuit and will require a cleared right-of-
way of approximately 125 feet .. Towers will be either steel or aluminum
and of the free-standing type; although depending upon final design
and local conditions, guyed towers may be used in some areas. The
conductors are of aluminum conductor reinforced with steel.
The sequence of final routing. and construction follows a general sequence
of final survey to locate towers and clearing widths, clearing and
access construction, erection of towers, stringing, tensioning, and
right-of-way restoration.
6
The final survey will involve photogrammetric determination of clearing
widths to minimize the amount of clearing; not only is this more economical,
but it also avoids the method of total clearing within set distances
from the center line. Final tower locations are also determined at
this time; tower spacings are usually on the order of four or five
per mile, but will be spaced closer as conditions warrant.
Tower designs will be determined in the final design; varying conditions
may call for several designs being used. Free standing towers are
more easily constructed on sections with good access roads; guyed
towers are more suitable for helicopter construction. Various guyed,0
and free-standing tower designs, for single and double circuits, and
several alternate structures for use in lieu of towers in special circumstances
are shown on Figures 2 and 3.
In heavily forested areas, clearing will be done by brush blades on
bulldozers and by hand removal of individual danger trees outside
01 'he main cleared strip. Danger trees are those trees that may grow
to such a size within five or ten years that they may fall within a set
distance from a conductor or tower. Distance from the center line,
growth rate, and maximum obtainable height will determine danger
trees. Disposal of cleared materials may vary from selling of merchantable
timber to chipping or burnii1g of slash.
In sections where permanent access roads are required, the road will
bP huilt and maintained to a standard suitable for four-wheel vehicles.
Not all sections will have access roads; in critical areas, winter con-
~ d'Uction, or helicopter construction will be used.
Right-of-way restoration after construction includes removal of temporary
structures and temporary roads, disposal of slash and refuse and
revegetation. In some cases, it may be necessary not only to maintain
access roads, but to upgrade them if it is determined by the State
Department of Highways that such a road would be a suitable addition
to the secondary road system.
Along some sections, periodic suppression of tall vegetation will be
necessary. This will be accomplished with manual application of
herbicides or hand clearing, or both. Vegetation maii,tenance will
need to be repeated every five years or longer.
7
----------~----------------------------
~---------54'-------~
-.--~-I
! _;
m m
SINGLE CIRCUIT SINGLE CIRCUIT
FLAT CONFIGURATION DELTA CONFIGURATION
FREE-STANDING TOWERS
I I • •
SINGLE CIRCUIT--
FLAT CON_FJGURATION
Sautee' Edison ElEctric lnsHtute
. GUYED TOWERS
SINGLE CIRCUIT
FLAT CONFIGURATION
r~-
1 !f'-.---r---"';1
I I !
~
I •
I • • ~--4d--~
DOUBLE CIRCUIT
STACK CONFIGURATION
NOTE• STRUCTURES DEPICTED ARE
DESIGNED FOR 345 KV. 230KV
STRUCTURES ARE SLIGHTLY
SMALLER.
UNITED STATES DEPARTMENT OF THE INTERIOR
ALASKA,POWER -AOMINISTRATIPN
ALTERNATIVE
TRANSMissioN' -. u NE
STRUCTURES
.
-"'" ly "
~ .\'--
L r-~j
-"' "'
v
SINGLE CIRCUIT
DELTA CONFIGURATION
GUYED TOWER
l 56'~
:-=1 ~ ~="j"'=l ~ =j
• • •
SINGLE CIRCUIT
METAL H-FRAME STRUCTURE
Source' Edison Eleclric Institute
SINGLE CIRCUIT
METAL H-FRAME STRUCTURE
SINGLE CIRCUIT
WOOD H-FRAME STRUCTURE
SINGLE CIRCUIT
WOOD H-FRAME STRUCTURE
NOTE• STRUCTURES DEPICTED ARE
DESIGNED FOR 345 KV. 230KV
STRUCTURES ARE SLIGHTLY
SMALLER.
UNITED STATES DEPARTMENT OF THE INTERIOR
ALASKA POWER ADMINISTRATION
ALTERNATIVE
TRANSMISSION LINE
STRUCTURES ::!!
oQ c
Ol
A. P. A.-JANUARY 1975 VJ
Periodic inspection of the line will be done from the air, complemen.te'~
by less frequent inspection from the ground. Inspection will reveal<'~~
potential failure of tower components such as vibration dampers, ins~llators,
and guy lines; condition of tower footings; condition of conductor;
presence of danger trees; and condition of access roads.
'-:<:<
Alternative methods of construction and maintenance which were ref~fred
to above, will be discussed in greater detail in the section Alternativt;s
to the Proposed Action.
/ ,'-:
The preferred system plan was chosen by Alaska Power Administratf(ll'l
after preliminary study of all feasible corridors joining the Upper ;Cc
Susitna complex to Anchorage and Fairbanks. The most feasible cqfgfdor
was selected on the basis of cost, reliability, and potential enviroriffi'!iDtal
impact; the remaining corridors represent alternatives of varying ~ ,
degrees of feasibility.
The following sections will discuss the proposed corridor and the
alternative corridors equally; no differentiation will be made.
reflects the process by which the preferred corridor was chosen,
in which no preference was given to any one corridor until all
had been given equal consideration.
10
', :_:_::::',';,~~;
---r<
THE CORRIDORS
THE CORRIDORS
The alternative system plans represent only general corridors, and do not
attempt to define an actual right-of-way. Thus the alternatives do not
distinguish among many minor variations, and as a result, are fairly
flexible.
There are four groups of alternatives: first, those that lead from
Devil Canyon-Watana to Anchorage via the Susitna watershed; second,
those that lead to Fairbanks via the Nenana and Tanana drainage; third,
those that lead to Fairbanks via the Delta and Tanana drainages; and
fourth, those that lead to Anchorage via the Copper and Matanuska
drainages (see Figures 4 and 5, and Strip Maps in Appendix II).
Susitna Corridors
There are basically four feasible c· -ridors which connect Devil Canyon to
Anchorage via the Susitna drainage. All four of these incorporate the
segment that runs from the endpoints of Point MacKenzie to Talkeeina,
so this segment can, therefore, be treated as separate and not included
in a comparison of the alternative corridors.
Of the four corridors that run from Talkeetna to Devil Canyon-Watana, the
first is the southern half of the proposed corridor, which follows the
Susitna valley north, paralleling the Alaska Railroad to Gold Creek, where
it a so leads east to tie into Devil Canyon-Watana (Susiina -1, in Figure 5) .
fhe next, and farthest west parallels the Anchorage-Fairbanks Highway
through Denali State Park, along Troublesome Creek, eventually leading
east to tie into Gold Creek and Devil Canyon-Watana (Susiina-2). The
third goes up the Talkeeina River and gaining the ridge to the east of
Disappointment Creek, leads north to the ridge leading to Devil Canyon
(Susitna-3).
The fourth and most easterly corridor follows the Talkeeina River to
Prairie Creek, which it follows to Stephan Lake, halfway between Devil
Canyon and Watana (Susitna-4).
Ken ana Corridors
There are five feasible corridors connecting the Upper Susitna with
Fairbanks by way of the Nenana River. The first is a corridor paralleling
the highwa" and railroad from Gold Creek to Cantwell, to Healy, and to
Fairbanks. This is the northern half of the preferred corridor (Nenana -1,
in Figure 5).
12
230 KV
Double CircuitHeoly
NENANA I CORRIDOR
13
FAIRBANKS
DELTA
CORRIDOR
Figure 4
230 KV
Double Circuit
Paxson
'"'11r10n STATES DEPARTMENT OF THE INTERIOR
ALASKA POWER ADMINISTRATION
DEVIL CANYON PROJECT
ALTERNATIVE
SYSTEM PLANS
Scale in miles
i
i'''!OPOSED
CORRIDOR-
14
Figure 5
DELTA CORRIDOR
, UNITED STATES DEPARTMENT OF THE INTERIOR
ALASKA POWER ADMINISTRATION
DEVIL CANYON PROJECT
ALTERNATIVE
TRANSMISSION CORRIDORS
Scale in miles
50 75
l The second duplicates the first corridor to Cantwell, but then leads east
paralleling the Denali Highway, north up as far as Wells Creek and over
the pass to Louis Creek, continuing over the Dean Creek Pass to the
Wood River. It then follows the Wood and Tanana Rivers to Fairbanks
(Nenana -2) .
The third corridor, (Nenana-3), duplicates the second to Dean Creek,
where it then continues up Yanert Fork and over Moody Pass, ending up
at Healy and joining the first corridor.
Corridor four (Nenana -4) leaves Watana and heads north, emerging
onto the Denali Highway near the Brushkana River. It then leads west,
goes up Wells Creek, and joins corridor three to Healy and Fairbanks.
Corridor five starts the same way as corridor four, except that instead of
going over Moody Pass to Healy, it leads east over Dean Creek into the
Wood River, and then leads north to Fairbanks, (Nenana-5).
Delta Corridor
There is only one basically f::asible corridor along the Delta River.
This corridor leaves Wat::ma ciamsite and leads east down Butte Creek
to the Denali damsite and co,,tinues east along the Denali Highway. It
then proceeds north near Paxson over Isabel Pass and parallels the
Richardson Highway into Fairbanks.
]I"" i'anuska Corridors
There are two corridors utilizing the Matanuska Valley as access to
Anchorage. The first follows the Delta route to Paxson, then leads
south to Glennallen. It then goes west, over Tahneta Pass, and into
the Matanuska Valley, tying into Point MacKenzie.
The second corridor connects Watana to Vee damsite, leads southeast to
the Little Nelchina River, which it follows to the Glenn Highway and
corridor one, which it follows to Point MacKenzie.
In order to more easily assess environmental impacts of a transmission
line on these corridors, they are reduced to smaller units, or corridor
segments. A segment is thus that part of a corridor, either between two
intersections with other corridors, or between an intersection and one
of the endpoints near Anchorage or Fairbanks. The length of a segment
15
Ester
16
Figure 6
!C' "''""'"n STATES DEPARTMENT OF THE !NTER!OR
ALASKA POWER ADM I N!STRATION
DEVIL CANYON PROJECT
TRANSMISSION
CORRIDOR SEGMENTS
Scale in miles
is not standard, nor is the length set by any physical criteria. These
segments are the minimum number of units that can be combined to form
the previously described alternative corridors (see Figure 6).
Assessment of the existing environment and of impacts of a transmission
corridor will be done on the segment level. As a convenience, these
assessments will be tabulated on matrix form, differentiated as to
environmental inventory and assessment of impacts . The Susitna and
Nenana corridors will each have separate matrixes; the Matanuska and
Delta corridors will be combined because of the fewer number of alternatives.
Segments are labelled in two ways; the first is a nodal label, in which
the nodes identify the segment (e.g. Wells Creek-Dean Creek), the
second is an assigned number which corresponds to a key map. Both
labels are used on the matrix. Matrixes will be found on pp. 18-20 and
PI-'· 33-35.
ENVIRONMENTAL ASSESSMENT OF CORRIDORS
17
-~
I
ENVIRONMENTAL ASSESSMENT OF CORRIDORS
Matrixes for Inventory of Corridor Segments:
The following matrixes are for inventory of the environment by nine
categories. The definitions of the categories and general information
are given in the Appendix I. The process from which the 22 corridor
segments are derived is explained on pages 10 -15.
Due to the problems attendant to reducing such large amounts of information
to such a constrained format, it would appear that some of the categories
are not treated on the same level of detail as others. Specifically,
climate, which is a less-studied and less stable situation than soils,
which are treated on a more detailed leveL Only data that was found
by searching the literature was entered. Thus, for example, caribou
may be found in a segment although no mention of it is made in the
matrix. One advantage to the matrix system of presentation is that
i' is easily updated; thus, descref~"ncies brought to our attention
can easily be changed.
The constraints of this format dlso oblige the use of abreviations;
MMCPM zone stands for the Mount McKinely Cooperative Planning
and Management zone, GVEA 1efers to the Golden Valley Electric Associa-
tion, MEA refers to the l\htanuska Electric Association, and the ARR
is the Alaska Railroad.
Tl c land status entries are based upon the land status situation of
'· rch 1974. State selections refer to not only patented, but also all
pending and tentatively approved State selections. Native village
deficiencies and regional deficiencies (NVD and NRD) will perhaps
be the most unstable areas at present, so it is quite likely that the
entries regarding these lands may not be presently valid.
19
Point MacKenzie -
Talk.eetna
TOPOGRAPHY/GEOLOGY
84 miles.Hig)lest point 500'at
Talkeetna to sea level at Pt.
fotKenzie.Wide river valley;
east bank more rolling than ex-
tremely flat west bank.Valley
widens and flattens to south.
Poorly drained,many bogs and
lakes,
SOILS
Glacial debris-groLald ..,raine
altered by outwash,flood plains,
silt,sand,gravel,SWa.q>5 and
lakes.Discontinuous permafrost.
Poorly-drained fibrous peat soils,
vulnerable to frost heaving and
well·drained strongly acid soils.
Low to mediun erosion potential.
VEGETATION
Bottomland S]>ruce-poplar,lowland
'S]>ruce -hardwood,muskeg/bog.
WILDLIFE
~bose everywhere,black bear,.
fur bearers.
SUSITNA GORRlDORS
INVENTORY
CLIMATE
Transitional -milder and wetter
in southern end of segment.
EXISTING DEVELOPMENTS
Various small towns along trans-
portation corridor.several
recreation areas and ~grounds
along highway.
LAND OWNERSHIP /STATUS
Primarily State potential sel-
ections j indeterminate (as of
3 -74)Natlve villages of Mmtana
Creek,Caswell,and I<nik.
EXISTING RIGHTS-OF-WAY
Anchorage:Fairbanks Highway,
Alaska Rallroad,MEA lines.
SCENIC QUALITY /RECREATION
Recreation areas:Big Lak.e,PDcky
Lake (Sucker Lake),Nancy Lake,
Willow Creek.~'edilml to low
scenic quality in south.~lediun
to hig)l around Talkeetna.
Talkeetna -Gold Creek
via Troublesome Creek
(2)
42 miles.Rolling hig)l plateau to
north,becaning flatter,lower,
forested hills to south.~'erges
into SUsitna Valley.Hig)l point
around 2000'.
In northern part,well drained
thin soils,stTOtlgly acid;deep
pennafrost table.Southern part Bottomland spruce-poplar,upland
poorly drained fibrous peat vul~spruce·hardl.'OOd,low brush,nus-
nerable to heaving and well'drained .~&!b?g.Alpine tundra (7).
strongly acid soils.Slopes on
north ')121.Low to mediun erosion
potential.
Caribou might be present,black.
bear,rJl)Qse.TTansitional/mo\.Dltain..None.State selected land.
Park.Denali State Parallels Anchorage-Fairbanks
Hig)lway in midsection.
Runs throug)l Denali State Park.
Hig)l scenic quality,penetrates
Denali State Park.
Talkeetna -Gold Creek
via Alaska RailrOad (3)
Talkeetna River (4)
Disappointment Creek
.(5).
Prairie Creek -Stephan
Lake (6)
Dcvi I Canyon -Gold
Creek (7)
38 miles.Hig)l point 900'.Vee
Canyon •moderately narrow valley
fl?"r widening to the south.
8 miles.500 I elevation.Wide~lling valley bottom.Many lakes.
37 miles.3800'elevation.
Rolling hills increase :in eleva-
tion to high plateau with several
incised creeks..
'42 miles.2200'elevation.Wide
valley narrows gradually as it
rises to wide,flat,poorly
drained pass.
14 miles.1500 I elevation above
damsi te.Narrow canyon incised
.in plateau widens as plateau
.changes to rolling hills to west.
Well drained,gravelly,strongly
acid soils.Southern third,poorly,
drained,fibrous peat and "''ell
drained,stTOtlgly acid soil.
Slopes on north >12'.Low to
medium erosion potential.,..
Poorly drained fibrous peat,
vulnerable to heavi.{lg and well
drained,strongly acid soils.
Slopes <12'.Low to mediun
erosion potential.
w,;ll drained,strongly acid soils
thin in northern parts in con·
junction with very steep and
rocky ground.Gravelly soil.
Slopes>12',Low erosion
pot"!'tial.
Well drained,strongly aCid,
gravelly soils.Slopes >12'.
Low to medium erosion potential.
Well drained,strongly acid,
.gravelly soils.Slopes >12'.
Low to medium erosion potent~al.
Bottomland spruce'poplar,upland
spruce·hardwood.
Bottomland S]>ruce-poplar.
Bottomland S]>ruce-poplar,upland
.spruce·hardwood,low brush,JII1S-
keg/bog and alpine tLaldr~.
Bottomland spruce-poplar,upland
spruce-hardwood,low brush mus-
keglbog in pass area.'
Upland sproc~-hardl-ood.
.~bose,black bear,fur bearers.
~bose,black bear,fur bearers.
~bose in lower elevations and
stream bottoms,black and griZZly
bear,possible caribou range.
~bose,black and grizzly bears.
~bose,black bear.
Transitional.
Transi tional.
~1c)lmtain/transitional.
lobuntain/transi tional.
Transi tianal.
T""ns of Gold Creek,CUny,Lane
OIase,and Sherman (railroad
stops).
None.
None.
None.
None .
State selected land,borders on
Denali State Park.
State selected land.
'1/3 State selected land,2/3
Native reglonal deficiency.
1/3 State selected land,2/3
Na~ive regional deficiency.
112 State selections,1/2 Native
regional deficiency.
Parallels A.R.R.
None.
None.
None.
None.
Parallel east boLaldary Denali
State Park.
~~ium scenic value,relatively
accessible by boat.
Hig)l scenic quality area -rela-
tively inaccessible.
Some recreational use of lakes in
Prairie Creek Pass area.High
scenic quality -accessible by
float plane.
H~gh scenic quality·iJriJressive
r~v~T valley.Limited accessi.blllty,
yi miles.2200'elevation.High
Devil Canyon -Stephan plateau wi.th deeply incised creeks
.Lake (8)and rivers.
Stephan Lake -Watana ~ra:~~SbC)l~~lb;lmI~O~~n~~
(9)and south,incised river and creeks
htell drained,strongly 'acid,
gravelly soils.Slopes>12'.
Low to.Vledi.um erosion potential .
Well drained,thin,strongly acid
soils with deep pennafrost table
and poorly drained soils with
.shallow to deep permafrost table.
Gravelly soils.Slopes <12'.
Medium erosion potential.
"Upiand S]>ruce-hardl-'OOd in river
·.and stream valleys,low brush and
bog/muskeg on plateaus.
Upland spruce-hardwood in river
and creeks,brush and bog and JIUS-
k:g on plateau.-
M:>ose,black and griZZly bear,I
fur bearers.
~bose,black and griZZly bear,.
fur bearers,caribou.
fok>untain/transi tional.
~iJuntain.
None.
None.
~tive.regional deficiency,power.
s>te wlthdrawal for Denali Canyon
Reservoir.
Native regional deficiency,power-
site withdrawal for Denali canyon .
Reservoir.
None.
None.
Hig)l scenic quality -limited
accessibility.
Recreational use of Fog Lakes
area.Hig)l scenic quality -
accessible by float plane.
20 SUS/TNA INVENTORY
I
I
TOPOGRAPHY/GEOLOGY SOILS VEGETATION WILDLIFE
NENANA CORRIDORS
INVENTORY
CUMATE EXISTING DEVELOPMENTS 'LAN'D OWNERSHIP/STATUS EXISTING RIGHTS-OF-WAY SCENIC QUAUTY/RECREATlON
62 miles.2400'elevation.Wide Well drained,thin,strongly acid High scenic quality along IN)st ofvalleywithmoderatelyincisedsoils,deep pennafrost table and Bottomland sha~e and poplar,lq)-~bose present,especially in lower Iotlultain/transition.SumUt weath-several small COIlIIUIities alon~
Gold Creek -Cantwell rivers in sooth,becoIning very poorly drained with surface peat State selected land,Native village this route,southem part borders
wide depression in Broad Pass,land spruce-rdwood,low brush -valleys,black bear on forested er:annual telllpllrature 25.9 F.,transportation lines.FAA strIpS 'M?mrage-Fairbanks Highway,Alaska Denali State Park.Major views to(10)traveling NE,with rolling val-and shallow pennafrost table.bog/lIl.ISkeg.areas.annual precipitation 21.85".at SUrmit and cantwell.""<horn withdra"1I.1,area within ~M:A-l Zone.RaIlroad.Io'est llJ'ld north of transportationBothsoilsgravellywithllIediunpartbordersDenaliStatePark.ley bottom.erosion potential.Slopes <12\.corridor of Alaska Range.
en slopes>12\:Well drained thin
46 miles.,nOD'at Deadlllan Pass.strongly acid soils with deep per-
Caribou concentrations,moose in Mediun scenic quality but inaCces-Series of moderately wide valleys mafrost table,gravelly.en slopes Upland spruce-hardwood,lOWland lower valleys and plateaus,Ilall ",",.ll-l "'ithdrawal,nortllem part withWatana-Wells Creek via joined by gentle passes,cuhlinat-<U\:Poorly drained loamy soils spruce-hardloOOd,low brush -IIl.ISkeg ~1clImtain.None.sible.
wi th surface peat and shallow per-I'X'g.Alpine tundra.sheep in high areas,black bear on in ~n::1'!>t Zone,Brushkana Creek (II)ing on wide valley of Brushkana mafrost table.Mediln erosion po-forested areas.
Creek and Nenana lliver..tential.
22 miles.2500'elevation.Valley
lI'ell drained,thin,strongly acid
soils with deep pennafrost table
Wells Creek -Cantwell ,t lI'ells Creek widens to west,with in conjunction with poorly drained l.o\dand spruce-hardwood.Caribou concentrations,moose pre-'Denali Ilighway,SOlTle settlement Native village withdrawal,State High scenic quali ty good views toflatbottOlllboundbyIIQlIltainstosoilswithsurfacepeatandshallowsent,Dall sheep in high areas,~Iountain.I.Ienali Highway.
(2)riorth and south.permafrost table.~lediln erosion black bear in forested area.along highway.selected land,within ~"l:R>t Zone.all sides.'
potential.Gravelly soils.Slopes
<12\.
39 miles.2200"at Cant'oo-el1.Wide
valley narrows to north to series ,1I'ell drained nonacid bT'O'on gravel Mountain.Hi~winds reported by Several small cormunities .•<-
of tight canyulS separated by wide soils in conjlmCtion with poorly Upland spruce-hardwood,lowland caribou concentrations south of GVEA to have ocked down 138 KV Kinley Park on ..-est bank of Nenana High scenic quality,iJI1lressive
Cantwell-Healy (13)valley of YllJ'IlCrt Fork.North of drained loamy soil with surface spruce'hardlolXld,alpine tundra,canyons,JOOOse present in more tow"crs.McKinlr weather:annual River.Flight strips of Yanert State selected 181ld 81Id U::Kinley Anchorage-Fai Thanks HIghway,Alaska canyons interspersed with open
canyon to Healy is wide rolling peat and shallow permafrost table.'SOlTle low brush -bog/lIL1Skeg.open parts of c81lyons,Dall sheep tCfl1)Crature 27.F.,annual precip-and ~k;:Kinley Village and Healy ~tional Park,within /If.OlM Zone.Railroad.areas of llllre distant views.Good
plain with stream terraces adjacen High erosion potential.Thin rocky in high areas,black bear present.itation 14.50".(FAA at /.t:Kinley).possibility of viewing wildlife.
to Nenana,Denali fau!t crosses a soils and rock on lower canyon.High tourist trade.
Windy.
2611liles.4,000'at Wells Pass.
",1"'"Wide valley narrowing to the north LQiland spruce-hardwood,Caribou concentrations,moose in
\~ells Creek -Dean to pass with Louis Creek,a high Thin soils and rock,very steep spruce-hardwood,low brush-nuske~h IOh-er elevations,flaIl sheep in ~Iountain,None.D·l and State selected land,Wells ",",.High scenic quality but inacces-
Creek (14)saddle.Abrupt drop into Louis slopes.Level areas poorly bog,and alpine tmdra,High bros hiRh areas,black bear in forested Creek within ~"mt Zone.sible.
Creek,down to Yanert Fork and drained.in Yanert Valley:area,griZZly bear in higher areas.
extTell'lely wide aggrading channel.
24 :.ules.
Thin rocky soils and rock,steep
Lowland ;pruce-hardwood,upland2700'at M:lody Pass.slopes on upper parts.Steep .Caribou concentrations,moose in
North up wide valley and over wide gravelly poorly drained soils wi th spruce-hardwood,low brush -1IL1S-lower elevations,naIl sheep in
MOuntain.
None in IDOUIltains;llsibelli Coal Medium scenic quality but inacces-
Dean Creek -Healy (15)flat pass into sinuous v-canyon,variable pennafrost table in con-keg/bog (in pass area),alpine high areas,black bear in forested Mines at Healy.State selected land.None.sible.
~~into wider val~ey of Heal junction ....i th steep gravelly ..-ell tundra (ridges along lower Moody areas,griu.ly bear in higher
drained gray soils,shallow bed-Creek).areas,
=k.~Ioderate erosion potential.
97 miles.1400'at Healy.350'at Healy-Nenana:Well-a~~eo.orown Bottomland spruce-poplar,uplandNenana,1500'in Goldstream Hills.gravel soils and poorly drained Caribou concentrations on west
Wide,terraced valley of Nenana loaDlS with surface peat,shallOW"·spruce-hardwood,lowland spruce-bank of Nenana bet\o.'Cell Healy and ~ll ~ormunities along transporta-Primarily State selected'land with High scenic quality near Healy and
flows north to merge with Tanana pemafrost table.Nenana-Ester:hardwood,low brush -IIL1Skeg/bog,south of Clear AFB,moose along Interior.Healy ..-eather:~w1 !lon llnes.Several flight strips.sane existing federal ....ithdrawals ~rage-Fairbanks Higtr..,-ay,Alaska the Goldstream Hills.Low to Ired-Healy to Ester (110)flood plain.Over Tanana lliver well-drained brOW"l\108Jl:S with level areas tend to bogs,north ,,'hole route,black bear in for-tetTflCrature 26.4°F.,annual pre-FAA station at Nenana.Tm.n of and Native village withdrawals.Railroad,GVF.A 138 lev,line.iun scenic quality along lower
trending N.E.are low rolling hills lenses of fines and poorly drained slopes are lowland spruce-hard-ested areas.cipitation 11.34"Nenana,Clear ~lilitary Reservation,,Nenana lliver.Dry Creek Archeo-
Active fault at Healy.Ice-rich loams with surface peat,shallOW"wood,slWly slopes are upland logical Site (National Register).
clay and silt at M:lody.pe~frost ~~~:l MediUlil to high spruce-hardwood.
110 Nles.4300'at Dean-Wood Pass llpper Wood RIver Thin rocky soils Alpine tundra,high brush,lowDeanCreek,sharp mountam valley Lower Wood lliver:Poorly drained Caribou concentrations in upper
beads in high pass into Wood lliver,108lllY soils with surface peat and brush bog and lIllSkeg,moist tundra Wood River,moose present in 1000'er Primarily State selected land ",",..Scenic quality ranges from highDeanCreektoEsterau-shaped glacier valley with ago shallow permafrost table.Shallow lowl81ld spmce-hardwood,lower elevations and stream bottoms,Dall ~lounta in,IIIISt part Interior.Blair lake Military Reservation.Na~i~village deficiency and'
(Wood P..iver)(17)t~stream,which eventually slopes.Some "'ell drained bl"O\oTI Wood lliver is area of interspersed sheep on high areas of upper Wood eXlstlng Federal withdrawals.to mediln but inaccessible.
s onto Tanana flood plain,nonacid soils.Jno,'to medium ero-bogs and levees and oounds wi th lliver,black and grizzly bear pre-
~at and poorly drained.sion potential.corresponding vegetat~\'e pattems.sent.
I
I
I
I
I
I
21 NENANA INVENTORY
98 !liles.4000'neal'Rock Creek.Low a:reu:poorly drained soils
Varies no.wide,flat,open tel'-with surfac;e~l and shallow Tana1e Lakes Archeological Dis-rain to rolling,post-glKial pe1"l'llfrost Ie.Textures
None.Low to no potential rOT State selections,Native regiON.!triel (Natimal Register).Denaliterrain.Valley floon are !'lIIl&e rn:.gravelly to fine.Nelchina aribw ben:!(61,000 in deficiency withdnwals,.00 0-1 ~.Tangle River BoatWalanatoPaxsonviausl,&).ly wide and flat,poorly Slopes:Men-drained,thin.Lowland SPru::e-hanlwcod;l4'bnd 1961)•.:lOSe present in moderately ~rcial fOTeSting and agri·wi~.Denali Dusite with-~li ttig.t..,.y.~.High scenic quality -Butte C",ek (18)drained.)Wty lakes,kettles,st1"Ol'li1y K.id soils;deep $pnJl:e-ha:rdwood.low brush bog high ~n.bl-el:;and grizzly Iobmuin.culture due to soils.'..-l.Ana anud Denali D!la.easily accessible with good viewsand.,rainal ridges east to J.tlc-~~frost table.Medi_to and _keg mist tI.ntr1o.bean,wolves present.site u within Nt.lClinley co-to north of Nt.Hayes sec::tion oflarenRiver.This ~land area p eTO$im rrtential.Large "P.Manaa-nt :one.Alaska 1WI&e.Clea~ter andcmtaiMaltiplanationterncesareasareentresoilsoflow-~itheater M:uttaiM.and is underlain with discm-lyinc type w,.ich is very vul-
tiroous penaa{rost.nenble to frost heaving.
"'?":.areas:_I"OOTly dn.iJ'Ied soils
with surface peat and shallow
Big DeiU"bison herd fall range Proposed Historical Sites:R8pids152ailes.2700'at Paxson,3000'pe~frost table.Slopes:Well Considerable setUement uaJ.g }lJntrn,Lodge,Mile 220;Bil DeltaatIsabelPass.Ilolling hilu at drained soils;sc.e thaw;SOIIle (200 ant.-ls),0.11 sheep am:on hiJhway near Fairbanks.Military St.lte selections.utility corridor Richardson Highway,Alyeska bdhous.e,Mile 252.Cleannater.Paxson lead to high fUlt pass and conta.inirlJ lenses of fives.MI range of vegetative types m Alaska RMge,blkk and griz:tly .bases.tOIo1'lS of Big Delta and Pipeline .DJnnelly,Fieldrn,~.waysideh,:.uon to FalrbUlka north to U-shape Ib.ntain Valley Shallcw to deep pe1"llla-frost table.rrc.botta.land spnEe-poplar bears,good cb:k habitat in sloughs Interior.OBlta .Junctim,potential agri-and ailiury reserwtions.Parks.Delta~.proposednearRainbowRidge-Black Rapids if wty.Medi..eTO$ion poten-to alpine nnlra.and exbends of 0Iena and Salcha culture at Big Delta-Clearwater Delta Wild River_excellent views
(9)area.RolliJlg hills near IQ-l_.tial.fbdcy son and bedrock in Rivers and aorainal ponds of Don-W<e.of Alaska Range f~Bif Ddtanellyn:.e del;rease to flat land Delta Canyon area.ThiJrotropic nelly I:aile.sooth.Easily accessib e.by Eielsm AfB.silts just north of s.-it ~.
PenDllfTO$t c:ontinDls froM 5hzw
Creek to Tanana River.
Low areas:Poorly drained soils
with peaty surface;shallow per-
To east is Lake Louise o:;IIIIIplex of90ailes.5000'elevatim at plat-_frost table.Med1ta erosim rocreational land.High sceniceauatheadofLittleNelchinapotential.~lands:"'ell Upland spruce-hardwood;low Nelchina ClIribca.i herd,..:JOse in
_.
Low to no potential for Native re,ionaJ deficiency and quality -land of la)(es and ponds.Watana to Slide Mtn.River.Generan,flat and rolling drained thin soils with dark brush bog and -...skeg;BOist IIlOderately high I1lIIbers,black Iobmtain/interior.carmen;:iu forestry or agricul-state selections.Wauna and Vee
_.
Accessible by dirt road froMviaVee(20),terrain;a high plateau extending acid surface;deep pertlll.frost """'rn.and grinly bears,wolves present.·ure b to soils.powersite withdrawds.Glenn Highway to Lake Louise orfroMSusitnaRivertoLakeLouisetable.GTavelly tenure.Med-
by nO/lt plane.area.rt.mJerous lakes and bogs.i ..erosi(l(1 potential.,.~.
frost is continuous on this
poorly drained,ice·rich area
of fino scdilllents.
Nelchina ClIriboo here,very high Sourdough Lodge (National Register)
~lajor portion of route:Poorly Proposed historical sites of !-k:-IIlOOse concentrations on Q.llkana
Towns of Glennallen,Q.llkana,Creary's Roadhouse,Mile 104;drained,fine grain soils with drainage.black and grizzly bears,Gakona Roadhouse,Mile 132;Pax-119 llliles.2100'at Paxson.surface peat;shallow pennafrost wolves present,good duck habitat settlement along highway.Recrea-State Selections and Utility son Lake Wayside Park;SourdoughPaXJIontoSlideMIn.Rolling hills and flat plateaus,table.Medilml erosion potential.Lowland spruce-hardwood,low brnsh along GJlkana fran S\mmit and Interior.tional development north of Glenn Corridor.Native village with-Richardson Highway,Alyeska Pipe-~d,Ory Creek Wayside,via.C:cnn:>lIcn (21)cut by incised streams.Poorly Upland areas:Well drained,bog and lrUSkeg.Paxson Lakes,Thaw Lakes.GJlkana Highway.This area has low drawaIs of Mkana,Gakata,line,Glenn Highway.Little Nelchina,Tolsona and Lakedrained,having lIDJIy lakes Md thin,strongly add soils with is most iq)ortant fishery in Cop-potential for carmercial forestry Tazlina and Copper Center.Louise Waysides."'-'''"""onbogs.deep pennafrost table.Penna-per River system.Paxson and and agriculture due to the IAHP
Lake Recreation Area and Q.llkanafrostiscontinuousinthisSumlitLakesare~rt.ant fish type soils present.
Wild River.High to lICdiUIIIarea.lakes.scenic quality.
138 miles.JOOO'at Tahneta Pass.
Knik Ardleological SiteWidepassapproachedfromeastbe-MiltanusQ,Valley:Well drained Independence Mines near Pa1l:lercomesnarTOWvalleytowestofloamyorgravellygraysoilsandStateselectionsprwrily."""(NlItional Register).Big Lake/"....Incised river and low
strongly acid soils.Medim to Lowland spruce-hanlwood,low brush />bose present,black and grizzly Considerable development in Milta·Native regional deficiency and Rocky Lake waysides.Clrugod>Slide MIa.to Point ridges OCOJPY valley botnded by
high erosion potential.lnil:bog and RlSkeg;l4l1and spn.oce-bear.IlIIll sheep m sUlTCUlding T1'ansition/lDI~tain.nuska Valley.Coal deposits near ~~f ~~~O:~l~u~-Glenn Highway,Alaska Railroad,State Park to south.MatanuskaMacKenzie(22)IIBjor IIIOUIltain ranges m north -,Poorly drained fibrous ha~;Botte.tland spruce-poplar -ola'Itains .SUttm.Fat'llinl in lower valley,VlIriOUS SIIIIll roads.Valley is high scenic qualityMdsouth.Valley debouches m-peat.vulnenble to frost heaving,agrlcultural land.l'eC'ftation use almg Knil:ArII.mel Knik.area.Several scenic overlookstoMatanuska-lnik flood plain,and well drained acid soils.Low along highway.Highly vividtoPt.M::.Ienzie,route Cl'OSses
to -'ilia erosim potential.llllldscape.lIla1Iy lakes on flat flood plains
and poorly drained ~lllllds.
-I
I
I
I
I
I
I
I
I
I
I
I
I
I
TOPOGRAPHY!CEOLOGY SOILS VEGETATION WILDUF£
DELTA AND MATANUSKA CORRJDORS
INVENTORY
CUMAT'E EXJSTmG DEVELOPM£P."T$LAND OWNERSHlP/STAnJS EXISTING RlCHTS-OF-WAY SCENIC QUAUTYJRECREATION
I
22 DELTA/MATANUSKA INVENTORY
I
ENVIRONJVIENTAL ASSESSMENT OF CORRIDORS
The proposed corridor is a combination of the corridors Susitna-1 and
Nenana-1. The common feature of both is their paralleling of the exist-
ing Alaska Railroad corridor, The Nenana-1 corridor is the shortest
and most economical corridor connecting Devil Canyon to Ester, and
is 198 miles long. The 136-mile long Susitna-1 corridor is only two
miles longer than the shortest corridor connecting Devil Canyon to
Point MacKenzie but since it adheres more closely to the existing corridors,
is the most economical and, at the same time, least environmentally
detrimental corridor,
Susitna-1
From Point MacKenzie the Susitna-1 corridor travels north along the
east flank of the Susitna Valley, ar extremely wide and poorly drained
p1din. Heavy forests of bottomland spruce and poplar, interspersed
with muskeg and black spruce, are typical. The soils tend to be deep,
very poorly drained peats in conjunction with well-drained gravels
and loams. The well-draiy,ed soils occupy more than half of the lower
Susitna Valley, to the east a]nng the terrace flanking the flood plain,
the ratio of well to poorly ,h·ained soils is higher. Although permafrost
is almost absent in this lower part of the Susitna Valley, the poorly
drained areas are subject to freezing and heaving in winter.
,, sizeable concentration of moose inhabit the lower Susitna River
, ,;lley, and the valley also supports a moderate density of water fowl.
B uth brown and black bear are present.
As the Susitna-1 corridor approaches the Nancy Lake area, it meets and
crosses the Alaska Railroad and the Anchorage-Fairbanks Highway,
both of which run northwest to southeast. Continuing north and to
the east of the highway /railroad corridor, the Susitna-1 corridor
crosses several major tributaries of the Susitna River which originate
in the Talkeetna Mountains. These are Willow Creek, Sheep Creek,
and more importantly, the Kashwitna River. In this area the terrain
has become more rolling, and the relative proportion of well drained
soils supporting thick poplar-spruce forest is considerably greater
than to the south.
The town of Talkeetna is the first sizeable community to be approached
by the corridor. Talkeetna is a small town, originally a stop on the
Alaska Railroad. Recreation plays a strong role in the town's economy
since several charter flying services provide access to the Alaska
Range and the Talkeetna Mountains.
23
' j
Talkeetna is at the confluence of the Susitna, Chulitna, and Talkeetna
Rivers; the corridor crosses only the Talkeetna River at this point.
The rolling terrain encountered to the south is more pronounced here,
and the valley of the Susitna River narrows considerably above Talkeetna.
The highway turns west about 15 miles south of Talkeetna; the railroad
continues north over the Talkeetna River and follows the river north
to Gold Creek. The west bank of the river is the eastern boundary
of Denali State Park.
At Gold Creek the Susitna River flows down from the east; the railroad
continues north to Chulitna and an eventual re-convergence with the
highway. The Susitna-1 corridor follows the river along the increas-
ingly restricted valley to the Devil Canyon powersite. Along the valley
floor and walls are forests of spruce and hardwoods based on relatively
well drained soils. The uplands above the valley support sparser
forests, and increasing amounts of permafrost soils are encountered.
The Susitna-1 corridor traverses n >ose concentrations for its entire
length; waterfowl density drops from moderate to low north of the
Tallceetna River.
The Nenana-} corridor retraces part of the Susitna-1 corridor to Gold
Creek, but leads north to Ch•_;~itna, paralleling the railroad, and eventu-
ally the highway, also. Pdst Chulitna the corridor lies within the
watershed of the Chulitna River until Broad Pass is crossed. The
Chulitna Valley is relatively wide, with a rolling floor, and incised
n, rs and streams. The valley leads up to the northeast, and the
' " rolling hills on the floor and flanks reflect this orientation.
The soils here are poorly drained clays along the river bottoms, and
well drained but thin soils. Permafrost, when present, is relatively
deep. The forests here are sparse and become more so as the head
of the pass is approached; generally upland spruce-hardwood, they
are interspersed with bogs and muskegs in poorly drained areas.
Some moose concentrations are traversed; Dall sheep inhabit the surround-
ing upland areas.
To the north of Broad Pass the Nenana-1 corridor lies within the Nenana
watershed, dropping from a maximum elevation of 2,400 feet at Summit.
Broad Pass, drained by a tributary of the Nenana, also maintains the
general character of the pass until Cantwell, at which point the Nenana-I
24
J
corridor converges to the Nenana River. A crossing is necessary, as
the west bank of the Nenana north of Cantwell is the boundary of the
Mount McKinley National Park. Following the east bank of the Nenana
the corridor pierces the Alaska Range, emerging at Healy.
The valley of the Nenana becomes constricted in its passage through the
Alaska Range; in two stretches it is particularly restricted. The entrance
of the Nenana River immediately north of Cantwell is a tight valley hemmed
in by loose, shaley talus cones for 10 or 15 miles. Downstream, a wide
valley at the confluence of Yanert Fork separates this upper canyon from
a canyon further downriver by the McKinley Park Headquarters. This
lower canyon is even more restricted than the upper canyon; the highway
is forced down next to the river, and bluffs and unstable slopes flank
both sides.
The vegetation in the canyons varies from upland spruce-hardwood to
alpine tundra; soils vary from poorly drained river bottoms to unstable
talus. Some localized moose cnnct,:•trations are crossed, particularly
iH the Yanert Fork confluence; in the restricted canyons Dall sheep
!nbitat is encountered.
Heading northward out of the Alaska Range, the Nenana-! corridor
debouches onto the plains arcund Healy. The Nenana River is strongly
incised from Healy northward for about 20 miles, and terraces are prom-
inent along both banks. The soils vary from poorly drained soils on the
terrace flats and river bottom to well drained soils on the slopes. These
c ditions are reflected in the vegetation, which tends to be black spruce
· ''d muskeg on the bottomlands and flats, and spruce-hardwoods on the
t.-lopes.
Coal is exposed on slopes on the east banks of the Nenana River. The
Usibelli Mining Company at Healy provides fuel for the Golden Valley
Electric Association steamplant, which is the southern terminus of a
138-kv transmission line to Ester. The Nenana-1 corridor parallels
the Alaska Railroad and Anchorage-Fairbanks Highway.
Scenic quality north of Healy is moderate to low; the terrain is flat,
blanketed with a fairly uniform mosaic of spruce-hardwoods and muskeg.
As the Tanana River is approached, the land becomes flatter and the
forest density heavier; the Nenana divides into many branches and
sloughs near its mouth.
The entire stretch of corridor from Healy to Nenana traverses good moose
habitat; over the west bank of the Nenana River lies a considerable
25
1
j
I
j
I
i
J
caribou winter range. Despite the large numbers of muskeg and ponds,
particularly toward Nenana, this stretch is a low-density waterfowl
habitat.
The corridor crosses the Tanana River, a major tributary of the Yukon
River, and ascends the hills immediately to the north. These hills vary
between 1,400 and 1,800 feet in elevation, and are oriented in a long
ridge flanking the north bank of the Tanana River. The fine grain soil
is easily eroded and is underlain by permafrost at varying depths. The
soil is well drained on slopes and poorly drained on creek bottoms, and
supports a moderately dense forest of upland and lowland spruce-hard-
wood. Small concentrations of moose habitat are crossed by the corridor.
No other major wildlife habitats exist in this stretch.
Historically, gold mining was extensive here, usually in the form of
dredging. The creek bottoms are often patterned with deposited tail-
ings from previous work ages. Th~ end point of Ester reflects previous
c'•·edging activity; considerable sp, !s occupy most stream bottoms.
Ester is an outlying community of Fairbanks, and the location of the Gold
Hill substation, the assumed terminus of the Nenana-l corridor.
Alternative Susitna-2
Alternative corridor Susitna-2 is 140 miles long, 4 miles longer than
Susitna-1. It differs from Susitna-1 in that from Talkeetna it crosses
the Susitna River, heads north into Denali State Park, then northwest
ovc Troublesome Creek and on to Gold Creek where it rejoins Susitna-1.
~ is alternate segment is 42 miles long. In its southern part the environ-
mental setting is similar to the Gold Creek-Talkeetna segment of Susitna-2;
however, it crosses some low, rolling mountains, reaching a crest of 2, 000
feet elevation before dropping back to the Susitna Valley. Alpine and
moist tundra ecosystems will be crossed in addition to those ecosystems
crossed on Susitna-1; however, these are limited in extent.
Alternative Susitna-3
Alternative corridor Susitna-3 is 134 miles long, 2 miles shorter than
Susitna-1. It is basically a more direct corridor from Talkeetna to
Devil Canyon, bypassing the Alaska Railroad between Talkeetna and
Gold Creek. The length of the alternate segment is 50 miles; the length
of the corresponding segment in Susitna-1 is 52 miles. Heading up the
Talkeetna River it crosses and heads north up and over a plateau of
26
l
I
almost 4,000 feet elevation. In the process, it crosses about 30 miles of
moist tundra in additiona to 20 miles of upland spruce-hardwood.
Alternative Susitna-4
Alternative corridor Susitna-4 is 149 miles long, 13 miles longer than
Susitna-1. As with the other alternative Susitna corridors, it deviates
from Talkeetna, heading up the Talkeetna River and Prairie Creek to
Stephen Lake, then heading west to Devil Canyon damsite, This segment
is 65 miles versus a distance of 52 for the comparable segment of Susitna-1.
This corridor will require at least one crossing of the Talkeetna River;
it traverses the upland spruce-hardwood ecosystem for most of its length,
and a few miles of moist tundra. The major soil for this segment is a
well drained gravel. Permafrost can be expected in the higher elevations.
The crest of this segment is at Stephen Lake, an elevation of 2, 200 feet.
Alternative Nenana-2
Alternative corridor Nenana-2 is 220 miles long, 22 miles longer than
Nenana-I. This alternative departs Nenana-1 at Cantwell, heads east
to Wells Creek, north to Dean Creek and the Wood River, and follows the
Wood River north to Ester. This segment is 158 miles. From Cantwell
the corridor parallels tho Denali Highway, then crosses the Nenana River
in the vicinity of the confluence of Wells Creek. Wells Creek valley pro-
gressively narrows and steepens as its head is approached, culminating
a 3,900 foot pass into Louis Creek which drains into Yanert Fort. From
Y anert Fork the corridor leads up and over the Dean CI·eek-Wood River
1.-ass at 4,000 feet and follows the Wood River Valley out to the Tanana River
\alley. A wide variety of ecosystems is traversed, from alpine tundra
to bog and muskeg. Permafrost can be assumed to be prevalent; soils
vary from poorly drained peats to rock. For 25 to 30 miles the corridor
runs adjacent to or through the Blair Lake Air Force Range. Habitat of
moose, caribou and Dall sheep are traversed.
Alternative Nenana-3
Alternative corridor Nenana-3 is 231 miles long, 33 miles longer than
Nenana-1. It is identical to Nenana-1 up to Cantwell; from Cantwell
it loops east and north through the Alaska Range, rejoining Nenana-!
at Healy. This segment is 72 miles. The comparable segment of Nenana-1
is 39 miles.
From Cantwell the corridor heads east along the Nenana River and Denali
Highway, thence north, up the Wells Creek valley, over the pass (3, 900 feet)
27
to Louis Creek andY anert Fork. From Y anert Fork the corridor goes
over another pass (2, 900 feet) to Moody Creek and follows this creek
to Healy and Nenana-1.
The terrain varies from rolling hills and valleys to high passes and
sharp ridges. Soils vary from poorly drained bottomland to exposed
bedrock; permafrost is prevalent. Ecosystems crossed are moist
tundra, alpine tundra, upland spruce-hardwood, and muskeg and
bog. Habitats of moose, caribou, and Dall sheep are traversed.
Except for 22 miles paralleling the Denali Highway, no other rights-
of-way are paralleled.
Alternative Nenana-4
Alternative corridor Nenana-4 is 223 miles long, 25 miles longer than
Nenana-1. From Devil Canyon it leads east and north, eventually
tying into Nenana-! at Healy. The length of this segment is 126 miles;
'he length of the comparable segn, nt of Nenana-! is 101 miles. The
corridor leaves Devil Canyon, heading east to Watana Damsite, and
then north up Deadman Creek and Brushkana Creek to Wells Creek.
From Wells Creek it heads "P over the pass (3, 900 feet) to Louis Creek
and Y anert Fork, over another pass (2, 900 feet) to Moody Creek,
which it follows to Healy. The terrain varies from rolling hills and
valleys to high passes :illd sharp ridges. Soils vary from poorly drained
bottomland to exposed bedrock; permafrost can be assumed to be prevalent.
Ecosystems traversed are moist tundra, alpine tundra, muskeg and
bc.g, and upland spruce-hardwood. Habitats of moose, caribou, and
')all sheet are crossed. There is no paralleling of existing corridors.
Alternative Nenana-5
Alternative corridor Nenana-5 is 212 miles long, 14 miles longer than
Nenana-1. It is totally separate from Nenana-!, being a parallel corridor
to the east of the preferred corridor. No existing rights-of-way or
corridors are utilized or paralleled.
From Devil Canyon, the corridor leads east to Watana, thence north
up Deadman Creek and down Brushkana Creek to Wells Creek. Climbing
over the Wells Creek pass (3,900 feet), it drops into Yanert Fork and
continues on up Dean Creek. The corridor crosses the Dean Creek-
Wood River pass (4,000 feet) and travels north along the Wood River
to Ester.
28
I
I
The corridor crosses terrain varying from the flat Tanana River valley
to high mountain passes such as Wells Pass. Soils vary from poorly
drained material on the Tanana flood plain to bare rock and talus in
the Alaska Range. Permafrost is prevalent. Ecosystems crossed are
alpine tundra, moist tundra, upland spruce-hardwood, lowland spruce-
hardwood, and bog and muskeg. Significant amounts of Dall sheep,
moose, and caribou winter range are encountered.
Alternative Matan uska-1
Alternative corridor Matanuska-1 differs radically from Susitna-1
in that it loops to the east and south, and approaches Point MacKenzie
from the east. Its total length is 265 miles, 129 miles longer than S usitna-
1. A considerable portion, 125 miles, parallels the Glenn Highway
corridor and other secondary road and existing or planned transmission
corridors~
From Devil Canyon the corridor heads east to Watana and Vee damsites,
,;,en travels southeast over a sparsely forested, poorly drained plateau
to the head of the Little Nelchina River. P1·edominantly rolling hills,
ilie terrain is fairly open and gentle. The corridor passes just to
ilie west of Slide Mountain, .,. here it turns west to parallel ilie Glenn
Highway. Once over the Tahneta Pass and into the Matanuska drainage,
the corridor leads west through a sharply defined valley floored with
rolling hills and drained by a strongly incised river. Continuing
west, the corridor encounters ilie flat land at the mouth of the Matanuska
v~ney and the diminutive farming area of the lower valley. Continuing
''outhwest along the northern shore of Cook Inlet it traverses considerable
.orests and muskegs on the flat lands north of Point MacKenzie.
The soils encountered vary from the poorly drained, fine grain materials
near ilie Little Nelchina to ground moraine and gravel in the Upper
Matanuska Valley, well drained gray loam in the Lower Matanuska
Valley, and poorly drained peat in the flatland nort of Point MacKenzie.
Permafrost is continuous from Vee damsite to Tahneta Pass, discontinuous
in the upper Matanuska Valley, and sporadic in the lower valley te
Point MacKenzie.
The corridor encounters the upland spruce-hardwood ecosystems
along ilie Susitna River to Vee damsite, and moist tundra to the Little
Nelchina, and upland spruce-hardwood to the lower valley. From
ilie lower valley to Point MacKenzie, bottomland spruce-poplar, farmland,
and bog-muskeg are encountered,
29
The section from Devil Canyon to the head of the Little Nelchina River
runs between major caribou calving and wintering ranges. The Nelchina
herd numbered over 61,000 in the late 1960's, presently it has between
4,000 and 5,000 animals. Some wintering range is crossed along the
Little Nelchina to the Glenn Highway and Tahneta Pass. Some Dall
sheep habitat exists in the Tahneta Pass; moose concentrations are
encountered in the Point MacKenzie area.
Alternative Matanuska-2
Alternative corridor Matanuska-2 is 384 miles, 119 miles longer than
Matanuska-1 and 248 miles longer than Susitna-1. From Watana damsite
it loops much further to the east than Matanuska-1, rejoining it at
Slide Mountain; this segment of Matanuska-2 is 216 miles, versus
97 miles, for the comparable segment of Matanuska-1.
From Watana damsite the corridor crosses the Susitna River, heading
n'>rtheast toward Butte Creek and ue Denali Highway. Recrossing
the Susitna in the vicinity of Denall damsite, the corridor continues
east, crossing the Maclaren River and still paralleling the Denali
Highway until it approaches Paxson. Turning south and crossing
the Gulkana River at least twice and paralleling the Richardson Highway
and the Alyeska Pipeline, it l.eads toward Glennallen. From Glennallen
the corridor heads west up the valley of the Tazlina River, paralleling
the Glenn Highway to Slide Mountain and the junction with Matanuska-1.
1a majority of the terrain is flat land; from Watana to Denali damsites
e corridor encounters hilly terrain dissected by long valleys and low
p z,sses. The highest point on this corridor is in the Tangle Lakes-Rock Creek
area between the Maclaren River and Paxson. This is a plateau of about
4,000 feet elevation, poorly drained and covered with post-glacial features
such as askers and te:r:rr.ina1 mornines ~ and many small lakes; perma-
frost is prevalent. The predominant ecosystem to this point is moist
tundra.
From Paxson to Slide Mountain the corridor lies within the Copper River . /
lowlands, a basin underlain by nearly continuous permafrost. Generally v
poorly drained, this basin is dominated by upland and lowland spruce-
hardwood, and muskeg ecosystems.
Except for the area around Glennallen, this entire corridor runs through
the winter range of the Nelchina caribou herd. Along the Copper, Gulkana
and Tazlina Rivers around Glennallen moose concentrations exist,
a.nd smalle;· concentrations are encountered around Watana and Denali
damsites and the Tangle Lakes. Almost all of this corridor traverses
medium density waterfowl habitat.
30
The Tangle Lakes Archeological District, and the Sourdough Inn on the
Richardson Highway, are listed in the National Register of Historical
and Archeological Sites, published in the Federal Register of February 4,
1975. With the exception of the stretch from Watana to Denali damsites,
all of Matanuska-2 parallels existing corridors.
The Delta Corridor Alternative
The Delta corridor is 260 miles long, 62 miles longer than Nenana-1.
This corridor utilizes the corridor through the Delta River canyon in
the Alaska Range, approaching Fairbanks from the southeast.
From Devil Canyon and Watana damsites this corridor heads east over
the hills north of the Susitna River, following Butte Creek to Denali
Damsite. Paralleling the Denali Highway, the corridor re-crosses the
Susitna and further east, the Maclaren River. Over the plateau between
the Maclaren River and Paxson the corridor reaches a crest of 4,000 feet.
At Paxson the corridor turns rwrtl , following the Richardson Highway-
Alyeska Pipeline corridor over Isabel Pass, a wide, gentle divide at
3000 feet of elevation.
North of the pass the combmed corridors pass through the Alaska Range,
following the Delta River. There are some constrictions in the southern
part of the Delta River canyon; however, the majority of the canyon is
not overly severe. North of the canyon the terrain consists of rolling
hills until the Tanana Valley is reached. The towns of Big Delta and
[" ta Junction, both small settlements, are near the confluence of the
"elta and the Tanana Rivers. The terrain in the Tanana Valley is a flat
flood plain to the southwest of the river, and rolling hills punctuated
by several major tributaries on the northeast. The hills on the northeast
flatten out as the corridor approaches Fairbanks.
The predominant soils in the stretch from Watana to Isabel Pass are
poorly drained peaty soils with shallow permafrost tables. Shallow,
rocky soils dominate the Delta River canyon stretch, followed by mixed
poorly and well drained soils with lenses of fine grain material, generally
loess.
Moist tundra is the predominant ecosystem from Watana to Isabel Pass; the
Delta River canyon and the hills northeast of the Delta and Tanana Rivers
are mostly within the upland spruce-hardwood ecosystem. Along the
31
1
j
-j
Tanana flood plain, bottomland spruce-poplar forests are found; localized
muskeg-bog conditions are found in the mouths of Salcha and Shaw
Creeks, and some lowland spruce-hardwood occurs just south of
Fairbanks.
From Watana to Paxson the winter range of the Nelchina caribou herd
is crossed, and from north of the Delta River canyon to just south of
Big Delta, bison range is crossed. The bison herd numbers about 200
animals and is the result of transplanting efforts . The corridor tra-
verses sporadic areas of moose concentration, the largest occuring along
the Tanana River. The corridor also intersects Dall sheep range in the
Delta River canyon. Waterfowl habitat along this corridol" is genel"ally
of low density, although local higher quality habitats exist neal" Donnelly,
Shaw Cl"eek, and Salcha River.
The area between Donnelly and Isabel Pass is one of good to high scenic
quality, providing good views of the Alaska Range, particularly of the
Mt. Hayes-Skarland gl."oup to the west. Several glaciel."s come within
one to three miles of the corridol."; many are visible from the highway.
The Black Rapids Glacier is particularly well known for its surging
activity.
This same mountainous a!"ea is highly mineralized, particularly with
copper and gold. Some gold occurs also near Fairbanks. The only
other significant mineral resources near the corridor are the areas
s 1thwest of the Tanana River which have a low potential for oil and gas.
Although attempts have been made, agriculture is not significant anywhere
aiong this corridor. This is due to a combination of problems with soil,
growing season length, and water supply. The forests from Big Delta
to Fairbanks are moderately dense and may support a sizeable forestry.
32
ENVIRONMENTAL IMP ACTS OF CORRIDORS
.~.
Matrixes for Assessment of Impacts on Corridor Segments:
The following matrixes are for assessment of impacts of a transmission
line by five categories. The definitions of the categories and general
information are given in Appendix I. The process from which the
22 coJ:"ridor segments are derived is explained on pages 10-15.
Due to the problems attendant to reducing such large amounts of information
to such a constrained foJ:"mat, it would appear that some of the categories
are not treated on the s arne level of detail as others. Specifically,
climate, which is a less-studied and less stable situation than soils,
which are treated on a more detailed level. Only data that was found
by searching the literature was entered. Thus, for example, caribou
may be found in a segment although no mention of it is made in the
matrix. One advantage to the matrix system of presentation is that
it is easily updated; thus, discrepancies brought to our attention
can easily be changed.
The constraints of this format also oblige the use of abreviations:
MMCPM zone stands for the Mount McKinley Cooperative Planning
and Management zone; GVBA refers to the Golden Valley Electric Associa-
tion; MEA refers to the Matanuska Electric Association; and the ARR
is the Alaska Railroad.
The land status entries are based upon the land status situation of
ivl.;. ch 1974. State selections refer to not only patented, but also all
onding and tentatively approved State selections. Native village
deficiencies and regional deficiencies (NVD and NRD) will perhaps
be the most unstable areas at present, so it is quite likely that the
entries regarding these lands may not be presently valid.
SUSITNA CORRIDORS
lMPACTS
SOILS VEGETATION WILDLIFE EXISTING DEVELOPMENTS SCENIC QUALITY/RECREATION
Dearth of suit~le soil types on t~o~ plam I!Mle" area. :ts_ pottomland spruce-.pop~ar ~ except ~struCtion of habitat for small a:n.ir..als. En-~lttle :tmpaet on scen~c quality from Nancy t6
floor -rnost of area is poorly drained fibrous for local ltllS1<eg, so considerable cleariDg is bancement of habitat for larger mamnals due to Some posslble conflicts with private landS from Pt. M:Kenz.ie since line can be concealed..
peat -vulnerable to frost heaving but with needed. Upland vegetation has a fast enough increased productivity of introduced brush and .Possible conflict with recreation areas in
Point A!acKenzie -low erosion potential. Upland soils are well regrowt:l'l rate to warrant maintenance, poorly second C. Harassment unlikely due to good Nancy Lake to Talkeetna. No impact on fore-Wasilla~ :Big Lake area and Nancy Lake area,
drained, but more susceptible to erosion. drained areas will probably need very little seeable agriculture -!:lOSt soils are unsuit-depending upon final location, No conflict TalkcattHI cover t roughout area. From Nancy Lake to able for agriculture. "' Permafrost is absent~ discontinuous, or deeply maintenance. Slash must be disposed of t:o Pt. I>tKenzie • access will be improved if access ·with Knik archeological site, Talkeetna
buried~ so thermal disruption is unlikely. No inhibit infestation Qf remaining trees with road left in; increased hunting pressure may to Nancy: line can be almost totally con-
major river crossings are anticipated on this spruce beetle or ips beetle, Vegetation has. result but. only adjacent to clearing. . cealed or laid parallel and adjacent to
route. hiRh resistance tq fire ~ontrol. ~~stin~ line clearings.
Some design problems inherent to soils around
tower elevation forest will need considerable Talkeetna: Frost heaving, possible penna.frost, Route opens up an inaccessible area; hOh'eVeT, poor drainage, slow revegetation. Upland clearing; regrowth rate fast enough to warrant High :impact on scenic quality ~ invades Denali
Talkeetna -Gold Creek soils are well drained~ but erosion potential maintenance. Upland areas will require less this area lies within Denali State Park and No existing developments -no impacts. ,State Park. Line can he concealed somewhat t
via Troublesome Or~k is higher. Possible river crossing needed for clearing and maintenance. Except :fur area is closed to hunting. ' but l'.':ill undoubtedly :interfere with potential
(2) 1'rouhlesome Creek, three needed for Susitna above timberline, vegetation has a high rate ' trail users. '
and Tall<ectna Rivers. Access road CNssing on of spread of £ire and a high -r:esistance to
Troublesome Creel;. may cause siltation. control.
Soils in northern part well dra.ined, deep
. .
No extensive 1naccessihle areas opened up Tree clearing needed along entire segmenti ~~dium impact on scenic quality. Most traffic permafrost table; southern part poorly drained maintenance will be needed. Vegetation has line parallels A.R.R.; access road -would If line adjoins Alaska Railroad, railroad
T01lkeetna -Gold Creek and susceptible to frost heaving. Talkeetna high rate of spread and high resistance to allow vehicles to reach this area i:ndepen-could be electrified and corridor consolid-through this stretch is by A.R.R. 1 and line
via Alaska Railroad (3) River only major river crossing; siltation here control. Brush l'.':ill be introduced by re-dently from the A.R.R., so hunting pressure ated, Low impact othetwise. can be hidden well from rail lines unless cor~
is not a problem as river carries glacial, silt • grtlwth. may increase. If the A.R.R. right~of-way is ~idor is consolidated.
a~ ready. adjourned or shared, inpacts 1<1i.ll be very low.
Mixture of poorly drained soils susceptible to Ex:Pensi ve clearing of heavy forest needed Pioneer route will open up new aTeas to acce'ss , frost heaving and poor foundations, and well Low impact on scenic quality. Line is nOt \>-:is:-drained soils on slepes less apt to cause pro-with maintenance. Brush will be introduced Bunting pressure will increase. Brosh int"l.'o~
Talkeetna River (4) blems. Low to medium erosion potential. . by "l.'egrowt.h. Vegetation has high rate of duction in this area will enhance habitats No existing developments -no impacts.· ible except from air. Wilderness quality some-
little likelihood of serious permafrost degra-fire spread and high resistance to controL for mose t bear. what impacted, but ea.o;e of concealment keeps
,dation. . · · impac~ low.
Low erosion poteD.tia.l but possible degradation'
Clearing and maintenance need :in lower eleva-
tions. Most of route is highland spruce-Pioneer roUte will open up considerable new Line will cross o~en alpine tundra for quite a
Jisappcintm<!nt Cre<!k or local permafrost. Soils well drained over hardwood and alpine tundra. Preservation of .areas to access. l-tost of this area is open No existing developments r:ost of route, sha.llm; to bedrock. Few fore-grmmd vegetation essential • disruption can ·forest to alpine tundra -damage to habitat ~ no impacts. distance, having ish impact on wilderness qual·
(5) seeable impacts from erosion, siltation, or result in longlived scars due to slow regl"Ohi:h could be severe (from fires, erosion). ity. Tcpact on scenic quality is low due to
permafrost degradation. ~ rate. Upper elevations have high rate of fire inaccessibility.
spread, low resistance to control.
Heavy forest clearing needed on Talkeetn~ Pioneer route will open up considerable new
Where 1tne emerges from Talkeetna RiVer valley
·Most soils well ·drained gravels~ so.'11e poorly' River valley with attendent maintenance and areas to access. Impact will be less on ~rivate land and/or cabin. leases on lake shores
Pra.id>: Cre-el{ -Stephan introduction of brush. Less clearing re~ upper areas due to less disruption of vege-m the pass areas. Most of these can be to Stephen Lake, scenic quality receives mediim:
drained areas near Stephen Lake. Few fore~ quired and more care for vegetative mat tation by clearing. Area is presently ac~ avoided. Othernise, no ic:pacts on existing impact; lakes received some recreational use.
Lake (t.i seeable irlpacts from erosion~ siltation or cessible by float plane and received con-IUJlact on wilderness is medium due to the
,permafrost degradation. • · needed in Prairie Creek valley to Stephen "siderable hunting pressure already. Access dev-elopments. existing recreational use and easy accessibil-Lake. High to meclium rate of fire spread., ·road will probably not be used by most ity by float plane, .
high to medium resistance to .control. . ' hunters.•
Devil Canyon -Gold Well drained gravel soils 1dth low to meclium Clearing of medium forest Kith perJodic main-1>-bose and bear habitat e;manced by regrowth Old jeep road exists~ connecting Devil Low impact on scenic quality -~is area is
~rosion potential and deep pel1TI8frost table, Canyon Damsite to Alaska Railroad~ t-Uning not presently easily accessiblet and Devil Can~
Creek (7) 2f any; Few foreseeable impacts from erosion, tenance. High rate of fire spread, medium re-on clearings. Access road may result in ·· claims, no longer operating, on Portage yon Darnsite road 1dll not be used Jl\lch by non~
SJ1ltahon or permafrost degradation. sistance to control. increased hunting pressure. .creek. These roads could be part of the project personnel; line can be concealed from
access road system. this road or can be used as the line access
road also.
Kell drair.ed gravel soils with low to medium Clearfug of Jnedium forest in river valley; Little impact on habitat of large 'lllo'll1aiUlls such
Devil Canyon -Stephan less clearing needed on plateau. Fire rate as moose and bear~ minima.l clearing on plateau No existing developments. Powersite with~ tow impact on scenic quality -area is o:f med--<:rosion potential and deep permafrost table, of spread in valley high, resistance to con~ areas and creek canyons can be spanned. N:.-drawal for Devil Canyon Reservoir. Possible' ium scenic quality. Serre recreational use in Lake (8) · if: any, Fell' foreseeable impacts froa erosion~ trol medium. Plateau rate of spread low~ . cess road l;'OUJ.d be under control from dam-use of edge of withdra1~al for right~of-way. Stephen Lake area. Line can be partially con~ siltation or permafrost degradation. res~stance to control high. site so unauthorized usc for hunting l'!nuld cealed but not totally.
be low.
Well drained gravel soils and poorly drained Heavier vegetation in creek bottoms can be Little impact on habitat of tmose and bear,
Stephan Lake-Watan;~.. soils hi th variable :pemafrost table. Few spanned over by line. Vegetation on plateau r.J.nimal clearing on plateau areas and span-No existing developments. Pol-.'eTSite with-C.bdium impact on scenic quality -area is o£
(9) erosion irepacts but possible p~rost is high brush, and low brush bay, neither of ning of creek canyons. Access would be drawal for Devil ~1ron Reservoir. Possible medium scenic quality. Some recreational
degTadation and frost hea-ving in poorly which require extensive cleaning. Rate of fin ·under control of dansites so mauthorized use of edge of withdrawal for, right-of-way. use of Stephen Lake area. Line can be par-
drained soils. spread low, resistance to control high. use for htmting would be low. tially concealed but not totally.
'
35 SUSITNA IMPACTS
NENANA CORRIDORS
iMPACTS
SOILS VEGETATION WILDLIFE EXISTING DEVELOPMENTS SCENIC QUALITY /RECREATION
Shallcth' slopes and gravelly soils ·will reduce Successively less clearing as ~egmenL goes
Entire segrr.ent w'i thin Mt. McKinley Cooper a-erosion impact to law levels. Shallow perna~ north. In Broad Pass, no trees need Some enhancement of bear and moose habitat
fros't in poorly drained areas susceptible to clearing and the only vegetation lost · in southern part of segment; no change in Few pri va.te holdings -small chance of con-tive Planning and Nanagement Zone. Southern
Gold Creek -Cantwell degradatim; since the access road can avoid would be from access road. Slow :regrowth noTthern part. This route opens up no flict. Low :impact very few existing part borders Denali State Park. Visible line
(10) these areas, this impact will be low. implies that maintenance will not be needed major new areas to hunting; overall impact developments. will have high impact, particularly if to west
and also that revegetation may be necessary is low. of highway and railroad. Line can be con-
along some areas. ~:ledium to high rate of cealed somewhat 1 however; in most of segment.
fire spread; high resistance to control. B-road Pass has least cover for line. .
Where the access road crosses shallow slopeS 1 Clearing varies from dense spruce-hardwoods Some enhancement of bear and ooose habitat
it has a high probability of crossing poorly to alpine ttmdra. Most vegetation loss in heavier forested areas, but no sil;nifi-i.ow impact on scenic quality; thi.s area' is
drained loam 1-~i.th surface peat and shall01.: will be from access road. Slow :regrowth cant change, Access road opens up it pre-of ctedium scenic quality and not readily
Watana Wells Creek vi pennafrost. Impact on pe:rm.::lfrost in this implies that maintenance will not be viously inaccessible area to intrusion No existing developments -no impacts~ accessible. However, there is a high im~
Brushkana Creek ( 11) case is high, and frost heaving is possible. needed and that in places revegetation and hunting; since caribou and moose are pact on wilderness~ espedally if an access
Upland soils are well drained with deep may be necessary. Meditlr.l to high rate o£ ~resent, this could haw a significant road is built.
pe:rm.:ifrost, so impact is low on pe:rm.::lfrost, fire Spread; high resistance to control; u;;pact on hLmting preserve. Firing on
medium on erosion. low resistance in alpine tLmdra. tLmdra areas could severely impact ca.ri ~
bou habitat.
Shallow slopes and gravelly soils will reduce Clearing varies from spruce-hardwoods to Some enhancement of bear and mose habitat erosion iJil!act to law levels. Shallow penna~ high brush. ~bst vegetative loss from ac-in heavier forested areas, but little signi-Apart from settle.71eJlts along Denali Highway t :Medium impact on scenic qua.li ty; area is of Wells Creek-Cantwell cess roads. Slow regrm'lth implies that
(12)
frost in poorly drained areas susceptible to :-.aintenance will not be needed. ~1edium to ficant change. No ne""fl areas opened up. no develop..."'":ents -no ~cts. high scenic quality, but line can be em-
degradation; since the access road can avoid Overall impact is low. cealed. Entire segment within l>i-IPCPM Zone.
these areas, this inlpact will be low. high r.ate of fire Spread; high resistance
to control.
lligh erosion potential throughout entire '
stretch. Exposed bedrock in canyons will pro-Heavy clearing in valley bouom by Yanert Some habitat destruction and enhancement due The addition of"a third right-of way throUgh vide solid tower foundations but will inhibit Fork; lighter clearing throughout rest of to clearing; overall impact of clearing is Severe impact on scenic quality; not only is
Cantwell-Healy (13) access road construction if needed on canyon route. H:igh rate of fire spread 1 high re~ low. No new areas opened up to huntlltg. the canyons may cause congestion unless the canyon an area of high scenic quality,
slopes. Poorly drained areas have mediwn sistance to control on valley floor; low Construction activities combined with trans-rights~of·way are consolidated. Possible concealment of the line is hard and the west
permafrost degradatim susceptibility. Active resistance in alpine tundra. . portation use of corridor may temporarily connection to GVED line at Healy. bank of the Nenana is park land.
fault near Healy; Denali Fault crosses near repulse some rnamrna.ls such as wolf and bear.
Windy. Crossing of Nenana River necessary.
Higll erosion potential and exposed bedrock on Heavy clearing on valley bottoms to no Construction activities may inhibit caribou Low impact to scenic quality due to the in-slopes. Soll'le areas of poorly drallted soil clearing in alpine tundra, Slow regrowth and sheep activities. Overall habitat modi-accessibility of this otherwise highly scenic
Welts Creek -Dean susceptible to pe:rm.:ifrost degradation in in hiaher elevations. High rate of fire fication low, especially jf winter roads a:rea. High impact to 1dlderness quality, but wider valley floors. Denali Fault crosses sprea ; high resistance to control at and/or helicopter construction is used. No existing developments " no ~cts. limited to the ilwnediate valley occupied by . Creek {14) Wells Creek. Crossing of Nenana River nee-lower elevations; low resistance to con-Fire can seriously impact sleep and caribou line; nature of terrain 1'>'ill adequately con-essary; river too deep for :furding and is trol in alpine tundra. habitat. Large new area opened by access ceal line tmless it i.l) nm on ridges (un-silt-laden normally 1 so siltation will have
low impact. road will increase hunting pressure. likely in this segment).
High ·erosion potential on slopes; high sus-
Heavy clearing in Yanert Fork; little to no COnstruction activities may inhibit caribou Low ilr:pact to scenic quality due to the
ceptibility to perr.afrost degradation on and sheep activities. Overall habitat modi-inaccessibility of this othexwise highly
poorly drained valley floors. 'fowa:rds clearing elsewhere. Slow regrowth in higher fication law, especially if winter road..:;/ Possible line connection at Healy Power scenic area, High impact to wilderness
Dean Creek Henly (15) Healy, well drained soils are subject to elevations and poorly drained areas. High Plant -Usibelli f.1ine roads may be used quality except for lO"r~er M:tody Creek
medii..Q erosion potential and lO'H suscepti-to low rate of fire spread; high to low helicopter construction is used. Fire can for access. · (Vsibelli Mine Harks). Nature of terrain
bility to pe:rm.:ifrost degradation. Active resistance to control. seriously impact sheep and caribou habitat. will conceal line except for ridge along Large new area opened by access road '!>till faults near Healy. Crossing needed on Healy if: crease hunting pressure. lower Moody Creek where line will be sil-,
Creek. houetted.
NenaM flood plain has medium erosion paten~ . Private holdings (claims, homesteads, etc.) No impact on Dry Creek archeological site
tial. Poorly drained areas subject to poten-Heavy clearing for most of route except Clearing will enhance considerable lli!'PLmt (\ along route -towns of Healyt Lignite, since line Hill travel on east bank of Ne-moose habitat. Caribou confined to ;.,:est ·Nenana: These tohns ma.y be affected by tial permafrost degradation and frost heaving. near Healy. lntroduction of bl"USh into bank of Nenana and thus will not be affectc J nana River. Medium impact near Healy and
Healy to Estn 06) Goldstream hills are fine-grain 'l>t'::ith right-of-way. High rate of fire spread; if line runs on east bank. No new signifi~"" construction activities since they are in the Goldstream Hills; low imp:act along
and are highly erosive and susceptible to high resistance to control. cant areas opened up, particularly if GV1!A transportation centers along the segment. lower Nenana River. Impact will be less
permafrost degradation and slope instability. If G\rr.A line is adjoined, there will be a if GVFA right-of~way is adjoined. L<lw im-
Crossing of Tanana River needed. right~of-way is paralleled or adjoined. conflict with the FAA airport at Nenana for pact on wilderness. clearance. ""
Upper Wood River: low erosion and permafrost Heavy t:learing on Tanana lowlands. Light to Construction activities and fire in trpp~ Low J.mpact on scenic quality due to extreme
impacts. Lower Wood River: medium to high no dearing in Upper Wood River in alpine Wood River •.rill negatively affect caribou and No existing developmints -no impact. inaccessibility. Wilderness quality will
Dean Creek to Est~r potential impacts on permafrost. High sus-and mist tundra, and the Tanana flood plain sheep. Clearing in lower Wood River will en-. receive high impact in upper Wood River,
(Wood River) (17) ceptibility to heaving. Low to medium ero-nruskegs. Varying rates of fire .spread and hance moose habitat. Very large area opened medium to low along lower Wood River be-
sion potential. Crossing of T~ River controllability. up by access road .... 'ill be subjected to .cause of varying concealment and presence
needed. greater hunting pressure. of civilization, ·
.
36 NENANA IMPACTS
DELTA AND MATANUSKA CORRIDORS
IMPACTS
SCENIC QUALITY /RECREATIONEXISTINGDEVELOPMENTSWILDLIFEVEGETATIONSOILS
Low impact on Butte Creek area,medium impact.'
Construction activities may interfere with on view as seen from Denali Highway;line canConsiderableareasofshallowpermafrosttableHinimalclearingthroughoutsegment;no need be concealed somewhat from highway.Prelim-soils with consequent vulnerability to degrada for maintenance.Possible disruption of caribou movements.Low impact on moose No existing developments except for scarce inary route surveys in Tangle Lakes Archeo-tion.Low-lying areas are poorly dramed and surface mat and subsequent erosion on slopes activities.Little change in habitat from settlements along Denali Highway.No impact.logical District will locate archeologIcalWatanatoPaxsonviasusceptibletoheavingandsettlement.Eros lOr or permafrost degradation on poorly drained construction,lll11ess severe scarring or ex-
sites;adjustment of route would alleviateButteCreek(18)cessive fires affect vegetation.Accesspotentialismediumtohigh.Access road wIll areas.Fires have low to medium resistance road will open up the ~utte Creek area and conflict.Right-of-way will avoid recrea-need to be adequately culverted over areas of to control.tion areas and east end of Denali Highwaypoordrainage.hunting pressures may lncrease.to lessen impact on recreation and scenic
quality.
Light clearing from Paxson to Donnelly Dome Possible interference with caribou and bison Settlements along Richardson Highway may be High impacts on scenic quality from PaxsonSoilvariesfromshallowcontinuouspermafrostmovements.Low impact on moose in southern impacted by line right-of-way acquisition.to Donnelly Dome,medium to Delta Junction,to frost free soils,with medium to high ero-area.Heavy clearing as route goes north.part,but will enhance habitat on more and low to Eielson A.F.B.Impact is a func-Brush introduction in clearings in Spruce-Towns of Delta Junction and Big Delta will tion of existing scenic quality and abilitysionpotential.Soil in Delta Canyon very heavily forested areas.Low impact on Dall receive some impacts,mostly beneficial,Paxson to Fairbanks (19)thin,so bedrock is easily reached for tower Hardwood forests.Slash must be disposed of Sheep in Delta Canyon since line will stay from transit of material and labor.Possi-to conceal the transmission line.If trans-foundations.Thixotropic silts north of to prevent beetle infestations.Vegetation low.Hinimal destruction of duck habitat ble congestion of right-of-way through Delta mission line is routed parallel to RichardsonSummitLakecombinedwithseismicriskwill.has medium to high rate of fire spread and if right-of-way crosses Salcha sloughs and Canyon unless rights-of-way are consolidated.Highway,recreation areas and historic siteshaveaneffectonline.Phelan Creek,Tanana high to medium resistance to control.Impacts ponds by Donnelly Dome.Siltation in Gul-Overall impacts would be less if Alyeska will be negatively affected.If line ad-River,Gulkana River,Shaw and Salcha Creeks overall would be less if Alyeska right-of-way kana,Salcha and Shaw creeks will affect right-of-way were to be adjoined.joins the Alyeska right-of-way,impacts willneedcrossings.were to be adj oined.anadromous fish.be less.
Low areas poorly drained Light clearing over most of route;some clear-Low impacts on scenic quality due to medium-Continuous permafrost.ing through Spruce-Hardwoods necessary around Possible interference with Nelchina caribou high existing scenic quality of very inacces-Watana to Slide Mtn.and vulnerable to heaving.Medium erosion lower Little Nelchina River.Risk of beetle herd movements.Low impact on moose except The probability of construction of Vee Dam sible area.To the east towards Lake Louise,potential.Considerable imp~ct to permafro~t infestation of slash.Vegetation on Upper is increased by routing a transmission lineviaVee(20)possible from access road;WLnter constructlon Susitna plateau has low to medium rate of fire on lower Little Nelchina,where clearings by the damsite.impact would be higher because of greater
will enhance caribou habitat.This route accessibility.Wilderness quality sufferspreferable.Access road will need to be ade-spread and medium to high resistance to.con-opens a very large area to hunting.since this would be a pioneer corridor.quately culverted over areas of poor dramage.·trol.Vegetation on lower L,ttle Nelch1na has
.high rate of spread and high resistance to
control.
Continuous permafrost.Low areas poorly Possible interference with Nelchina caribou Low impact on scenic quality -line can bedrainedandvulnerabletoheaving.Medium Medium to heavy clearing throughout segment.herd movements.Although moose are numerous,Town of Glennallen will receive some impacts,easily concealed for entire segment.Pos-erosion potential.Considerable impact to Brush introduction will occur in clearings.major impact should be the enhancement of mostly beneficial,from transit of material sible conflicts with recreational and his-Paxson to Slide Mtn.permafrost possible from access road;winter Risk of beetle infestation of slash.Vege-habitat along clearings.Fire will be and labor.No other major impacts.Overall toric sites depending on final location.via Glennallen (21)construction preferable.Access road will tation has high rate of fire spread and high destructive to caribou habitat,may enhance impacts would be less if Alyeska right-of-Impacts would be less if Alyeska right-of-need to be adequately culverted in areas of resistance to control.Overall impacts would moose habitat.Overall impacts would be way were to be adjoined.way were to be adjoined.-poor drainage.Overall impacts would be be reduced if Alyeska right-of-way were to be less if the Alyeska right-of-way were to•reduced if Alyeska right-of-way were to be adjoined were possible•be adjoined.adjoined where possible.-
Except for Tahneta Pass and Gunsight Mountain Considerable farming community on Palmer -Severe impact on scenic quality of Upper~~tanuska Valley soils have medium to high
Matanuska Val~ey and Tahneta Pass.Partialerosionpotential;impact from construction and area,segment required medium to heavy clear-Low impact on Dall Sheep.Clearing will en-conflicts may arise in land use.Roads by concealment is possible.Impact lessens asSlideMts.to Point access road can be high.Permafrost degradation ing for entire length.Brush introduction hance moose habitat.Low impacts on wildlife abandoned coal mine areas can be used as valley widens,and agricultural use becomesisunlike1y.Knik Arm soils have low erosion I will occur in clearings.Clearings will need in general.access.Lower Matanuska Valley has a high more apparent and concealment increases.MacKenzie (22)potential,so impact of·construction and road periodic maintenance.Risk of beetle infest-ratio of privately owned land which will Low impact on Knik Arm area;line can avoidwillbelow.Permafrost degradation is unlikel)!at ion of slash.Vegetation has medium to result in acquisition for right-of-way.all recreation areas and be concealed frombutfrostheavingisveryprobableinpoorlyhighrateoffirespreadandhighresistance
roads.drained areas.to control.
I
I
I
37
DELTA/MATANUSKA IMPACTS
ENVIRONMENTAL IMPACTS OF CORRIDORS
Impacts of Prefened Corridor Susitna-1
Soils: In the lower Susitna Valley the corridor will encounter substantial
areas of poorly drained soils that although not vulnerable to erosion will,
however, pose the problem of frost-jacking of tower footings and anchors.
Unless measures are taken to counteract this potential problem, additional
maintenance and its corresponding impacts will be necessary. The better
drained upland soils are less vulnerable to heaving, but, as with many
flood plain soils, is rather susceptible to erosion, particularly stream
erosion. Since the relative proportions of these two soil types vary
from poorly drained soils in the southern portion to well drained upland
soils in the northern, the impacts associated with them will have a similar
distribution.
Access road construction, although requiring heavy clearing, will be
relatively easy in the upland soils. Water erosion will occur somewhat,
particularly during the construction phase, influencing water quality
in the clearwater streams crossed. Road construction in the areas of
poorly drained peats will i.nvolve problems of hardening the surface
sufficiently to bear construction traffic. Rutting and gouging of tracks
will occur if conventional vehicles attempt to cross an unhardened
surface. Corduroy, piles, deep fills, and drainage are methods of
hardening muskeg surfaces, all of which are expensive and will involve
lc •1 impacts. Avoidance of the problem by careful routing, winter con-
' 'ruction, and/or use of low-pressure tread vehicles will involve less
_uJ,pacts.
Permafrost is generally not present. Where isolated masses do exist,
they are buried fairly deeply. Potential thermal disruption of perma-
frost along this corridor is unlikely.
The corridor parallels the Susitna, involving no crossing, but inter-
sects several tributaries from the Talkeetna Mountains. Fording of
machinery and yarding of logs across these strea1ns will result in
increased siltation. In the smaller clearwater streams this may result
in reduction of spawning habitat and potential gill damage in fish down-
stream of the crossing.
Vegetation: If the line to Point MacKenzie is 345 kv, the a1nount of
clearing for the right-of-way will be up to 2,308 acres; if the line is to
be 230 kv, the amount of clearing will be up to 2,060 acres. The actual
38
clearing will probably not be as high as these acreages since vegetation
along some stretches may not require clearing, except around tower
bases. The terrain being relatively flat, the access road can utilize
the right-of-way without additional clearing.
The immediate effect of this clearing will be the destruction of the
vegetation; the much more significant impact will be upon erosion
and wildlife habitats. In hilly terrain mechanical clearing methods
such as bulldozing will cause considerable disruption of the soil and
subsequent erosion and stream siltation. The use of brush blades
will reduce this effect. On steep slopes hand clearing will mitigate
the otherwise heavy erosion potential likely with mechanical clearing.
To reduce available fuel for forest fires, and to reduce potential infesta-
tion of healthy trees by spruce beetles (Dendroctomus rufipennis)
and ips beetles, slash must be disposed of. This can be either by
sale of marketable timber or by burning. Although burning will reduce
o:ir quality temporarily, it is more economical and less damaging than
the alternatives. (See Mitigating Measures)
Regrowth rates along this corridor are fast enough, particularly in
the southern portion, to warrant periodic suppression of tall growing
trees which pose a hazard to the transmission line. The preferred
method along this corridor is manual application of a suitable herbicide.
The amount of clearing to be maintained, the modest regrowth rates,
and high cost of labor make this alternative preferrable in this corridor
over aerial application of herbicides on the one hand, or hand cutting
, residual trees on the other. If proper application techniques are
adhered to (see Mitigating Measures), there will be no other impacts
other than the maintenance of a sub-climax vegetation. Accidental
overspraying or wind drift, or improper dilution resulting in unneces-
sary destruction of vegetation, and spraying of water bodies resulting
in habitat destruction for aquatic life is not likely to occur with manual
application. Sections needing vegetation suppression occurs in the
bottomland spruce-poplar, lowland spruce-hardwood, and upland
spruce-hardwood forests, particularly in the bottomland spruce-poplar
and muskeg-bog areas, which comprises a significant proportion of
the ecosystems crossed by this corridor, will need little clearing and
no vegetation suppression. Lowland spruce-hardwood areas will
not need to be maintained as often as bottomland spruce-poplar.
39
Wildlife: Alteration of vegetation patterns will affect wildlife. This
corridor traverses many areas of moose concentration, and moose
should benefit from the introduction of brush resulting from the regrowth
on the clearing. Since the clearing must be maintained, this brush
area will last for the life of the line. Most brush areas are in transition,
changing from the brush phase to some other phase nearer the climactic
phase; the brush in a transmission clearing can be counted as a more
permanent source of browse.
Animals dependent upon climactic forest, such as squirrels, will
suffer loss and displacement. However, their faster reproductive
rates will allow their populations to adjust rapidly.
Most animals will benefit from the edge environment, offering both
forage and cover for the adjacent forest and brush. Initially, animal
movements may occur along the right-of-way, but as the brush grows
into a dense cover this will be limited. In any event, this impact
s:•ould be low in this corridor.
Construction itself will affect wildlife. Larger mammals may temporarily
leave the area to return afte ,. the construction activity. Smaller animals
will suffer loss of individuals. but should recuperate rapidly once
construction is completed. The density of forest in this corridor will
allow animals to move o:nly a short distance to avoid contact with construc-
tion activities .
Vegetation suppression, by whatever method, will periodically remove
~-.>ver from along the right-of-way. However, due to the surrounding
c<-ver of the uncleared forests, this impact will be insignificant.
Recreation: The Susitna-1 corridor will approach within 10 miles
of several recreational and wayside areas in the lower Susitna valley.
The largest of these is the Nancy Lakes Recreation Area. In addition,
the corridor will run adjacent to the Denali State Park for 22 miles.
However, the Susitna River will separate the corridor from the Park;
the main access to lands within the Park is the Anchorage-Fairbanks
Highway, and this is an average of 10 miles away to the west over
a 2,000 to 2,500 feet high ridge.
Depending upon the policies of the land managing agencies involved,
this corridor will provide access to areas previously difficult of access.
The largest such area is that south of Nancy Lake to Point MacKenzie.
Dense forest and muskeg limit travel. A service road would allow
access for Lunters, boaters, and campers.
40
I
!
'
Cultural Resources: The National Register of Historic and Archeo-
logical Sites lists only one site in the area, Knik Village. The corridor
will run at least 10 miles to the west of this site. It is likely that archeo-
logical sites will be found along the corridor, either during the location
survey or during construction. If so, minor route relocations, or
careful tower locations, will protect these sites. Inadvertent alteration
of a site will reduce or destroy its historical value.
Scenic Resources: This corridor does not traverse any areas of good
or high quality scenic values. The northern portion is, however,
more scenic than the southern portion. In the northern portion the
fairly continuous moderately dense forest will provide ample screening
from transportation routes. Further south, the forests are more interming-
led with open muskeg. Glimpses of the transmission line can then
be seen from the highway or railroad through these muskegs. South
of Nancy Lake the corridor and the transportation corridors diverge,
and although cover becomes more sporadic, the line will no longer
b~ visible from the transportation routes. The transmission line will
not be visible from the Nancy Lake Recreation Area.
As the Alaska Railroad and the transmission corridor approach Gold
Creek, the valley becorn"s more confined, and screening becomes
more difficult. However, i.t appears that the line can be concealed
through most of this portion.
J.::c.-d Use and Resources: From Point MacKenzie to Nancy Lake the
c•1rridor follows no existing corridor for 32 miles. North of Nancy
L<ke to Gold Creek the corridor parallels the Alaska Railroad, and
to Talkeetna the Anchorage-Fairbanks Highway and Matanuska Electric
Association distribution lines.
Although agriculture in this area is virtually non-exlstant beyond
occasional subsistence gardens, there is potential in the better drained
soils to support farming. The corridor will encounter some agriculture
near Nancy Lake, and again about 25 miles north near the settlement
of Montana. Impact on agriculture will be very low.
Good stands of black cottonwood and balsam poplar exist near the
Talkeetna River, but there is no extensive forestry to be impacted
by the corridor. Future forestry may utilize the access road both
for logging and as a fire road, but this impact is low and depends
also upon the land ownership.
41
l
Impact on mineral resources is low; the corridor does not traverse
significant areas of potential metallic minerals, and does not approach
any existing coal or oil developments although the potential for coal,
oil and gas exists along nearly the entire length of the corridor.
Due to the inefficiency of local tap on a 345 kv line, the likelihood
of the development of these resources due to the proximity of a transmis-
sion line is low.
Social: Few towns are encountered by the corridor. Whenever possible,
the final location will circumvent communities. The construction phase
will last about three years. During that time, work on the transmission
line will affect these communities. The numbers of workers needed
on a transmission line relative to a pipeline is low. Workers will
be housed in camps, or will be based in Anchorage or Fairbanks,
both of which are large enough to absorb the workfo1·ce. Labor will
probably be recruited from these cities or brought in by the contractors.
Little or no labor force will be dr,•vn from the smaller communities
smce it is not expected that their residents might have the skills and
qualifications for transmission line work.
Some economic imp act can be expected, as flying services, motels,
restaurants, and entertainments receive business, not only from the
transmission line workers, but from related personnel, also. Talkeetna
is the only community, except Anchorage, receiving these impacts
from corridor Susitna-1. It can be e::,:pected that Anchorage could
a ept this impact with little strain, but the impact may be high for
'''allceetna. The impacts may be adverse in that services might be
temporarily monopolized by the construction activity, and good in
that it would bring considerable money to business in the town.
Impacts of Preferred Corridor Nenana-1
Soils: The incidence of permafrost increases from Devil Canyon north
to Fairbanks; however, it is generally discontinuous, with a fairly
deep table. Impacts resulting from thermal degradation will be low,
except for soils in the Moody area which are ice-rich.
As in Susitna-1, soils vary from poorly drained soils on lowlands,
and better drained soils on slopes. Erosion potential for the majority
of the corridor is low to medium since the greater portion of the corridor
is on relatively levelland. Two significant exceptions are the sections
in the Nenana Canyon and the "Goldstream Hills .11
The Nenana Canyon area poses severe erosional problems due to the
steep slopes encountered. Discontinuous permafrost is found, which
presents a high potential for degradation.
42
Due to the physical and political restraints, the corridor will have
to traverse many slopes. Soils are often shallow on these slopes;
indeed, many of them are talus. Foundations may have to be blasted
into rock; construction of an access road would be prohibitive, and
for this and other reasons an access road will not be used on this
stretch. The upper canyon is constricted between Panarama Mountain
and the Nenana River, and an extensive, unstable talus slope lies
at the foot of Panorama Mountain. In the lower canyon, thin, unstable
soil blankets the steep slope to the east of the highway, Where the
corridor traverses slopes such as these, erosion will be a serious
problem, especially on thin soils or unstable soils. This impact will
be especially objectionable since erosion scars may be visible from
the Anchorage-Fairbanks Highway and Mt. McKinley National Park.
The Nenana Canyon area is also in the vicinity of several large faults,
The Denali Fault crosses the corridor just north of Cantwell, and another
active fault is encountered near Hc.1ly, north of the lower canyon.
This factor will affect location of the transmission line on unstable
slopes.
The soil in the Goldstream Hills contains lenses of fine grain material
which, combined with t.he slopes encountered by the corridor, poses
a potential erosion problem. Fortunately, rainfall is scant in this
area. The low lying areas in the Goldstream Hills have a shallow permafrost
table; so avoiding the potentially erodable fine grain soils by locating
tJ,_. transmission line low will present a problem with frozen soils
· cd muskegs.
The corridor will cross Portage Creek, the West and Middle Forks
of the Chulitna River, the Jack River, the Nenana River, Yanert Fork,
Healy and Lignite Creeks, and the Tanana River. With the exception
of the Nenana and Tanana Rivers and Yanert Fork, these are clearwater
streams. Fordings and crossings which disturb the bottom will affect
water quality, as will run-off into these streams from a disturbed
clearing.
Vegetation: Up to 1, 440 acres will need clearing along this corridor.
Actual acreage of clearing will probably be much less since this figure
assumes clearing to the full width of the right-of-way. In many areas,
only the areas around the tower bases will require clearing, particu-
larly in the lowland spruce-hardwood and muskeg-bog ecosystems.
The heaviest clearings will be necessary in the bottomland spruce-
poplar and upland spruce-hardwood ecosystems along the lower Nenana
River and the Tanana floodplain. Along the greater part of the corridor,
the access road can be incorporated into the clearing due to level
terrain. From Devil Canyon to Healy, there will be no access road.
43
. i
The most immediate effect of clearing will be the destruction of the
cleared vegetation. The timber cleared from the bottomland spruce-
poplar will be sold, if merchantable. Otherwise, downed timber and
slash must be disposed of by open burning when possible to prevent
infestation of standing stocks with spruce beetle (Dendroctonus rufipennis)
and the accumulation of fuel f01· wildfire.
Some disruption of the soil from clearing is to be expected; increased
erosion because of this, and enhanced by the lack of cover, will result.
If vegetation is cleared up to river banks on stream crossings, this
may result in additional siltation. Clearing will entail habitat modifi-
cation, to be discussed under "Wildlife."
Regrowth rates along this corridor are slow enough to not require
a progl:'am of vegation suppression other than occasional cutting during
routine inspection and maintenance patrols.
Wildlife: There will be loss of individual smaller animals, and displace-
ment of others; howe vel:', this is a temporary setback. High repl:'oducti ve
rates of smaller mammals and yo-invasion will alleviate this impact.
A permanent habitat modif:icat:wn will J:"esult from the clearing and
maintenance; a corridor of brush will be maintained through other,dse
forested land. Animals d"pendent upon climax forest, such as squirrels,
will suffer some habitat loss. Animals dependent upon brush and forbs
for browse will gcin.
"part from local concentrations, the only major moose concentration
".ong this corridor occurs from Healy to the Tanana River along the
Nenana River.
After the construction phase, moose will benefit from the "edge" environ-
ment, offering increased browse immediately adjacent to forest, which
provides cover.
Depending upon the final location, the access road may result in additional
hunting pressure upon moose in this area. This will also depend
upon the chance of more hunters in the area than presently since if
the number of hunters remains the same, there is no reason to suspect
that increased access will result in better hunting success.
In passing through the lower Nenana Canyon, the Nenana-! corridor
traverses Dall sheep habitat. However, since the sheep tend to inhabit
areas higher than any feasible line location, and since no access road
will be used in this area, impact on Dall sheep will be low to none.
44
Recreation: The Nenana~ 1 corridor will parallel eight miles of the
northeast border of Denali State Park, but will be separated from the
boundary by Indian River, the Alaska Railroad, and at least one mile
of buffer. Further north, it parallels the east border of Mt. McKinley
National Park for 30 miles, being separated by the Nenana River, the
Anchorage-Fairbanks Highway, and the Alaska Railroad. At no point
will the corridor cross lands proposed as additions to the Mt. McKinley
National Park.
The access road will open up no extensive previously inaccessible areas
since it will parallel existing transportation a few miles distant; no
recognized wilderness areas are infringed. Use of the access road by
the public will be determined by the relevant land-managing agency.
If the final route location crosses the Clear MEWS, restrictions may be
placed upon public use of this portion of the access road.
Cultural Resources: The National Register of Historic and Archeological
Sites lists only one site approache ' by the Nenana-1 corridor, the Dry
Creek archeological site. This lies to the west of Healy, the Nenana
River, and the existing transportation corridors. Since the corridor
runs along the east bank of the l'<enana, there will be no impact on this
site.
If the final route survey discloses an unsuspected archeological or
historical site with potential for inclusion in the National Register,
minor route relocations, or careful tower location, will protect these
s , s. Inadvertant alteration of a site will reduce or destroy its
1 istorical value.
Scenic Resources: The corridor passes through an area recognized as
being of good to highs cenic quality from Devil Canyon to Healy. The
possibility of screening throughout this area varies from moderate in the
southern portion around Chulitna, to minimal in the Broad Pass and the
upper and lower canyons of the Nenana River. Scenic quality will be
impacted, the impact being a function of existing scenic quality and the
opportunity for screening. Impact in the Nenana Canyon will be high;
impact on Broad Pass will be moderate to high; impact elsewhere will
be moderate. Two favorable factors mitigate the impact somewhat:
1) The corridor is not visually intact as the Alaska Railroad and the
Anchorage-Fairbanks Highway have already reduced scenic quality
somewhat. 2) The major views south of the canyons are to the west,
toward the Mt. McKinley massif, whereas the corridor lies to the east
of the transportation routes, the most likely viewpoints. (See Mitigating
Measures.)
45
. .
j
• !
J
Land Use and Resources: The Nenana-1 corridor follows e:ldsting
corridors for its entire length. For 10 miles it follows the Alaska
Railroad from Gold Creek. From north of Chulitna to Ester it follows
a combined Railroad/Highway corridor. From Healy north it also
parallels the Golden Valley Electric Association 138 kv transmission
line .
Although the potential for agriculture e:ldsts along this corridor in
the Tanana Valley portion, it e:ldsts in the form of home gardens and
grazing if at all. Impact on e:ldsting and potential agriculture is low
to none.
Some forestry e:ldsts in the bottomland spruce-poplar forests along
the lower Nenana River and the Tanana River. Possible sales of merchant-
able timber from the clearing in this area will bring short-lived business
to the town of Nenana, but this impact will be low. Use of the access
road as a logging road and firebreak may occur, but this use will
not significantly affect logging in !'js area.
Although the corridor approaches and crosses several mineralized
areas and fossil fuel deposits, 1t will not make power directly available
for development except th1·ough distribution systems of the e:ldsting
electric utilities. The access road may be used as a prospecting road,
but will not serve for hee.vier use. The value of the minerals and
fuel is such that if a profitable area were to be developed, it would
be feasible to relocate small sections of the transmission line. On
tL. whole, impact on existing and potential mineral and fuel extraction
<c low .
Slightly more than half of the length of this corridor passes through
the Mt. McKinley Cooperative Planning and Management Zone of Ecological
Concern. This is a study area of a joint State-Federal Planning and
Management Committee responsible for land use planning in the area
peripheral to the Mt. McKinley National Park.
Social: These towns will be affected by the corridor: Cantwell, Healy,
Nenana, and Fairbanks. Cantwell is a small community with no electric
utility, and few services apart from a railroad station and a few restaurant/
motel/gas stations. Incoming material may arrive at the Alaska Railroad;
possible congestion of the station may occur. This is an insignificant
impact, however, and quite temporary. It is possible that Cantwell
will tap directly from the 230 k v transmission line. Electrical service
will either be via future distribution lines of one of the existing utilities
or by tapping from a new substation. The presence of a nearby transmission
4!.
line will undoubtedly result in increased pressure from the community
for electrical service; although which of the two methods will be determin-
ed by the cost and feasibility of both. Healy is similar to Cantwell,
except that it is served by the GVEA system's Healy steamplant.
Nenana is a fairly important transportation node, situated at the crossing
of the Tanana River, a navigable waterway, by the railroad and highway
corridors. Situated in a bottomland spruce-poplar area, if the timber
from a line clearing is to be sold, then the logs will pass through Nenana,
offering some business and jobs. It is unlikely that much labor for
the actual line construction will be drawn from Nenana. The town
is already served by the GVEA system. The existing Healy 138 kv
line passes very close to the town. For a short stretch it uses shorter
towers and spans to minimize hazards to aircraft using the FAA strip
south of town. The corridor will be far enough from the airstrip to
reduce this hazard to a minimum, and any spans deemed hazardous
by the FAA will be marked.
Impacts of Alternative Susitna-2
Alternative corridor Susitna-2 duplicates Susitna-l from Point MacKenzie
to Talkeetna. Impacts are identical for this segment, and are discussed
under imp acts of preferred corl'idor Susitna-l. Imp acts dis cussed here
are for the segment from Talkeetna to Gold Creek via Troublesome Creek.
Soils: In the southern portion of this alternative there is a high propor-
iir., of poorly drained soils which can be expected to present problems
for tower footings and access roads. The severity of the problem will
c.epend upon the vulnerability of the soil to frost heaving and the ability
of the final line survey to avoid areas of poor soils.
In the upland areas around Troublesome Creek, gravelly soils will
present erosional problems, particularly since steeper slopes are
encountered. Frost heaving should be less of a concern, and mainten-
ance of footings will be less.
There will be little or no problem with thermal disruption of permafrost
as there is only discontinuous, deeply buried permafrost along this
alternative. However, final line survey can locate and avoid any high
risk areas. Thermal disruption, particularly in the upland areas, could
lead to gulleying and other forms of erosion.
Crossings of the Talkeetna and Susitna Rivers, paralleling of Whiskers
Creek, and a possible crossing of Troublesome Creek are necessary.
Fording of the Talkeetna and Susitna Rivers is unlikely. In any event,
the rivers are both already silt laden rivers and will be little affected
47
1
j
by additional silt. Silt will negatively impact fish habitat in the
Whiskers and Troublesome Creeks, both of which are clearwater
streams.
Vegetation: The amount of clearing for the Susitna-2 alternative is
up to 2, 375 acres, 67 acres more than that for Susitna-1, if the line is
to be 345 kv. A 230 kv line would require up to 2,121 acres, 61 more
than a similar line along Susitna-1. The actual acres of clearing will
probably be less than these figures since some stretches may only
require clearing for the access road and the tower bases. In the
southern portion the terrain is flat enough so that the clearing will
include the access road; in the steeper terrain the access road may
have to deviate from the right-of-way to maintain grade, and this will
require additional clearing.
The immediate effect of this clearing will be the destruction of the vege-
tation. The much more significant impact will be upon erosion and
""·i.ldlife habitats. In hilly terrain, mechanical clearing methods such as
bulldozing will cause considerable disruption of the soil, and subsequent
erosion and stream siltation. The use of brush blades will reduce this
effect. On steep slopes hand clearing will mitigate the otherwise heavy
erosion potential likely with mechanical clearing.
To reduce available fuel for forest fires, and to reduce potential
infestation of healthy trees by spruce beetles (Dendroctonus rufipennis)
end ips beetles, slash must be disposed of. This can be either by sale
c. uerchantable timber or by burning. Although burning will reduce
.ir quality temporarily, it is more economical and less damaging than
tl1e alternatives. (See Mitigating Measures.)
Regrowth rates along this corridor are fast enough, particularly in the
southern portion, to warrant periodic suppression of tall growing trees
which pose a hazard to the transmission line. The preferred method
along this corridor is manual application of a suitable herbicide. The
amount of clearing to be maintained, the modest regrowth rates, and
high cost of labor make this alternative preferable in this corridor over
aerial application of herbicides on the one hand, or hand cutting of
individual trees on the other. If proper application techniques are
adhered to (see Mitigating Measures), there will be no other impacts
other than the maintenance of a sub-climax vegetation. Accidental
overspraying or wind drift, or improper dilution, resulting in unneces-
sary destruction of vegetation and spraying of water bodies resulting in
habitat destruction for aquatic life is not likely to occur with manual application.
Sections needing vegetation suppression occur in the bottomland spruce-
poplar, lowland spruce-hardwood, and upland spruce-hardwood forest,
48
particularly in the bottomland spruce-poplar. Muskeg-bog and moist
tundra areas, which comprise a significant proportion of the ecosystems
crossed by this corridor, will need little or no clearing and no vegetation
suppression. Lowland spruce-hardwood areas will not need to be
"':Untained as often as bottomland spruce-poplar.
Wildlife: Alteration of vegetation patterns will affect wildlife. This
corridor traverses many areas of moose concentration, and moose
should benefit from the introduction of brush resulting from the regrowth
on the clearing. Since the clearing must be maintained, this brush
area will last for the life of the line. Most brush areas are in transition,
changing from the brush phase to some other phase approaching the
climactic phase. The brush in a transmission clearing can be counted
as a more permanent source of browse.
Animals dependent upon climactic forest, such as squirrels, will
suffer loss and displacement. However, their faster reproductive
rates will allow their populations lr.• adapt rapidly.
Most animals will benefit from the edge environment, offering both
forage and cover from the adjo.cent forest and brush. Initially, animal
movements may occur along the right-of-way, but as the brush grows
into a dense cover, this will be limited. In any event, this impact
should be low in this corridor.
Construction itself will affect wildlife. Larger mammals may temporarily
lc. ve the area to return after the construction activity. Smaller animals
will suffer loss of individuals, but should recuperate rapidly once
construction is completed. The density of forest in this corridor will
allow animals to move only a short distance to avoid contact with construc-
Jdon activities .
Vegetation suppression, by whatever method, will periodically remove
cover from along the right-of-way. However, due to the surrounding
cover of the uncleared forests, this impact will be insignificant.
Recreation: This corridor penetrates 26 miles of the Denali State Park,
coming within 4 miles of the Anchorage-Fairbanks Highway near the
Parle's southern border. This puts the corridor within easy walking
distance of the highway for a significant part of its length within the
Parle. This will affect present and potential trails intersecting the
corridor.
49
i
I
'i
Accessibility to the Park would be increased by the creation of an
access route parallel to the highway; however, the highway and the
Susitna River are not separated more than nine or less than four and
a half miles, so the corridor, which separates the two, will not service
an inaccessible area. Hunting is presently prohibited in Denali State
Park so an access road will have no value as hunters' access. Impact
on recreation will be negative since the entire area of the Park to the
east of the highway will be limited for hiking and day trails.
Cultural Resources: The National Register lists no historical or archeo-
logical sites along this corridor. If the final route survey locates
an archeological site, minor relocation or careful tower location will
avoid disruption of the site. Inadvertant disruption of an archeological
site will reduce or destroy its archeological value.
Scenic Resources: The transmission line can be effectively hidden
from the highway for its entire length; however, its impact is still
high because of conflicts with !he c ]sting and potential trails in the
St .. te Park. A significant value of these trails is aesthetic, and visibility
of a transmission line from an intercepted or adjacent trail will seriously
detract from the original purpose of these trails.
Land Use and Resources: The major land use of this segment is scenic
and recreational. Impacts are as described above under "Recreationn
and 11 Scenic Resources. 11
Tl Ye will be no significant impact on forestry or agriculture because
or the exclusive nature of the State Park land use. There will be no
<1npacts on other resources in this segment.
Impacts of Alternative Susitna-3
Soils: The soils encountered along this alternative are basically well
suited to the construction of an access road. The low erosion potential,
absence of significant permafrost, and the gravelly texture indicate
that effects of erosion and consequent siltation will be low.
Depending upon the final route survey, several small clearwater creeks
will be crossed. Some siltation will occur from fording of construction
equipment. This siltation will be of a temporary nature, and of low
significance since this upland area is not an important fishery. The
Talkeetna River will need at least one crossing, but probably will
not be forded. Since the Talkeetna River carries a glacial silt load,
additional siltation will not be significant.
50
J
The upland soils are quite shallow; excavation of footings may require
blasting. Access road location may have to deviate from the transmission
line in order to keep an acceptable grade without extensive excavation.
Vegetation: The Susitna-3 alternative for 345 kv could require up to
1, 900 acres, 407 acres less than that for Susitna-1. For 230 kv, this
alternative would require up to 1,696 acres, 364 acres Jess than a similar
line along corridor Susitna-1. The majority of this clearing will occur
in the Talkeetna River valley. Little or no clearing will be required
in the upland areas toward Devil Canyon.
The immediate effect of this clearing will be the destruction of the
vegetation. The much more significant impact will be upon erosion and
wildlife habitats . In hilly terrain mechanical clearing methods, such as
bulldozing, will cause considerable disruption of the soil and subse-
quent erosion and stream siltation. The use of brush blades will reduce
this effect. On steep slopes, hand clearing will mitigate the otherwise
heavy erosion potential likely with mechanical clearing.
To reduce available fuel for forest fires and to reduce potential infesta-
tion of healthy trees by spruce beetles (Dendroctonus rufipennis) and
ips beetles, slash must be disposed of. This can be either by sale of
merchantable timber or by burning. Although burning will affect air
quality temporarily, it is more economical and less damaging than the
alternatives. (See Mitigating Measures.)
R cTowth rates along this corridor are fast enough' particularly in
the southern portion, to warrant periodic suppression of tall growing
" ;es which pose a hazard to the transmission line. The preferred method
akng this corridor is manual application of a suitable herbicide. The
amount of clearing to be maintained, the modest regrowth rates, and high
cost of labor make this alternative preferrable in this corridor over aerial
application of herbicides on the one hand or hand cutting of individual
trees on the other. I£ proper application techniques are adhered to
(see Mitigating Measures) , there will be no other impacts other than the
maintenance of a sub-climax vegetation.
Wildlife: Alteration of vegetation patterns will affect wildlife. This
corridor traverses many areas of moose concentration in the Talkeetna
River valley, and moose should benefit from the introduction of brush
resulting from the regrowth on the clearing. Since the clearing must
be maintained, this brush area will last for the life of the line. Most
51
brush areas are in transition, changing from the brush phase to some
other phase nearer the climactic phase. The brush in a transmission
clearing can be counted as a more permanent source of browse.
Animals dependent upon climactic forest, such as squirrels, will
suffer loss and displacement. However, their faster reproductive
rates will allow their populations to recuperate rapidly.
Most animals will benefit from the edge environment, offering both
forage and cover from the adjacent forest and brush. Initially, animal
movements may occur along the right-of-way, but as the brush grows
into a dense cover, this will be limited. This impact should be low
in this corridor,
There may be a possible impact on the caribou winter range reported
to exist in in the upland areas along this alternative. Summer construc-
tion will reduce contacts of ca:riboe and the construction activity.
}, :·es started by const:ruction may destroy potential winter browse.
The degree of this impact depends upon the area burned and the season
of the burning.
La:rger mammals may temporarily leave the area to return after the
construction activity. Smaller animals will suffe:r loss of individuals,
but should recuperate rapidly once construction is completed. The
density of forest in this corridor will allow animals to move only a
s]--·rt distance to avoid contact with construction activities .
. egetation suppression. by whatever method, will periodically :remove
cover from along the right-of-way. However, due to the surrounding
cover of the uncleared forests, this impact will be insignificant.
Herbicides will not directly affect animals in the dilutions used for
manual spraying; herbicides used on right-of-way maintenance are
non-cumulative and are readily excreted. The overall adverse impact
of herbicide spraying will be low, as it will be necessary only every
five to ten years, whereas the availability of forage provided is as
permanent as the transmission line.
Recreation: This corridor approaches no recognized recreation area.
Since the entire length of this segment from Talkeetna to Devil Canyon
parallels no exis ling transportation line, a sizeable amount of land
is opened up to access by four-wheel drive vehicles, dependent upon
the policies of the landowners or managing agency. For recreation
requiring vehicular access, this increased access will have a beneficial
impact. For recreation dependent upon primitive values, increased
access will have a detrimental aspect.
52
Cultural Resources: There is no known impact on cultural resources
in this segment.
Scenic Resources: In terms of viewer contacts, this corridor will have
a low impact on scenic quality due to its relative inaccessibility. How-
ever, this corridor will have a higher impact upon the intactness of
this area than the comparable segments of Susitna-1 and Susitna-2.
The high primitive values and medium to high scenic value of this
corridor, coupled with relatively high visibility of a transmission line
in the upland area, will result in a high impact on scenic quality, dis-
regarding the factor of viewer contacts.
Land Use and Resources: No impact on agriculture is anticipated along
this corridor from Talkeetna to Devil Canyon. An access road will not
enhance forestry in the Talkeetna River valley since it would be unsuit-
able for a logging road unless it were overbuilt, and since the access
road would run very close to the tl·nnsmission line itself. Impacts on
rmneral resources will also be low; not enough potential exists along
the corridor to be influenced by the increased access.
Social: No communities are encountered along this corridor; so there
is no imp act.
Impacts of Alternative Susitna-4
Sc~·~ For soils in the portion of this corridor that follows the Talkeetna
P· ver and Prairie Creek, impacts from erosion, siltation, and permafrost
~ccgradation are low. Crossings of the Talkeetna River and Iron Creek
will be necessary. Both of these streams are sediment laden; so addi-
tional siltation will have little effect.
The soils on the upland portion of this corridor are more susceptible to
erosion, although the slopes are shallower. An improperly constructed
access road will cause erosion, Very few creeks are crossed. Siltation
would be a very minor problem. Some permafrost associated with poorly
drained, peaty soils may present problems, not only of permafrost
degradation, but of frost-heaving. However, final line survey should
reduce this potential impact. Unavoidable stretches of poorly drained
soils may be rutted and scarred by vehicle tracks unless the access road
is hardened with a gravel bed.
Vegetation: For a 345 kv line this corridor could require up to 2,257
acres of clearing, 50 acres less than Susitna-1. For a 230 kv design
it would require up to 2,105 acres, 45 acres less than a similar line on
53
Susitna-1. Actual acreages of clearing will probably be less than
these figures since the entire right-of-way will in most cases not be
cleared, and along some stretches only the access road and tower bases
need to be cleared.
The immediate effect of this clearing will be the destruction of the vege-
tation. The much more significant impact will be upon erosion and wild-
life habitats. In hilly terrain, mechanical clearing methods such as
bulldozing will cause considerable disruption of the soil and subsequent
erosion and stream siltation. The use of brush blades will reduce this
effect. On steep slopes, hand clearing will mitigate the otherwise heavy
erosion potsntial likely with mechanical clearing.
To reduce available fuel for forest fires and to reduce potential infesta-
tion of healthy trees by spruce beetles (Dendroctonus rufipennis) and
ips beetles, slash must be disposed of. This can be either by sale of
merchantable timber or by burning. Although burning will affect air
quality temporarily, it is more economical and less damaging than the
alternatives. (See Mitigating Measures.)
Regrowth rates along the Talkeetna River valley are high enough so that
periodic suppression of tall growing trees within the clearing is required.
The method to be used will bee manually applied herbicide, applied to
target trees during reguhr maintenance patrols. If properly applied,
there will be no contamination of water bodies or destruction of non-target
vegetation. The most important impact of this program will be the mainte-
n ce of sub-climax brush within forested areas.
~lldlife: Alteration of vegetation patterns will affect wildlife. This
corridor traverses an area of moose concentration in the Talkeetna
Valley, and moose should benefit from the introduction of brush result-
ing from the regrowth on the clearing. Since the clearing must be
maintained, this brush area will last for the life of the line. Most brush
areas are in transition, changing from the brush phase to some other
phase nearer the climactic phase. The brush in a transmission clearing
can be counted as a more permanent source of browse.
Animals dependent upon climactic forest, such as squirrels, will suffer
loss and displacement. However, their faster reproductive rates will
allow their populations to adapt rapidly.
Most animals will benefit from the edge environment, offering both
forage and cover from the adjacent forest and brush. Initially, animal
movements may occur along the right-of-way, but as the brush grows
into a dense cover, this will be limited. In any event, this impact
should be low in this corridor.
54
Construction itself will affect wildlife. Larger mammals may temporarily
leave the area to return after the construction activity. Smaller animals
will suffer loss of individuals, but should recuperate rapidly once con-
struction is completed. The density of forest in this corridor will allow
animals to move only a short distance to avoid contact with construction
activities.
Vegetation suppression, by whatever method, will periodically remove
cover from along the right-of-way. However, due to the surrounding
cover of the uncleared forests, this impact will be insignificant. Herbi-
cides applied as outlined under "Vegetation," will produce few effects
upon animals. Since the herbicides are applied only to target vegeta-
tion, the probability of ingestion is reduced to a minimum. Herbicides
are not toxic to animals in the concentrations normally used, and are
not cumulative in effect.
Hecreation: Although this corrido.· does not approach any State or
Federal recreation areas or parks, it will affect the recreational use of
the upland area near Stephen Lake. Readily accessible by float plane,
this area is popular with sportsmen and vacationers. The lakes have
many cabins along their shores. The access road would provide another
means of access for this are e., which would tend to increase the recrea-
tional use, and at the sarr,e time, the transmission line would be visible
for most of its length over the upland area. If one of the perceived
values of this area is its relative inaccessibility, then increased access
"'· :. a visible transmission line would have a highly detrimental impact.
··creased accessibility to other areas traversed by the corridor would be
b"nefici.al to recreational use dependent upon easy access.
Cultural Resources: I£ the final survey discloses an unsuspected
archeological site along the right-of-way, the location of the line or
towers will be altered to avoid damage to such sites. Inadvertent damage
to an archeological site will reduce its historical value. At the same time,
discovery of an archeological site during survey or construction will be
a beneficial aspect.
Scenic Resources: In terms of viewer contacts, impact of a transmission
line along the Talkeetna River valley will be low. Along the upland area
it will be high. This area is a heavily used recreation area, sparsely
forested, and of moderate to high scenic quality. Thus, the construction
of a transmission line and the inherent visibility of such a line would
result in a high impact.
55
i
• J
Land Use and Resources: There will be significant impacts, both bene-
ficial and detrimental, on the predominant land use, recreation. These
impacts are discussed under the "Recreation" section above. There will
be no impact on agriculture, forestry, and mineral resources.
Social: There will be no social impacts from this corridor.
Impacts of Alternative Nenana-2
Soils: Impacts on soils along this corridor will be identical to those out-
lined in Nenana-1 up to Cantwell. The generally flat, gravelly soil from
Cantwell to Wells Creek is vulnerable to water erosion. Construction
activities may cause gulleying in this area. The peaty permafrost soils
also found in this area will present problems in constructing the access
road. Possible rutting and scarring may lead to degradation of the under-
lying permafrost and further erosion.
From Wells Creek to the upper Wood River, impacts will vary with the
type of soil encountered, which can be localized poorly drained frozen
soil, thin soils and gravel, ar,d bare bedrock and talus. Local pockets
of poorly drained soils can be avoided to an extent. Unavoidable encounters
will :result in disturbance of ti>e soil and possible consequent disruption
of the permafrost. Thin ~oils and gravel are very susceptible to erosion,
particularly since they will be found in conjunction with steep slopes.
Access road construction will have a detrimental affect in both these soils.
No tmpact on bare bedrock and talus is anticipated; however, footings for
.vers will require blasting and construction of an access :road will be
ey tr em ely difficult .
Increasing amounts of poorly drained, frozen, peaty soils encountered
from along the lower Wood River to the Tanana River will cause increasing
problems with access road construction, footing stabilization, and :rutting
and scarring of the soils. Unless the access road is bedded on gravel,
there is a strong potential for permafrost degradation and consequent gulley-
ing and maintenance problems. Immediately adjacent to the Tanana River,
stratified soils present a potential water erosion problem, yet are easier
to construct on than the surrounding poorly drained peats. These strati-
fied materials are often levees of extinct or existing channels. They are
linear, but sinuous, and may provide not only the best foundation for a
road, but also the highest point above flood waters.
56
The impact of siltation on glacial rivers will be low. Siltation impact on
clearwater streams will be medium for Wells Creek, Louis Creek, and
Dean Creek. Siltation impacts upon the numerous clearwater tributaries
of the Wood River will be low since they will be crossed close to their
confluences with the silt laden Wood River.
Vegetation: This corridor could require up to 1, 500 acres of clearing,
60 acres more than that for Nenana-1. Actual acreage cleared will
probably be less than this figure since the entire right-of-way need not
be cleared, and the terrain requiring the heavier clearing is generally
flat enough to allow the access road to run within the clearing.
The immediate effect of this clearing will be the destruction of the vege-
tation. The much more significant impact will be upon erosion and
wildlife habitats. In hilly terrain mechanical clearing methods such as
bulldozing will cause considerable disruption of the soil and subsequent
erosion and stream siltation. The use of brush blades will reduce this
effect. On steep slopes, hand cl~e;··ing will mitigate the otherwise heavy
erosion potential likely with mech;;;nical clearing.
To reduce available fuel for fr>1·est fires and to reduce potential infesta-
tion of healthy trees by sp1·uce beetles (Dendroctonus rufipennis) and
ips beetles, slash must be diFposed of. This can be either by sale of
merchantable timber or by burning. Although burning will affect air
quality temporarily, it is more economical and less damaging than the
alternatives. (See Mitigating Measures.)
Vxcept for the bottomland spruce-poplar forest along the Tanana River,
regrowth rates are low enough so that little vegetation suppression
other than routine trimming of danger trees is necessary. More exten-
sive cutting programs may be necessary in the area around the Tanana
River.
In the moist tundra and alpine tundra ecosystems, disturbed areas will
be very slow to recuperate. Revegetation with appropriate species will
be necessary to minimize surface erosion and permafrost degradation.
Proper construction and access road design will limit vegetation loss to
the area occupied by the road bed and tower bases. No clearing is
necessary in these areas.
Fires caused by construction and maintenance will have little impact,
providing they are discovered quickly and stopped without excess
disturbance of the soiL The present patterns of forests are caused by
previous naturally caused fires which are an integral factor of these
57
ecosystems. Impact from a small number of additional fires of limited
area will be low.
Wildlife: The greatest anticipated impact upon wildlife will be the altera-
tion of vegetative patterns, and this impact will be a function of the degree
of clearing. Animals dependent upon climax forest will suffer loss of
individuals and loss of habitat. Generally, these are the small mammals
such as squirrel and marten. Moose will benefit from the creation of
an area of maintained browse. Since the clearing will not be allowed
total regrowth, the browse created can be considered as permanent as
the line. The conjunction of forest and open brush creates a favorable
"edge" environment for most animals, offering forage on the clearing
and cover in the forest.
Construction activity will temporarily frighten away wildlife; however,
this is an extremely local and temporary impact. Jvfaintenance patrols will
not be frequent enough to keep animals from returning to the corridor.
Impact upon the caribou wintering ranges on either sides of the Alaska
Range will be low if construction is done in summer, which may be pre-
ferrable in any case becau5e of better working conditions. Dall sheep
habitat will be impacted in thot they will be frightened away from con-
struction activity more so than caribou and moose. Again, this impact
is of a temporary nature. Unchecked fire in either of these habitats
will adversely impact both caribou and sheep. With caribou particularly,
dr 'ruction of their key winter browse, lichen, may have long lasting
pffects due to slow regrowth rates.
R"creation: This corridor does not traverse any Federal or State parks
or recreation areas. It does, however, briefly approach within five
miles the southeast corner of McKinley National Park.
Except for 22 miles along the Denali Highway, the corridor will provide
access to an area previously accessible only by air or foot. In some
cases, access is presently possible with all-terrain vehicles. Increased
access will impact game animal populations somewhat; the actual impact
will depend upon the desirability of the area for hunting, and access and
hunting regulations imposed by the land managing agencies.
Cultural Resources: This alternative approaches no National Historic
or Archeological Sites. If the final survey discloses an unsuspected
archeological site along the right-of-way, the location of the line or
58
towers will be altered to avoid damage to such sites. Inadvertent damage
to an archeological site will reduce its historical value. At the same time,
discovery of an archeological site during survey or construction will be
a beneficial aspect.
Scenic Resources: This alternative traverses areas of low to high scenic
quality. In terms of viewer contacts, this corridor will have little impact
since it will not be visible from transportation routes for most of its length.
Disregarding viewers, high visual impact to scenic and wilderness quality
in the mountainous portion of the corridor can be expected.
Land Use and Resources: There will be no impacts on forestry and
agriculture throughout this alternative. There will be no impacts on
mineral or fossil fuel resources.
Apart from obtaining easements. no impact is expected on existing land
use.
Impacts of Alternative Nenana-3
Soils: The majority of the soils on the portion of this alternative which
differs from the proposed Nenana-1 corridor are rocky, thin soils and
bedrock. and as such arc; well suited generally for tower foundations.
Access road construction will be hampered by steep slopes, bedrock, and
talus encountered by this corridor. Erosion will generally be low, although
(, , '.hin soils or unstable slopes, erosion will be severe unless corrective
easures are employed. Permafrost can be assumed to be continuous, but
v. ,n not usually be of concern to tower location unless the soil is ice-rich.
This condition is assumed to be restricted to valley floors.
Soil impacts for the remainder of the alternati.ve are described under soil
impacts of the proposed corridor.
Vegetation: The Nenana-3 corridor could require up to 1,318 acres of
clearing, 121 acres less than Nenana-1. Almost no clearing is needed
on the portion which differs from the Nenana-1 corridor since mostly
alpine and moist tundra ecosystems are encountered in this portion.
Impacts resulting from clearing will be similar to those discussed under
Nenana-1. Along the differing segment destruction of vegetation will
be limited to those areas directly occupied by the roadbed and the tower
bases. This will be a permanent impact, although some revegetation of
tower bases can be expected.
59
Destruction of the vegetative mat in tundra areas will result in long
lasting scars unless corrective and preventive measures are taken.
This scarring could lead to subsequent degradation of ice-rich permafrost
and erosion.
Fires resulting from construction and operation, unless suppressed
quickly, will result in extensive destruction of vegetation. These
ecosystems are adapted to natural wildfires, and unless the occurrence
of man-caused fires is very high, they should recuperate as quickly
as they would under normal circumstances.
Wildlife: Impacts on wildlife for those segments of this alternative
corridor to Nenana-1 are discussed under impacts to wildlife of the
proposed corridor.
Along the differing segment, there will be little impact from habitat
modification due to clearing. Increased incidence of fire resulting
from operation or construction will adversely affect habitat for Dall
sheep and caribou. Moose habitat will be enhanced, up to a point,
by fire.
Construction activity may cause avoidance of the corridor by animals;
however, this is a temp e>rary imp act. Operation and maintenance
will not affect the animals· occupation of the corridor.
Increased access afforded by the access road may increase hunting
1 ssure on Dall sheep, caribou, and to a lesser degree on moose.
he degree of this impact is dependent upon the desirability of this
c n·ridor for hunting, and access and hunting regulations imposed
by the land managing agencies.
Recreation: This corridor does not traverse any Federal or State parks
or recreation areas. It does, however, briefly approach within 5 miles
the southeast corner of McKinley National Park.
Except for 22 miles along the Denali Highway, the corridor will provide
access to an area previously accessible only by air or foot. In some
cases, access is presently possible with all-terrain vehicles. Increased
access will impact game animal populations somewhat. The actual impact
will depend upon desirability of the area for hunting, and access and
hunting regulations imposed by the land managing agencies.
Cultural Resources: This alternative approaches no 1\atlonal Historic
or Archeolr;gical Sites. If the final survey discloses an unsuspected
60
.
I
l
archeological site along the right-of-way, the location of the line or
towers will be altered to avoid damage to such sites. Inadvertent damage
to an archeological site will reduce its historical value. At the same time,
discovery of an archeological site during survey or construction will be
a beneficial aspect.
Scenic Resources: This alternative traverses areas of moderate to high
scenic quality. In terms of viewer contacts, this corridor will have little
impact since it will not be visible from transportation routes for most of
its length. Disregarding viewers, high visual impact to scenic and
wilderness quality in the mountainous portion of the corridor can be
expected.
Land Use and Resources: There will be no impacts on forestry and
agriculture throughout this alternative. There will be no impacts on
mineral or fossil fuel resources.
Impacts of Alternative Nenana-4
Soils: From Healy to Ester, this corridor duplicates Nenana-I, and
impacts to soils are identical to those discussed under impacts of
Nenana-I.
The soils from Watana Damsite to Wells Creek will be very vulnerable
to permafrost degradation and frost heaving. The vegetative mat must
UL preserved, and construction activity must be planned to minimize
1isruption of the soil. Erosion caused by permafrost degradation and
:cess road construction will have adverse impacts on water quality in
the clearwater streams encountered.
Fording of streams in this segment, given the sensitive soil conditions,
could result in extensive bank erosion. To minimize this and to ensure
the integrity of the transmission line, the corridor will avoid river
crossings when possible.
From Wells Creek to Healy via Nenana-4, the soils are rocky, thin soils
and bedrock, and as such are well suited generally for tower foundations.
Access road construction will be hampered by steep slopes, bedrock, and
talus encountered by this corridor. Erosion will generally be low, although
on thin soils or unstable slopes, erosion will be severe unless corrective
measures are employed. Permafrost can be assumed to be continuous,
but will not usually be of concern to tower location unless the soil is ice-
rich. This condition is assumed to be restricted to valley floors,
61
Vegetation: The Nenana-4 alternative could require up to 1,182 acres
of clearing, 25 7 acres less than Nenana-1. Actual acres cleared will
probably be less than this since the entire right-of-way need not be
cleared.
Impacts on vegetation from Healy to Ester are identical to those discussed
for that segment under impacts of Nenana-1. Almost no clearing is
needed on the portion which differs from the Nenana-1 corridor since
mostly alpine and moist tundra ecosystems are encountered in this
portion. Impacts resulting from clearing will be similar to those dis-
cussed under Nenana-1.
Along the differing segment, destruction of vegetation will be limited to
those areas directly occupied by the roadbed and the tower bases. This
will be a permanent impact, although some revegetation of tower bases
can be expected.
D..cstruction of the vegetative mat in tundra areas will result in long lasting
scars unless corrective and preventive measures are taken. This scarring
could lead to subsequent degradation of ice-rich permafrost and erosion.
Fires resulting from construction and operation, unless suppressed
quickly, will result in extendive destruction of vegetation. These eco-
systems are adapted to natural wildfires, and unless the occurrenc of
man-caused fires is very high, they should recuperate as quickly as they
v;onld under normal circumstances.
lcdlife: Impacts on wildlife for those segments of this alternative corridor
to 'lenana-1 are discussed under impacts to wildlife of the proposed
corridor.
Along the differing segment there will be little impact from habitat modi-
fication due to clearing. Increased incidence of fire resulting from
operation or construction will adversely affect habitat for Dall sheep and
caribou. Moose habitat will be enhanced, up to a point, by fire.
Construction activity may cause avoidance of the corridor by animals;
however, this is a temporary impact. Operation and maintenance will
not affect the animals 1 occupation of the corridor.
Increased access afforded by the service road may increase hunting
pressure on Dall sheep, caribou, and to a lesser degree on moose. The
62
degree of this impact is dependent upon the desirability of this corridor
for hunting, and access and hunting regulations imposed by the land
managing agencies.
Recreation: This corridor does not traverse any Federal or State parks
or recreation areas. The corridor will provide access to an area pre-
viously accessible only by air or foot. In some cases. access is presently
possible with all-terrain vehicles. Increased access will impact game
animal populations somewhat. The actual impact will depend upon the
desirability of the area for hunting, and access and hunting regulations
imposed by the land managing agencies.
Cultural Resources: This alternative approaches no National Historic
or Archeological Sites. If the final survey discloses an unsuspected
archeological site along the right-of-way, the location of the line or
towers will be altered to avoid damage to such sites. Inadvertent damage
to an archeological site will reduc<' 'ts historical value. At the same time,
discovery of an archeological site during survey or construction will be
a beneficial aspect.
Scenic Resources: This aliet·native traverses areas of low to high scenic
quality. In terms of viewer cr;ntacts, this corridor will have little impact
since it will not be visible from transportation routes fo:t" most of its length.
Disregarding viewers, high visual impact to scenic and wilderness quality
in the mountainous portion of the corridor can be expected.
r ·•nd Use and Resources: There will be no impacts on forestry and
'"g•·iculture throughout this alternative. There will be no impacts on
mineral or fossil fuel resources .
Impacts of Alternative Nenana-5
Soils; The soils from Watana Damsite to Wells Creek will be very vulner-
able to permafrost degradation and frost heaving. The vegetative mat
must be preserved, and construction activity must be planned to mini-
mize disruption of the soil. Erosion caused by permafrost degradation
and access road construction will have adverse impacts on water quality
in the clearwater streams encountered.
Fording of streams in this segment, given the sensitive soil conditions,
could result in extensive bank erosion. To minimize this and to ensure
the integrity of the transmission line, the corridor will avoid river
crossings when possible.
63
From Wells Creek to upper Wood River the soils are rocky, thin soils and
bedrock, and as such are well suited generally for tower foundations.
Access road construction will be hampered by steep slopes, bedrock, and
talus encountered by this corridor. Erosion will generally be low, although
on thin soils or unstable slopes erosion will be severe unless corrective
measures are employed. Permafrost can be assumed to be continuous, but
will not usually be of concern to tower location unless the soil is ice-rich.
This condition is assumed to be restricted to valley floors.
The Wood River valley and Tanana River valley present problems with
locating well drained soils. Large areas of poorly drained peats with
continuous shallow permafrost will result in potential severe impacts such
as permafrost degradation, rutting and scarring of the surface, bank
erosion where clearwater streams are forded, and erosion caused by
access road construction. The necessary clearing will also greatly add
to erosion and siltation. Preventive and corrective measures will need
to be used to minimize these imp a•. ''.
Vegetation: This corridor will require up to 1,369 acres of clearing,
74 acres less than Nenana-1. Actual acres cleared will probably be
less than this figure since the entire right-of-way need not be cleared.
The majority of the clearing '-'.'ill be along the Tanana River valley and
lower Wood River in the bottomland spruce-poplar and upland spruce-
hardwood ecosystems. Along the greater part of the corridor the access
road can be incorporated into the clearing due to level terrain.
'T '1e most immediate effect of clearing will be the destruction of the
Lleared vegetation. Downed timber and slash must be disposed of by
OIJen burning when possible to prevent infestation of standing stocks
with spruce beetle (Dendroctonus rufipennis) and the accumulation of
fuel for wildfire.
Destruction of the vegetative mat in tundra areas will result in long
lasting scars unless corrective and preventive measures are taken.
This scarring could lead to subsequent degradation of ice-rich perma-
frost and erosion.
Fires resulting from construction and operation, unless suppressed
quickly, will result in extensive destruction of vegetation, These eco-
systems are adapted to natural wildfires, and unless the occurrence of
man-caused fires is very high, they should recuperate as quickly as
they would under normal circumstances.
64
Some disruption of the soil from clearing is to be expected. Increased
erosion because of this, and enhanced by the lack of cover, will result.
If vegetation is cleared up to river banks on stream crossings, this
may result in additional siltation.
Wildlife: There will be loss of individual smaller animals and displace-
ment of others; however, this is a temporary setback. High reproductive
rates of small mammals and re-invasion will amend this impact.
A permanent habitat modification will result from the clearing and mainten-
ance. A corridor of brush will be maintained through othe:rwise forested
land. Animals dependent upon climax forest, such as squirrels, will
suffer some habitat loss. Animals dependent upon brush and forbs for
browse will gain.
The large concentration of moose along the lower Wood River and the
Tanana River will benefit from tl1e regrowth of brush into cleared areas.
L.'ll sheep and caribou in the mountainous areas will suffer some loss
of forage to the roadbed and tower bases. Excessive fire will adversely
affect the forage for these last two game animals since they are dependent
upon climax vegetation which has a slow regrowth rate. Moose will
benefit from fires, up to a point. Excessive fires may trigger erosion
which would degrade, rather than enhance, browse for moose.
Construction activity may cause avoidance of the corridor by animals;
h""·ever, this is a temporary impact. Operation and maintenance will
'''ll affect the animals' occupation of the corridor.
Tr..:reased access afforded by the service road may increase hunting
pressure on Dall sheep, caribou, and moose. The degree of this impact
is dependent upon the desirability of this corridor for hunting, and
access and hunting regulations imposed by the land managing agencies.
Recreation: This corridor does not traverse any Federal or State parks
or recreation areas. The corridor will provide access to an area pre-
viously accessible only by air or foot. In some cases, access is presently
possible with all-terrain vehicles. Increased access will impact game
animal populations somewhat. The actual impact will depend upon the
desirability of the area for hunting, and access and hunting regulations
imposed by the land managing agencies.
Cultural Resources: This alternative approaches no National Historic
or Archeological sites. If the final survey discloses an unsuspected
65
archeological site along the right-of-way, the location of the line or
towers will be altered to avoid damage to such sites. Inadvertent damage
to an archeological site will reduce its historical value. At the same time,
discovery of an archeological site during survey or construction will be
a beneficial aspect.
Scenic Resources: This alternative traverses areas of low to high scenic
quality. In terms of viewer contacts, this corridor will have little impact
since it will not be visible from transportation routes for most of its
length. Disregarding viewers, high visual impact to scenic and wilder-
ness quality in the mountainous portion of the corridor can be expected.
Land Use and Resources: There will be no impacts on forestry and
agriculture throughout this alternative. There will be no impacts on
mineral or fossil fuel resources .
Impacts of Alternative Matanuska-1
Soils: From Devil Canyon to Vee Damsite, some problems related to poorly
drained wails will be encountered. Generally, erosion potential along
this segment will be low to moderate. Permafrost degradation potential
is low. The relatively level nature of the terrain will facilitate construc-
tion of an access road without undue erosional problems. Several clear-
water streams will need crossing. Siltation may occur from these cross-
ings, but since they will be crossed close to their confluences with the
sHt-laden Susitna, this impact will be low .
. om Vee Damsite to Slide Mountain the potential for permafrost degrada-
ti(·n is very high. The poorly drained fine-grain soils encountered are
very vulnerable to frost heaving, which will entail much maintenance of
the line and road. The potential for s earring and rutting of the surface
is high, and the subsequent erosion may cause significant siltation in
t.'cle many clearwater streams in this area.
From Slide Mountain to Palmer, the corridor encounters less sensitive
soils. Once over Tahneta Pass permafrost becomes increasingly discon-
tinuous, and well drained soils predominate. Erosion potential is low to
moderate and construction of an access road should present no undue
erosional impacts.
Steep slopes in the upper Matanuska Valley may present some erosional
problems, but the slopes are generally stable. Thin soils are also
common, and potential for denudation of slopes below an access road
cut exists, ·uut should be easily preventable.
66
I
J
In the lower Matanuska Valley soils susceptible to water erosion are
encountered, and location of towers and road will have to be planned
not only to prevent bank cutting, but also to avoid a threat to the integ-
rity of the line. Since this area is also the State's only major agricul-
tural area, extensive care should be taken to avoid adversely affecting
good quality, arable soils.
From Palmer to Point MacKenzie large areas of poorly drained soils will
again necessitate great care in location of the transmission line. Although
permafrost is absent, scarring of the soft peat soils is still a possibility,
and the subsequent siltation of clearwater streams will have an adverse
impact on aquatic life. The heavier clearing necessary in this area will
also contribute somewhat to siltation; to what degree is dependent upon
the care exercised in minimizing disruption of the soil.
Vegetation: If a 345 kv transmission system is constructed, this alter-
native could require up to 2, 817 acres of clearing, 510 acres more
than Susitna-l. If a 230 kv system is used, up to 2,514 acres of clear-
ing will be necessary, 454 acres more than a similar system along
Susitna-1. The majority of this clearing will be in the lower Matanuska
Valley and along the north shore of Cook Inlet to Point MacKenzie. Very
little clearing will be required along the portion from Vee Damsite to
the Little Nelchina River. Actual acres of clearing will probably be
less than the above figures since the entire width of the right-of-way
need not be cleared. The terrain is generally level; so the access road
C< •• be incorporated into the line clearing without additional clearing .
• .:e immediate effect of this clearing will be the destruction of the vege-
(a,ion. The much more significant imp act will be upon erosion and
wildlife habitats. In hilly terrain, mechanical clearing methods such as
bulldozing will cause considerable disruption of the soil and subsequent
erosion and stream siltation. The use of brush blades will reduce this
effect. On steep slopes hand clearing will mitigate the otherwise heavy
erosion potential likely with mechanical clearing.
To reduce available fuel for forest fires, and to reduce potential infes-
tation of healthy trees by spruce beetles (Dendroctonus rufipennis)
and ips beetles, slash must be disposed of. This can be either by sale
of merchantable timber or by burning. Although burning will reduce
air quality temporarily, it is more economical and less damaging than
the alternatives. (See lvfitigating Measures.)
67
l
.. 1
1
J
Regrowth rates along this corridor are fast enough, particularly in the
southern portion, to warrant periodic suppression of tall growing trees
which pose a hazard to the transmission line. The preferred method along
this corridor is manual application of a suitable herbicide. The amount
of clearing to be maintained, the modest regrowth rates, and high cost
of labor make this alternative preferrable in this corridor over aerial
application of herbicides on the one hand, or hand cutting of individual
trees on the other. If proper application techniques are adhered to (see
Mitigating Measures), there will be no other impacts other than the
maintenance of a sub-climax vegetation. Accidental overspraying or
wind drift, or improper dilution, resulting in unnecessary destruction
of vegetation and spraying of water bodies resulting in habitat destruc-
tion for aquatic life will not occur. Sections needing vegetation suppres-
sion occur in the bottomland spruce-poplar, lowland spruce-hardwood,
and upland spruce-hardwood forests, particularly in the bottomland
spruce-poplar. Muskeg-bog areas, which comprise a significant pro-
portion of the ecosystems crossed by this corridor will need little
c.Learing and no vegetation suppn:b:.icn. Lowland spruce-hardwood
areas will not need to be maintained as often as bottomland spruce-poplar.
In the moist tundra ecosystems encountered between Vee Damsite and the
Little Nelchina River, destruction of vegetation will be limited to those
areas directly occupied by the roadbed and the tower bases. This will
be a permanent impact, although some revegetation of tower bases can
be expected.
Destruction of the vegetative mat in the tundra areas will result in long
>ting scars unless corrective and preventive measures are taken. This
st .:l'Ting could lead to subsequent degradation of ice-rich permafrost
and erosion.
Fires resulting from construction and operation, unless suppressed quickly,
will result in extensive destruction of vegetation. These ecosystems are
adapted to natural wildfires, and unless the occurrence of man-caused
fires is very high, they should recuperate as quickly as they would
under normal circumstances.
Wildlife: Alteration of vegetation patterns will affect wildlife. This
corridor traverses many areas of moose concentration, and moose should
benefit from the introduction of brush resulting from the regrowth on
the clearing. Since the clearing must be maintained, this brush area
will last for the life of the line. Most brush al'eas are in transition,
changing from the brush phase to some other phase nearer the climactic
phase. Th. brush in a transmission clearing can be counted as a more
permanent source of browse.
68
Animals dependent upon climactic forest such as squirrels will suffer
loss and displacement. However, their faster reproductive rates will
allow their populations to adapt rapidly.
Most animals will benefit from the edge environment, offering both
forage and cover from the adjacent forest and brush. Initially, animal
movements may occur along the right-of-way, but as the brush grows
into a dense cover, this will be limited. In any event, this impact
should be low in this corridor.
Construction itself will affect wildlife. Larger mammals may temporarily
leave the area to return after the construction activity. Smaller animals
will suffer loss of individuals, but should recuperate rapidly once
construction is completed. The density of forest in this corridor will
allow animals to move only a short distance to avoid contact with construc-
tion activities.
vegetation suppression, by whatever method, will periodically remove
cover from along the right-of-way. However, due to the surrounding
cover of the uncleared forests, this impact will be insignificant.
Areas requi:ring clearing coincide with moose populations. The resulting
brush will be to their benefit. Caribou on the upland between the Susitna
and Little Nelchina Rivers will suffer some direct loss of forage from
the vegetation covered by the roadbed and tower bases. Of more import-
" -e to caribou habitat is the potential overburning of key winter
hrowse, and the subsequent reduction of winter range. Since the
,.dchina caribou herd has undergone drastic reductions in population
(LL·om an estimated 61,000 in the late 1960's to an estimated 4,000 to
5,000 presently) any adverse impact on caribou habitat can be considered
serious. The access road will seriously affect hunting success unless
hunting is further restricted in this area. There will be only slight
impact on Dall sheep range in Tahneta Pass.
Recreation: This corridor approaches no State or Federal park or
>·ecreation area. However, areas with a high recreational use are
encroached upon. The Lake Louise area is a complex of interconnected
lakes set upon a gentle, rolling uplands, and receives high use for
vacationing, fishing, and camping. Lake Louise itself lies approximately
10 miles east of this alternative corridor. Increased access and visibility
of transmission structures will have impacts upon the recreational
use. Since the area is served by only one road to the Glenn Highway,
an access road would increase access to the area. This may be perceived
as an adverse impact by people already owning or leasing sites along
the lakes who value the relative solitude, and may be perceived as
beneficial by fishermen, hunters, and others wanting access to cabin
sites on these lakes.
69
l
i
' .J
From Devil Canyon to Slide Mountain this corridor will traverse areas
previously accessible only by foot or air. The impact of an access road
has been dis cussed above. For access to the north of Lake Louise,
increased access will allow greater use of this upland area. For hunters
particularly, the increased access may be perceived as desirable.
Access will be controlled by the land managing agency having jurisdic-
tion over these areas .
Cultural Resources: This corridor will approach the sites of the
Independence Mines and Knik Village, both National Historical Sites.
The corridor will avoid the Independence Mines by at least 8 miles; so
no impact on this site is anticipated. The Knik site will be approached
up to 3 to 5 miles; however, impact on this site will be low to none.
If the final survey dis closes an unsuspected archeological site along the
right-of-way, the location of the line or tower will be altered to avoid
damage to such sites. Inadvertent damage to an archeological site will
reduce its historical value. At the same time, discovery of an archeo-
lof5ical site during survey or construction will be a beneficial aspect.
Scenic Resources: There will be a medium to high impact on scenic
quality of the Tahneta Pass-upper Matanuska Valley area. High existing
scenic quality, large number. of viewers along the Glenn Highway. and
some difficulty in conceal!nent of a transmission line contribute to this
impact. Development of the lower Matanuska Valley, which has already
affected the intactness of that area, will lessen visual impact. The appor-
t· ;ties for concealment are greater also in the lower valley. Low numbers
r·f viewer contacts and ease of concealment will greatly mitigate visual
""'pact fcrom Palmer to Point MacKenzie. Visual impact here is low to
medium.
Visual impact from Vee Darnsite to Slide Mountain is low. This is a factor
of low viewer contacts, low to medium existing scenic quality, and toward
Slide Mountain some measure of concealment.
Land Use and Resources: A low impact is expected on agriculture on
the Matanuska, The final route can avoid presently developed land and
high quality undeveloped land. Even if land in production were to be
crossed, only the land directly occupied by the tower bases would be
rendered unfarrnable, Much of the agricultural land is devoted to dairy-
ing and hay. There would be a very low impact on these uses. Truck
farming would be impacted more than dairying or hay since the patterns
of row crops would be affected by tower locations.
70
No significant impacts are expected on potential forestry along this
alternative, nor are any significant impacts expected on minerals
extraction.
Social: Some socio-economic impacts can be expected for Palmer, Wasilla,
and the several small communities along the north shore of Cook Inlet.
Skilled labor will most likely not be drawn from these communities,
although it is possible that unskilled labor from these communities might
be employed on the construction phase. Local services such as food and
lodging should experience an increase in business, but this will be a
temporary impact, and due to the relatively small amount of workers
needed and the shifting aspect of the construction, an insignificant
impact, also.
Easements will need to be purchased over privately owned lands. This
will give a lump sum payment, which will be a positive impact upon the
land owner. Future rise in land pdces and assessed taxes due to
encroaching residential development will adversely impact land owners
who have easements on their land. They will pay tax on land they
cannot develop, at rates far beyond the rates for undeveloped land. In
cases where this may occu1·, some arrangement such as an increased
lump sum payment or annual payments equal to the difference in tax
rates should be made.
Impacts of Alternative Matanuska-2
c; ils: Impacts on soils from Slide Mountain to Point MacKenzie are
"den tical to those described under impacts on soils of alternative corridor
Mat an uska-1.
Throughout the entire segment from Watana Damsite to Slide Mountain by
way of Glennallen, the potential for permafrost degradation is very high.
The poorly drained fine-grain soils encountered are very vulnerable
to frost heaving, which will entail much maintenance of the line and
road. The potential for scarring and rutting of the surface is high, and
ihe subsequent erosion may cause significant siltation in the many
clearwater streams in this area.
Particularly sensitive is the Gulkana a_.nd its tributaries. The corridor
parallels ihis system for approximately 50 miles, and multiple crossings
will have cumulative effect on siltation.
71
Vegetation: The Matanuska-2 alternative could require up to 3,869
acres of clearing if a 345 kv system is constructed. This is 1, 561 acres
more than the proposed Susitna-1 corridor. If a 230 kv system is used,
up to 3,454 acres will need clearing, 1,394 acres more than Susitna-1.
Actual acreage of clearing will probably be less than these figures since
not all of the right-of-way need be cleared, and the terrain is level enough
so that the access road can be incorporated into the line clearing.
The immediate effect of this clearing will be the destruction of the vege-
tation. The much more significant impact will be upon erosion and
wildlife habitats. In hilly terrain, mechanical clearing methods such as
bulldozing will cause considerable disruption of the soil and subsequent
erosion and stream siltation. The use of brush blades will reduce this
effect. On steep slopes, hand clearing will mitigate the otherwise heavy
erosion potential likely with mechanical clearing.
To reduce available fuel for forest fires, and to reduce potential infesta-
tion of healthy trees by spruce bee'les (Dendroctonus rufipennis) and
ips beetles, slash must be dispose a of. This can be either by sale of
merchantable timber or by burning. Although burning will reduce air
quality temporarily, it is more economical and less damaging than the
alternatives. (See Mitigating Measures.)
In the moist tundra ecosystem crossed from Watana Damsite to within
10 or 20 miles of Paxson, destruction of vegetation will be limited to
those areas directly occupied by the roadbed and the tower bases.
1 ~will be a permanent impact, although some revegetation of tower
' -tses can be expected.
Destruction of the vegetative mat in tundra areas will result in long
lasting scars unless corrective and preventive measures are tal<en.
This scarring could lead to subsequent degradation of ice-rich perma-
frost and erosion.
Fires resulting from construction and operation, unless suppressed
quickly, will result in extensive destruction of vegetation. These
ecosystems are adapted to natural wildfires, and unless the occur-
rence of man-caused fires is very high, they should recuperate as quickly
as they would under normal circumstances.
72
Wildlife: Alteration of vegetation patterns will affect wildlife. This
corridor traverses many areas of moose concentration 1 and moose
should benefit from the introduction of brush resulting from the regrowth
on the clearing. Since the clearing must be maintained, this brush
area will last for the life of the line. Most brush areas are in transition,
changing from the brush phase to some other phase nearer the climac-
tic phase. The brush in a transmission clearing can be counted as
a more permanent source of browse.
Areas requiring clearing coincide with moose populations. The resulting
brush will be to their benefit. Caribou on the uplands between the
Susitna and Little Nelchina Rivers will suffer some direct loss of forage
from the vegetation covered by the roadbed and tower bases. Of more
importance to caribou habitat is the potential overburning of key winter
browse, and the subsequent reduction in winter range. Due to the
drastic reduction in the population of the Nelchina herd, (from an
estimated 61,000 in the late 1960's to an estimated 4,000 to 5,000 in
:"74) any adverse impact on caribGct is a serious impact. Increased
access will be a serious adverse impact unless hunting is further
restricted in this area.
Animals dependent upon climactic forest such as squirrels will suffer
loss and displacement Howe·,er, their fast reproduction rates will
allow their populations t0 adapt rapidly.
Most animals will benefit from the edge environment, offering both forage
a:r,,, cover from the adjacent forest and brush. Initially, animal move-
'nts may occur along the right-of-way, but as the brush grows into a
dr·nse cover, this will be limited. In any event, this impact should be
low in this corridor.
Construction itself will affect wildlife. Larger mammals may temporarily
leave the area to return after the construction activity. Smaller animals
will suffer loss of individuals, but should recuperate rapidly once con-
struction is completed.
Recreation: This corridor approaches no State or Federal park or recrea-
tion area. However, areas with a high recreational use are encroached
upon. The Lake Louise area is a complex of interconnected lakes set
upon a gentle, rolling uplands, and receives high use for vacationing,
fishing, and camping. Lake Louise lies approximately 35 miles to the
west. Since the corridor will parallel an existing highway, it is unlikely
that it will contribute greatly to increased access to this lake complex.
73
Except for the portion from Watana Damsite to Denali Damsite, the
corridor will parallel existing highway. Threfore, it is not expected
that the corridor will provide access to significantly large areas.
Cultural Resources: Apart from Independence Mines and the Knik
site discussed under alternative Matanuska-1, the only National Archeol-
ogical site is the Tangle Lakes Archeological District west of Paxson.
Careful examination of the final route will minimize any chance of
disruption of archeological sites within this district. A National Historical
Site, Sourdough Lodge, will not be approached enough to be affected.
If the final survey discloses an unsuspected archeological site along
the right-of-way, the location of the line or towers will be altered
to avoid damage to such sites. Inadvertent damage to an archeological
site will reduce its historical value. At the same time, discovery of
an archeological site during survey or construction will be a beneficial
aspect.
;:;,,enic Resources: Impact to scenic quality from Denali Damsite to
Paxson will be high. Large numbers of viewer contacts, little opportunity
for concealment, and areas of high existing scenic quality are factors
in this high impact. From Watana to Denali Damsites, visual impact
is low. From Paxson to Slide Mountain visual impact will range from
low to moderate.
For the rest of this alternative, visual impacts are as described for
al+·'rnative Matanuska-1.
_.md Use and Resources: Little or no impact is expected on agriculture,
fm·estry, or mineral extraction.
This corridor will parallel the right-of-way of the Alyeska Pipeline and
the Richardson Highway. It will, by doing so, reinforce the existence
of a utility corridor and subsequently, the location of future rights-of-
way. Some savings of total width of this corridor could be achieved by
sharing of rights-of-way. (See Alternatives to the Proposed Action.)
Social: Socio-economic imp acts will be identical to those discussed for
alternative Matanuska-1, with the exception of two additional communi-
ties, Glennallen and Paxson. Since the corridor will run so close to
both, it is very likely that they will receive impacts upon their services
such as lodging and food. This is a temporary impact, and not very
significant. Same local labor may be employed during construction,
but this will probably be unlikely.
74
' 1
l
'
Easements will need to be purchased where private land must unavoid-
ably be crossed. This will result in the land owner receiving a lump sum
payment, and will provide some influx of capital to these areas.
Impacts of the Delta Alternative
Soil: This alternative crosses significantly large areas of soils having
moderate to high erosion potential. There are two sensitive soil areas:
1) The poorly drained, ice-rich permafrost found throughout the entire
length of the route. This soil is vulnerable to permafrost degradation,
frost heaving, and rutting and scarring of the top soil. 2) The second
sensitive soil type is the fine-grain soils, generally well drained upland
soils, found between Shaw Creek and Fairbanks. This soil is vulner-
able to gulleying, unstable slopes, and wind erosion.
Erosion from either of these two soil types may cause siltation in the
.nany clearwater streams that are tdbutaries to the Tanana River. Gen-
erally, these clearwater tributaries are limited to those draining the
northeast portion of the Tanana River valley in this area, Tributaries
of the Tanana from the Alaska Range are silt laden and will not be
significantly impacted from erosion,
Local problem areas will be encountered. North of Summit Lake, in
Isabel Pass, is an area of thixotropic soils which become plastic under
seismic shock. Unless this soil can be feasibly circumvented, trans-
mc~sion towers in this area will be under higher than normal seismic
sk. Through the Isabel Pass, rocky soils interspersed with bedrock
and talus will present problems in placing of tower foundations and
access road. Excessive cutting and filling for an access road through
this area, in conjunction with thin soils or unstable slopes, can cause
severe erosion.
A large, extremely marshy area around the Shaw Creek confluence will
be encountered. Tower foundations will need special attention and the
access road will need special design. Frost heaving will be severe in
this marshy soil.
Vegetation: The Delta alternative could require up to 1, 737 acres of
clearing, 288 acres more than Nenana-1. The actual acreage cleared
will probably be less than these figures since the entire width of the
right-of-way need not be cleared. In areas where clearing is required,
the terrain is level enough to permit the access road to be incorporated
into the lir.e clearing.
75
I
.J
The majority of the clearing will be done in the upland spruce-hardwood
and bottomland spruce-poplar along the lower Delta River and the
Tanana River.
To reduce available fuel for forest fires, and to reduce potential infesta-
tion of healthy trees by spruce beetles (Dendroctonus rufipennis) and
ips beetles, slash must be disposed of. This can be either by sale of
merchantable timber or by burning. Although burning will reduce air
quality temporarily, it is more economical and less damaging than the
alternatives. (See Mitigating Measures.)
The immediate effect of this clearing will be the destruction of the vege-
tation. The much more significant impact will be upon erosion and
wildlife habitats. In hilly terrain, mechanical clearing methods such as
bulldozing will cause considerable disruption of the soil and subsequent
erosion and stream siltation. The use of brush blades will reduce this
effect. On steep slopes, hand clear ng will mitigate the otherwise heavy
erosion potential likely with mechanical clearing.
In the alpine and moist tundre. ecosystems found from Watana Damsite
through Isabel Pass and the Alaska Range, destruction of vegetation
will be limited to those areas ..iirectly occupied by the roadbed and the
tower bases. This will be a permanent impact, although some revege-
tation of tower bases can be expected.
D<e .. ruction of the vegetative mat in tundra areas will result in long
ting scars unless corrective and preventive measures are taken.
1hi.s scarring could lead to subsequent degradation of ice-rich perma-
frost and erosion.
Fires resulting from construction and operation, unless suppressed
quickly, will result in extensive destruction of vegetation. These eco-
systems are adapted to natural wildfires, and unless the occurrence
of man-caused fires is very high, they should recuperate as quickly as
they would under normal circumstances.
Wildlife: The areas requiring the most clearing coincide with many
areas of moose concentration, and moose should benefit from the
introduction of brush resulting from the regrowth on the clearing. Since
the clearing must be maintained, this brush area will last for the life of
the line. Most brush areas are in transition, changing from the brush
phase to some other phase nearer the climactic phase. The brush in a
transmission clearing can be counted as a more permanent source of
browse.
76
Scenic Resources: This corridor will have visual impacts ranging from
high along the Denali Highway and through the Isabel Pass-Alaska Range
area, moderate from Donnelly Dome to the Salcha River, and to low from
the Salcha River to Fairbanks. Since nearly the entire corridor is
exposed to viewers from the Denali and Richardson Highways, the vari-
ables are the existing scenic quality and the opportunities for conceal-
ment. Along this alternative, generally the higher the existing scenic
quality, the less the opportunity for concealment.
Land Use and Resources: No impacts are expected on minerals extrac-
tion. The area around Big Delta and Delta Junction is a potentially major
agricultural area, particularly in grain crops such as barley. Crossing
of good quality arable land will result in the removal from production of
the land occupied by the tower bases. Row crops will be more affected
than field crops in that patterns of tilling and harvesting will be more
disrupted by tower locations.
Along the lower Delta River and the Tanana River there is potential for
forestry, particularly in the bottomland spruce-poplar ecosystems. The
Delta alternative will have little effect on forestry, apart from minimal
use as logging roads or firebreaks. Merchantable timber from clearing
operations can be disposed of by sale. The proximity of a highway and
river will facilitate salvage of logs.
Paralleling of the Alyeska Pipeline and the Richardson Highway will
reinforce the utility corridor along the Delta and Tanana Rivers, and
wi 11 affect location of future rights-of-way. the total width of this
utility corridor can be reduced by sharing of rights-of-way. (See
;.,; Iernatives to the Proposed Action.)
Social: The towns of Paxson, Delta Junction and Big Delta will benefit
from use of services such as food and lodging by construction workers.
It is unlikely that much of the labor needed for construction will be
drawn from the smaller communities.
Logging of timber and clearing contracts will affect towns along the
Tanana River by providing jobs and capital from sales of timber. This
will be a short-lived impact, however.
Some easements across private land may need to be purchased. The
majority of the alternative can be routed along the utility corridor along
the Alyeska Pipeline. Purchases of easement will provide a lump sum
influx of capital to the affected land owners. This influx is temporary,
unless arrangements are made for yearly payments.
78
The large numbers of caribou in the Nelchina herd south of the Alaska
Range will suffer some direct loss of forage from the vegetation covered
by the roadbed and tower bases. Of more importance to caribou habitat
is the potential overburning of key winter browse, and the subsequent
reduction in winter range. Due to the drastic reduction in the population
oftheNelchinaherd, (from lin estimated 61,000 in the 1960's to 4,000
to 5,000 in 1974) any adverse impact is a serious impact. Increased
access will seriously affect·.the herd unless hunting is further restricted.
There will be only slight impact on Dall sheep range in Isabel Pass
and the canyon of the Delta River.
Animals dependent upon climactic forest such as squirrels will suffer
loss and displacement. However, their faster reproductive rates will
allow their population to adapt rapidly.
Most animals will benefit from the edge environment, offering both
forage and cover from the adjacent forest and brush. Initially, animal
movements may occur along the right-of-way, but as the brush grows
into a dense cover this will be limited. In any event, this impact
should be low on this corridor .
Construction itself will affect wildlife. Larger mammals may temporarily
leave the area to return after the construction activity. Smaller animals
will suffer loss of individuals, but should recuperate rapidly once
construction is completed. The density of forest in this corridor will
an··v animals to move only a short distance to avoid contact with construc-
tion activities.
Vegetation suppression, by whatever method, will periodically remove
cover from along the right-of-way. However, due to the surrounding
cover of the uncleared forests, this impact will be insignificant.
Recreation: This corridor does not infringe upon any Federal or State
park or recreation area. Since the Delta alternative parallels existing
highways and the Alyeska Pipeline, it will not provide new access
to any significantly large area. Use of the access road is dependent
upon regulations imposed by the landowners or land managing agency.
Cultural Resources: For the segment from Watana Damsite to Paxson
the impacts are as described under impacts of alternative Matanuska-2.
From Paxson to Fairbanks there are no National Archeological or Histori-
cal Sites, If the final survey discloses an unsuspected archeological
site along the right-of-way, the location of the line or towers will be
altered to avoid damage to such sites. Inadvertent damage to an archeo-
logical site will reduce its historical value. At the same time, discovery
of an archeological site during survey or construction will be a beneficial
aspect.
77
------------------------------------~----------
:.'r/,:1.
,~ .,
..
~· : 'vft..(~;.,;:, .
MITIGATION OF IMP ACTS
. 1
'
_j
MITIGATION OF IMPACTS
Most mitigating measures are basically standard practices stringently
enforced. If basic applicable regulations issued by the Federal, State,
and local governments regarding envil·onment quality are adhered to,
most impacts affecting air and water quality will be minimized. Application
of practices and guidelines such as those issued in "Environmental
Criteria for Electric Transmission Systems", a joint Department of the
Interior, Department of Agriculture publication, will reduce visual
and environmental imp acts .
Consultation with agencies proficient in certain areas of concern, such
as the Soil Conservation Service and the State Department of Fish and
Game, will provide further guidance on mitigation of impacts.
More specific mitigating measures 2 ·e discussed below. It must be
remembered that many of these are standard practices intended not only
to minimize damage to the environment, but also to protect the integrity
of the transmission line.
Soils
Since it is expected that most damage to soils will occur during the
construction phase, the construction schedule can be arranged so that
cor~'derable amounts of the work, particularly those requiring the use
of an access road, such as delivery of materials, can be done in winter
a"u spring, when the ground is least vulnerable to physical disturbances.
Temporary roads will be avoided as much as possible; access roads
will be built to a standard applicable to the expected use. If so designated
by t.he State Department of Highways, some sections of access roads
will be built to secondary road standards.
Not all sections of the line will require an access road; particularly
sensitive areas may be protected by the use of helicopter construction
and maintenance, or the use of winter access roads and helicopter
maintenance. It should be recognized, however, that dependence
on aerial methods leaves the construction and/or maintenance program
more vulnerable to weather conditions. One major section will be
constructed without access roads from Devil Canyon to Healy.
For ground work, roads must be adequately constructed to avoid erosion,
slope instability, degradation of the permafrost, and alteration of
drainage. Gravel or other insulating material should underlay permanent
access roads on permafrost area; culverts and bridges where necessary
should be placed to avoid disruption of drainage and possible icing
conditions. Slopes on cuts and fills should be of proper gradient
and revegetated as soon as possible to prevent erosion and slumping.
Revegetation will be done with species recommended in the vegetative
guide for Alaska published by the Soil Conservation Service.
For ground work off of the access road, or where no access road will
machinery compatible to the surface should be used. For shallow permafrost
areas, soft muskeg and bogs, and highly erosive soils, machinery
with low-pressure treads or tires shall be used to avoid scarring the
vegetative mat and incurring subsequent erosion.
On sensitive soils, such as ice-rich soils with a shallow permafrost
table, disturbed soil will be protected with an organic insulating mulch,
such as straw, or when available, chipped slash from the clearing.
Revegetation with appropriate cover plants will immediately follow
construction. To reduce the likelihood of disturbance of marshy soils,
mats of slash, bogs, or other matel"ials will be used.
On erodable slopes, no bulldozing ' ill be done on slopes greater than
35%. All cuts and fills shall be angled back sufficiently to minimize
slumping and immedately seeded with appropriate plants. Sodding
or fabric mats may need to be used in some cases to minimize erosion
until revegetation can control slope erosion. Culverts and water breaks
will be placed to reduce water flow over the bare roadbed. No machine
clearing will be permitted within 100 feet of any streambed.
To protect the integrity of structures in extremely marshy soils or
soils with a shallow ice-rich, permafrost table, and to minimize use
of ~. .. e access road for maintenance of tower footings on these soils,
at transfer devices may be used if necessary to keep tower footings
and guys frozen into place. This is especially important in those
stretches not having an access road. By keeping poorly drained soils
and the shallow active zone around tower bases permanently frozen,
eliminating frost-heaving of anchors and settling of foundations due
to changes in the permafrost. There are several types of these devices
in use; their use is widespread along the Alyeska Pipeling where
elevated sections of pipe are vulnerable to settling.
A good discussion of several types of these devices is found in the
article "Settling a Problem. of Settling", in the Northern Engineer,
Vol. 7 no. 1.
The basic principle of these devices is that of "pumping" heat from
the soil to the air. Year-round operation would require an actual
pump to keep coolant flowing, but several types use no pump, relying
instead upor the difference between soil and ambient air temperatures
in winter and one-way flow of coolant to retard heat transfer to the
81
soil in summer. These heat-transfer devices may provide the best
available solution to the problem of suitable footings and anchors for
structures in muskeg.
Fire control will be quick and efficient to limit fires to small areas.
Fire control methods and machinery should not ultimately cause more
damage than the fires themselves; soil disruption by fire control must
not aggravate soil disturbance already caused by a fire. Aerial control
and ground vehicles with low-pressure treads will be used where
needed.
Crews will be instructed on fire safety. Extinguishing tools will be on
hand; machinery will be suitably maintained to minimize sparking.
Work will go on a special basis during high-risk periods. The permanent
access road can double as a fire break and a fire-control road for con-
tinuing wildfire management.
On unbridged stream crossing, gravel fords will be constructed where the
bottom is not already gravel. No trees shall be felled or yarded across
streams. No waste material will be dumped into streams or abandoned
on their flood plains. Towers will be located well away from streams not
only to reduce the potential for erosion, but also for their own safety.
Vegetation
Only the necessary vegetation will be cleared to minimize impact and cost.
Photogrammetric identification of clearing zones will be used; this
,~chnique, already in use by Bonneville Power Administration, uses a
cumbination of factors, including spacing of towers, line sag, topography,
profiles, and growth rates, to determine exactly which trees need to be
eliminated in a forested area. Designation of the minimum safe clearing
will be in keeping with the National Electric Safety Code.
Clearing will be with brush blades on bulldozers to reduce unnecessary
'disruption of vegetation. No bulldozing will be permitted on slopes greater
than 35%. Clearing on steep slopes will be by hand; stumps and roots
will be allowed to remain to help keep slopes stable.
Slash will be immediately chipped to provide erosion control where necessary
or burned to avoid potential insect epidemics and to reduce fire hazard.
Disturbed areas will be graded back to merge with the contours of the land,
and fertilized or revegetated if necessary to provide a ground cover. In many
cases, chipping of brush, a very suitable method of reducing soil erosion
in the clearmg, will also provide some increase of insulation in areas of
shallow permafrost. Fire hazard will be low, since the chips will usually be
in wet soils in these conditions.
82
Revegetation of cleared areas can be with plant species that will enhance
habitat for animals, yet can successfully dominate taller-growing species.
Typical of these species are grasses and legumes. Revegetation will be
carried out in accordance with the "Vegetation Guide for Alaska" presently
used by the State Department of Highways.
Those sections of clearing needing periodic maintenance to keep
down tall-growing trees will be cleared in such a way as to minimize
further soil disruption. If mechanical methods are used, selective
cutting is preferable over brush hogs or brush blades on tractors,
which not only can be destructive to the soil, but inefficient also in
that little selective cutting is possible. If herbicidal control is to be
used, proper application methods and proper herbicide methods will
be used. Aerial application will not be used; manual application is
not only very selective, but accidental misapplication is less likely
to occur. Herbicides will not be applied next to streams or lakes;
a buffer strip will be left untreated adjacent to water bodies. Application
will be of a coverage and dilution appropriate to the vegetation being
treated.
Fire control will be as discussed in the preceding section on soils.
Wildlife
A policy of minimal clearing of vegetation should have the least impact
upon wildlife in terms of destruction of habitat. Avoidance of unique
habitat, or habitat of rare and endangered species will minimize impact
or 'hese important, but usually localized, areas. Seasonal scheduling
of construction will minimize contacts with migrating mammals, although
uus may conflict with winter construction in areas used by wintering
ca1·ibou or moose.
Any access roads will be designed to minimize river crossings, which
should reduce siltation caused by fording machinery. Where possible,
drainage will be preserved through proper placing of culverts and
bridges, Borrow pits will be located to avoid siltation of clearwater
streams and lakes and subsequent impacts on aquatic ecosystems.
Spills of fuel, oil, and other chemicals will be avoided, particularly
if streams or lakes may be affected. Herbicides, if used, will be applied
properly. Wildfire control will be as discussed in the section on soils.
Harassment of wildlife by ground vehicles, planes, or helicopters,
either deliberate or inadvertant will be minimized by strict enforcement
of vehicle use and aircraft use by either the contractors or the supervisors.
Hunting and trapping activities of work crews will be controlled.
The Alyeska Pipeline camps restrict firearms possession to control
83
hunting and harassment, not to mention accidental shootings. The
Alyeska Pipeline camp and construction areas have also been closed
to hunting and fishing by the Alaska State Department of Fish and Game.
Increased exposure of wildlife to hunting or trapping because of the
increased access of a service road can be controlled to a degree, if
deemed necessary by game management agencies. Access roadheads
can be barricaded or concealed, breaks can be designed on the access
road to limit use by standard four-wheel drive vehicles, and the road
can be posted.
However, it is not expected that such access-control measures will
entirely succeed. In most areas, Alaska Power Administration favors
multiple-use of the right-of-way; final regulation of access will be
at the discretion of the land owner or land-managing agency.
Existing Developments
To avoid preemption of private lands, the final route will be flexible
enough to circumvent small blocks of private land. Larger privately
owned sections will entail a purchase of easement. All of the alternative
corridors can avoid communities en route. Sections of the line deemed
hazardous by the FAA will be adequately marked as outlined in Part
77, FAA regulations "Objc:cts Affecting Navigable Air Space".
The project will provide services for its workers, thus avoiding the
potential straining of a community's services. However, the local
cc" munities should benefit economically from fringe services, such
--entertainment, and services to transmission line-related workers
outside of the actual project.
Scenic Quality-Recreation
The obtrusiveness of a transmission line can be lessened by proper
design and location, In forested areas, placing the clearing far enough
from a parallel highway or railroad is sufficient to conceal the transmission
line. In areas having shorter trees, using the topography to conceal
a line behind ridges, in swales, and along breaks in slopes will help
to lessen its visibility. In completely open areas, the only alternatives
are using a combination of topography and distance to conceal a line,
or to keep it close to the road if it cannot be concealed. By keeping
an obvious line next to a road, one can walk under the line to get
an unobstructed view of scenery on the other side of it; merely keeping
an unconcealable line a short distance from a parallel road does not
lessen its obtrusiveness, and it precludes getting a clear view of
scenery beyond it.
84
Other techniques of concealing or mitigating the presence of a line
are to avoid clear-cuts for clearings, but instead to feather back the
break between original forest and clearing; use of photogrammetric
selective clearing will ease the abrupt appearance of clearings, Where
road crossings are necessary, it is best to cross at less than right
angles and to leave a buffer strip of original vegetation to mask the
right-of-way. This might involve using taller than usual towers on
either side of the highway to provide the additional clearance. Placing
lines on ridges silhouettes them, and will be avoided; ridge crossings
are best put in notches or low spots.
Whenever possible, a line will avoid an area of particular scenic quality;
especially when an unconcealed line has to be seen against a very
scenic background. Where such conflicts are inevitable, extra design
and location attention is called for to reduce the obtrusiveness of the
line. Forsaking an access road for helicopter maintenance, minimal
right-of-way clearance, alternative tower designs and special finishes
on line components help considerably. Replacing the standard guyed
tower designs with alternative wood-pole and metal designs considered
to be more aesthetic, using anodized or painted towers, and using
dull finish conductors minimize the visibility of the line components.
In all cases, all temporary structures will be removed upon completion
of the construction phase. Smaller recreation areas and scenic areas
will be avoided altogether; usually these recreation areas are State-
mc.:ntained wayside parks of relatively small size. Archeological
sites will be identified on preliminary surveys of the chosen corridor
and the final route adjusted accordingly to avoid disruption of these
sites.
Whenever possible, existing rights-of-way should be shared or paralleled
to avoid the problems associated with pioneering a corridor in inaccessible
areas, Trails in these "inaccessible" areas should however, be avoided;
preserving wilderness quality entails sharing or paralleling all rights-
of-way except trails, and from these, lines should be shielded as
much as possible .
85
ADVERSE ENVIRONMENTAL IMP ACTS
ADVERSE ENVIRONMENTAL IMPACTS
All generation of power will create adverse impacts, all transmission
of power will create adverse impacts; all generation sites, except
for local generation, need a transmission system. The degree of adverse
impact of a transmission line will vary with its length, the character
of the terrain, and the care exercised in design, construction, operation,
and maintenance.
Adherence to regulations and guidelines issued by the National Environ-
mental Policy Act of 1969, the Water Quality Act, and relevant State
and local agencies and application of mitigating measures as outlined
on the preceeding section will reduce unavoidable detrimental impacts
to a considerable degree. However, some unavoidable impacts are
inevitable. These impacts are of two kinds: Those resulting from
the construction activities, and thv.e inherent in the existence of
a transmission line.
Unavoidable impacts due to construction activities are usually temporary;
these include effects such as disruption of the surface vegetation and
subsequent erosion on slope,·, disruption of animal habitat due to
human presence; and los5 of vegetation due to clearing. The degree
of these impacts will depend upon the mitigation measures taken, timing
of the construction phase, and ecological factors; these impacts will
ie." on or cease after construction, as regrowth of vegetation and
~·'invasion of fauna occurs.
Unavoidable impacts of a more permanent nature associated with mainten-
ance and operation of the transmission line include modification of
habitat due to a maintained clearing; increased access and subsequent
impacts of increased access; influence on existing and future land
use; influences on existing and future utility corridors; and very
importantly ,.impacts on scenic quality.
The maintenance of a clearing through forested areas will have impacts
on wildlife for the life of the transmission lines. Animals dependent
upon successional vegetation for browse, such as moose and snowshoe
hare, will benefit by the introduction of brush into an otherwise forested
area. Animals dependent upon climax forest for habitat, such as red
squirrel, will suffer a reduction of habitat. In general, both of these
impacts will be insignificant due to the small ratio of affected land
to the area ef unaffected forest traversed by a transmission route.
87
1
!
Increased access due to the existence of a transmission line will depend
upon the type of access used to the line, the degree of present access-
ibility, the area of inaccessible land opened up, and the attraction for
activities other than line maintenance 0
Some sections of the line will have no access road; some will be serviced
by temporary construction roads or winter roads; some sections will
be serviced by an access road suitable for four-wheel drive vehicles 0
Thus, access will be effectively denied to vehicles unable to negotiate
a road of this standard, and in many areas, to all vehicles except all-
terrain vehicles or aircraft.
If the area is already suitably served by an existing road of higher
standards, it would be expected that a transmission line access road
will not appreciably affect the existing access 0 Also, it would be
expected that large areas opened Ufl by a new access road would receive
nl'-1re impacts than smaller areas; huwever, it can also be reasoned that
larger areas can absorb the greater impacts of increased access more
easily than smaller areas o If oth2r factors are considered equal, impacts
of increased access will dey:-u1d upon the area 1s attractiveness for hunting,
packing, camping, and s1ghts0eing 0
Alaska Power Administration presently favors multiple-use of transmission
rights-of-way o Since most of the rights-of-way will be easements on
Sh+e and private lands, and lands managed by other agencies, deter-
mination of access will be left to the land owners or managers 0
There will be an unavoidable impact on present and future land use;
the degree of this impact is a function of the existing use and the potential
uses of not only the land occupied by the transmission line, but also the
adjacent lands o Presently, there is little agriculture or forestry along
the alternative corridors; residential areas are largely limited to the
Anchorage-Palmer and Fairbanks areas 0
However, future patterns of land use will change; agricultural patterns
adjacent to a transmission line will be affected somewhat, depending on
the crop and the method of agriculture o Since the transmission line
will probably predate agricultural land use along the corridor, this
impact will be slight, and probably beneficial, since a right-of-way
would provide cleared land at little or no expense to the farmer o
Irrigation and tilling methods will have to adapt themselves to the spacing
of the towers; land occupied by the tower bases will be unusable, but
this land is a small fraction of the right-of-way 0
88
Forestry is presently limited by physical, economic, and ownership
factors. Present forestry areas can easily be circumvented; potential
areas may benefit from the existing access road of the transmission line
not only for logging, but also for fire control. The existence of a trans-
mission corridor in general will have a minimal impact on forestry.
Present residential areas will be unaffected by any of the alternative
corridors, potential residential areas adjacent to an existing transmission
line will accommodate themselves to its presence. The voltage of
the transmission line precludes direct service to small communities;
these will have to be served by lower voltage distl:"ibution lines, emanating
from existing or future major substations. The potential for service
to small communities is a significant impact in that these communities
may strongly desire to tap the tl"ansmission line; if they are serviced
by the transmission line, they will essentially become part of the inteJ:"con-
nected system. Since the cost of power will most likely decrease in
these communities after intel:"comoe• •ion, local growth can be expanded.
The existence of a transmission corridor may tend to attract future
corridors; to a considerable extent, this is a beneficial impact in that
it is more economical for rights-of-way to be shared or to be adjacent;
there is a lessened likelihood d large areas of wilderness to be cut
into a multitude of smallel" areas by redundant rights-of-way; and
the possibility exists for "symbiotic" use of a right-of-way by two
different types of utilities. Examples are the use of access roads for
trz .. ;portation and the electrification of railroads and pipelines. In
crwridors limited by physical and/or political constraints, such as
uw Nenana Canyon through the Alaska Range, proliferation of rights-
of-way will lead to congestion; in cases such as this, it is most desirable
to set a future pattern by attempting to utilize existing corridors to
minimize potential congestion.
One of the most significant unavoidable adverse impacts will be upon
scenic quality. A transmission line will always cause a detrimental
impact; the degree of this impact is determined by the visibility and
obtrusiveness of the transmission line as seen by the majority of the
viewers. Since most of the viewers of the alternative corridors will
be on the existing transportation routes, it is inferred that increased
visibility and obtrusiveness from these routes can be equated to greater
visual impact. Visual impact on viewers from the transportation routes
will be minimized, from total screening in heavily-forested areas, to
camouflaging by means of colored towers and intelligent tower location.
89
However, it is impossible to hide any line from all viewers from all
directions. Any transmission line is easily visible from the air; placing
a line away from a road to hide it from motorists will not conceal it from
hunters, hikers, and campers, to whom the line may be especially
obtrusive. This dilemma becomes more severe in open country, particularly
in scenic surroundings.
In summary, adverse environmental impacts will be:
clearing of vegetation from as much as 3747 acres.
subsequent periodic control of the regrowth on the clearing created.
permanent removal of vegetation from tower bases, access roads, and
any future substations to be added to the system.
impacts to soil from constructim. and maintenance operations.
impacts to fisheries in clearwater streams affected by construction and
maintenance.
impacts to wildlife, both benefical and adverse, stemming from the above
effects of construction and maintenance.
visual impacts to scenic and recreational resources from Talkeetna north
to Healy.
effects on air quality due to burning of slash resulting from clearing
operations.
90
RELATIO!'SHIP BETWEEN SHORT-TERM USES
OF THE ENVIRONMENT AND LONG-TERM
PRODUCTIVITY
I
j
RELATIONSHIP BETVV'EEN SHORT-TERM USES
OF THE ENVIRONMENT AND LONG-TERM PRODUCTIVITY
The transmission line can be assumed to have a very long life; as long
as loads are expected to increase, as they are, and as long as the Upper
Susitna project is a viable source of power, the transmission route can
be considered operative. Individual components will be replaced, and
it is foreseeable that the line itself may be upgraded to higher voltages
and capacity, but it will still be essentially the same transmission system.
The bulle of the impacts on the environment of the line will be encountered
during the relatively short construction phase. Of the long-term effects,
some would terminate immediately or shortly after the retirement of
the line. Some of these effects would be those springing from access
road maintenance, vegetation control, noise and electromagnetic interference,
(see Appendix I "Hazards") and visual impact. Other impacts will
be "imprinted" into the environmer;'. Wildlife patterns may have been
aftected by continual hunting or habitat modification; these patterns
will linger for a considerable time after a possible removal of the line.
Vegetation patterns, altered by continual maintenance or introduction
of grasses or other nonnative plants, may continue for a very long
time. Unchecked regrowth of the clearing will eventually result in
successional vegetation clr;~er to the stage of the surrounding forests;
this regrowth will entail habitat modifications opposite to those caused
by the original clearing, but of course over a much longer time period.
T'·,e above assumes that the transmission right-of-way will retain its
'c' cginal function for the life of the project. However, this right-of-
way may influence land use patterns that, like vegetation patterns,
will linger after the term of the actual transmission line. The right-
of-way may assume the function of a transportation route; this transport-
ation route may eventually have more impact than the original transmission
line and even outlive the line. Other rights-of-way may be routed
adjacent to the transmission line, thus setting a regional pattern of
corridors that again may outlive the lifetimes of the original utilities.
A transmission line which presently pioneers a right-of-way into undevel-
oped areas may imprint a pattern, which although it might shift and
fluctuate somewhat, will determine future land use and transportation
and transmission networks for that area far beyond its own lifetime.
This effect is similar for other rights-of-way which pioneer large
undeveloped areas. A good example of this is the Alaska Railroad,
which is now paralleled by distribution and transmission lines and
a highway, and which resulted in the creation of several small communities
along its length .
92
Another effect on the long-term productivity of the area by the transmission
corridor would spring from the interconnection of the electric power
grids of the two largest population centers in the State. Interconnection
would enable use of the cheapest generation and the maintenance of
smaller reserve capacity, while at the same time resulting in greater
reliability for both systems. Interconnection would assume an importance
nearly as great as the function of delivery of Upper Susitna power.
New population centers arising in the Railbelt area would be aided
by proximity to this interconnected system. The growth of energy-
intensive heavy industry along the corridor due to the availability
of power is presently unlikely; this is due to the high transportation
and labor costs of the area, which would outweightthe advantage of
the availability of relatively cheap power. The construction of an
interconnected power system for the Railbelt is a response to the increased
demand for electric power. In itself, the availability of power is not
enough to induce growth of an area: other factors, some of which
are intra-and inter-regional transportation, the availability of labor,
the existence of a market for manufactured goods, produce, and/or
raw materials, must exist also to spur regional growth. These other
factors are probably more responsible for growth than the availability
of power.
There are no important potential hydro powersites along the alternative
corridors except the Wood Canyon site. The viability of this project
m2:· be enhanced by the existence of the transmission route which
follows the Richardson Highway route. However, other factors such
@ large size of the potential project and environmental impacts of
th~ Wood Canyon project reduce the probability of this project being
spurred on by the probability of an alternative corridor.
93
\
I
IRREVERSIBE AND IRRETRIEVABLE
COMMITMENTS OF RESOURCES
IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES
The materials directly used in the construction of the transmission
line and access roads will be irretrievably committed for the life of
the transmission line. These materials include the aluminum and steel
in the towers, aluminum and steel in the cables and guys, insulators,
steel culverts, gravel and concrete. Of these, aluminum and steel
have scrap value and can be recycled. Maintenance vehicles will
be irretrievably committed, since their resale value after full use
can be expected to be low. The fuel expended on construction and
maintenance is irretrievably committed, as are other chemicals, such
as paint, if steel towers are to be coated, and herbicides, if chemical
control of vegetation is used.
The land occupied by the right-of-way is irreversibly committed for
the life of the project, although it e-m revert to its original use or
some other use after retirement of the line. This land can, for the
most part be used for other activities, such as recreation, access,
or agriculture. This is, however, at the discretion of the landowner
or land-managing agency. Land use patten1s may be permanently
affected by the pattern originated by the transmission corridor, with
effects outliving the original transmission line.
Irreversible ecological changes may result, depending upon the amount
of 1 earing or large-scale change imposed upon an area by a right-
of-way. Most of these changes, such as the maintenance of successional
vegetation in an otherwise climatic forest, will eventually revert to
their original condition, after retirement of the transmission line,
although this may take a considerable period of time.
Mineral extraction may be affected by the location of the transmission
line; such effects probably will last for the lifetime of the line, unless
the line is later re-routed around ore bodies. This would not be practical
for low unit-value minerals, such as sand and gravel.
Inadvertant disruption of undetected archeological sites would result
in irreversible damage to such sites, reducing the amount of information
obtainable and their historical or archeological value. Discovery
of unharmed sites during construction will be a beneficial effect, however.
The labor spent in construction, operation, and maintenance of the
transmission line is irreversibly committed, as are the secondary
effects of the increased employment afforded.
95
MATERIALS AND LAND COMMITTED
Conduc-1 Struc-
Length tors l tures ?:./ ROW 'Y Clearing Y
Corridor: System miles Ton Ton acres acres
Susiina-1: 345-kv -DC 136 4,624 13' 668 2,308 2,308
Susiina-1: 230-kv -DC 136 3,509 7,344 2,060 2,060
Susiina-2: 345-kv -DC 140 4, 760 14,070 2,376 2,376
Susiina-2: 230-kv -DC 140 3,612 7,560 2,121 2,121
Susiina-3: 345-kv-DC 134 4,556 13,467 2,274 1,900
Susiina-3: 230-kv -DC 134 3,457 7,236 2,030 1,697
Susiina-4: 345-kv -DC 149 5,066 14,975 2,529 2,257
Susiina-4: 230-kv -DC 149 3,844 8,046 2,257 2,015
Nenana-1: 230-kv -sc 198 2,254 6' 138 3,000 1,439
Nenana-1: 230-kv-DC 198 5' 108 10 ,692 3,000 1,439
Nertana-2: 230-kv -SC 220 2,838 6,820 3,333 1,500
Nenana-2: 230-kv -DC 220 5,676 11,880 3,333 1,500
Nenana-3: 230-kv -SC 231 2,980 7' 161 3,450 1,318
Nenana-3: 230-kv -DC 231 2,960 12,474 3,450 1,318
Nenana-4: 230-kv -SC 223 2,876 6,913 3,378 1,182
Nenana-4: 230-kv -DC 223 5,753 12,042 3,378 1,182
Nenana-5: 230-kv -SC 212 2,735 6,572 3,212 1,364
Nenana-5: 230-kv -DC 212 5,470 11,448 3,212 1,364
Mata,. ,s ka-1: 345-kv -DC 265 9.010 26,633 4,497 2,817
Ma• !"luska-1: 230-kv -DC 265 6,837 14,310 4,015 2,515
l\1atanuska-2: 345-kv -DC 384 13.056 38,592 6,516 3,869
Matanuska-2: 230-kv -DC 384 9 '907 20 '736 5,818 3,454
Delta: 230-kv -DC 280 7,224 15,120 4,242 1, 727
Delta: 230-kv -SC 280 3,612 8,680 4,242 1, 727
y Assumes Rail and Pheasant conductors can be 10% greater in rough
?:./
3/
4/
terrain.
Assumes
terrain.
Assumes
Assumes
steel free-standing towers can be 10% greater in rough
R.O.W. width of 140' for 345 kv, and 125' for 230 kv.
total clearing for full width of right-of-way.
DC=Double Circuit; SC=Single Circuit.
96
OTHER ALTERNATIVES TO THE PROPOSED ACTION
OTHER ALTERNATIVES TO THE PROPOSED ACTION
Alternative corridors have already been discussed and compared on
the previous sections and on the matrixes in the appendix. In this
section, alternatives to basic assumptions of the proposed transmission
line will be discussed along with the alternative of non-construction.
Sharing of Rights-of-Way
The assumption is made in the proposed and the alternative corridors
that an entirely new right-of-way will need to be obtained for the
entire corridor. Sharing right-of-way with another utility (not necessarily
electrical) may obviate many potential impacts in that access may already
exist, reducing construction activity somewhat, and that pioneering
of new corridors, with attendant problems , is no longer necessary.
The proposed transmission corridor could adjoin or share the rights-
of-way of five types of systems: other electrical transmission, communica-
tio,~, pipelines, railroads, and highv. ays. Although the benefit in
each case is a savings in total land use, the adverse impacts upon
these five systems vary. Elect~ical transmission systems that are
jointly using one right-of-w'"Y will suffer a reduction in reliability,
in that a catastrophe affecting cne l]ne, such as seismic activity, is
very likely to affect the oth ~r. Safety during maintenance will decrease
somewhat.
Jed~ use of an existing communiciation right-of-way will entail possible
domage to the existing system during construction of the transmission
~~"· Steady state noise may be induced into the communication line;
the communication line will also be more vulnerable to fault and lightning
damage. In the case of buried communication cables, errosion will
occur unless corrective measures are used.
Pipelines are subjected to corrosion risk also. The hazards of construction
damage, shock and fires or eJcplosion will exist.
Railroads will be subjected to shock and fire hazards. Communications
may suffer interference, and in the case of electric signals, induced
current may cause false control signals.
Along highways, transmission lines can contribute to radio and audible
noise, and in the case of accidents, can cause a fire and shock hazard.
In the case of joint use of railroad and highway rights-of-way, the
risk of accid~nts on these systems affecting the integrity of the transmission
system must also be considered.
98
1
J
1
j
The above risks are considered with no compensation or mitigation.
For instance, corrosion of cables can be controlled, as can induced
currents. Proper construction techniques will greatly minimize risk
of damage. Effects such as audible noise and resulting risks of fire
and explosion from accidents cannot be resolved with joint right-of-
way use. However, the use of a buffer strip between right-of-way
will not entail a savings in land; in the case of adjoining or partial
overlap of rights-of-ways requiring clearing through forest, the use
of a buffer of standing trees will realize no savings in clearing.
Not all rights-of-ways are visually compatible; for instance, sharing
of right-of-way with a major highway or trail systems will cause an
unacceptable scenic impact. For highways, this incompatibility must
be weighed against ihe additional scenic visual impact uf viewing U:u~
parallel, but separate rights-of-way. However, utilities not directly
involving human transportation or those in commercial or industrial
surroundings are suited for right-of-way sharing particularly if the
utility is an existing transmission '·ne.
On the proposed corridor to Fairbanks, the Golden Valley Electric
Association owns a 138 kv trar:<smission line from Healy to Ester.
It is possible to combine tlc.is line with the proposed 230 kv double-
circuit line from Devil Canyor. by upgrading the proposed line to 345
kv double-circuit and adc1:ng enough width to make a 140 foot wide
right-of-way. This would be a more efficient use of the land, along
with the elimination of redundancy of parallel transmission lines.
Ar10ther existing right-of-way which could be shared is that of the
,Ll.Jveska Pipeline. This is a right-of-way with an existing road for
nearly its entire length; use of this utility would, however, entail
a longer transmission line. The pumping stations along the pipeline
are planned to operate with a portion of the transported oil; however,
if the stations were to be electrically operated, they could draw power
from an adjacent distribution line which taps the transmission line.
Extra width will need to be obtained for the right-of-way if the transmission
line were to follow the pipeline. The feasibility of having individual
taps to serve the pumping stations is low, due to the inordinate expense
involved.
One utility right-of-way closely follows the proposed transmission
corridor for nearly its entire length. This is the Alaska Railroad,
owned by the Federal Government and operated by the Department
of Transportation.
99
.J
In some cases, the use of underground transmission can be justified
to reduce visual impacts where these impacts are judged to be greater
than the adverse impacts of undergrounding. Such a situation is typical
in those highly scenic areas where the transmission structures would
either be silhouetted, highly visible, or highly obtrusive, yet where
the access road and trenching scar of an underground cable would
not be overly visible. This sort of situation will rule out canyons
and other high-relief areas, but will favor relatively flat land.
The greatest visual difference between underground and overhead
transmission is obviously the lack of the transmission structures.
However, an underground system in all cases will require not only
an access and construction road, but also a trench which will be visible
for quite some time after construction. Overhead systems, however,
can be built without the need for an access or construction road, and
the only excavation needed will be for the tower foundations spaced
out at a rate of four or five to a mile .
It ,he location, design, and construe uon of an overhead system are
properly specified, the access road and clearing will be as visible,
and usually more visible, than the structures themselves. Where
clearing is not needed, the :Gost visible component will then be the
access road, and as indicated. even this need not be constructed for
an overhead system. In contrast, an underground system will alwavs
need a clearing in any area and will always need a construction road.
Thus, an underground system in rolling or steep terrain may well
!.. ·1ore visible than an overhead system in these situations. For
t]" 1s reason, coupled with the seismic risk to be discussed below,
• >S not recommended that the section of corridor through the Alaska
Range be underground.
A major factor in the use of underground systems is the cost. Transmission
systems are usually designed to meet given requirements for the least
cost; in almost all situations, overhead lines will meet system requirements
at a lower cost than underground cables. The A. D. Little Report
to the Electric Research Council (October 1971) states that underground
transmission costs can be as high as ten times greater than overhead
systems, and in the case of compressed gas cable systems, up to
20 times.
Underground systems generally involve higher materials cost for
the cable and for associated materials such as insulating backfill or
protective sheeting. Installation is more complicated, involving excava-
tion and backfilling and labor use is higher than for overhead systems.
Splicing of" 365 kv cable can take eight or more full workdays and
must be performed in specially constructed air-conditioned rooms,
("Underground Power Transmission", P.H. Rose, Science, Vol. 170,
Oct. 1970).
101
Theoretically, overhead systems have more outages than underground
systems since they are exposed to weather, vandalism, and accidents;
however, unless damage is exceptionally severe, including failure
of one or more towers, or access is restricted by weather, these outages
are of short duration. Faults in underground cables may result in
long-term outages up to several weeks; this results from the difficulty
in location of the fault, the time involved in excavation and backfilling,
and the time needed to :t'eplace the faulted section by splicing in a
new section.
In seismically active areas, such as can be found in the l'ailbelt, the
reliability of unde:t'g:t'ound cables must be questioned. Slicing of
the cable can result from settling or slumping of the soil; oil-filled
or compress-gas filled cables may rupture during soil movement.
Other agents can cause faulting, such as rodents, corrosion, and
subsequent excavation. Location and correction of faults in a cable
following quakes may involve considerable time and effort as opposed
tc the location of faults in an overL, ! system. Overhead transmission
lines have more inherent resiliency than underground cables. and
faults are more accessible and easier to locate.
Environmental impacts of an undc:rground cable can be quite significant
in that a continuous trer.ch ~¢ required and an access road is mandatory
for the construction vehides and the laying of the cable. The backfilled
trench may cause erosional problems, particularly if the trench cuts
up or down slopes. A cleared right-of-way must be provided for
ma'" tenance vehicles needed to unearth a faulted line; however,
; clearing need not be as wide as for an overhead system. Repairs
wi l' involve re-excavation, with attendant impacts due to potential
erosion. An underground cable in use will continuously give off
heat; this can be very serious in ice-rich permafrost areas, which
occur in all of the alternative corridors. Insulating backfill will retard
but not eliminate this heat flow; heat-transfer devices will be necessary
to prevent excessive slumping and settling of ice-rich areas traversed
by an underground cable.
Generated heat will also affect the growth of vegetation, but this does not
appear to be a significant impact.
Due to the expense and difficulty of installation, underground cables are
rather inflexible with regards to changing power needs. The addition
of another circuit or the addition of taps for local communities is very
difficult in comparison to overhead systems, where the addition of an
additional ci ::-cuit will not require another right-of-way. and the addition
of a tap will not involve the excavation of the cable, splicing, and terminal
facilities for the oil or pressurized gas insulation.
On hilly terrain, unreinforced low-pressure, oil-filled cable is subject
to possible rupture due to the increased oil pressure at the low points
of cables. Reinforcing and pressure compensation devices are necessary
in this type of cable over hilly ground.
High-pressure oil-filled pipe cable requires a continuous high pressure
maintained by pumps. This type of underground system is also subject
to pressure differentials due to elevation changes.
Cables filled with nitrogen or SF6 gas contain conductors wrapped with
oil-impregnated paper; on hilly terrain, this oil will seep to the lower
ends, and so this cable is only suited for level terrain.
Cables insulated with solid insulation, such as cross-linked polyethylene
are subject to manufacturing flaws, such as small voids, which can later
develop into electrical faults; the probability of faults is proportional to
the voltage. Usage is usually lin.\h'd to 138 kv or lower.
A major disadvantage of underground systems is the carrying capacity
dictated by capacitive reactance. Capacitive reactance is inherent in the
cable construction, and res,_:;lls in a charging current which decreases
the usable power that can be transmitted. The power loss in an underground
cable is 25 to 30 times great-er than for an overhead system. If a cable
exceeds a certain length, its transmission capacity becomes zero. For
a cable of 115 kv, this length is about 45 miles; for a 230 kv cable the
lerrrtl1 is about 35 miles. In other words, for a 230 kv cable 35 miles long,
th•· ,oss is equal to the input power.
To JVercome capacitive reactance losses, and thus lengthen the critical
length of an underground cable, shunt reactors must be installed at
periodic intervals along the cable. These shunt reactors are preferrably
located above ground for access and heat dissipation, and are basically
equivalent to a series of miniature substations with the attendant similar
environmental impacts, high reduction in reliability, and addtional costs.
Research to improve the underground transmission technology is carried
on by the Department of the Interior through the Office of the Assistant
Secretary for Energy and Minerals, and by private industry through
the Electric Power Research Institute; private industry is making by far the
greater contribution, spending $14 million during fiscal year 1974 in
efforts to advance underground transmission technology.
One result of recent efforts is the Compressed Gas Insulated Bus (CGIB).
Although still 10 to 20 times more expensive than overhead trans-
mission and of untested reliability, this sytem can handle 500 kv with a
critical length of up to 200 miles, a tenfold improvement over previous
103
critical lengths for this voltage. The potential advantages of such a
system include reduced visual impact, no audible noise as electro-
magnetic interference, small volume, simplicity of maintenance, and power
handling capability approaching that for overhead systems. Bonneville
Power Administration plans to operate a length of prototype 500 kv CGIB
near Ellensburg, Washington starting the summer of 1974 to accumulate
experience with this system. Eventually, underground cables may be
expected to equal overhead systems in performance and overall reliability;
however, since most of the cost of an underground system is attributable
to labor, the cost differential between the 1:\vo systems is not expected
to decrease significantly.
Direct Current Transmission
Direct current transmission has been used in several countries for
bulk transmission of power over long distances. Due to the higher
costs of conversion, this type of tr".nsmission is usually used for distances
o1 500 to 1,000 miles between converter stations. If no itermediate
taps are planned between the generation site and Anchorage and Fairbanks,
then the 136 mile and 198 mile lengths of the proposed corridors are
considerably shorter than the economical distances. Intermediate
taps to serve presently uncor:aected town and future population centers
along these corridors wo11ld require converter stations and even shorter
transmission lengths .
J::L lronmental impacts of d-e transmission systems are generally the
c"me as for a-c systems, except that d-e systems require only two
conductors instead of three, and thus would require a slightly narrower
right-of-way. For underground transmission, the use of direct current
will obviate losses from capacitive reactance, and in this way, enhance
the viability of undergrounding while imposing the additional costs
of converters at each end of the cable. The use of d-e in underground
systems will not lower the installed cost per cable, nor will it enhance
reliability. The need for only two cables will lower the total cost
versus a-c transmission, and if one cable is faulted, the other can
function at half-capacity with proper grounding.
The limitations of d-e transmission presently are great enough so
that it cannot be recommended for the Upper Susitn.a River Project.
However, technological advances may eventually provide a cheaper
alternative to the present converters, and thus provide the flexibility
possessed by the a-c system.
104
Alternative System Plans
The proposed system plan specifies a 345 kv double circuit line from
the generation site to Anchorage and a 230 kv double circuit line from
the generation site to Fairbanks. The "Transmission Report" discusses
an alternative system plan with a 230 kv double circuit line to Anchorage
and a 230 kv single circuit line to Fairbanks. For design details,
refer to the 11 Transrnission Report".
The environmental impacts of this alternative system plan will be essentially
identical to the proposed one. There will be some major differences,
however, in the amount of right-of-way and clearing for all the alternative
corridors from the generation site to Anchorage, and in the amounts
of materials committed for all the alternative corridors. These differences
are reflected in the table on page 88.
The right-of-way width for 230 kv is 125 feet; for 345 kv it is 140
ftod. Double and single circuit line .. , of the same voltage require identi-
cal widths. The structures needed for 345 kv are slightly larger than
those for 230 kv, and in some cases, may be more visible, but this
is unlikely.
Another alternative is the construction of transmission lines along
the Matanuska-1 or -2 and the Delta corridors in conjunction with
the proposed system. These corridors would not necessarily be construc-
J,cCI 'lt the same time nor same voltages or capacities as the proposed
sv,,em. The main advantage of such a system would be the increased
iability of redundant lines, and the interconnection of communities
ale ,,g the Glenn and Richardson Highways, the Copper Valley Electric
Association and the interconnected system produced by the proposed
system plan.
The environmental impacts of these additional corridors would essentially
be the same as those outlined for Matanuska-1 and -2 and the Delta
corridors. However, the amounts of right-of-way, clearing, and materials
committed will depend upon the voltage and capacities of these additional
corridors. For details, refer to the "Transmission Report".
Alternative Methods of Construction and Maintenance
Access Roads versus Helicopter Construction: It is proposed to
build permanent access roads for the length of both the proposed Susitna-1
and Nenana-1 corridors with the exception of one--from Gold Creek
to Healy. TLis area will be constructed by helicopter access.
105
The advantages of an access road over helicopter access are: less
expensive per mile over most terrain; ease in transportation of machinery
and materials, tower erection, strength of conductors, and removal
of merchantable timber; more reliability of access for maintenance
and inspection; and multiple-use of corridor.
Disadvantages of an access road are: increased maintenance problems;
unauthorized use of access road; potential increase in erosion and
siltation; and increased visibility, more clearing required with subsequent
impacts.
Since neither alternative method is suitable for the entire length of
the proposed corridor, the proposed method of access is that which
was judged to be most suitable to the location.
Winter Access versus Year-Round Access: Transportation of materials
and machinery and construction dnring winter would eliminate many
in.,>acts related to access road cOl1'oH'Uction and tower erection. With
total winter construction, the access road would not be necessary.
Disadvantages of winter accc:<;s and construction are: the construction
season would be rather lirmted: conditions will be harsh on men and
machinery; snow and frozen ground may interfere with excavation
and placement of tower footings; the lack of an access road will affect
the reliability of maintenance access, and will elimiate any multiple-
us o of the clearing.
,;vnsidering the site of this project, it is necessary to use as much
of the year as possible in order to complete construction within a reasonable
time. Also, given some of the weather conditions and the length of
the corridors, reliability of access is imperative, especially since
there is no proposed back-up transmission line in case of a fault.
Thus, whenever possible, year-round construction will be used.
As outlined above, access roads will be used whenever indicated.
Alternative Methods of Clearing: Presently, some of the clearing
methods used by the utilities are as simple as bulldozing over any
and all trees within a set distance from the centerline of the right-
of-way, insuring enough width for an access road, ease of construction,
and clearance between falling trees and the conductors. This method
is fairly direct, involving little discretion between what is cleared,
and actually what is minimally necessary for construction and maintenance.
However, this method also results in excessive disturbance of the
soil and unnc:cessary destruction of vegetation.
106
Considerably cheaper and less environmentally damaging, the technique
of only clearing that vegetation necessary for construction and maintenance
is recommended. Instead of toppling trees with a bulldozer, selective
cutting is used, allowing stumps to remain.
There are three methods of disposal of cleared vegetation: sales of
merchantable timber, burning, or chipping. All three alternative
methods will be used where applicable.
Sale of timber will require an access road; some of the timber can
be used in road construction in timber bridges and corduroy in muskeg.
Also in this category is the offering of timber to any who wish to remove
it for firewood; this will only be significant near settled areas, and
any timber not disposed of in this way after a few months will be disposed
of in other ways.
If no access road is to be used, then open burning is the only available
n." thad of disposal. A temporary dC"cline in air quality is inevitable,
and open burning, in any case, will be subject to local ordinances
of the affected boroughs.
Forced-draft burning will ~onsJderably reduce particulates, but will
require an access road Ior t};e large tub burners. In any case where
burning is allowable, where an access road will be built, and where
chipping is not necessary, forced-draft burning will be used.
In a.·eas where large-scale burning is prohibited, or where chipping is
.-e suitable, then slash and unsalable timber will be chipped.
All tough most expensive and time consuming of the three methods,
chipping in many instances is preferable. Where permafrost degradation
is likely, where the surface mat of vegetation has been seriously disturbed
or destroyed, or on potentially erosive soils, the use of chips as a
protective humus is indicated. Chips will provide a measure of insulation
over ice-rich frozen soils, some protection for bare soils, and although
decomposition rates are slow, an organic mulch to aid revegetation.
Since the chips will lie on the ground, and usually be somewhat wet,
they will present less of a fire hazard than unchipped slash.
A fourth method of disposal is to stack slash and allow it to naturally
decompose. Although this will provide a temporary habitat for small
mammals, it will also provide good habitat for destructive insects,
provide fuel for fires, and reduce the value of the clearing as a firebreak.
Thus, this option is not recommended.
107
l
Alternative Methods of Clearing Maintenance: In areas of fast :regrowth,
some periodic suppression of tall plants is necessary. There are
three major alternative methods: aerial application of herbicide, manual
application of herbicide, and physical cutting of trees and brush.
Aerial spraying involves the coverage of large a:reas with herbicides
sprayed £:rom an airplane, or more frequently, a helicopter. Due
to the non-selective nature of application and the risk of accidental
overs praying, spraying of water bodies, and improper concentrations,
this method is not recommended.
Manual application of herbicides involves the spraying of target trees,
dispersal of pellets at the base of target trees, or selective spraying
of thicket of brush. It is relatively safe from the risks associated with
aerial spraying, and also much more selective. It can be carried out
during routine ground inspections or during scheduled programs
of brush suppression.
Physical cutting involves the identification and destruction of danger
trees and the periodic suppre~sion of brush. Chain saws, brush axes,
and motorized rotary axes can be used for this. The labor expended
is greater than for manual ap;,;Hcation of herbicide, but is safe for
use adjacent to water bodies. If large areas of brush are cut, the slash
must be burned or chipped. Small amounts of slash widely dispersed
will not pose an insect hazard.
~-e recommended method of control is the manual application of herbicides
wi'h cutting in sensitive areas; aerial spraying is not proposed.
Alternative Endpoints
For this feasibility study, it was necessary to postulate definite endpoints
to allow determination costs, clearing, etc. This in no way will finally
define the endpoints of the actual transmission, just as the location
of a corridor does not attempt to locate the actual placement of a transmission
line within that corridor.
The choice of endpoints of the Nenana and Delta alternative corridors
is relatively limited to those already postulated--Ester and Fairbanks.
Unless new substations were to be built, these are the only two feasible
choices. However, for the Matanuska and Susitna alternative corridors,
two alternative endpoints are obvious. Point MacKenzie is the terminus
of a set of underwater cables to Anchorage; Palmer is the northern
end of an existing AP A transmission line,
108
Paint MacKenzie is far closer to the main load center at Anchorage
than Palmer; the transmission corridor will crass relatively less developed
land to approach Anchorage via Point MacKenzie than via Palmer.
Power would be marketed directly to Chugach Electric Association,
and wheeled over their system to Anchorage Municipal Light and Power,
Hamer Electric Association, Matanuska Electric Association, and the
Seward Electric System.
Delivery to the existing APA system at Palmer would avoid the limitations
and risk of the submarine crossing of Knik Arm, but would involve
more crossing of privately owned land. Power would be marketed
directly to Anchorage Municipal Light and Power and Chugach Electric
Association. Power would be wheeled aver the CEA system to HEA,
SES , and MEA.
The environmental assessment for the Susitna corridor with an endpoint
at Palmer would be substantially the same as that far the proposed
~o: stem. Mileage, clearing, and aLer impacts would remain virtually
the same. If the corridor were to be routed along the uplands north
of the Anchorage-Fairbanks Highway, somewhat better sails would
be encountered, and mare P'ivately awned land and farms would be
crossed.
Far the Matanuska alternative corridors, there would be mare substantive
differences: the corridor would be about 45 miles shorter, and would
involve up to 764 acres less of right-of-way and clearing. Also,
}f,, materials would be used, and less labor expended by utilizing
~Palmer endpoint.
APA will continue to propose the Point MacKenzie endpoint until mare
input favorable to the utilization of the Palmer endpoint is received.
No Action (Nancanstructian)
In discussing the alternative of non-construction of the proposed trans-
mission line, the viability of the Upper Susitna hydroelectric project
must be considered, since the primary purpose of the transmission line
will be to deliver the generated power to the major centers in the Rail-
belt. In essence, nan-construction of the transmission line implies non-
construction of the Upper Susitna pawersites.
No action will mean that the potential power of the Upper Susitna will not
be made available to the Railbelt area. Since use of power is projected
to increase, alternate sources of power will have to be used. If present
plants are upgraded, this will result in the increased use of fossil fuels
such as coal and gas. It is not likely that costs of fossil fuels will remain
109
the same, and they will almost certainly not decrease. Development of
large-scale hydro projects will probably be beyond the capability of the
present utilities, so fossil fuels will be used for a relatively low-priority
use whereas a renewable resource, water power, will go untapped.
If additional power sites are required to satisfy energy needs, as they
probably will be, then they will require their own transmission systems
to deliver their power. Thus, non-development of the Upper Susitna
and its transmission system will not halt further construction of transmission
systems by other agencies or utilities, and if new powersites tend to be
small-scale due to inability of utilities to develop large hydro sites,
then more transmission lines may result than if the Upper Susitna were
to be developed.
Another effect of non-construction will be to preserve the insular and
disconnected character of the utility systems presently serving the
Railbelt. A transmission line to be ·,uilt with the main purpose of inter-
connection would not be likely in the near future, and the duplication
and waste of the present situation will be prolonged.
110
ACKNOWLEDGEMENTS
·.,, .. · ........ : .....
ACKNOWLEDGEMENTS
In the preparation of this draft environmental assessment, Alaska
Power Administration has worked in close coordination with the Alaska
District Corps of Engineers. In addition, APA has received valuable
assistance from the Bonneville Power Administration, particularly
in the selection of alternative corridors. Further assistance has been
given by the Bureau of Land Management, the Bureau of Reclamation,
the Fish and Wildlife Service, the National Marine Fisheries Service,
and the National Park Service.
Comments and advice have been given by various State agencies,
chiefly the Alaska Department of Fish and Game and the Alaska Department
of Highways; also the University of Alaska helped with comments and
advice.
112
APPENDIX I
Appendix I
The following appendix will discuss general characteristics of the
physical and social categories used in the assessment of the proposed
corridors and their alternatives. Both a definition or description
of the category and a description of potential impacts in these categories
from a transmission line corridor will be discussed. Note the phase
"potential impacts"; not all impacts described will necessarily occur.
This section is intended only for background information; specific
and more detailed treatment of the proposed corridors and their alternatives
is covered under "Environmental Assessment of Corridors" and "Assess-
ment of Impacts".
Topography and Geology
This is one of the more important categories, for topography influences
most of the succeeding ones. Tor•' ,raphy is itself a surface expression
ot underlying geology and tectonicL (for convenience, tectonics will
be considered under geology while hydrology will be covered along
with topography),
The Railbelt area is ch2ract~-1zed by three lowland areas separated
by three major mountain ;;reas. To the north is the Tanana-Kusldkwim
Lowland, which is delineated by the Alaska Range to the south. The
Susitna Lowland is to the southwest, bounded to the north by the Alaska
;e, and to the east by the Talkeetna and Chugach Mountains. The
.~ \}per River Lowland in the east is bounded on the north by the Alaska
''"''ge, and the west by the Talkeetna Mountains. Each basin is underlain
by quaternary rocks surfaced with glacial debris, alluvium, and eolian
deposits, The mountains are primarily metamorphic and sedimentary
rocks of the Mesozoic, with several areas of intrusive granitic rocks
in the Talkeetna Mountains and the Alaska Range, and Mesozoic volcanic
rocks in the Talkeetna Mountains. Figure 1 delineates the major features.
The Railbelt is an active seismic area; the 1964 earthquake was perhaps
one of the most destructive earthquakes on record. The seismic history
is short relative to the time over which strains accumulate to produce
an earthquake, so historic seismicity is a poor guide to potential seismic
risks. There are several significantly active faults in the Railbelt
area. The most spectacular fault in terms of length and prominence
is the Denali Fault, a long arc bisecting the entire Railbelt through
the Alaska Range. Maximum expectable earthquakes in the area can
be of at leasi a magnitude of 8. 5 on the Richter Scale. Figure 2 depicts
seismic history of the railbelt from 1899 to 1964.
I -1
H
I
1\:l
SEDllviENT AHY
QUATERNARY
deposits, alluvium,
eolian sand and silt
TERTIARY
Sandstone,
MESOZOIC
, shale,
Sandstone shale; marine nonmarine;
includes some rocks
PALEOZOIC AND PRECAMBRIAN
Sandstone, shale, limestone; mostly ma.rine;
includes some early Mesozoic rocks
PALEOZOIC Al'lD PRECA!vi.DRIAN
Metamorphic rocks: schist, gneiss, etc.;
ma.inly Paleozoic
IGNEOUS ROCKS
and volcanic
Mesozoic intrusive mainly
Mesozoic volcanic rocks
Paleozoic volcanic rocks
Paleozoic intrusive rocks; granitic and ultramafic
Fault
(Dashed where inferred)
Sot:rce; C.S.G.S.
APA-1975
0
I-3
ES=
MAGNITUDE~6
SOURCE: U.S.C.SG.S.I966
IOOMilos
A.P.A.-JULY 1975
consideration, is pierced
south to its mouth
Soils
I-4
Fi9ure 3
~~~~~~~~~~~~ ~~~
I-5
so even in
moisture.
table which thaws
moist;
soil permeability,
is considerable soil
material, is very susceptible
ice lenses. Shallow
loess, or wind
are evident
from L~e
cause slow
of rivers
will as result of
any access roads. Construction
surface mat
, can result
The existence and maintenance of an access
cause erosion though to a lesser than construction
activities
may be altered by an
on finegrain soils. This result
land or gullying on side
I -6
and the resultant
increased insolation where the
direct
and erosion may
mat has
vehicles , or from over-
may also
may
is similar to bottomland
characteristic trees,
species
on poorer soils or sites ,
fans, or on
trees are white , black spruce,
Coastal Hemlock-Spruce
Bottomland Spruce-Poplar
Upland Spruce-Hardwood
Lowland
High Brush
Low Brush, Muskeg-Bog
Alpine Tundra
Wet Tundra
Source: Joint Feder<;el-State Land Use
1arm1ng Commission
APA-1975
ALASKA POWER ADMINISTRATION
.,
~.
BASED ON VEGETATIVE TYPES
Figure 5
ALASKA POWER ADMINISTRATION
0
I-9
rivers.
berries.
two sub-types. One exists
exists on plains of major
, alders and
on outwash and old
lowlands.
alders, willows, and
tundra exists on rolling foothills of and
ofthe River.
mountain areas,
Characteristic a1·e resin
, Labrador tea, mountain , rhododendron and
is a
among which is
areas.
of climate soil,
of a transmission line and access road upon
ratio of occupied of the
unaffected
greater consequence.
is limited
Primary
areas it will probably
I -10
, Limited regrowth and maintenance along the right-of-way
plant community in forested areas; regrowth
areas will reach climax as far as
allow,
the
introduction of non-native or Hweed 11
not adapted to the
tundras, will be to
stacked or
small animals > there is a high 'rlrl•TC1n71
debris , this
slash may
slash
increased fire hazard and increases in insect
forests . Slash be
burner':
smoke and ash ,
than open
to the soil and
slash
use of herbicides to control in
than physical destruction.
type or
and drifting are problems with aerial
is much more selective and accurate.
is
on chemical used, soil , moisture,
rate of biodegradation. Most herbicides m
I -11
for
right-of-way control are of low toxicity to animals, and appear to
be non-cumulative, unlike many pesticides. Contamination of lakes and
streams is possible; potential destruction of aquatic plants may
result, destroying fish habitat. However, this possibility is offset
by the decomposition and dilution of herbicides. There is little
or no evidence of long-term accumulation of herbicides on the soil;
leaching, sunlight, microbial action, and degradation by vegetation
itself inhibits accumulation.
Physical disruption of the vegetative mat, either from clearing or
machine tracks, or from road construction, will reduce the insulation
of frozen soil from summer warmth. The exposure of darker soil will
increase warmth from insolation; these factors can combine to alter
the permafrost-vegetation relationship. Settling from permafrost
destruction will cause erosion and thermokarst; lowering of the permafrost
table will alter the ground water regime. These effects in turn will
affect the vegetation cover. AY<' with thin permafrost, such as in
' e taiga, are in a more delicate be. ance with vegetation than more
heavily frozen areas, particularly if the active layer is shallow also.
Experience in farming in the Matanuska and Tanana Valleys has shown
that lowering of the permaf:rc1st table due to disruption of the original
vegetation can also cause: of the water table and subsequent
changes in vegetation a deeper 2.ctive layer and dryer topsoil.
Although taiga ecosystems are adapted to wildfire exceptionally deep-
fires in peat can change the permafrost regime of an area,
subsequent change in vegetation. Excessive repetition of fires
2.n area can achieve the same result, and also can have a result
maintaining a low subclimax vegetation. Secondary impacts to wildlife
are varied, destruction of habitat and cover to enhanced habitat
due to increased productivity. Construction and maintenance
activities provide additional potential for fire; to what degree fires
will increase is impossible to predict. Potential man-caused fires
depend upon the distribution and flammability of plant communities
along the right-of-way, the seasonal schedule of construction, and
annual climatic variation. During construction, potential of man-caused
fire will be great, but detection should be early, and areas burned
small. During operation and maintenance of the t:t·ansmission line,
potential of man-caused fire will be low, but detection slower, and
consequently, areas burned will be larger. Operation of fire-fighting
machinery off the access roads may cause considerable damage.
I -12
Various plant communities differ in rate of fire spread and resistance
to fire control:
Upland Spruce-Hardwood
Lowland Spruce-Hardwood
Bottomland Spruce-Poplar
High Brush
Moist Tundra
Alpine Tundra
Rate of Spread
High
High
Medium
Low
Medium
High
Resistance to Control
Medium
High
High
High
Medium
Low
Man-caused fire potential exists mainly during the period of May
through September, Uncontrolled use access roads will increase
the potential for man-caused fires.
Wildlife
~ume generalities can be drawn as the fauna of the taiga and tundra
ecosystems. The most important factor governing wildlife populations
and distribution is the relatively low primal productivity of the taiga,
and the even lower produc~l nty 0f the tundra. Herbivore-based food
chains are more developed a; J. diverse on the taiga then the tundra.
In both areas, a relatively small number of herbivore species exist,
with less on the tundra. Some herbivores experience cyclical population
fluctuations; these fluctuations are coupled to fluctuations in predator
ulations. There is high mobility of the larger mammals and birds.
~grating mammals are an expression of the low bearing capacity of
land for large herbivores. Migrating birds reflect extremes in
seasonal of food. (consuming of dead plant
and animal an important role in the food chain.
The low number of species in the tundra ecosystem food chain makes
this an extremely sensitive area. A disturbance affecting one species
will have an inordinate subsequent effect on other species in the food
chain. An expression of this tenuous balance is in the fluctuations
in populations. Examples of these fluctuations are the periodic explosions
of lemming and snowshoe hare populations, which are related to the
somewhat milder and slightly lagging fluctuations of predators, such
as lynx or wolf. Distribution of moose, bear, Dahl sheep, caribou,
bison and waterfowl are shown in Figures 6, 7, and 8.
Aquatic ecosystems have similar features of the above terrestrial ecosystems.
Low species diversity, low growth rates, and long life spans are charac-
teristics of the lake fish. Anadromous fish such as salmon are extremely
important in the railbelt area; the lower Susitna, Copper, and Tanana
Rivers are the basis for a considerable commercial, subsistence, and
sport fishery.
I-13
l/{] Moose Concentration
~ """
Doll Sheep Range
/
I-14
ALASKA POWER ADMINISTRATION
LOLl
MOOSE, DALL SHEEP, BROWN BEAR
0 50 !OOMilo•
A.P.A.-JULY 1975
~Caribou Summer Range
~Caribou Calving Range
liB Bison Range h~~~~(::~6.\~~
Source• Joint Federal-State Land
Use Planning Commission
I-15
ALASKA POWER ADMINISTRATION
0
WILDLIFE
CARIBOU AND BISON
SCALE
50 JOOMiles
A.P.A.-JULY 1975
ll1llliiiJI High Density
IITIIIIIJ Medium Density
ITIOJ Low Density
lj
)
I
I-16
Figure 8
ALASKA POWER ADMINISTRATION
WILDLIFE
WATERFOWL HABITAT
SCALE
0 50 IOOMiles
A.P.A.-JULY 1975
A transmission line per se will not have many impacts upon wildlife;
most of the impacts will be as a result of const>:-uction and maintenance.
Direct destruction will affect the less mobile animals such as the small
mammals, whose territories may be small enough to be encompassed
by the construction area. The significance of this impact is small
in relation to the animal population in the surrounding areas. The
construction area will be reinvaded by animals from the surrounding
area after the line is built and regrowth proceeds. Hunting and trapping
by construction workers can be considered direct destruction; mortality
from project-related fires can also be considered direct destruction.
A more serious impact than direct destruction is the preemption of
habitat. Animals forced out of their habitat by construction may not
find another niche; this assumes that the land is at its carrying ·capacity
for that species which is affected. Some animals, such as carnivores,
will flee at almost all human intrusion; if they are forced into a lower-
grade area, or are dislocated for a long period, they will be weakened
and increased mortality can be "''+-'cted.
Deliberate or inadvertant harassment of wildlife, particularly large
mammals, will be a serious impact. Flights to construction sites,
maintenance flights, and operation of vehicles on open areas, all have
the potential for animal harassment. Harassment during calving for
sheep and caribou can c;cuse increased stillbirth.
Although a transmission and access road will not impose a barrier
tc ligration of caribou, construction work during certain seasons
" J.y inhibit herds from approaching work areas. The creation of
a cleared corridor through heavy forest may result in increased animal
movement along the right-of-way.
Migrating birds may suffer some mortality from collisions with towers
or lines, but these losses should be negligible. The cables are not
spaced close enough nor are they invisible enough to be efficient
snares; also the probability of a bird flying in an appropriate area
at the right elevation and at the proper angle to the line simultaneously
is rather small.
Electrocution of birds is also unlikely; the distance between lines
and between lines and ground is great enough to make shorting out
by a bird almost impossible. Birds can safely perch on cables or
towers.
I -17
The most significant impacts result from habitat modification resulting
from impacts on soils and vegetation. Clearing in forest areas and
maintenance of a sub climax plant community of brush and low plants
will enhance habitat by increasing the primary productivity of the
cleared area. Browse for moose will be increased; the conjunction
of good cover in the original forest with a swath of browse creates
a diverse "edge" habitat for many animals dependent on subclimax
growth. Animals dependent on climax or near-climax vegetation will
suffer loss of habitat; examples are the red squirrel and northern
flying squirrel, both of which depend upon White Spruce.
Destruction of climactic lichen on tundra areas will destroy winter
browse for caribou. The decline of the caribou herds in Alaska is
attributed not only to hunting, but also to destruction of tundra lichen
by man-caused fires. Lichen is the key browse for caribou, for it
is their prime food during the winter. It is estimated that approximately
50 years are required for a burm••. area to recover a usable cover
of lichen for caribou.
Destruction of climactic vegetation by fire often enhances moose habitat.
Taiga ecosystems are adapted to wildfire, and present mosaics of
vegetation communities are c>fcen a reflection of former fires. An increase
of fires resulting from man-made causes will, up to a point, have
not much more impact than the incidence of lightning-caused fires.
A significant increase ovel:" natural-caused fires will result in increased
m -tality from fires, excessive destl:"uction of cover and habitat for
'"ildlife dependent upon climactic or near-climactic vegetation, increased
silting of rivers and lakes, potential disl·uption of seasonal habits
and migrations, and potential disruption of the permafrost-vegetation
relationship.
Impact upon aquatic life from a tt"ansmission line should be small.
The aquatic food chain in the taiga and tundra is extremely simple,
and as a result, disruption of habitat for one species quite often indirectly
affects many other species. Potential impacts are the increased siltation
of rivers and lakes; alteration of flows; eutt"ophication and pollution
of lakes and streams; disruption of habitat due to gravel borrow,
fill, and excavation; and withdrawal of water, especially during winter.
I -18
Siltation can result from erosion along the construction sites, burned-
over areas, borrow pits, and river crossings. The impact of siltation
depends upon the severity of siltation, the existing water quality,
and the amount of aquatic life in the stream or lake. In rivers already
carrying glacial silt, the effect of man-caused siltation will be slight.
Clear water streams and lakes supporting large aquatic populations
will be most affected. Siltation can cause gill damage in fish and may
result in filling interstices in gravel beds, reducing suitability for
spawning.
Alteration of drainage by an access road may influence river flow,
but a transmission line project should not affect surface drainage to
any appreciable degree.
Spills of oil or fuel, herbicides, and other chemicals into water bodies
will impact aquatic habitat. Fast-flowing streams will be the least
affected by spills, due to the rapid dispersal and dilution of the contamin-
<>r>t; lakes and slow streams will b<· most affected. The actual impact
is dependent upon the type of spill, the amount, and the volume of
water affected. Addition of excessive nutrients or organic matter
to lakes, such as disposal of ,;lash, may cause eutrophication, either
from excessive algal growrh o:r from decomposition or organic material.
Excessive oxygen depletion ir1 lake waters will lead to fish kills.
Alteration of stream and lake beds will destroy habitat. Some of the
alterations, such as gravel extraction, will add an inordinate amount
oi :.: ~lt to a clear water stream.
A ,cecondary impact of great significance to wildlife from a transmission
line will be the increased access to areas now unserviced by roads.
If an access road is maintained for line maintenance, it is very likely
that it will be used by the public. Bonneville Power Administration
has experienced unauthorized public use of those access roads which
are supposedly closed to all non-maintenance use. To many mammals,
the presence of man has an impact, particularly the presence of hunters.
Increased access to presently inaccessible areas will certainly add
to hunting pressures on game in those areas. The degree of the impact
depends upon regulation by game management agencies, the quality
of the area for hunting, and the season.
Climate
This category adheres to the definition of climate, that is, the average
weather cor. Jitions over a long period; however, there are very few
climatic data for the study area, particularly in regards to wind speeds.
I -19
Thus, each segment is assigned to one or more of three general climatic
zones. These are the Transitional, Interior, and Mountain zones.
The Transitional Zone is a modified continental climate, having some
of the characteristics of the Maritime Zone along the coast of the Gulf
of Alaska, yet being partially subject to the greater temperature extremes
and drier climate of the Interior Zone.
The yearly average temperature for this zone is about 29°F in the
northerly part to 38° in the southerly part. Temperature extremes
range from about -400 to 85°F. Precipitation ranges from 12 to 24
inches per year; snowfall ranges from less than 50 to more than 200
inches per year. Winds are generally calm, although high winds
over 50 mph can be expected.
The Interior Zone is a true continental climate. It is relatively dry,
being dominated by high pressure >ir masses. As a result, extreme
seasonal temperature variations and relatively mild winds can be expected.
The yearly average temperature for this zone is about 24° to 29°F;
annual temperature extremes range from -60° to nearly 100~. Precipita-
tion has an annual range of ahout 8 to 16 inches a year. Snowfall
amounts from less than 50 to almost 100 inches a year. Winds are generally
very light, with high winds recorded at less than 50 mph.
Si-ce this area is dominated by stable high pressure air, temperature
inversions are common, and ventilation is low. Thus the potential
~.,ists for smog, fog, and ice-fog around sources of particulates and/or
mvisture. Ice-fogs repeatedly cover Fairbanks and seriously reduce
visibility; the temperature usually must be below -35°F for this to
occur.
The Mountain Zone is basically a modification of a more prevalent
zone, in this case, either the Transitional or the Interior Zones.
The causes of the modification are elevation and relief. Increased
elevation tends to lower the yearly average temperature without decreas-
ing seasonal temperature variations present at lower elevations.
High relief combined with elevation results in increased precipitation
due to adiabatic cooling of uplifted air masses, and an increase in
the force of local winds. Since mountainous terrain is anything but
uniform, wind patterns can vary tremendously. However, it is safe
to assume high extremes of wind throughout the entire zone.
1 -20
1
I
Land Ownership and Status
Land ownership is considerably less influenced by physical factors
and more by social factors. At present, land ownership is an unstable
situation, for although the majority of the land traversed by the route
segments is presently Federal land, that ratio is destined to change,
with more land being in State and native ownership. With the exception
of the Matanuska Valley and the more heavily settled areas, there
is presently relatively little privately owned land.
Land Status is an even more changing situation than land ownership.
The present land status situation is largely a result of the Statehood
Act of 1959, ANCSA in 1971, and the Alaska Conservation Act of 1974.
All Federal lands in Alaska are presently in a withdrawal status; not
only will a considerable portion of Federal land be transferred to State
and Native ownership, but all the remaining Federal lands are slated
either for inclusion into either the existing National systems such
s National Parks and the National Forests, or for withdrawals for
classification and public interest.
At present, apart from privc,te holdings, only patented State land and
existing Federal withdrawals can be considered constant. Most of
the corridor segments lie jy, lands that are pending or tentatively approved
State selections, Native village withdrawals, and Native regional
deficiency withdrawals, all of which are in flux at the present.
1 Lc!refore, assessment of the land status of a segment reflects only
e situation at the time of this publication.
Direct impacts on existing developments will generally be low, mainly
because there are so few existing developments along the segments.
Due to the changing nature of land use and ownership, impacts may
change considerably in the space of a few years.
With the present pattern of land ownership, there will be few conflicts
with land ownership, as most of the land along the routes are presently
in Federal and State ownership. Distribution of lands to Natives and
other private owners by the Federal and State governments in the
future will increase the likelihood of purchase of easement of private
lands and possible subsequent displacement of private owners.
Little impact is expected upon land use; the right-of-way width required
for a transmission line is a small fraction of the land the line traverses.
There will Je almost no conflict with agricultural ands; at present,
agriculture is basically limited to the lower Matanuska Valley, and
smaller al."eas in the Tanana and Copper River Valleys. The potential
for agriculture exists over a considerable area of the railbelt (see
Figure 9), but the impact of a transmission line on these potential
areas is less than on the existing areas. Forestry at present is very
limited in the Railbelt, more from ownership causes then natural causes.
Forestry can be expected to increase, but impacts from a transmission
line will be minimal.
Known and potential areas of coal, oil, natural gas, and minerals
exist in the Railbelt area. The fossil fuels are predominant in the
three basins of the Tanana River, Cook Inlet, and the Copper River
lowland. Minerals are more usually found in the more mountainous
areas. A transmission line itself will have little effect on development
of these resources. The availability of power from the Upper Susitna
project might spur development, but this is dependent upon the local
utilities and their distribution systems. Location of these mineral
resources is shown in Figures 10, ll, and 12.
Little direct impact on towns from a transmission line can be expected;
this results from the ability to circumvent the few towns encountered.
The endpoint substations ar<' outside of Anchorage and Fairbanks,
so these towns will not be peneh·ated by a right-of-way.
Some employment can be drawn from communities on the Railbelt for
the construction of the transmission line. Larger towns, such as Anchorage
and Fairbanks, could be expected to contribute a higher proportion
o, killed workers than the smaller towns. Since line crews would
' : working well away from towns and residing in camps, they should
n• t present a strain to services in communities. Activities associated
with the transmission line may cause impacts on services in communities;
these impacts will probably represent use of the communities goods
and services, and if not an inordinately large use, will be beneficial
to the economies of the communities. Thus, disruption of the economies
and services of communities along the route by the construction phase
should be low.
Operation and maintenance impacts on communities will also be low;
a relatively small crew of workers can periodically inspect and maintain
the transmission line, and actual operations will be concentrated in
the powersites and the terminal substations. Since it is relatively
inefficient for small communities to tap a transmission line of 230 kv
or higher, the probability that the transmission line will serve adjacent
communities is low.
I -22
Figure 9
POWER ADMINISTRATION
E I L A ABLE
IN THE RAILBELT ARE
SCALE
0 50
RY 1975
Figure 10
ALASKA POWER ADMINISTRATION
!L AN GAS
OTENTIAL
0 IOOMilos
I-24 A.P.A.·JULY 1975
Figure 11
0
A.P.A.·JULY 1>175 I-25
Figure 12 ---"''I
ALASKA POWER ADMINISTRATION
POTENTIAL MINERAL
ENT
0 lOOM lin
l-26 A.P.A,-JULY 1975
is concerned with
possibility exists
transmission and
shared rights-of-
an transmission or transportation
a transmis-
Two examples
electric pumping
transmission
this is a much
to the difficulty
are several
will define this
the visual
high scenic value,
(beautiful,
of more components of scenic are scale,
, intactness, and vividness. Scale is relationship of
·viewed area to the viewer. Scales range detail, or close-up views,
as views of small elements of the as plants, rock "formations,
etc.) to views, such as one could have in a forest, in which
still hold most the to distant or scenic
elements are to
view rather than of
harmony among elements in a landscape; put
, it is the of the lack discordant elements. A
acres is considered most people to be less discordant
landscape than a five acre farm. Unity
, and as such, is variable not only among the
groups, but also is variable over time as tastes change.
I-28
Figure 13
LOCATION MAP
ISSI N E
INLET AR
X-~<-x-x-K 33 KV Transmission Line
,._·-x-·-x-·-x 69 KV Transmission Line
x-··-X-··-x 115 KV Line
Line
\
)
FAIRBANKS
Figure 14
LOCATION MAP
\
/
UNITED STATES DEPARTMENT OF THE INTERIOR
ALASKA POWER ADMINISTRATION
I-29
ISS I
NAN LLEY
x-l'I-X-)( 33 KV Transmission Line
x-·-x-·-x 69 KV Transmission Line
11---X-··-x 115 KV Transmlssloo Line
)1-··-X-···-x 138 KV Transmission Una
A.P.A.-JULY 1974
Variety is the degree of diversity in a landscape; its converse is uniform-
ity, the degree of homogeneity. Variety may be a function of scale;
a landscape perceived as uniform, such as tundra, may have detail
views of amazing variety, particular I y in its plant life. There appears
to be no obvious relationship between variety and unity or between
variety and intactness.
Vividness is the strength of the impression of landscape. It is a function
of degree of pronouncement of the major qualities in a landscape.
Vividness is interrelated with the components of unity, intactness,
and variety. It does not imply strong variety or strong uniformity,
but rather the degree to which variety or uniformity is perceived and
remembered. As two examples, the highly diverse view of M t. McKinley
as seen from Wonder Lake and the highly uniform landscape around
Lake Louise are both very vivid to the author, whereas the landscape
of lower Talkeetna River is much less vivid.
Since scenic quality is a complex s1 bject, some assumptions must
in order to use it as category in a matrix. The first assumption
is that we will only be considering large-scale views; detail and middle-
views should not be affected by a transmission line. Second, no attempt
will be made to quantify scenic qualities; the study of perception is
not yet advanced to the point ":here one can confidently quantify a
subject of such widely varying individual perceptions. Third, the
area within National and State Parks or other scenic reserves will automa-
tically be considered more sensitive to scenic degradation because
of recognized scenic qualities. Fourth, landscapes visable from
surface public transportation routes will be considered more
c..tnsitive than those that are not. The reasoning behind this is that
scenic values are not intrinsic to the landscape, rather, they are
responses of the individuals perceiving that landscape. An area with
a high number of viewer contacts would then be more sensitive to
scenic degradation than an area with no viewers, or with very few
viewers.
Obtrusiveness is the lack of unity of an element with the rest of a landscape,
the degree to which an element is perceived as incongruous. A transmission
line in a valley bottom seen from two miles away is less obtrusive
and visible than a line silhouetted on a ridge one mile away. Factors
affecting obtrusiveness are tower design and height; design and width
of dearing; reflectiveness of tower and cable; topography; and distance
from viewer. Where natural cover and topography enable a line to
be hidden, impact on scenic quality is low; on open tundra, impact
will be medium to high, depending on distance and topography.
I -30
There are several recreation and scenic reserves affected by the alterna-
tive routes; most important are Mount McKinley National Park and
Denali State Park. Both are rather sensitive areas, as they attract
and are the result of a considerable tourist trade. Parks in Alaska
have the image of open, unspoiled wilderness, particularly to tourists
from outside the State. Visibility of a transmission line in or around
these parks will have a greater impact than in other areas. There
are a variety of State-owned recreational areas and waysides adjacent
to the highways in the Railbelt; impact on these recreational sites
will be low; due to their relatively small size, they can be circumvented
easily.
The National Register of February 4, 1975 lists six registered historical
and archaeological sites that might possibly be affected by the alternative
routes. These are shown on Figure 15. In most cases, impact on
these will be low to none; the others can be circumvented to minimize
disturbance.
1ue alternative routes cross no proposed or existing scenic, wild
or recreational rivers, nor do they cross any proposed or existing
wilderness areas or wildlife refuges. However, in segments where
the transmission line will pioneer a corridor through a previously
intact area, the quality of wiUerness will suffer, especially if the
transmission line is easilj visible. However, in most segments the
transmission line will parallel existing corridors or will traverse
no significantly large areas of intact wilderness. A pioneer corridor
c ssing a significantly large wilderness area will have a high impact
r '' access and future location of other rights-of-way. These in turn
w11l degrade wilderness quality further, but to the benefit of increased
access for recreational uses involving motorized access.
Figure 16 shows an approximation of existing scenic quality.
I -31
Variety is the degree of diversity in a landscape; its converse is uniform-
ity, the degree of homogeneity. Variety may be a function of scale;
a landscape perceived as uniform, such as tundra, may have detail
views of amazing variety, particularly in its plant life. There appears
to be no obvious relationship between variety and unity or between
variety and intactness.
Vividness is the strength of the impression of landscape. It is a function
of the degree of pronouncement of the major qualities in a landscape.
Vividness is interrelated with the components of unity, intactness,
and variety. It does not imply strong variety or strong uniformity,
rather the degree to which variety or uniformity is perceived and
remembered. As two examples, the highly diverse view of Mt. McKinley
as seen from Wonder Lake and the highly uniform landscape around
Lake Louise are both very vivid to the author, whereas the landscape
of lower Talkeetna River is much less vivid.
Since scenic quality is a complex subject, some assumptions must
be made in order to use it as 1ry in a matrix. The first assumption
is that we will only be considering large-scale views; detail and middle-
views should not be affected by a transmission line. Second, no attempt
will be made to quantify scenic qualities; the study of perception is
not yet advanced to the puh:.t where one can confidently quantify a
subject of such widely varyh" g individual perceptions. Third, the
area within National and State Parks or other scenic reserves will automa-
be considered more sensitive to scenic degradation because
recognized scenic qualities. Fourth, landscapes visable from
'o:r surface public transportation routes will be considered more
Fzmsitive than those that are not. The reasoning behind this is that
scenic values are not intrinsic to the landscape, rather, they are
rt::sponses of the individuals perceiving that landscape. An area with
a high number of viewer contacts would then be more sensitive to
cenic degradation than an area with no viewers, or with very few
viewers.
Obtrusiveness is the lack of unity of an element with the rest of a landscape,
the degree to which an element is perceived as incongruous. A transn1ission
line in a valley bottom seen from two miles away is less obtrusive
and visible than a line silhouetted on a ridge one mile away. Factors
affecting obtrusiveness are tower design and height; design and width
reflectiveness of tower and cable; topography; and distance
viewer. Where natural cover and topography enable a line to
be hidden, impact on scenic quality is low; on open tundra, impact
will be medium to high, depending on distance and topography.
I -30
(
ALASKA POWER ADMINISTRATION
NATI AL HI RICAL
ARCHEOLOGIC L Sl
I-32
I l'l:J"f o;:; I U
MAP
Ill! I ~ Good to High Quality Scenic
888883 High Quality Scenic Area
Source• Joint Rldemi-Siole Land Use
ALASKA POWER ADMINISTRATION
SCENIC VALUES
0 50 IOOMI!n
I-33
APPENDIX II
Appendix II
Strip Maps covering the Alternative Corridors.
The following strip maps are in three groups: those showing the
general features, those depicting land status, and those delineating
soil types. The alternative corridors are covered by seven maps
for each group; there is some overlap from map to map, but not
all alternative corridors are entirely depicted on any one map .
On each map is a gray stripe showing the approximate position of
an alternative corridor on that map; these positions are very
approximate, and the exact location and width are indeterminate.
The land status mapped is based upon the land status situation
of March 1974. State selections include patented, pending, and
tentatively approved State-selected lands. Due to the present
unstable condition of land status, it must be recognized that there
may be changes since the date of the map.
The soils maps are based upon the 1:250,000 soils overlay map
published by the Joint Fede:ral-State Land Use Planning Commission.
UNITED STATES DEPARTMENT OF THE INTERIOR
ALASKA POWER ADMINISTRATION
INDEX TO
ALTERNATIVE
CORRIDOR MAPS
Scale in miles
50 75 100
A. P.A.-March
ANCHORAGE -DEVIL CANYON
....P.A.-_~
2520z10 15
Scale in miles
5o
I
<1<.I <Is
'1-<1
I 0'<11tcI~
I
I
I
I
I
I
~rEI<A CNILNcHU
,~~
RIVE!?,,,,
~"i>-
\",-~
~-
\=I\~S ~~1"P>-
IV
I'JIOU
~cale in miles @
1"~P>-\j
25
1
20
1Zt.t.
~-10 15
1"P>-'-
0 5)
APA.-"".".191S
SUSITNA
CANTWELL-FAIRBANKS
rIJ!fJ~1'jJ'oe,,"""
~.AIR FORCE RANGE
yr
/,,'
:
2520
Scale in mi les
10 155
"'-\
NATIONAL //
MOUNT Me KIN LEY
I
I
I
I
I
I
I
I
I
I
I
252015
CANTWELL-PAXSON
10
v
Scale in mi les
5o
RANGE
I
I
I
BLAIR LAKE
FORCE RANGEAIR
Ie in milesSea
.....--1\10 15o 20
2520
VALDEZ-R~~~,
10 15
Scale in miles
--z...-_..~
5o
Scale in miles
I
MOUNTAINS
-o -5 10 15 20 25
"
C'
PALMER-GLEN~LLEN
SOILS LEGEND
Soil 111 ~ . Cf]:? •
Slope Group -... ---~ Textural Group
Erosion Potential
Soils
EAT -Poorly drained soils, normally in waterlaid materials.
EFT -Well drained soils, in stratified materials on flood plains and low terraces.
EOL -Well drained gray soils; shallow bedrock.
EOP -Well drained loamy or gravelly gray soils; deep permafrost table.
HMT -Poorly drained partially decomposed peat; seldom freezes in winter.
HMV -Poorly drained partially decomposed peat; contains lenses of volcanic ash.
HY (B)G -Poorly drained fibrous peat; freezes in winter.
HYP -Poorly drained fibrous peat; shallow permafrost table.
IAHP -Poorly drained soils with peaty surface layer; shallow permafrost table.
IAP -Poorly drained soils; shallow to deep permafrost table.
IAW Moderately well to poorly drained soils; may contain deeply buried ice masses
ICF -Well drained brown soils; contains lenses of fine-grain material.
ICP -Well drained thin grown soils; deep permafrost table.
ICT -Well drained grown soils; non-acid.
IND Well drained dark soils formed in fine volcanic ash.
IUE -Well drained soils with clark, acid surface layer.
IUL -Well drained soils with dark, acid surface layer; shallow bedrock.
IUP -Well drained thin soils with dark acid surface; deep permafrost table.
RM -Very steep, rocky, or ice-covered land.
SOP Well drained, thin, strongly acid soils; deep permafrost table.
scr;. -Well drained strongly acid soils.
SOU -Well drained, strongly acid soils; very dark subsoil.
The mapping units, while referring to only one or two dominant soils in the
association, include other soils and less extensive soils.
Slope Groups
1-Slopes dominately less than 12%.
2 -Slopes dominately steeper than 12%.
Textural Groups
c-sandy
f-clayey
Erosion Poten'ial
E-1-low
g-very gravelly
m loamy (medium)
E-2-medium E-3-high
I
I
[;>tJ.
SOP IAHP
~-Im
E-2
RM
DEVIL CANY"O[!},..-_'l
DAMSITE
,,",1'/1,."'...~1975
!M.b-R2g
E-I
SOILS:ANCHORAGE-DEVIL CANYON
20
Scale in mi les
o 5,10 15
/~--Z
RM
lli_HY(BIG1m
E-I.2
RM
SOT -HY(BlG2g
E-2
RM
I
I
I
I
I
I
I
I
I
I
IAHP EOP1m-,E-2
.ol.'!'P-Mo""197$
SOILS:SUSITNA
/__.:.:8V,;..TT~£..:C...<<:i''f-
_IU_L_RM29
~
252015
WATANA DAMSITE
S P-IAtlP\i.o~cE~2
RM
\~UL_RM
j2 9
)
J
J
IUL-2-9 -RM~~~--=:::::;:SOP-IAHP
29 £-2
RM
ll!.!:.-RM29
£-1
~
\o
I
I
Scale in mi les
ICF-IAHP
2m lin
E-2,3
IAHP -HYP
1m____E-2
.,,".-..,1!>
SOILS:CANTWELL-FAIRBANKS
ICT
Tni
E-I
ICT IAHPiV-1ril
E-2
~E-I1m
252015
RM
10
~_1AtIf
2g 1m
E-2,3
IAP-EOP
2g
E-2
-H'o 5
RM
RM
IL ~CANTWELL-PAXSON
RANGE
15 20
RM
25
ICT-IAHP E-2,3
2g 1m
ICF lAHPZin-""iiii""
ICF _IAH P E-2,3
2m 1m
IAHP E_21m
ICT IAHP10-2m
lAW ICTIin-IO E-2
RM ,.....--o 5 10 15 20
RM
5 10
SOILS:VALDEZ-R~"".
o
!M!f E.2
If
IUP E.3
20
RM
RM
RM
PALMER-GLENNALLENSOILS
RM
25201510
Scale in miles
RM
--o 5
RM
RM
SOU-IUL \~2Q RM fl D.,9
E-I IUP-IAHP Q
2Q
E-2 IAHP IAHP
RM 1m -11-
E-2
E-2
RM
LAND STATUS LEGEND
Major withdrawals prior to Alaska Native Claims Settlement
Act, (December 18, 1971)
Withdrawals for possible inclusion on the four National
systems (D-2)
Withdrawals for classification and public interest (D-1)
State selections-patented, tentatively approved, and
pending (SS)
Withdrawals for Native villages eligible for land selections
Withdrawals for Native villages, eligibility for land selection
· not finally determined
Village deficiency withdrawals (NVD)
Regional deficiency withdrawals (NRD)
Utility corridor (UC)
The:·e maps represent the land status situation as determined by
the Bureau of Land Management, December 18, 1973
I
55
5
Scare in miles
10 15
Z=
20 25
NRD
.Pol -.IAoodI 19~
LAND STATUS I ANCHORAGE-DEVIL CANYON
A PA.-M.,'~1915
:SUSITNA
2520
0-1
15
=
10
,
-r~
Scale In mi les
NRD
~
\
~
I
\
55
55
i'l/""-~aswell
III"M~ontanQ Creek
Mt.McKinley National Park
--J
-'f.:
·;\,55
Scale in mi les
....,- -10 15o5
55
55
25201015
A.PA.-MOleh 197~
Scale in miles
NRD
,......-
o 5
RANGE
LAND
Militory Reservotion 55 55
Scale in mi les
10 1·~5-.....J20-~1 ~25STATUS-~'FAIRBANK;g~=-=--"~-PAXSON
25201510
NRD
Scale in mi les
P""""lj --o 5
LAND STATUS:VALDEZ-R"""",,-A.III.
NRC
NRC
55 0-1
55
NRO
Q,
'"
a
-'"
<0,F
,
0
"I
.p
\55
\d}
Cl
""~
f>'0
LAND
\':::,
A p-,.~"",,,.~l'11S ENSTATUS·PALMER-GLENNALL
I I
I
l I
' I \ • J
·.·•
APPENDIX III
l
1
J
l
J
]
0
J
]
J
J
J
J
J
u
APPENDIX III
Photographs
The following photographs depict typical views and critical points along
the proposed corridors and their alternatives:
Photos 1 -4 are illustrations of Corridor Susitna-1
Photos 5 -25 are illustrations of Corridor Nenana-1
Photos 26 -28 are illustrations of Corridor Susitna-2
Photos 29 -30 are illustrations of Corridor Susitna-3, 4
Photos 31-40 are illustrations of Nenana-2, 3, 4, 5
Photos 41-56 are illustrations of Matanuska-1, 2
Photos 57 -69 are illustrations of Delta Corridor
All photographs in this appendix were taken by AP A personnel. The
majority were taken in September of 1974.
l
l
l
Lower Susitna River Valley. This area is charac-
terized by extensive muskegs, intermingled with
bottomland spruce-poplar forests. Permafrost is
absent or discontinuous in this area, although the
soils are generally poorly drained.
III-1
l
l
1
l
Susitna River Valley. Lakes are prevalent and assoc-
iated with muskegs, which succeed them in formation.
Muskegs are succeeded in turn by forests dependent
upon well-drained soils. The three stages of success-
ion are shown here.
111-2
Susitna River Valley near Talkeetna. As the terrain
.·becomes more rolling, the relative ammmt of muskeg
becomes less.
III-3
.....
1-1
1-1
I
-'='"
--
Town of Talkeetna. This town is at the confluence of the Talkeetna,
Susitna, and Chulitna Rivers. The Alaska Railroad can be seen cross-
ing the Talkeetna River near the right edge of the picture.
-~
l _. L_j L_:
...... ...... ......
I
(.1'1
L--
Stnmni t Lake at Broad Pass. Broad Pass is an aptly named feature; a
structurally-controlled depression in an otherwise motmtainous area.
It is the divide for tributaries of the Omlitna and Nenana Rivers.
---" __j __j ~~
~~
~
...... ...... ......
' 0'\
~
r-·~
____; ~
Alaska Range from Anchorage-Fairbanks Highway near Broad Pass, late
spring. Vegetation biome is lowland spruce-hardwood. Soils here are
basically glacial deposits.
j
_] i -----'
....... ....... .......
I
"'
t.-_____I _____I __J
---~~-------··-------
Alaska Range from Anchorage-Fairbanks Highway near Broad Pass. Soil
here is poorly drained; trees visible are black spruce.
J
...... ...... ......
I co
Entering Alaska Range on Anchorage-Fairbanks Ilighway, north of Cantwell.
Concealment of line will be difficult in areas such as this.
-----' J
.,
l
l
Looking south along Nenana River to Upper Nenana
Canyon. The Anchorage-Fairbanks Highway parallels
the left bank. Mot.mt McKinley National Park and
the Alaska Railroad are on the right bank of the
river.
III-9
..___
...... ...... ......
' __,
0
----l
Nenana River and Sugar ~~untain, seen from Anchorage-Fairbanks Highway
near Yanert. Yanert Fork enters Nenana River near right-hand edge of
photo. Visible also is communication line for Alaska Railroad.
-------' -•
J
J
Very restricted canyon along Nenana River north
of McKinley Park. Alaska Railroad is off left-
hand edge of photo. Land left of river is
within Mount McKinley National Park.
II I-11
J
Another view of canyon on Nenan a River .
...... ...... ......
I
w
L _j .__j _j
Nenana River valley in vicinity of :Moody bridge on Anchorage-
Fairbanks Highway.
J
....... ....... .......
I __,
~
__j __J
Alaska Railroad north of McKinley Park.
L___
....... ...... .......
I .....
U'1
Usibelli Coal Mines near Healy. Note the seams of coal in the
scarp. This coal is the fuel for the Healy steamplant.
------' ------' _j
....... ....... .......
I ......
m
'---------'
Nenana River flood plain near Healy. Note the terraces
characteristic of the Nenana Valley in this area.
_I
l__..
...... ...... ......
I _.
"'--
138 KV Healy transmission line. Looking south from Anchorage-
Fairbanks Highway towards Healy.
___J J
.,
l
I
l
J
./
... ~-. , ... /'w; /i ....
(
l /
/ '
' '
Guyed tangent tower in foreground; guyed dead-end
towers in background; Healy 138 KV transmission
line.
III-18
-J
l
l .~
l ..,: -
'
~--/
<'
;r E
l ~
l
l
Guyed 138 KV tower on the Healy transmission line.
III-19
...... ...... ......
I
N
0
L__
_J __ j _j
Nenana River valley, looking south to Alaska Range. Terraces are
fairly evident along right background.
_j _j J
...,
l
1
J
Town of Nenana, at confluence of Tanana River and
Nenana River, which flows in from lower right.
Double-span bridge is for the Anchorage-Fairbanks
Highway; single-span bridge is for Alaska Railroad.
II I-21
L__
...... ...... ......
I
N
N
'---__j
Alaska Railroad siding along Tanana River at Nenana. Large free-
standing tO\ver is part of river crossing of Healy 138 KV transmission
line.
-____J
..... ..... .....
I
N w
I..-.---.. c.--L._! '-------' ---.J
Town of Nenana; frontage on Tanana River. Nenana handles considerable
river traffic on the Tan ana River.
__j ____]
I
J
..... ..... .....
I
N .:::.
"Goldstream Hills". On the slopes, the predominant vegetation is
birch-white spruce, on poorly drained areas and some north-facing
slopes; black spruce predominate.
J
l___. ~
---I
N
(.11
__j
View to the west from the "Goldstream Hills". These hills flank the
north bank of the Tanana River; the Anchorage-Fairbanks Highway enters
them immediately across the river from Nenana, and follows their
crest to Ester and Fairbanks.
~ _j
l--~
...... ...... ......
I
N
0"1
.____ ______,
N ,~• .,,;
Clearing for Matanuska Electric Association (MEA) distribution line.
Vegetation is predominantly poplar and spruce. Clearing was done
by uprooting trees with a bulldozer.
l
.... .... ....
I
N ......,
Near Honolulu on the Anchorage-Fairbanks Highway. Biomes shown on
law brush muskeg in foregrmmd and upland spruce-hardwood in back-
ground. Black spruce in foreground are associated with poorly drain-
ed soils and/or shallow permafrost tables.
_I
.,
l
l
l
l
1
l
J
J
J
Little Coal Creek in Denali State Park. Vegetative
biome is classified as upland sp!1::1ce-hardwood.
Streams in this area are incised into a relative-
ly gentle plain. ,
III-28
--J
j
l
l
1
1
}
j
l
J
Talkeetna River near town of Talkeetna. This photo
shows the de nsity and conformity of the forest of
the lower Susitna Valley in the Talkeetna area.
II I-29
...... ...... .......
I w
0
..... <: '~
·~~~'' ;;
;,.,.;!"
#, ~~
Detail of bottomland forest near Talkeetna. Predominant trees are
poplar and white spruce with considerable brush understory. This
forest type can easily conceal a transmission clearing.
Upper Wells Creek, approaching pass to Louis
Creek. Biome is alpine tundra.
III-31
Wells Creek Pass as seen from Louis Creek side.
'-
,_. ,_. ,_.
I w w
Moody Pass fran Yanert Fork to Moody Cree~,. which is visible in the
upper left. This pass is relatively low (2900') and wide, but
soils are poorly drained and subject to permafrost.
J
L--~
...... ...... ......
I w
~
Lower Moody Creek. This is a well-dissected area, covered with
upland spruce-hardwood. Routing of transmission may prove diffi-
cult in this stretch.
___J J
-I
l
LCMer MoodyCreek at confluence with Healy Creek
(top of photo). Unstable slopes are evident.
I II-35
---I w
~
Looking north from western end of Denali Highway. Typical low
brush and muskeg biomes. Trees are black spruce.
__j __j J
...,
I
l
J
J
.Aerial view looking west along Denali Highway and
Nenana River to Cantwell. Note that forests are
limited to the terrace slopes and levees of the
river channel.
II I-37
L_ '---
..... ..... .....
I w co
Surface view of area typical of that shown in photo above; in this
case, the Nenana River is in the vicinity of the Wells Creek con-
fluence. The lowland spruce-l1ardwood is limited to the terrace
slope and river bottom.
J
...... ...... ......
I w
\0
Looking west up the Nenana River and Denali Highway. The sources of
both the Nenana and Susitna Rivers are in the Alaska Range visible in
the upper left. In the upper left also is the divide between these
two rivers, a wide, poorly-drained area called Monahan Flat.
J
l
1
1
l
Susitna River between Watana and Vee damsites.
Heavier vegetation, in this case upland spruce-
hardwood forest, is limited to the valley slopes,
the vegetative biome on the upper plateaus is
generally moist ttmdra, muskeg, and alpine ttmdra.
111-40
...... ...... ......
I
~ .......
Susitna River at Vee damsite. This demonstrates the typically in-
cised character of the Upper Susitna fran1 Devil Canyon to the Tyone
River. Note that heavier vegetation is limited to slopes and creek
valleys.
~ __j
..,
J
J
J
J
J
J
Jt»ist tundra near Butte Lake; looking north to ~ahan Flats and
Alaska Range. ATV tracks are visible in the foregromd; these
tracks start fraa the Denali Highway, which cTOSses the flats in
the b ackgromd.
III-42
-~ -'
I
j
j
J
J
j
ATV tracks leading from Denali Highway. This photo
shows typical mois t tundra vegetation with low-
growing brush, peaty soi l , and poor drainage.
II I-43
L__ L___. ~
...... ...... ......
I
~
~
'---.
Susitna River above Denali damsite, looking west. The few spruce to
be found are limited to the river bottom.
___ ......J J
~ (__ L_
---I
~
(.1'1
Irnpm.mdment area of Denali damsite. The Susitna here is a rneandezy, ·
aggrading river, the surrmmding land is vezy poorly drained and
underlain by fairly continuous permafrost.
____J -----' J
L-L__
---I
~
0'\
L______; .....__ l__j
Maclaren River, looking north to the Cleanvater Mountains. The fore-
ground knob is part of a morainal ridge. These morainal features
are reltaively well-drained, whereas the flat low-lying lands are
poorly drained with shallow permafrost tables.
-----.J __j ---' J
L_ L_ L_
....... ....... .......
I
~ ........
'--_____j __j
Looking north along the Denali Highway to the Amphitheater Mountains.
Morainal ridges run across the middle of the photo. The biome along
most of the eastern half of the Denali Highway is moist tundra.
----' _____j J
...... ...... ......
I
~ co
----'
Uplands near Sourdough on the Richardson Highway. This is typical of
the plateau bordering the Copper River lowland on the north and east.
Poorly drained, it supports many lakes, the largest of them in the
Lake Louise complex.
__j ._____j ___J __j ~l
LJ [ ,
.. J
...... ...... ......
I
.J::o
1.0
:..__......,; l_._...; ~ ,_________,
The Lake Louise plateau. Biomes are predominantly lowland spruce-
hardwood and muskeg. These uplands are lm.derlain by continuous
permafrost.
J
....... ....... .......
I
(J'1
0
The Copper River lowlands, a large basin tn1derlain by permafrost.
J
l
l
l
l
J
...J
Tazlina River as seen from the Glenn Highway.
III-51
---I
01
N
L-t..____.. L
Tahneta Pass area between the Tazlina and Matanuska River drainages .
Lakes and muskegs are indicative of poor drainage. The mmmtains
are part of the Omgach Range.
--J
l
l
I
l
l
l
j
l
J
j
J
Talkeetna Mmm.tains; Glenn Highway nms across
the lower portions of the photo. The Matanuska
valley is bordered on the north by the Talkeetna
Range, on the south by the Omgach.
III-53
.......___. '------.. L...___...
---I
(J'1
~
HCMell Glacier and the Chugach Range. The Matanuska River flc.Ms in an
incised channel across the middle of the photo.
J
I
J
J
J
I
l
l
l
1
l
Caribou Creek and the Talkeetna Mountains; Glenn
Hi ghway on lower portion of photo. This tributary
of the Matanuska River typifies the incised charac-
ter of many rivers eroding through glacial debris
and loess, such as the Matanuska , Copper, Gulkana,
and upper Nen ana Rive rs.
II I-55
...____.. '---... L.____, L___;
---I
U'1 en
c._
....____) '-----.. __J __J
Matanuska River and Omgach Range. The Matanuska River has a braiding
channel due to the high silt load from the Howell and J.fatanuska
Glacier, and the glacial tributaries entering from the Chugach Range.
_j
.__ ~ L-l.__; l____j
..... ..... .....
I
tTl
"'-J
'----.J
'------'
Looking north by Paxson Lake on the Richardson Highway to the
Alaska Range. Paxson Lake is an important part of the fisheries of
the Gulkana River.
'-------'
---I
0'1
CX>
L_ L______.
·1:
Surnnit Lake and the Alaska Range. SUIIUllit Lake is drained by the
Gulkana River and is just south of Isabel Pass.
__j
J
....... ....... .......
I
U'1
~
____j
Isabel Pass, looking north to Rainbow Ridge. The Richardson High-
way, the Delta River, and the Alyeska Pipeline cross the photo at the
base of Rainbow Ridge.
__j -~
.... .... ....
I
0'1
0
---' ___J ___J
.--~-~·'"··~···""'"'"""'""'"''"''"'
Rainbav Ridge, as seen from the south. The Richardson Highway crosses
under the ridge from right to left. The slope of the ridge is a
series of adjoining talus cones some of which are unstable.
__j _. _] _.
~ t_:
--.......
I
0) .....
Delta River by Black Rapids Glacier. The glacier is partially visible
in the upper center of the photo. The Delta River carries considerable
'glacial silt, resulting in aggradation and braiding of the channel.
L__,
...... ...... ......
I
0'1
N
Alaska Range seen fran the north Jrom the Richardson Highway. This
is not true perspective as seen from the highway, since the photo was
taken with a telephoto lens. --
....... ....... .......
I en w
L_____
The Alaska Range seen from the Richardson Highway near Donnelly Dome,
looking south. The dust is from the channel of the Delta River, which
·is extremely tmdersized for its channel.
-~
---I en .::..
_.J --..J
Another view of the Delta River as seen fran near Donnelly Dome.
Again, the bla.ving dust from the channel is evident.
__j __j ____J .I
'"
..... ..... .....
I m
01
Alaska Range from Big Delta, taken with telephoto, In the foreground
is the Delta River channel, which near here joins the Tanana River.
j
...... ...... ......
I m m
----.J __J
Fann near Delta Jtmction. Some attempt at fanning is made in the
CleaiWater Lake area, but agriculture is relatively tmimportant except
for the lower Matanuska Valley area.
_j ----.J
L J J
Silhouetted notch on a clearing for a GVEA distribution line.
l
1
J
Looking up the T8D811& River across the confluence of Shaw Creek.
The braiding of channels characteristic of the Delta and Tanana
Rivers is evident.
III-68
•
The Tanana River flood plain. This area is extreme-
ly flat and poorly drained. Three types of biome
are represented in this picture: nruskeg, lowland
spruce-hardwood, and bottomland spruce-poplar. The
dark forests are mainly black spruce. The sinuous
lighter forest is white spruce, aspen and birch.
This forest type prefers well-drained soils, and
so is found on old levees of existing and extinct
channels.
lii-69