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SUSITNA HYDROELECTRIC PROJECT
TRANSMISSION LINE CORRIDOR SCREENING
CLOSEOUT REPORT
TASK 8 -TRANSMISSION
FINAL REPORT
MARCH 1982
Prepared by:
[Ii]ARLIS
Alaska Resources
Library &InfonnauonServlces
Anchorage.AlasKa
ALASKA POWER AUTHORITY __---'
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ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
TASK 8 -TRANSMISSION
SUBTASK 8.01 -CLOSEOUT REPORT
TRANSMISSION LINE CORRIDOR SCREENING
TABLE OF CONTENTS
Page
LIST OF TABLES....................................iii
LIST OF FIGURES...................................................tv
1 -INTRODUCTION
1.1 - Organization of Report 1-1
1.2 -Existing Transmission Systems in the Ra i lbelt 1-2
1.3 - Plan Formulation and Selection Process 1-2
2 -SUMMARY
2.1 -Scope of Work (Section 3}..........•........•.........2.1
2.2 - Previous Studies (Section 4)2-1
2.3 -Selection of Alternative Corridors (Section 5)2-2
2.4 -Screening of Cor r i dors (Section 6)2-2
2.5 - Conclusions and Recommendations (Section 7)2-3
3 -SCOPE OF WORK
,3.1 -Objectives 3-1
'3.2 -Approach....3-1
4 -PREVIOUS STUDIES
4.1 -The Corps of Engineers Study 4~1
4.2 -The IECO Report .............•.........................4-1
5 -SELECTION OF ALTERNATIVE CORRIDORS
5.1 - Objective .
5.2 -Data Base .
S.3 -As sump t ions .
5.4 ...Selection Cr i ter i a .............................•......
5.5 -Identification of Corridors ........................•..
5.6 -Description of Corridors .
6 -SCREENING OF CORRIDORS
6.1 Objective .
6.2 Uata Base .....................•.......................
6.3 -Assumptions .
6.4 -Reliability .
6.5 Screening Criteria .
6.6 - Screening Methodology .
6.7 Screeni ng Results .
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ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
TASK 8 -TRANSMISSION
SUBTASK 8.01 -CLOSEOUT REPORT
TRANSMISSION LINE CORRIDOR SCREENING
TABLE OF CONTENTS (Cont'd)
7 -CONCLUSIONS AND RECOMMENDATIONS
7.1 -Conel us;ons II ••••••••••••
7.2 -Recommendations .
7.3 -Other .
8 -BIBLIOGRAPHY AND AUTHORITIES CONTACTED
APPENDIX A-GENERIC PLAN FORMULATION AND SELECTION METHODOLOGY
B-SOILS INFORMATION
C -REVIEW OF PREVIOUS STUDIES
D-RECORD OF EVENTS
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Page
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LIST OF TABLES
Number
1.1
5.1
5.2
5.3
5.4
6.1
6.2
Title
Utility Companies Serving the Railbelt Area
Technical,Economical,and Environmental Criteria Used in
Corridor Selection
Environmental Inventory -Southern Study Area
Envi ronmenta 1 Inventory -Central Study Area
Envi ronmental Inventory ..Northern Study Area
Economi ca1 and Techni ca 1 Screening -
Southern Study Area
Economi ca 1 and Techni ca 1 Screeni ng - Central Study Area
6.3 Economical and Technical Screening -Northern Study Area
6.4 Environmental Constraints -Southern Study Area
6.5 Environmental Constraints -Cental Study Area
6.6 Environmental Constraints -Northern Study Area
6.7 Summary of Screening Results
A.1 Step 2 -Select Candidates
A.2 Step 3 - Screening Process
A.3 Step 5 - Plan Evaluation and Selection
A.4 Examples of Plan Formulation and Selection Methodology
B.1 Soil Associations within the Proposed Transmission Corridors -
General Description Offroad Trafficability Limitations (ORTL)
and Common Crop Suitability (CCS)
8.2 Definitions for Offroad Trafficability ~imitations and Common
Crop Suitability of Soil Associations
C.1 Corridor Analysis -Project Power to Anchorage/Cook Inlet Area
C.2 Corridar An alysi s -Project Power to Fai rbanks/Tanana Area
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LIST OF FIGURES
Number
1.1
5.1
5.2
5.3
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
A.1
C.1
Title
Anchorage to Fairbanks
Proposed and Exi sti ng Transmi ssi on Line Corridors
Alternative Transmission Line Corridors Southern
Study Area
Alternative Transmission Line Corridors Central
Study Area
Alternative Transmission Line Corridors Northern
Study Area
Recommended Tr ansmi ssi on Corridor Southern St udy Area
Recommended Transmission Corridor Southern Study Area
Recommended Transmission Corridor Central Study Area
Recommended Transmission Corridor Central Study Area
Recommended·Transmission Corridor Northern Study Area
Recommended Transmission Corridor Northern Study Area
Recommended Tr ansmi ssi on Corridor Northern Study Area
Recommended Transmission Corridor Northern Study Area
Plan Formulation and Selection Methodology
Devil Canyon Projects,Transmission Segments
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TABLE 1.1:UTILITY COMPANIES SERVING THE RAILBELT AREA
Area Utilities
Anchorage -Cook Inlet Anchorag~Municipal Light &Power (AML&P)
Chugach Electric Association (CEA)
Hat anuska Eleet r ic Assoc i at ion (~IEA)
Homer Electric Associ at ion (HE,:X)
Seward Electric System (SE5)
Fairbanks -Tanana Valley
Glennallen -Valdez
Fairbanks Municipal Utility Systems (FHUS)
Golden Valley Electric Association (GVEA)
Copper Vailey Electric Association (CVE~)
1 -INTRODUCTION
The Acres American Incorporated (Acres)Plan of Study (POS)for the Susitna
Hydroelectric Project was issued by the Alaska Power Authority (APA)for public
review and comment in 1980.The POS outlined the selection of the most environ-
mentally, economically,and technically acceptable route for transmission lines
which would carry power from the proposed Watana and Devil Canyon damsites to
the cities of Fairbanks and Anchorage.
Subsequent to February 1980,APA engaged Commonwealth Associates,Incorporated,
(CAl)to study and recommend a location for a proposed transmission line inter-
tie between the Anchorage and Fairbanks electrical utility systems (see Appendix
D -Record of Events).The eXisting Fairbanks transmission system extended
southward to Healy,and the Anchorage transmissi on system terminated in the
vicinity of Willow.The corridor connecting Willow and Healy will be designated
for the purpose of this report as the Intertie Corridor;this corridor must also
contain the Susitna transmission lines.The corridor,therefore,is a north-
south alignment along the Susitna/Chulitna/Nenana river valleys.See Figure 1.1
for general location of the study area.
This report,therefore,contains the results of studies conducted by Acres to
determine the optimum corridor locations to bring power:1)from the damsites
to the connection with the Intertie;2)from the northern terminus of the Inter-
tie at Healy to Fairbanks;and 3)from the southern terminus of the Intertie at
Willow to Anchorage.The results of this report will be used in the license ap-
plication submittal to the Federal Energy Regulatory Commission (FERC).
Terrestrial Environmental Specialists,Inc.collected the environmental data for
this report and conducted the environmental aspects of the corridor selection
and screening analysis.
1.1 - Organization of Report
In order to improve readability of the report,it is structured in seven sec-
tions as follows:
Section 1 contains the introduction.
Section 2 is a summary of the work undertaken and the findings to date.
Section 3 describes the scope of work and approach utilized to meet the study
objectives.
Section 4 briefly summarizes previous stUdies of transmission line corridors
conducted in the rai lbe lt area by others.
Section 5 discusses the methodology and results of the corridor selection study
conducted by Acres and a brief description of alternative corridors.Figures
5.1 through 5.3 show the alternative corridors investigated.
Section 6 presents the screening of corridors and the criteria established by
Acres for that purpose which are based on environmental,economical,and techni-
cal aspects.The methodology of screening is also discussed.Table 6.7 shows
the summary of the screened corridors,together with their ratings.
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The findings and recommendations are discussed in Section 7. Figures 7.1
through 7.8 show the location of the recommended corridor.
The following appendices are also included:
A- Generic Plan Formulation and Selection Methodology
B -Soils Information
C -Critique of Previous Reports
o -Record of Events
1.2 -ExistingTransmission Systems in the Railbelt
The railbelt area is presently served by three separate transmission systems.
Each system operates independently and maintains its own reserve generation.
The three areas in which the three systems operate are Anchorage-Cook Inlet,
Fairbanks-Tanana Valley,and Glennallen-Valdez.
The utilities serving these areas are listed in Table 1.1.The Alaska Power
Administration operates the Eklutna Hydroelectric Project and markets wholesale
power to Chugach Electric Association,Anchorage ~~unicipal Light and Power,and
Matanuska Electric Association.
1.3 - Plan Formulation and Selection Process
(a)rl.an Formulation
A key element in this study is the process that was applied for selection
and comparison of several altern~tive transmission line corridors.Empha-
sis was placed on consideration bf all aspects that may influence the
choosing of a most likely candidate corridor.A description of a generic
plan formulation and selection methodology is presented in Appendix A.
(b)Selection Process
The selection process generally follows that described in Appendix A.
The POS defines the objective for Subtask 8.01 as screening of transmission
line corridors from the Susitna sites to Fairbanks and Anchorage.Since
then,the extent of the geographical areas has been changed by the proposed
prebuild of the Intertie.The objective has been revised to define three
areas which were investigated as outlined in Section 5.
Alternative corridors have been identified in each area.The results of
the screening of these corridors were based on technical,economical,and
environmental considerations.Successful candidates are identified and
recommended.
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ALASKAN
RAILROAD
LEGEND
--0--HIGHWAY
I I I I RAILROAD
-.-PROPOSED SUS ITNA LI NE
----EXISTING TRANSMISSION LINE
D SUB -STATION
MT.McKINLEY
NATIONAL PARK
ALASKAN
RAILROAD
TALKEETNA MOUNTAINS
I38KV .
WILLOW "115KV •.--:::::~.~.--~~~~~~,.~.~~.....,-.d;"III~-J-t---+--S •~,.......Us ../r;:;-N-;7.4~--
/i'l V;;.E:":/i':-----U..l
\",,,
UNDER CONSTRUCTION~~\
( TO BELUGA POWER PLANT),\'
230 KV LI38 KV
*THE PROPOSED INTERTIE FROM WILLOW TO HEALY WILL BE CONSTRUCTED
FOR 345KV CAPABILITY AND INITIALLY OPERATED AT 138KV.IF SUSITNA
IS PROVED FEASIBLE,THE FULL 345KV CAPACITY WILL BE UTILIZED.
12
ANCHORAGE TO FAIRBANKS
PROPOSED AND EXISTING TRANSMISSION LINE CORRIDORS
SCALE IN MILES
FIGURE 1.1
2 -SUMMARY
This section summarizes the studies conducted and the results of these studies.
2.1 -Scope of Work (Section 3)
One of the main objectives of Task 8 -Transmission,is the recommendation of a
transmission line route linking the Susitna Hydro sites with the Anchorage and
Fairbanks areas and selecting intermediate station sites for switching or other
system functions.
Figure 1.1 shows the general transmission line configuration and related loca-
tions of the stations.
Subtask 8.01 is the preliminary step in carrying out the Objective of connecting
the generation with the load areas.The 8.01 subtask included the following
functions which resulted in this closeout report:
(a)Review previous studies and reports.
(b)Assemble all data from U.S.Geological Survey (USGS)maps,available aerial
photography,and field investigations.
(c) Obtain aerial photography.
(d) Obtain land status information.
(e) Obtain and util ize input from environmental sources.
(f)Identify the geographical areas to be considered in the study.
(g)Identify all previously selected corridors that will meet basic technical,
economical,and environmental criteria established in Section 5 and select
new corridors that meet these requirements.
(h) Screen the candidate corridors and select the preferred ones.
(i)Identify the selected corridors for further 1981 field investigations and
aerial photography.
2.2 - Previous Studies (Section 4)
A number of studies have considered an electrical interconnection from Fairbanks
to the south-central and Anchorage areas.The Susitna Hydroelectric Project In-
terim Feasibility Report produced by the U.S.Army Corps of Engineers,hereafter
called the CaE report,reviewed a number of alternative transmission corridors
in considerable depth.None of the studies included a specific route for a
transmission line.
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International Engineering Company,Inc./Robert W.Retherford Associates
(IECO/RWRA)produced the Economic Feasibility Study report for the Anchorage-
Fairbanks Intertie.The preferred corridor selected in the COE report was
further refined and a specific route identified.The study presents a determin-
ation of the economic feasibility for a transmission line interconnection be-
tween the utility systems of Anchorage and Fairbanks.
2.3 -Selection of Alternative Corridors (Section 5)
The proposed prebuilding of the Intertie has indicated three areas that will re-
quire study:the northern area to connect Healy with Fairbanks;the central
area to connect the Watana and Devil Canyon damsites with the Intertie;and the
southern study area to connect Willow with Anchorage.
Utilizing existing data,previous reports,and assumptions concerning trans-
mission tower configuration,corridor width,and certain key locations (tie-in
points),twenty-two corridors were selected for screening.This selection was
based on those corridors which met certain technical,economical,and environ-
mental criteria (Table 5.1).
Of these twenty-two corridors,four are in the southern study area,fifteen in
the central study area,and four in the northern study area.Two of the corri-
dors in the southern study area run in a north-south direction,while one runs
northeast to Palmer, then back no.thwest to Willow.Corridors in the central
study area are in two general groups:those running from Watana damsite wester-
ly to the proposed Intertie and those running northerly across the Denali High-
way and the Chulitna River.Corridors to the northern study area run either
westerly or easterly to bypass the Alaska Range,then proceed northerly to Fair-
banks.
(.4 -Screening of Corridors (Section 6)
Corridors selected previously were screened utiliZing technical,economic,and
environmental criteria similar to but more precise than those used in the selec-
tion process.Corridors were rated in terms of their acceptability from each of
a technical,economical,and environmental standpoint as follows:
A =recommended
C =acceptable but not recommended
F =unacceptable
The results of these ratings were used to form a summary rating for each corri-
dor.Technical,economical,and environmental tables are presented which re-
flect the criteria and rating for each corridor.
Elevation,length,and extensive clearing were the primary reasons corridors
were rated unacceptable from a technical or economical aspect.Potential con-
flicts with land use,visual impacts,and increased access resulted in many
corridors being unacceptable from an environmental standpoint.In each study
area,however,one corridor was considered acceptable for technical,economical,
and environmental aspects and was therefore recommended.These corridors are
described in Section 7 and 2.5 below.
2.5 - Conclusions and Recommendations (Section 7)
The preferred corridor described in the CaE report was also recommended by
IECOjRWRA.Other alternatives have been considered in this study area and com-
parisons made for the purpose of further investigation.Some of the alterna-
tives appear to be feasible,and others have been rejected for economic or reli-
abil Hy reasons.
The APA decision to proceed with the Intertie has resulted in a split of this
study into three separate geographical entities;namely,the southern,the cen-
tral,and the northern areas.For each area,one corridor has been recommended
the most feasible.
The recommended corridors have attained higher ratings than any others in the
selection and screening process.Any transmission lines located in these corri-
dorswill have the advantage of being relatively accessible via existing trans-
portation corridors and being relatively short compared to other corridors under
consideration.These lines can also be constructed in a manner that will mini-
mize environmentally unacceptable impacts,particularly those regarding aesthet-
ics,crossing of private land,and increased access to remote areas.
The recommended corridor in the southern study area stretches from an area north
of Willow Creek southward to Poi nt MacKenz;e.The corri dor is located east of
the lower Susitna River and crosses the Little Susitna River.It is located in
a sparsely inhabited area,thereby reducing land use and visual impacts.The
corridor is also accessible from the Parks Highway and Anchorage,resulting in
economic and reliability advantages.
The corridor recommended in the central study area connects Watana Dam to the
Devil Canyon Dam and continues westward to connect with the Intertie near Gold
Creek. This corridor,on the south side of the Susitna River,is the shortest
in the study area and has no technical constraints.Although clearing of vege-
tation would be required and some wetlands crossed,the corridor1s short length
and potential use of a service or access road in this area result in a minimiza-
tion of environmental impacts.
In the northern study area,the recommended corridor1s short length,low eleva ...
tion,and few water crossings result in a favorable technical and economical
rating.This corridor,stretching from Healy to Fairbanks,is in the vicinity
of the Parks Highway and is visible in the floodplain of the Nenana River. This
corridor offers routing potential for the final right-of-way that will minimize
any adverse visual and land use impacts.
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3 -SCUPE UF WORK
The scope of work discussed in this section includes the objectives and the ap-
proach used to achieve the objectives.It also reviews events which occurred
after the issuance of the POS.These events have had an impact on the corri~or
selection process.For purposes of this study and this report,corridors were
defined as being three to five miles wide.
3.1 -Objectives
The objectives of this study were to:
(a)Review reports from previous studies of Susitna Hydroelectric transmission
line options.
(b)Choose feasible corridors from these studies.
(c)Identify new corridors for consideration.
(d) Screen these corridors to select the one most acceptable considering eco-
nomical,technical,and environmental constraints.
3.2 -Approach
The following approach was used to meet the objectives described above:
(a) Reports prepared by COE and by IECO!RWRA were revi ewed to develop an under-
standing of the physical conditions in the railbelt area.
(b)Alternative corridors described in the previous reports were assessed from
an economical,technical,and environmental view.
(c)New alternative corridors were established and assessed economically,tech-
nically,and environmentally.
(d)The above information was utilized to select preferred corridors for fur-
ther study.
(e)Selected corridors were identified on one-inch to one-mile USGS maps for
use in the environmental and geotechnical studies.
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4 PREVIOUS STUDIES
In this section of the closeout report,a summary is presented of studies under-
taken by COE and IECO/RWRA.
Critiques and review of these studies may be found in Appendix C.
4.1 -COE Studies
The main element of the COE study was an evaluation of alternative corridor lo-
cations to select those maximizing reliability while minimizing cost.
The corridor evaluation began with map identification of all potentially feasi-
ble corridors and a field reconnaissance which eliminated those for which topo-
graphy,elevation,and climate factors would be unacceptable.The remaining
corridors were then evaluated in more detail to determine their relative advan-
tages and disadvantages.Much of the detftil of the environmental evaluation is
presented in the Alaska Power Administration's environmental assessment which
was incorporated in the COE report.
The COE concluded that Susitna I Corridor (between the damsites and Anchorage)
and Nenana I Corridor (between the damsites and Fairbanks)were the preferred
corridors (see Appendix C).The Susitna I and Nenana I fall within existing
transportation systems and likely present the least construction impacts of all
the alternatives considered.It is worth noting that the corridors'locations
are general in nature and serve the purpose of demonstrating project feasibil-
ity.
4.2 -The IECO(RWRAReport
The IECO/RWRA study made use of the COE report as background information for
both the economic feasibility and the selection of a transmission line corri-
dor.
The selected corridor is almost the same as that recommended by the COE report
with further definition.The corridor was chosen because of its favorable
length,accessibility,and environmental considerations.
The report presents a detailed economic feasibility study for the Anchorage-
Fairbanks transmission system.However,it is general in nature when dealing
with environmental studies.
The report points out that construction and maintenance of other Alaskan trans-
mission systems have shown that careful route selection and proper mitigation
measures can substantially reduce environmental impacts.
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5 -SEL~CTION OF ALT~RNATIVE CORRIDORS
This section of the report outlines the study areas,the data base,and the as-
sumptions used in planning the selection process.It also describes the selec-
tion criteria used in choosing corridors from previous reports and identifying
new corridors for this study.The corridors are then described according to
geographical location,topography,soils,vegetation,and stream and road cross-
ings.
5.1 -Objectives
The main objective of this POS subtask was to select feasible transmission line
corridors from those identified in previous studies and to list new alternative
corridors as candidates for consideration in the screening methodology.The
proposed prebuilding of the Intertie has indicated three areas which will re-
quire study:
(a)The northern area to connect Healy with Fairbanks.
(b)The central area to connect the Watana and Devil Canyon damsites with the
Intertie connecting Willow to Healy.
(c)The southern area to connect Willow with Anchorage.
5.2 -Data Base
The data base used for this analysis was obtained from the following sources.
(a)Existing aerial photos taken in the area for previous projects.
(b)USGS maps.
(c)Land status maps.
(d)The Interim Feasibil ity Report prepared by the COE for the south central
railbelt area,1975.
(e)The Economic Feasibility Study Report for Anchorage-Fairbanks Transmission
Intertie by IECO/RWRA in 1979.
(f)Results and observations of field trips by Acres· personnel and subcontrac-
tors which included aerial and ground reconnaissances of the potential
corridors.
5.3 -Assumptions
The following assumptions were made for the selection process.
(a)The main purpose of the transmission system is to deliver electrical power
from Watana and Devi 1 Canyon to the Anchorage and Fairbanks areas.
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(b)The transmission lines will be built on single-circuit towers (345 kV)to
ensure reliability of operation.
(c)An Intertie will be built by 1984 between Willow and Healy to 345 kV speci-
fications but \'I'i11 initially be operated at 138 kV.If the Susitna Hydro-
eiectric Project is proved feasible,the full 345 kV capability will be
utilized.If constructed,the Susitna lines will parallel the prebuilt
Intertie and will share the same right-of-way.
(d)Access roads will be constructed to the Watana and Devil Canyon damsites in
the central study area wherever possible,and the transmission line will
parallel this road.
(e)The transmission system configuration will consist of three single-circuit
lines from Devil Canyon to Anchorage and two single~circuit lines from
Devil Canyon to Fairbanks.The connection between Watana and Devil Canyon
will consist of two single-circuit lines .
(f)Corridors will be three to five miles wide.
(g)The Willow area will be the f~ture site of the state capital.
5.4 -Selection Criteria
This subsection outlines the guidelines used for establishing the criteria for
selecting feasible transmission line corridors adopted in this study.The main
classifications are:
-technical
..economical
- environmental
Since the corridors being studied could range in width from three to five miles,
the base criteria had to be applied in broad terms.The study also indicated
that the criteria listed for technical purposes could reappear in the economic
or environmental classification.The technical criteria will be defined as re-
quirements for the normal and safe performance of the transmission system and
its reliability.
The selection criteria are:
(a)Techni cal Criteri a
The criteria,listed in Table 5.1,are established and evaluated to ensure
that the corridors chosen are technically sound for the ultimate perform-
ance of the transmission system.
(b)Economical Criteria
The criteria are established and evaluated to incorporate economic consid-
erations into corridor selection;they appear in Table 5.1.
5-2
(c)Environmental Criteria
ftllA_SKit~fr"'lh~"YI,.'\\,'U'ic'c,C,kY
U.S.Department
The criteria,listed in Table 5.1,are established and evaluated to aid in
selecting the corridor with the least amount of environmental impact.
5.5 -Identification of Corridors
As discussed previously,theSusitna transmission line corridors studied are
located in three geographical areas;namely:
-The southern study area between Willow and Anchorage.
-The central study area between Watana,Devil Canyon,and the Intertie.
-The northern study area between Healy and Fairbanks.
The selection process resulted in the corridors identified in Figures 5.1,5.2,
and 5.3 for each study area,taking into consideration the criteria established
in the previous Subsection 5.4 (technical,economical,and environmental),and
according to the generic plan formulation and selection methodology (Append.ix
A).
5.6 -Description of Corridors
Figures 5.1 through 5.3 portray the corridors under evaluation in the southern,
central,and northern study areas,respectively.For purposes of simplifica-
tion,only the centerline of the three-to-five-mile-wide corridors are shown in
the figures.The figures have been produced as large fold-outs so the reader
can more:easily understand the fo 11 owi ng narratives.
In each of the three figures,~ach corridor under consideration has been identi-
fied by the use of letter symbols.The various segment intersections and the
various segments,where appropriate,have been designated.Thus,segments in
each of the three study areas can be separately referenced.Furthermore,the
segments are joined together to form corridors.For example,in the northern
study area Corridor ABC is composed of Segments AS and ~C.
The alternative corridors selected for each study area are described in detail
in the following paragraphs.In addition,Tables 5.2,5.3,and 5.4 contain de-
tailed environmental data for each corridor segment.The data were also used in
the screening process as described in Section 6.
(a) Southern Study Area
The alternative corridors for the southern study area are identified in
Figure 5.l.
(i)Corridor One -Willow to Anchorage via Palmer
Corridor ABC',consisting of Segments AS and BC', begins at the in-
tersection with the Intertie in the vicinity of Willow.From here,
the corridor travels in a southeasterly direction,crossing wetlands,
5-3
Willow Creek,and Willow Creek Koad before turning slightly to the
southeast following the drainage of Deception Creek.The topography
in the vicinity of this segment of the corridor is relatively flat to
gently rolling with standing water and tail-growing vegetation in the
vicinity of the creek drainages.
At a point northwest of Bench Lake,the corridor turns in an easterly
direction crossing the southern foothills of the Talkeetna Mountains.
The topography here is gently to moderately rolling with shrub- to
tree-sized vegetation occurring throughout.As the corridor ap-
proaches the crossing of the Little Susitna River,it turns and heads
southeast again,crossing the Little Susitna River and Wasilla Fish-
hook Road.
Passing near Wolf Lake and Gooding Lake,the corridor then crosses a
secondary road,some agricultural lands,State Route 3,and the Glenn
Highway,before intersecting existing transmission lines south of
Palmer. In the vicinity of the Little Susitna River,the topography
is gently rolling.As the corr-idor travels toward Palmer,the land
flattens,more lakes are present,and some agricultural development
is occurring.After crossing the Glenn Highway,the corridor passes
through a residential area before crossing the broad floodplain of
the Matanuska River.
Just west of Bodenburg Butte,the corridor turns due south through
more agricultural land before crossing the Knik River and eventually
connecting with the Eklutna Power Station.All of the land south of
Palmer is very flat with some agricultural development.Just south
of Palmer, the proposed corridor intersects existing transmission
facilities and parallels or replaces them from a point just south of
Palmer,actoss the river,and into the vicinity of the Eklutna Power
House.From here into Anchorage,the corridor as proposed would
parallel existing facilities,crossing near or through the communi-
ties of Eklutna,Peters Creek,Birchwood,and Eagle River by using
one of the two existing transmission line rights-of-way in this area.
The land here is flat to gently rolling with a great deal of residen-
tial development. This corridor segment is the most easterly of the
three under consideration in the southern study area and avoids an
underwater crossing of Knik Arm.
(ii)Corridor Two -Willow to Point MacKenzie via Red Shirt Lake
Corridor ADFC,consisting of Segments ADF and FC,commences again at
the point of intersection with the Intertie in the vicinity of
Willow;but immediately turns to the southwest,first crossing the
railroad,then the Parks Highway,then Willow Creek just west of
Willow.The land in the vicinity of this part of the segment is very
flat,with wetlands dominating the terrain.
Southwest of Florence Lake,the proposed corridor turns,crosses
Rolly Creek,and heads nearly due south,passing through extensive
5-4
wetlands west and south of Red Shirt Lake.The corridor in this area
parallels existing tractor trails crossing very flat lands with sig-
nificant amounts of tall-growing vegetation in the better drained
locations.
Northwest of Yohn Lake,the corridor segment turns to the southeast,
passing Yohn Lake and My Lake before crossing the Little Susitna
River.Just south of My Lake,the corridor turns in a generally
southerly direction,passing Middle Lake,and east of Horseshoe Lake
before finally intersecting the existing Beluga 230 kV transmission
line at a spot just north of MacKenzie Point.From here,the corri-
dor parallels MacKenzie Point's existing transmission facilities be-
fore crossing under Knik Arm to emerge on the easterly shore of Knik
Arm in the vicinity of Anchorage.The land in the vicinity of this
segment is extremely flat and very wet,supporting dense stands of
tall-growing vegetation on any of the hig~er or better drained
areas.
(iii)Corridor Three -Willow to Point MacKenzie via Lynx Lake
Corridor AEFC is very similar to and is a derivation of Corridor
ADFC;it consists of Segments AEF and FC.This corridor also extends
to the southwest of Willow.West of the Parks Highway,however,just
north of Willow Lake,this corridor turns and travels southwest of
Willow and east of Long Lake,passing between Honeybee Lake and
Crystal Lake.The corridor then turns southeastward to pass through
wetlands east of Lynx Lake and Butterfly Lake before crossing the
Little Susitna River.The land is well developed in this area.It
is very flat and, while it is wet, also supports dense stands of tall-
growing vegetation on the better drained sites.Corridor Three re-
joins Corridor Two at a point south of My Lake.
(b) Central Study Area
The central study area encompasses a broad area in the vicinity of the dam-
sites.From Watana,the study area extends to the north as far as the
Denali Highway and to the south as far as Stephan Lake.From this point
westward,the study area encompasses the foothills of the Al aska Range and,
to the south,the foothills of the Talkeetna Mo~ntains.Included in this
study area are lands under consideration by the Intertie Project investi-
gators.The alternative corridors would connect both Devil Canyon and
Watana dams with the Intertie at one of four locations,which are identi-
fied in Figure 5.2.
As for the southern study area,individual corridor segments are listed in
the text.This is to aid the reader both in determining corridor locations
in the figures and in examining the environmental inventory data listed for
each segment in Tables 5.1,5.2,and 5.3.
(i)Corridor One -Watanato Intertie via South Shore,Susitna River
Corridor ABCD consists of three segments:AS,BC,and CD.This
5-5
corridor originates at the Watana Dam site and follows the southern
boundary of the river at an elevation of approximately 2,000 feet
from Watana to Devil Canyon.From Devil Canyon,the corridor con-
tinues along the southern shore of the Susitna River at an elevation
of about 1,400 feet to the point at which it connects with the Inter-
tie,assuming the Intertie follows the railroad corridor.The land
surface in this area is relatively flat,though incised at a number
of locations by tributaries to the Susitna River.The relatively
flat hills are covered by discontinuous stands of dense,tall-growing
vegetat ion.
(ii)Corridor Two -Watana to Intertie via Stephan Lake
ABECD,the second potential corridor,is essentially a derivation of
Corridor One and is formed by replacing Segments BC with BEC.Origi-
nating at Point B,Corridor Segment BEC leaves the river and gen-
erally parallels one of the proposed Watana Dam access road corri-
dors.This corridor extends southwest from the river,passing near
Stephan Lake to a point northwest of Daneka Lake.Here the route
turns back to the northwest and intersects Corridor One at the Devil
Canyon Dam site.The terrain in this area,again,is gently rolling
hills with relatively flat benches. Vegetation cover ranges from
sparse at the higher elevations to dense along the river bottom and
along gentler slopes of the Susitna River and its tributaries.
(iii)Corridor Three -Watana to Intertievia North Shore,Susitna River
Corridor Three (AJCF),located on the north side of the river,con-
si sts of Segments AJ and CF.Starting at the Watana Dam site,the
corridor crosses Tsusena Creek and heads westerly,following a small
drainage tributary to the Susitna River.Once crossing Devil Creek,
the corridor passes north and west of High Lake.
The corridor stays below an elevation of 3,700 feet as it crosses
north of the High Lake area,east of Devil Creek,on its approach to
Devil Canyon.From Devil Canyon,the corr tdor again extends to the
west,crossing Portage Creek and intersecting the Intertie in the
vicinity of Indian River.In the drainages,to elevations of about
2,000 feet,tree heights range to 60 feet.Between Devil Creek and
Tsusena Creek,however,at the higher elevations,very little vegeta-
tion grows taller than three feet.Once west of Devi 1 Creek,discon-
tinuous areas of tall-growing vegetation exist.
(iv)Corridor Four -Watana to Intertie via Devil Creek Pass/East Fork
Chulitna River
Another means of connecting the two dam schemes with the Intertie is
to follow Corridor One fromWatana to Devil Canyon and then exit the
Devil Canyon project to the north (ABCJHI).This involves connecting
Corridor Segments AB,BC,CJ,HJ,and HI.With this alternative,the
5-6
corridor extends northeast at Devil Canyon past High Lake to lJevil
Creek drainage.From there,it moves northward to a point north of
the south boundary of the Fairbanks Meridian.The corridor then fol-
lows the Portage Creek drainage beyond its point of origin to a site
within the Tsusena Creek drainage.Likewise,it follows the Tsusena
Creek drainage to a point near Jack River,at which point it para-
llels this drainage into Caribou Pass.From Caribou Pass,the corri-
dor turns to the west,following the Middle Fork Chulitna River until
meeting the Intertie in the vicinity of Summit Lake.
While along much of this corridor the route follows river valleys,
the plan also requires crossing high mountain passes in rugged ter-
rain.This is especially true in the crossing between Portage Creek
and Tsusena Creek drainages,where elevations of over 4,600 feet are
involved. Tall-growing vegetation is restricted to the lower eleva-
tions along the river drainages with little other than low-growing
forbs and shrubs present at higher elevations.
(v) Corridor Five-Watana to Intertievia Stephan Lake and the East
Fork Chulitna River
A variation of Corridor Four, Corridor Five (ABECJHI)replaces Seg-
ment BC with Corridor Segment BEC (of Corr t dor Two)with the previ-
0usly described corridor.This results in a corridor that extends
from the Watana Dam site southwesterly to the vicinity of Stephan
Lake,and from Stephan Lake into the Devil Canyon Dam site.From
Devil Canyon to the Intertie,the corridor follows the Devil Creek,
Portage Creek,and Middle Fork Chulitna drainages previously men-
tioned.As before,the corridor crosses rolling terrain throughout
the length of the paralleled drainages,with some confined,higher
elevation passes encountered between Portage Creek and Tsusena Creek.
(vi)Corridor Six -Devil Canyon to the Interti e via Tsusena
Creek/Chulitna Riv~r
Another option (CBAHT)for connecting the dam projects to the Inter-
tie involves connecting Devil Canyon and Watana along the south shore
of the Susitna River via Corridor Segment CBA,then exiting Watana to
the north on Segments AH and HI along Tsusena Creek to follow this
drainage to Caribou Pass.The corridor then contains the preViously
described route along the Jack River and Middle Fork Chulitna until
connecting with the Intertie near Summit Lake.The terrain in this
corridor proposal would be of moderate elevation with some confined,
higher elevation passes between the drainages of Tsusena Creek and
the Jack River.
(vi i) Corridor Seven -Dev il Canyon to lnterti e vi aStephan Lake and
Chul Una River
This alternative uses Corridor Six but replaces Segment BC with
5-7
Segment BEC from Corridor Two.This route would thus be designated
CEBAHI.Terrain features are as described in Corridors Two and
Six.
(viii)Corridor Eight -Devil Canyon to Intertie via Deadman/Brushkana
Creeks and UenaliHighway
Yet another option to the previously described corridors is the in-
terconnection of Devil Canyon with Watana via Corridor One (Segment
CBA),with a segment then extending from Watana northeasterly along
the Deadman Creek drainage (Segment AG).The segment proceeds
north of Deadman Lake and Deadman Mountain,then turns to the west
and intersects the Brushkana Creek drainage.It then follows
Brushkana Creek north to a point east of the Kana Bench Mark.This
segment of the corridor would parallel one of the proposed access
roads.From there,the corridor turns west,generally parallel to
the Denali Highway,to the point of interconnection with the Inter-
tie in the vicinity of Cantwell.The area encompasses rolling
hills with modest elevation changes and some forest cover,espe-
cially at the lower elevations.
(ix)Corridor Nine -Oevil Canyon to Intertie via Stephan Lake and
J?ena"li Hi ghway
Corridor Nine (CEBAG)is exactly the same as Corridor Eight with
the exception of Corridor Segment BEC,utilized to replace Segment
BC.Each combination of segments has been previously described.
(x)Corridor Ten -Devil Canyon to Intertie via North Shore,Susitna
River,and Denali High~ay
Corridor Ten connects Devil Canyon-Watana with the Intertie in the
vicinity of Cantwell by means of Corridor Segments CJAG.Segment
CJA is part of Corridor Three and, as such, has been previously
described.Segment AG has also been described above as part of
Corridor Eight.As noted earlier,the Corridor Ten terrain con-
sistsof mountainous stretches with accompanying gently rolling to
moderately rolling hills and flat plains covered in places with
tall-growing vegetation.
(xi)Corridor Eleven-Devil Canyon to the Intertie via Tsusena
Creek/Chulitna River
Another northern route connecting Devil Canyon with Watana is that
created by connecting Corridor Segment CJA (part of Corridor Three)
with Segment AHI of Corridor Six.
(xii) Corridor Twelve - Devil Canyon;.Watana to the Intertie via Devil
Creek/Chulitna River
Another route under consi derat i on is Corridor JA-CJHI.From north
to south,this involves a corridor extending from the Intertie near
5-8
Summit lake,heading easterly along the Middle Fork Chulitna drain-
age into Caribou Pass.From here,it parallels the Jack River and
connects with the Portage Creek-Devil Creek route,Segment HJ.At
p6int J,located in the Devil Creek drainage east of High Lake,the
corridor splits,with one segment extending westerly to Devil
Canyon and the other extending east to the Watana Dam site along
previously described Corridor Segments JC and JA,respectively.
Terrain features of this route have been previously described.
(xiii)Corridor Thirteen -Watana to Devil Canyon via South Shore, Devil
Canyon to Intertie via North Shore,Susitna River
Corridor Segments AB,BC,and CF are combined to form this corri-
dor.Descriptions of the terrain crossed by these segments appear
in discussions of Corridor One (ABCD)and Corridor Three (AJCF).
(xiv)Corridor Fourteen -Watana to Devil Canyon via North Shore, Devil
Canyon to Intertie via South Shore,Susitna River
This corridor would connect the damsites in the directionally op-
posite order of the previous corridor,and include Corridor Segment
AJCD.Again,as parts of Corridors One and Three, the terrain fea-
tures of this corridor have been previously described.
(xv)Corridor Fifteen -Watanato Devil Canyon via Stephan Lake,Devil
Canyon to Intertie via North Shore,Susitna River
Corridor Two (ABEC)and Corridor Three (CF)form to create this
study-area corridor.Terrain features have been presented under
the discussions of each of these two corridors.
(c)North~rn Study Area
In the northern study area,four transmission line corridor options exist
for connecting Healy and Fairbanks (Figure 5.3).
(i)Corridor One -Healy to Fairbanks via Parks Highway
Corridor One (ABC),consisting of Segments AB and BC,starts in the
vicinity of the Healy Power Plant.From here, the corridor heads
northwest,crossing the existing Golden Valley Electric Association
Transmission Line, the railroad,and the Parks Highway before turn-
ing to the north and paralleling this road to a point due west of
Browne.Here,as a result of terrain features,the corridor turns
northeast,crossing the Parks Highway once again as well as the
existing transmission line,the Nenana River,and the railroad,and
continues northeasterly to a point northeast of the Clear Missile
Early Warning Station (MEWS).
5-9
Continuing northward, the corridor eventually crosses the Tanana
River east of Nenana,then heads northeast,first crossing Little
Goldstream Creek, then the Parks Highway just north of the Bonanza
Creek Experimental Forest.Before reaching the drainage of Ohio
Creek,this corridor turns back to the northeast,crossing the old
Parks Highway and heading into the Ester Substation west of Fair-
banks.
Terrain along this entire corridor segment is relatively flat,with
the exception of the foothills north of the Tanana River.Much of
the route,especially that portion between the Nenana and the
Tanana River crossings,is very broad and flat,has standing water
during the summer months and, in some places,is overgrown by dense
stands of tall-growing vegetation.This corridor segment crosses
the foothills northeast of Nenana,also a heavily wooded area.
An option to the above (and not shown in the figures),that of
closely paralleling and sharing rights-of-way with the existing
Healy~Fairbanks transmission line,has been considered.While it
is usually attractive to parallel existing corridors wherever pos-
sible,this option necessitates a great number of road crossings
and an extended length of the corridor paralleling the Parks High-
way.A potentially significant amount of highway-abutting land
would be usurped for containment of the right-of-way.These fea-
tures,in combination, preclude this corridor from further evalua-
tion.
(ii)Corridor Two -Healy to Fairbanks via Crossing Wood River
The second corridor (ABDC)is a variation of Corridor One and con-
sists of Segments AB and BOC.At point B,east of the Clear MEWS,
instead of turning north,the corridor continues to the northeast,
crossing Fish Creek, the Totatlanika River,Tatlanika Creek, the
Wood River,and Crooked Creek before turning to the north.At a
point equidistant from Crooked and Willow Creeks~the corridor
turns north,crosses the Tanana River east of Hadley Slough,and
extends to the Ester Substation.North of the Tanana River,this
corridor segment also crosses Rose Creek and the Parks Highway.
Where it diverges from the original corridor,this corridor traver-
ses extensive areas of flat ground, with standing water very pre-
valent throughout the summer months.Heavily wooded areas occur in
the broad floodplain of the Tanana River, in the vicinity of the
river crossing,and in the foothills around Rose Creek.
(iii)Corridor Three-Healy to Fairbanks via Healy Creek and Japan
Hill s
Corridor Three (AEDC),consisting of Segments AE and EOC,exits the
Healy Power Plant in an eas ter ly dtrect ton.Instead of proceeding
northwest,this corridor,following its interconnection with the
5-10
Intertie Project,heads east up Healy Creek, passing the Usibelli
Coal Mine.Near the headwaters of Healy Creek, the corridor cuts
to the east,crossing a high pass of approximately 4,700 feet ele-
vation and descending into the Cody Creek drainage.From Healy to
the Cody Creek drainage,the terrain is relatively gentle but
bounded by very rugged mountain peaks.The elevation gain from the
Healy Power Plant to the pass between the Healy Creek-Cody Creek
drainages is approximately 3,300 feet.From here,the segment
turns to the northeast,following the lowlands accompanying the
Wood River.The corridor next parallels the Wood River from the
Anderson Mountain area,past Mystic Mountain,and out into the
broad floodplain of the Tanana River east of Japan Hills.Near the
confluence of Fish Creek and the Wood River,the corridor turns
north and intersects the north-south portion of Corridor Two (Seg-
ment DC),after first passing through Wood River Buttes.Much of
the area north of Japan Hi 11 sis fl at and very wet wi th stands of
dense,tall-growing vegetation.
(iv)Corridor Four -Healy to Fairbanks via Wood~iver and Fort
Wainwright
Corridor Four (AEF)is a derivation of Corridor Three and is com-
posed of Segments AE and EF.Point E is located just north of
Japan Hills along the Wood River.From here,the corridor deviates!
from Corridor Three by running north across the Blair Lake Air
Force Range,Fort Wainwright,and several tributaries of the Tanana
River, before reaching the crossing of Salchaket Slough. Corridor
Four passes Clear Creek Butte on the east.A new substation would
be located on the Fairbanks side of the Tanana River just north Of
Goose Island.From Point E to Point F, the terrain of the corrido~
is flat and very wet,and again,dense stands of tall-growing vege--
tation exist both in the better drained portions of the flat lands
and in the vicinity of the river crossing.
5-11
TABLE 5.1:TECHNICAL,ECONOt4IC,AND ENVIRONI,IENTAL CRITEHIA
USED IN CORRIDOR SELECTION
Type
1.Technical
-Primary
-Secondary
2. Economical
-Primary
Secondary
3.Environmental
-Primary
-Secondary
Criteria
General Location
Elevat ion
Relief
Access
River Crossings
Elevation
Access
River Crossings
Timbered Areas
I'letlands
Development
Existing Transmission
Hight-of-Way
Land Status
Topography
Vegetation
Selection
Connect with lntertie near Gold Creek,Willow,
and Healy.Connect Healy to Fairbanks.Con-
nect Willow to Anchorage.
Avo id mountainous areas.
Select gentle relief.
Locate in proximity to existing transportat ion
corridors to facilitate maintenance and repairs.
Minimize wide crossings.
Avoid mountainous areas.
Locate in proximity to existing transportation
corridors to reduce construction costs.
Minimize wide crossings.
Minimize such areas to reduce clearing costs.
Minimize crossings which require special designs.
Avoid existing or proposed developed areas.
Parallel.
Avoid private lands,wildlife refuges,parks.
Select gentle relief.
Avoid heavily timbered areas.
Table 5.2
Environmental Inventory - Southern Study Area (Willow to IInchorage/Point ~lacKen7.ie)
CorrIdor
Segment
AU
BC'
AOF
Approx.
Length
(HUes)
38
35
26
Approx.,
Road Crossings
2 hwy
(Rt.3,Glenn)
6 lIght duty roads
1 unimproved road
2 tralls
1 ra Ilroad
4 hwy (GTenn,4x)
3+light duty roads
7 unimproved roads
1 trail
several railroads
1 highway (Rt. 3)
3 tractor trails
Approx.,
River/Creek
Crossings
1 river
17 creeks
4 rivers
11 creeks
1 river
6 creeks
Topoqr aploy
Willow (100'),crosses
Willow n,follows
Deception Ck (1000') along
ridge of Talkeetna Mts,s.e.
into Palmer (200')
Palmer (200'),crosses Knlk
River to base at Chugach Mts.
(500'),along Knik Arm
(200'-300'),to Anchorage
(200')
Willow (100'),s,along
Susltna River plains (flat,
wet area,with drier,raised
levees,200'-400'),to F at
ISO'
Soils a
Willow to near
Pa1mer-SlJ4
Palmer EO!
Palmer-EOI
Kn Ik Arm - EFl
S. of Eklutna
to n.of A"~horage
-S05
Anchorage -S04
Wlllow-SQ4
S.of Willow to
to F-SOI
bLandQwnershIp/
Status._
A to s.of Willow Ck Rd.
crossing-mostly P, with
some HAP and some SP;••• to
due n. of Wasilla-mainly
SPTA;..•to ll-mostly P,
with some nl\f'and Sf'
B to Knik R.-P; '" to
ilfrchwood-main1y VS with
some SPTA,P and BAP;
Birch~ood area-I';S.w. of
Birchwood to near C'-U.S.
Army Military Wd1;C'-Oata
voH
Near A-P;route fairly even
mix of RAP and SpTA;some I'
near Fish Ck; area
surrounding L Susltna R -
SusltnaFlats Game Refuge;
near F-SPTA
Ex ist lng/Proposed
Oevelopments
Ag.uses n.&w.of
Palmer;agfres.use
near L.SusHna;
proposed capital
site;mixed res.
area at Willow Ck.;
WI How air str tp;
callin near 1\
Urban uses In Anch.;
passes through/near
several communities:
Eagle R,Birchwood
Ekl,utl1<l.Chugiak,
Peters Ck,
Red Sh Irt lake-
mlKed residential
use; near residential
&recr.areas s.w.
of Willow;Susitna
Flats State Game
Refuge
Existing
Rights-or-Way
Follows no known right-
er-way ror appreciable
distance
parallels trans.line
KnikR. to Anch.;
parallels Glenn Hwy frorr
Knlk R. to Birchwood;
parallels RR-Eag1e to
C'
Generally parallels a
tractor trall
AEF 27 1 highway (Parks)1 river Willow (100').s. along flat Near l.Susftna A,s. to Rainbew l.-Mixed res.areas;No known
1 tractor Trail 6 creeks wet area (200'-400'),to F at River -S05 mostly 1',small parcels BAp;1akes used to 1and
about ISO'Remainder-S04 State Selected Fed. Parcel float planes
w.of Willow l.;s. to l.
SusItna R. -Nancy lake State
Rec.Area;to F -mix of
SPTI\and BliP
FC 12 2 tractor tralls 2 creeks f at 150' along flats to C !lear f -S04 F to 1 mt.s.-SpTA;••• s, tonear sea level Near C -SOl
Scattered Gener ally foil ows aHor'seshoe L.-Pt HacKenz Ie residential/cabins tractor trall
Jlgr. Sale;...s, to C-on Horseshoe Lake;
mainly SpTA,some BAP proposed ago uses
in area
a. Source: United States Oepartment of Agriculture.Soil Conservation Service
1979.See Appendix Table B-1 for explanation of soll units.
b.Source:CIRI/Holmes and "arver.1980. P=Prlvate,SPTA=State Patented or
Tentatively Approved,SP=State Patented,BAP=Boreugh Approved or Patented.
Table5.2 (Cont'd)
Environmental Inventory - Southern Study Area (Wi !low to Anchorage/Point MacKenZie)
:orridor
Segment
AB
BC'
ADF
Scenic Quality/Cultural a
Recreation Resources
Gooding l.-bird-Data void
wijtdling;rec,trails e. of
Wt110w-hunting.hiking.x-c
skiing,dog sledding,snow-
mobiling.snowshoeing;rec.
trail by Decep.Ck-snow-
mobiling. dog sledding.
fishing
Passes near 2 camping Data void
grounds;parallels
Idilarod racing trail
(x-c skiing.sledding.
snowmobiling);
birdwatching at Eklutna
Fl ats and Matunusk a
River
X-c ski &snowmobile Data void
trails;recreation
area s.w. of Willow
Vegetation b
Upland.mixed deciduous-
conifer forests (birch-
spruce)- open and closed
mostly
Tall shrub (alder);some
woodland black spruce;
bogs along DeceptionCk.
Deciduous forest (balsam
poplar) along river.
probably birch/spruce
forests on uplands in most
of area
Data void
Higher grounds: Spruce-
birch-poplar forests
Wet sedge grass bogs and
black spruce forests
prevalent in lower half
Fish c
Resources
Willow Ck.-chinook salmon.
grayling.burbot.longnose sucker.
round whitefish.Oolly Varden.slimy
sculpin;lake trout &rainbow trout
In lakes;l.Susitna R. -king salmon;
Decep.Ck. - king. pink salmon
Sockeye,chinook, pink.chum.coho
salmon in large rivers;grayling
burbot,longnose sutker,round white-
fish.Dolly Varden.slimy sculpin.
lake and rainbow trout in lakes &
stream;salmon of partiCUlar
significance in the Matanuska and
Knik Rivers
Willow Ck.-chinook salmon;l~ke and
rainbow trout posible in S(llllt!lakes;
also,to streams are grayling.burbot.
longnose sucker.round whitefish.
Dolly Varden.slimy sculpin;Red
Skirt L. -lake trout.sockeye salmon
d d
Birds Furbearers
Data void Data void
Waterfowl and Data void
shore bird nesting
areas around Knik
Arm and Eagle
River Flats
Waterfowl and Data void
shore bird nesting
in Willow Creek/
Delta Islands
d
Big Game
Except near Palmer-
black bear summer
range.moose winterl
sumner range. migrating
corridors and calving
area; near Aalso
brown bear sumner
range and feeding
area
Data void
Brown and black bear
feedinq area.moose
winter/summer range
and calving area
AEF
FC
Mixed rec. areas;
Uancy Lake State Rec.
area;tra ils and
multiple uses;may
cross Goose Bay St.
Game Refuge
May cross Susitna flats
State Wildlife Refuge
Data void
Data void
Upper half;mostly upland
birch.spruce &aspen
Lower half:wet sedge-grass
bogs and black spruce;some
birCh. spruce; aspen on
higher ground
Spruce forests.spruce-
birch forests.sedge-grass
bogs and black spruce bogs
lakes may contain rainbow and lake
trout;poss ibly grayling in the
region
lake may.contain rainbow and lake
trout;possibly grayling in the
region
Same as AOF
Waterfowl and
shore bird
migration route.
feeding,and
nesti ng area
Furbearer and small
mamma 1 sumner /
winter range
Same as AOF
Black bear sumner
range and feeding
area;moose winter!
summer range. feeding
and calving area
a. Coastal area probably has many sites,available literature not yet reviewed.
b.Tall shrub=atrler;low shrub=dwarf birch,and/or willow;open spruce=black (wet)
or white spruce.25%-60:1:cover;woodland spruce=whlte or black spruce.10%-25%
cover.mixed foras t>spruce-btrch.
d.little data available.Source of information in this table:Alaska
Department of fish and Game 1978b.
c.little data available.Source of information in this table:Alaska
Department of Fish and Game 1978a.
Table 5.3
Enyironmental Inventory - Central Study Area (Dam Sites to Intertie)
Corridor
Segment
AB
BC
CD
BEC
~J
JC
CF
AG
AH
HI
HJ
Approx.
Length
(Miles)
18
15
23
18
8
15
65
22
21
23
Approx.I
Road Crossings
o
o
1+
o
o
o
o
o
o
o
o
Approx.If
River/Creek
Crossings
5 creeks
8 creeks
1 river
4 creeks
Bcreeks
11 creeks
1 creek
2 creeks
1 river
35 creeks
9 creeks
15 creeks
13 creeks
Topography
Moderate sloping s.rim of
Susitna R.Valley;crosses
deep ravine at Fog Cle.at
about 2000'contour
2000'contour along s.rim
of Susitna River: crosses
3 steep gorges
Moderately sloping terrain;
crosses 5usit"a R. near Gold
Creek (800')
Crosses moderate slopes
around Stephan Lake:w•• then
n,to avoid deep ravine at
Cheechako Ck., then follows s,
rim of SU5itna at about 2000'
A (about 2000') to 3500';
crosses deep ravine at Devil
Ck.(2000');goes by several
ponds
J (2000'), s.w.through gently
sloping High Lake area,to C at
Devil Canyon (2000')
Devil Canyon «2000')west
across' 600'deep Portage
Creek gorge:w.across
gentle terrain to F (1200')
A (2000'), n. along Deadman
Ck.to 3200'; crosses
Brushkana drainage (at
3200'):drops to Nenana River
(2400')and fairly flat
terrain to G (2200')
A (2000'), along Tsusena Ck.:
past Tsuser.a Butte;through
mt. pass at 3600'
H(3400')through mts.; along
Jack R.drainage and Caribou
Pass; to I at 2400'
H(3400')through mts. along
Portage Ck.drainage,through
pass at 3600'; into Dev il
Creek drainage; to J at 2000'
Soils a
SOlS
8 westward-S015:
near C-SOlO
OSlO
B,westward -OS15;
between B &C -
IU3;near C-SOlO
A,westward -OS15:
remainder,except J -
OS16;near J -SOlO
OSlO
SOlO
Near A and along
Denali Hwy ~OS15;
through mts.-S016
Near A-S015;
mt. base -S016;
mts ••RMl
Mts.-RM1:
along hWy -5015
Near J -5016;
mid elevations-
S017;mt5.-RMl
Land Ownersh ip/
Statusb
VS
vs
C to 1 1/2 mi. e.
of Susitna R.-
VS:Sus itna R. te
1 1/2 mi.e. -
SPTA:••. to D-P
VS except where
corridor skirts
Cheechako Ck.
ravine,whiCh is
classified SS
Suspended
SS except at J er
at A westward
across Tsusena
Ck.,which are V~
SS except at J ar
C which are VS
C to 1 1/2 mi.e
of Miami L.mainl
VS with small
parcel of S5: '"
to F-P
A -VS;n,of A t
s ,«.of Big L. -
5S;...to s,of
Deadman L. -SPTI
to Denali Hw~
-Fed.0-1 Land:
data void for 8
mi.;around G -
Small Fed.Parce
A -V5;to n.
ot Tsusena Butte
5S;data void
beyond here
I -VS;data voie
to east
J -V5:Devil Ck
drainage -5S:
data void beyond
here
a.Source:United States Department of Agriculture, Soil Conservation Service
1979.See Appendix Table 8-1 for explanation of'soil units.
b.Source:CIRI/Holmes and Narver ,1980.P"Private,SPTA=State Patented or
Tentatively Approved,SS=State Selection,VS=Village Selection.
Table 5.3 (Collt'd)
Ellvironmental Inventory -Central Study Area (Dam Sites to Intertie)
Corridor
Segmellts
AB
BC
CO
BEC
AJ
JC
CF
AG
AH
HI
HJ
Fish a
Resources
Fog Lakes·Dolly Varden.sculpin;
Stephan Lake contains lake and rainbow
trout.sockeye &coho salmon.
whitefish.longnose SUcker,grayling;
burbot
Several small tributaries crossed.
perhaps USed by grayling
Same as BC
Several small tributaries crossed.
perhaps used by grayling. burbot
Dolly Varden;grayling in Tsusena
Creek
Burbot;no data for High Lake
Portage Creek has king,chinook.chum
and pink salmon,grayling.burbot
Dolly Varden;lakes·lake trout.
grayling, white-fish;tributaries to
Nenana River and Brushkana Creek n. of
Deadman Mt,and Jack R.near Denali
Hwy considered important fish habitat
Dolly Varden;grayling
Lake trout,Caribou Pass area;Jack
River s. of Caribou Pass considered
important fish habitat;data void
Portage Creek -king.chinook.chum,
and pink salmon,grayling. burbot
Birds
Potential raptor
nesting habitat in
Fog Creek area
Potential raptor
nesting habitat
along Devil Canyon
Potential raptor
nesting habitat
along Devil Canyon
Potential raptor
nesting habitat along
Devil Canyon and along
drainages upstream;
Stephan Lake area
important to waterfowl
and migrating swans
Data void
Potential rapt or hab.
by Devil Canyon;golden
eagle nest along Devil
Ck.s. of confluence of
ck.from High Lake
Potent ia1 raptor
habitat along lower
Portage Ck.and from
Portage Ck.mouth
through Devil Canyon
Waterfowl numerous at
Deadman Lake;impor-
tant bald eagle habitat
by Denali Hwy and
Nenana R.just w.of
Monahan Flat;unchecked
bald eagle nest alongDeadmanCk,s.e.of
Tsusena Butte
Known active bald
eagle nest s.e.of
Tsusena Butte
Data void
Dah void
Furbearers
Excellent fox and
marten habitat;
Fog Lakes support
numerous beavers and
muskrat;otters
common
Excellent fox and
marten hab itat
Area around Devil
Canyon has
excellent fox and
marten habitat
Excellent fox and
marten habitat,
particularly
around Stephan
Lake
Red fox denning
sites.numerous
beaver,muskrat and
mink.especially
around High Lake
Same as AJ
Area between Parks
Hwy and Devil Canyon
supports numerous
beaver,muskrat,
and mink
Population
relatively low,
although beaver,
mink.fox present;
Deadman Mt.to
Denali Hwy.-
moderate ~op.red
fox
Papulation along
Tsusena Ck.pro-
bably relatively
low;with beaver,
mink.and fax
probably present
Data void
Numerous beaver,
muskrat,and mink
around High Lake
Big.Game
Supports large pop.
of moose;wolves.
wolverine and bear,
(especially brown)
common;caribou
regularly use atea
Area around Stephan
Lake &Prairie Ck.
supports large pop.
of moose;wolves,
wolverines,and same
bear (especially
brown)commOn;
caribouregul ar
users
Moose.caribou,and
bear hab i tat
Same as AB
Mouth of Tsusena Ck.
important moose
habitat;heaVily
used by black
and brown bear
Important moose and
bear habitat;data
void
Probably important
moose Wintering
area and black bear
habitat;at least
one wo If pack
Probably important
area for caribou.
expecial1y in the
north
Data void
Data void
Data void
a.Little data available.Sources of information in this table;Alaska
Department of Fish and Game 197Ba.Friese 1975.and Morrow 1980.
Table 5.3 (Cont"d)
Environmental Inventory - Central Study Area (Dam Sites to Intertie)
Old Corps trail,Scenic area;possible
Gold Ck.to Devil fishing
Canyon
Corridor
Segment
AB
BC
CD
BCC
AJ
JC
CF
AG
AH
HI
HJ
Existing/Proposed
Developments
Follows general
route of proposed
Susitna acce~s rds.;
cabins on Fog Lakes;
planes use lakes
Follows general
route of Susitna
proposed access rds.;
cabins and lodge on
Stephan L.
Follows proposed
Susitna access rd.-
Dev il Canyon to
Susitna R.;scattered
cabins in Canyon/Gold
Creek area
Follows general route
proposed Susitna
access rd.; cabins
and lodge on Stephan
Lake
Follows a proposed
Susitna access rd.
from Watana westward
for appro x •BmL;
10cge at High Lake
Generally follows
proposed Susitna
access rd.;lodge
at High Lake
Follows a proposed
Susitna access rd.
for about 3 mi.from
Dev il Canyon to
Portage Ck.;
mining,cabins
Follows a proposed
Susitna access rd. -
Watana to just n. of
Deadman Mt.;
occasional cabins;
1anding strip along
Denal i Hwy;airport
near G
Cabins near Tsusena
Butte
Cabins near Summit
Susitna access rd.
along Devil Ck.for
about 4 mi.; cabins
along Devil Ck.
drainage
Existing
Riohts-of-Way
No known
No known
No known
No known
NO known
No known
Parallels Denali
Hwy beyond
Brushkana Ck.
drainage to G
No known
No known
No known
Scenic Quality!
Recreation
Fog Lakes - high
aesthet icqua1ity;
fish ing in Fog
Lakes
Stephan Lake - high
aesthetic Quality
Stephan Lake - high
aesthetic quality;
major reereat ion area
for fishing/baating!
planes
High Lake and other
lakes -high aesthetic
quaiity;fishing/
hunting in High Lake
area
Same as AJ
Boating in Susitna;
hunting,fishing,
hiking
Remoteflat areas -
high visibility;
Deadman L.and Mt.,
Alaska Range -high
aesthetic quality;
fishing,float planes;
major rec. areas by
Brushkana and Nenana
R.,Drasher L.
Tsusena Butte -
aesthetic quality;
major sheep hunting
area
Major sheep hunting
area; bird watching
at SUrrJnit L.
Scenic drainage;Sheep
hunting in n,
Cultural
Resources
Arch.sites
identified near
Watana Dam site
and w.shore of
Stephan Lake;
potential for
more sites
around Fog Lakes
and StePhan Lake
Arch.sites near
Stephan I.ake
Hist.sites near
Gold Ck.;data
void
See AB
Arch.sites at
Portage Ck.and
Sus ltna R. con-
fluence and
near Watana Dam
s rte
Nc known arch.
sites
Arch.sites at
Portage Ck.;
hist.sites near
Canyon
Arch.sites
along Deadman
Ck.
Arch.site n. of
Tsusena Butte
along Tsusena
Ck;data void
Data void
Data void
Vegetationa
Mostly woodland black
spruce (wet);some low
shrub
Open and woodland spruce
forests,low shrub,oPen
and closed mixed forest
in about equal amounts
Mostly closed mixed
forests
Woodland spruce and bogs
around Stephan Lake;10\'1'
shrub,mat 8<cush ion and
sedge-grass tundra at
upper end of CheeChako
Ck.drain-age;tall shrub
(alder)and mixed forest
along Cheechako Ck.and
towards Devil Canyon
Mostly low Shrub,mat 8<
cushion, sedge-grass
tundra some tall Shrub
(alder)
Tall shrub (alder),low
shrub and open mixed
forest
Open 8<closed mixed
forest,tall shrub,low
shrub.
Mostly low shrub in
southern end; northern
end -data void
Low shrub,ta 11 shrub,
wood1 and spruce
Data vaid
Mat 8<cush.ton,sedge-
grass tundra,tall shrub
and open mixed forest in
southern end
a. Tall shrubve lder;low shrub=dwarf birch, and/or willow;open spruce"black (wet)
or white spruce,25%-60%cover;woodland spruce=white or black spruce,10%-25%
cover,mixed forest=s~ruce-birch.
Table 5.4
Environmental Inventory - Northern Study Area (Healy to Fairbanks)
Corridor Approx.Approx.II Approx.,Topography bSegmentlengthRoadcrosstnqsRiver/Creek Soils
(Miles)Crossings --
AB 40 2 highway (Park)3 rivers Follows Nenana River north HUO
3 trails (1 winter) 15 creeks at 1000' to Browne-crosses
2 unimproved rds.River;n.w,to Clear flEWS at
1 railroad 500'
BC 50 Parks HighWaY
1 winter trail
1 river
25creeks
Clear MEWS (500') north
across plain {400'},n.e.
across Tanana River Valley
to Ester (600')
Near 8 -IRI0;flats
s. of Tanana River-
IQ2;Tanana River-
IQ3;Tanana R. to
Ester~IR14
Land Ownership!
Status c
Ato e.ofDry Ck.-small
fed.Parcel;...to s,of
Clear MENS and at B-mostly
SPTA,sma l1parceIs of P,
small fed. Nat.Allot.along
Nenana R.;Clear.MEWS
area-parcel CIRI Selection,
and U.S.Army Wdl.Land
8 to 1 1/2 mi n. -SPTA;
...to s,to Tanana R. - SS;
••.to Tanana R. -P;...
to crossingt.Goldstream
Ck.- mostly SPTA;••• to
Bonanza Ck.Crossing -SS;
••• to near C - SP;
remainder - data void
Existing!Proposed
Developments
Scattered
res idential and
otheru~e5 alon9
Parks Hwy;cabin
near Browne;air
str ip at Hea ly
Scattered
resIdentia1 and
other uses along
Parks Hwy;cabin at
Tanana R. crossing
Existing
Rights-of-Way
Generally parallels
Parks Hwy.RR and
tr ails.1 ine-Ilea ly
to Browne
Follows w/in several
mi. Parks Hwy,RR,
and trans.line;
more closely follows
Parks Hwy.and trans.
line and sled rd. n.
of Tanana R•
BDC 46 1 winter traB 2 rivers
29 creek
Clear MEWS (500'),n.e.
across plain to a point
about 24 mi. due s. of
Ester;n.across plain to
Tanana R. (400')and n. to
Ester
Near 8 -IRIO
Remainder -IQ2
B area -SPTA;
Fish Ck to Tanana R.-data
void; remainder -SPTA.BAP
with P at C and just n.
of Tanana R.
ft.Wainwright
Hi1.Reservation tlo known
AE 65 1 hwy.(Parks)
1 trall
1 river a
50 creeks
Up Healy Ck.to pass at
4500';down Wood R.
drainage to Japan Hills
(1100');steepmts.;
valleys
Near A-fRIO;
mt. base -IQ25;
mt. area -RMl;
near E - IRI
Ato Nenana.R.- small Fed.
Parcel;••• to e. of Gold
Run -SPTA ••• remainder -
data void
Air strips -Healy
and Cripple/Healy
Cks. confluence;
cabins-Cody Ck/
Wood R••Snow Mt.
Gulch
Parallels small rd.-
near Healy to Coal
Ck.; small RR - Healy
to Suntrana;trail
at pass between Healy
and Cody Cks.
Parallels Bonnlfield
Trail-Clear Ck.Butte
to Fairbanks;trans.
11 ne just s. of
Fairbanks
No knownFt.Wainwright Mil.
Res.;Wood R. Butte
VABM
ft.Wainwright Mil.
Res.; cabin -Wood
R. crossing s.of
Clear Butte
Data void
Same as BOC north of the
Tanana River
c. Source:CIRI/Holmes and tlarver.1980. P=Private,SPTA=State Patented or
Tentatively Approved;SP=State Patened, SS=State Selection.BAP=BorouQh
Approved or Patented..
Near E -lRI;
between E and
open flats -IRIO;
open flats IQ2;
Tanana R. -IQ3;
Ester -IR14
Near E - tRI; s.
section of Hats-
IRIO;flats -IQ2;
Fairbanks -IQ3
Japan Hills (1100')n,
across plain to Tanana
R.(500' ).; n, to Fairbanks
Japan Hills (lIDO') n.w.
on plain along Wood R.;
through Wood R. Buttes
area,n. across Tanana
R.;n,to Ester
2 rivers
22 creeks
2 rivers
10 creeks
Sa1chaket
Slough
7 trails
40
50
Several roads
in Fairbanks,
depending upon
exact route; 3
trails
a,Assumes corridor is located on n. side of Healy Ck.for IOOSt of its length. n.
side of Cody Ck., and n.w. side of Wood R.
b. Source: United States Department of Agriculture,Soil Conservation Service
1979.See Appendix Table B-1 for explanat ion of soil units.
EF
fOC
____•.._.___.•__...A'_J.,....:-'.•w-..""'.....·_~...................,,.,._,....."oI-".,.',hjJ>,.
II
Table 5.4 (Cont'd)
EnvIronmental Inventory -Northern Study Area (lIo<lly to Fairbanks)
Corridor
Segment Scenic Quality/
Recreation
CuHlIral
Resources
aVegetation Fish b
Resources
c
Birds
c
Furbearers._---
c
8ig Game
AB Parks Hwy-scen Ie area;
raftinQ.kayaklng on
Nenana R.
Dry Ck.arch.
site near Healy;
quod possibility
for other sites;
data void
Southern end -data void
Northern end -low shrUb,
sedqe-qrass tundra
Grayling,burbot,longnose sucker.
Dolly Varden, round whitefish,slimy
sculpin
Important golden
eagle habitat
near A
Prime habitat -15
ml.from Nenana to
B
From Nenana R. to 8-
prime moose and
important black bear
habitat;trom A north-
ward about 10011.-
prime moose habitat
BC
BDC
AE
Parks IIwy -scenic
at'ea:
hunting,fishing
Wide open flat-high
vis ibil Ity:
snownlobiling in flats
s. of Fairbanks
Scenic quality data
void; lIealy Ck '-rafting
area
Good poss ibll ity
for arch.sites:
data void
Good possibllity
for arch.sites;
data void
Dry Ck.arch.
site near lIealy;
few arch.sites
In mountains;
maybe near Japan
lIills:data void
S. of Tanana River - wet
old river floodplain,low
shrub and sedge-grass
bogs;Tanana R.crossing-
willow and alder shrub
types,white spruce,
balsam poplar forests
along river;n. of Tanana
R.-open and closed
deciduous (bIrch and
aspen)forests on slopes,
w/woodland spruce and
bogs,low shrub, and wet
sedge-grass on valley
bottoms
Probably wet,low shrub,
bogs. wet sedge-grass,
alder shrub, lowland
spruce;n,of Tanana-
upland deciduous forests
Data voId
GraylIng.burbot , Ionqnose
sucker.Dolly Varden.round
whitefish.slimy sculpin.
salmon (coho,king.chum).
sheefish;lake chub possible
Same as 8e
Same as AB
Prime peregrine
habitat at Tanana
R.;priwe water-
fowl habitat
along Tanana R.s.
of corridor
Near Totatlanlka Ck.
to Tanana R.- prime
w~terfowl habitat;
near Wood R.-
important raptor
habItat;between 0 &
C by Tanana R.-
prime peregrine
habitat
Important golden
eagle habitat at A &
along lIealy Ck. s.
of Uslbelli Pk;
pr ime.peregd ne
habitat on Keevy Pk.
Prime habitat -
from Clear MEWS
across the
Tanana
Prime habitat from
B to across Tanana
River
Prime habitat from
E to the s. about
15mt.
Clear ~[WS to across
Tanana R - prime
moose and Important
black bear habitat;
n. of Bonanza Ck.
Exp.forest - prime
black bear habitat
B to across Tanana
R -prime moose.
important b lack bear
hablt~t;Wood R.
to just s. of the
Tanana R.-prime
black bear habitat
Usibel1i to Japan Ilflls-
prime moose &caribou
habitat:between A &
Mystic Mt.- prime sheep
habitat:E to the s.-
import.black bear hab.
a.Tall shrub=alder:low shrub=dwarf.birch,and/or willow;open spruce=black (wet)
or white spruce,25%-60%cover;woodland spruce=white or black spruce,10%-25%
cover.mixed forest=spruce-birch.
b.little data available.Sources of informatIon in this table:Alaska
Department of Fish and Game 1978a and Morrow 1980.
WIde open flats - high IIlgh possibility
visibilty:snowmobiling for arch.sites;
in flats s. of fairbanks data void
E to just n. of Tanana
R.-prIme moose,
important black bear
habitat;Wood R.to just.
s.of Tanana.R.-prime
black bear habitat.
E to TanJnaR.-prime
moose and important
black bear habitat;
Clear MEWS to Tanana R.
- prime black bear
habitat
Prime habitat from
£to Tanana River
PrIme habitat from
E to just n.of
Tanana River
From WoodR.Buttes to
n. of Tanana R.-prime
wat.erfowl habitat:
between 0 &C along the
Tanana R.- prime
peregrine habitat.
N.of Blair lake Air
Force Range to the
Tanana R.'-prime
waterfowl habitat;s.
of Fairbanks along
TananaR.-prime bald
eagle habitat
Source:VanBallenberghe personalcommunlcat Ion.Prime habitat=minimum amount.of land
necessary to provide sustained yIeld for that species;based upon knOWledge of that
specIes'needs from experience of AOF&G personnel.Important nabitat=land whIch the ADF&G
considers not as critical to a species as is Prime habitat but is valuable.
c.
Same as A8. lake chub possible
Same as BC with the exception
of coho salmon.which Is not
recorded
Probably sImilar to £DC;
wet
Probably sImIlar to BOC
Arch.sites have
been Ident !fled
for the Ft.
Wainwright and
Blair lakes areas
Wide open flats -high
visibility
EnC
Ef
r-
FAIRBANKS
LOCATION MAP
LEGEND
---STUDY CORRIDOR
.•.•..••......I NTERTIE
(APPROXIMATE)
ALTERNATIVE TRANSMISSION LINE CORRIDORS
SOUTH ERN STUDY AREA FIGURE 5.1
FAIRBANKS
LOCATION MAP
LEGEND
----STUDY CORRIDOR
..............I NTERTIE
(APPROXIMATE)
o 5 10iI
SCALE IN MILES
ALTERNATIVE TRANSMISSION LINE CORRIDORS
CENTRAL STUDY AREA FIGURE 5.2
LOCATION MAP
LEGEND
-------STUDY CORRIDOR
••••••••••••••I NTERTIE
(APPROXIMATE)
ALTERNATIVE TRANSMISSION LINE CORRIDORS
NORTHERN STUDY AREA
o 5
i
SCALE IN MILES
10
!
FIGURE 5.3
6 -SCREENING OF CORRIDORS
6.1 -Obj€ctive
The objectives of the screening process were to focus on the previously selected
corridors and select those best meeting technical,economic,and environmental
criteria;more specifically:
-To eliminate ,the less eligible corridors identified in the selection process;
-To select initial corridors for further study;
-To identify sensitive areas within the selected corridors that may require
additional studies;and
-To provide a basis for the 1981 field data collection.
6.2 - Data Base
In addition to the data base used for the selection of alternative corridors,
the following data were used in the screening process:
- Additional field studies to cover the environmental aspects;
-An up-to-date land status map;
- Larger scale aerial photos for sensitive segments of the potential corridors;
-Preliminary input from other Susitna project subtasks;
Discussions and information from pUblic utilities personnel and agencies and
their experience and comments on previous transmission lines built in Alaska;
and
- Input from Intertie public participation program.
6.3 -Assumptions
The same assumptions as mentioned in the previous chapter for the selection of
alternative corridors were used in the screening process.
6.4 -Reliability
The purpose of electric transmission lines is to provide electrical power.Re-
liability was introduced at this stage of the study as a critical element in the
screening process,as described below.
Reliability is an uncompromising factor in screening alternative transmission
line corridors.Many of the criteria utilized for economic,environmental,and
technical reasons also relate to the selection of a corridor within which a line
can be operated with minimum power interruption.Six basic factors were con-
sidered in relation to reliability:
6-1
-Elevation:
-Aircraft:
Stabil ity:
-Existing
Power
Lines:
Topography:
- Access:
Lines located at elevations below 4,000 feet will be less exposed
to severe wind and ice conditions,which can interrupt service.
Avoi dance of areas near ai rcraft 1andi ng and takeoff operati ons
will minimize risks from collisions.
Avoidance of areas susceptible to land,ice,and snow slides will
reduce chance of power failures.
Avoidance of crossing existing transmission lines will reduce the
possibility of lines touching during failures and will facilitate
repairs.
Lines located in areas with gentle relief will be easier to con-
struct and repair.
Lines located in reasonable proximity to transportation corridors
will be more quickly accessible and,therefore,more quickly re-
paired if any failures occur.
6.5 -Screening Criteria
(a) Technical Screening Criteria
Corridor location objectives are to obtain an optimum combination of relia-
bility and cost with the fewest environmental problems.In many cases,
these objectives are mutually compatible.
Throughout the corridor screening and evaluation,the question arises
whether it is more desirable to place lines relatively close to existing
surface transportation facilities,where an easily accessible line could
assure reliability of service during the line's operating life,or to pio-
neer new corridors across lands where the line would be seen by few people.
In the final analysis,when choosing the final line route,there will be
enough room in a three-to·five-mile corridor to adjust the centerline to
meet the technical,economical,and environmental objectives.
Four primary and two secondary technical factors were considered in the
screening of alternative corridors.
(i)Primary Aspects:
-Topography
Topography plays a key role in corridor selection,since it affects con-
struction,operating,and maintenance.Areas of broken or steep terrain
add to access difficulties and thus reduce reliability.Also,condi-
tions in which the slope of the terrain exceeds the angle of repose of
the soil increase the chances of land, rock, or mud slides.Snow~rock,
or mud slides are an additional hazard on steep slopes.During the
screening process,therefore,emphasis was placed on screening out those
corridors that did not have gentle terrain.
6-2
- Climate and Elevation
Low temperatures,snow depth,icing,and severe winds are very important
parameters in transmission design,operation,and reliability.
The climatic factors become more severe in the mountains,where extreme
winds are expected for exposed areas and passes.Alaska Power Adminis-
tration believes that elevations above 4,000 feet in the Alaska Range
and Talkeetna Mountains are completely unsuitable for locating major
transmission facilities.Significant advantages of reliability and cost
are expected if the lines are routed below 3,000 feet in elevation.
This elevation figure was used in the screening process.
- Soil s
Although transmission lines are less affected by soils and foundation
limitations than railroads and pipelines,it is more reliable to build a
transmission line on soil that does not appear to be underlain by seis-
mically induced ground failures or on a swampy area where maintenance
and inspection may create problems.These factors were utilized in the
screening process.Because of the vast areas of wetlands in the study
area,particularly in the southern portion,it was not possible to lo-
cate a corridor that would avoid all wetland areas.
-Length of Corridors
The ideal distance between two load centers is the straight line joining
them.In many cases,this idealistic situation cannot be achieved be-
cause of geographic or environmental obstacles.A shorter line,in gen-
eral,will be easier to maintain and will have fewer technical obstacles
than a longer one.
(ii)Secondary Aspects:
- Vegetation and Clearing
Heavily forested areas must be cleared prior to construction of the
transmission line.Clearing the vegetation will cause some disruption
of the soil.If not properly stabilized through restoration and vegeta-
tion,increased erosion will result.If the vegetation is cleared up to
river banks on stream crossings,it may result in additional sedimenta-
tion.During the corridor screening,those corridors crossing through
large expanses of heavily timbered areas were eliminated.
- Other
Highway and river crossings should be avoided as much as possible.These
crossings may require additional temporary structures to protect the
cable while permitting the uninterrupted flow of traffic.
(b)Economic Screening Criteria
The purpose of this exercise is to compare the conditions under which
6-3
corridors for each study area would be economically feasible.Several eco-
nomic criteria are important in screening the transmission line corridors.
Three primary and one secondary aspect of the economic criteria were con-
sidered.
(i)Primary Aspects:
-Length
Length of transmission line corridors has a definite influence on the
capital cost of the line.Alonger line will require additional right-
of-way clearing,structures,foundations,electrical conductors,and
hardware.At a cost of approx imately $350,OOO/mi 1e (1981 do 11 ars)for a
345 kV single-circuit line,it is economically preferable to build the
shortest line possible.A shorter line will also require less mainten-
ance and, hence,lower operating costs.
- Right-of-Way
Right-of-way is an important factor in transmission line costs.Al-
though the shortest line is more desirable from a point of view of capi-
tal cost,it may sometimes be more economical to avoid existing develop-
ments,residential areas,and agricultural lands.This will result in
easement purchases being kept to a minimum.
Whenever possible,existing rights-of-ways should be shared or para-
lelled to avoid the problems associated with pioneering a corridor in
previously inaccessible areas.
The transmission line corridor should also avoid areas of heavy forest
to reduce the cost of clearing the right-of-way.However,this should
be carried out only if it does not add significantly to the length of
the line.
-Access Roads
Corridors in relative proximity to existing surface transportation
routes will require minimal access roads.This will reduce the cost of
transmission lines and make it easier for maintenance purposes.
(ii)Secondary Aspects:
In addition to the major considerations concerning economic screening of
corridors,some other aspects were also considered.These include topo-
graphy,since it is more economical to build a line on a flat corridor
than on a rugged or a mountainous one;and limiting the number of stream,
river,highway,road,and railroad crossings in order to minimize costs.
6-4
(c)Environmental Screening Criteria
Because of the potential,adverse environmental impacts from transmission
line construction and operation,environmental criteria were carefully
scrutinized in the screening process.~ast experience has shown the pri-
mary environmental considerations to be:
-Aesthetic and Visual (including impacts to recreation)
-Land Use (including ownership and presence of existing rights-of-way)
Also of significance in the evaluation process are:
-Length
-Topography
-Soils
-Cultural Resources
- Vegetation
- Fishery ~esources
-Wildlife Resources
A description and rationale for use of these criteria are presented below:
(i)Primary Aspects:
-Aesthetic and Visual
The presence of large transmission line structures in undeveloped areas
has the potential for adverse aesthetic impacts.Furthermore,the pres-
ence of these lines can conflict with recreational use,particularly
those nonconsumptive recreational activities such as hiking and bird
watching where great emphasis is placed on scenic values.The number of
road crossings encountered by transmission line corridors is also a fac-
tor that needs to be inventoried because of the potential for visual im-
pacts.The number of roads crossed,the manner in which they are
crossed,the nature of existing vegetation at the crossing site (i.e.,
potential visual screening),and the number and type of motorists using
the highway all influence the desirability of one corridor versus
another.Therefore,when screening the previously selected corridors,
consideration was focused on the presence of recreational areas,hiking
trails,heavily utilized lakes,vistas,and highways where views of
transmission line facilities would be undesirable.
-Land Use
The three primary components of land use considerations are: 1) land
status/ownership,2)existing rights-of-way,and 3)existing and pro-
posed development .
•Land/Status/Ownership
The ~wnership of land to be crossed by a transmission line is impor-
tantbecause certain types of ownership present more restrictions than
6-5
others.For example,some recreation areas such as state and federal
parks and areas like game refuges and mil itary lands,among others,
present possible constraints to corridor routing.Private landowners
generally do not want transmission lines on their lands.This infor-
mation,when known in advance, permits corridor routing to avoid such
restrictive areas and to occur in areas where land use conflicts can
.be minimized .
•Existing Rights-of-Way
Paralleling existing rights-of-way tends to result in less environ-
mental impact than that which is associated with a new right-of-way
because the creation of a new right-of-way may provide a means of ac-
cess to areas normally accessible only on foot.This can be a criti-
cal factor if it opens sensitive,ecological areas to all terrain
vehicles.
Impact on soils,vegetation,stream crossings,and others of the in-
ventory categories can also be lessened through the paralleling of
existing access roads and cleared l~ights-of-way.Some impact is still
felt,however,even though a right-of-way may exist in the area.For
example,cultural resources may not have been identified in the origi-
nal routing effort.Wetlands present under existing transmi~sion
lines may likewise be negatively influenced if ground access to the
vicinity of the tower locations is required.
There are common occasions where paralleling an existing facility is
not desirable.This is particularly true in the case of highways that
offer the potential for visual impacts and in situations where para-
lleling a poorly sited transmission facility would only compound an
existing problem .
•E~isting and Proposed Developments
This inventory identifies such things as agricultural use; planned
urban developments,such as the proposed capital site;existing resi-
dential and cabin aevelopments; the location of airports and of lakes
used for float planes;and similar types of information.Such infor-
mation is essential for locating transmission line corridors appropri-
ately,as it presents confl icts with these land use activities.
(ii)Secondary Aspects:
-Length
The length of a transmission line is an environmental factor and, as
such,was considered in the screening process.A longer line will re-
quire more construction activity than a shorter line,will disturb more
land area,and will have a greater inherent probability of encountering
environmental constraints.
6-6
-Topography
The natural features of the terrain are significant from the standpoint
that they offer both positive and negative ~spects to transmission line
routing.Steep slopes,for example,present both difficult construction
and soil stabilization problems with potentially long-term,negative en-
vironmental consequences. Also, ridge crossings have the potential for
visual impacts.At the same time, slopes and elevation changes present
opportunities for routing transmission lines so as to screen them from
both travel routes and existing communities ..When planning corridors
then, the identification of changes in relief is an important factor.
-Soi 1s
Soils are important from several standpoints.First of all,scarifica-
tion of the land often occurs during the construction of transmission
lines.As a result,vegetation regeneration is affected,as are the re-
lated features of soil stability and erosion potential.In addition,
the development and installation of access roads,where necessary,are
very dependent upon soil types.Tower designs and locations are dic-
tated by the types of soils encountered in any particular corridor seg-
ment.Consequently,the review of existing soils information is very
significant.This inventory was conducted by means of a Soil Associa-
tions Table,found in Appendix Table 8.1,of this report.Appendix
Table 8.2 presents the related definitions as they apply to the terms
used in Appendi x Tab 1e B.1.
-Cultural Resources
The avoidance of known or potential sites of cultural resources is an
important component of the routing of transmission lines.In planning
for Susitna Project transmission lines,however,information on the
presence of cultural resources is,for the most part,unavailable at
present.Identification of data-voids for this category highlights the
need for further evaluation of this resource,not only in the planning
stage but also in the final route selection analysis.Further identifi-
cation of known,as well as potential,sites will be accomplished as the
routing and impact analyses continue..
-Vegetation
The consideration of the presence and location of various plant communi-
ties is essential in transmission line siting.The inventory of plant
communities,such as those of a tall-growing nature or wetlands, is sig-
nificant from the standpoint of construction,clearing,and access road
development requirements.In addition,i dentificati on of .locati ons of
endangered and threatened plant species is also critical.While several
Alaskan plant species are currently under review by the U.S.Fish and
Wildlife Service,no plant species are presently listed under the En-
dangered Species Act of 1973 as occurring in Alaska.Murray (1980)has
published a state listing of endangered and threatened species.No cor-
ridor currently under consideration has been identified as traversing
any location known to support these identified plant species.
6-7
-Fishery Resources
The presence or absence of resident or anadromous fish in a stream is a
significant factor in evaluating suitable transmission line corridors.
The corridor"s effects on a stream's resources must be viewed from the
standpoint of possible disturbance to fish species,potential loss of
habitat,and possible destruction of spawning beds. In addition,cer-
tain species of fish are more sensitive than others to disturbance.
Closely related to this consideration is the number of stream crossings.
The nature of the soils and vegetation in the vicinity of the streams
and the manner in which the streams a-re to be crossed are also important
environmental considerations when routing transmission lines.Potential
stream degradation,impact on fish habitat through disturbance,and
long-term negative consequences resulting from siltation of spawning
beds are all concerns that need evaluation in corridor routing.There-
fore,the number of stream crossings and the presence of fish species
and habitat value were considered when data were available.
-Wildlife Resources
The ~hree major groups of wildlife which must be considered in trans-
mission corridor screening are big game,birds,and furbearers.Of all
the wildlife species to be considered in the course of routing studies
for transmission lines,big game species (together with endangered
species)are most significant.Many of the big game species,including
grizzly bear,caribou,and sheep, are particularly sensitive to human
intrusion into relatively undisturbed areas.Calving grounds, denning
areas,and other important or unique habitat areas as identified by the
Alaska Department of Fish and Game were identified and incorporated into
the screening process.
Many species of birds such as raptors and swans are sensitive to human
disturbance.Identifying the presence and location of nesting raptors
and swans permits avoidance of traditional nesting areas.Moreover,if
this category is investigated,the presence of endangered species (viz,
peregrine falcon~)can be determined.
Important habitat for furbearers exists along many potential transmis-
sion line corridors in the railbelt area,and its loss or disruption
would have a direct effect on these animal populations.Investigating
habitat preferences,noting existing habitat,and identifying popula-
tions through available information are important steps in addressing
the selection of environmentally acceptable alternatives.
6.6 - Screening Methodology
(a) Technical and Economical Screening Methodology
The parameters required for the technical and economical analyses were ex-
tracted from the environmental inventory tables (Tables 5.2 through 5.4).
The tables,together with the topographic maps,aerial photos,and existing
published materials,were used to compare the alternative corridors from a
technical and economical point of view.The parameters used in the analy-
sis were:length of corridors,approximate number of highway/road cross-
ings,approximate number of river/creek crossings,land ownership, topo-
graphy,soils,and existing rights-of-way.The main factors contributing
to the economical and technical analyses are combined and listed in Tables
6.1,6.2,and 6.3.It should be noted that most of the parameters are in
miles of line length,except the tower construction.In this analysis,it
was decided to assign 4.5 towers for each mile of 345-kV line.
In order to screen the most qualified corridor,it was decided to rate the
corridors as follows:
Corridor rated A -recommended
Corridor rated C -acceptable but not preferred
Corridor rated F -unacceptable
From the technical point of view,reliability,as discussed in Section 5,
is the main objective.An environmentally and economically sound trans-
mission line was rejected if the line was not reliable.Thus,any line
which received an F technical rating,was assigned an overall rating of F
and eliminated from further consideration.
The ratings appear in each of the economical and technical screening tables
(Tables 6.1,6.2,and 6.3)and are summarized in Table 6.7.
(b)Environmental Screening Methodology
In order to compare the alternative corridors (Figures 5.1,5.2,and 5.3)
from an environmental standpoint,the environmental criteria discussed in
Section 6.4 were combined into environmental constraint tables (Tables 6.4,
6.5,and 6.6).These tables combine information for each corridor segment
into the proper corridors under study.This permitted the assignment of an
environmental rating,which identifies the relative rating of each corridor
within each of the three study areas.The assignment of environmental rat-
ings is a SUbjective,qualitative technique intended as an aid to corridor
screening.Those corridors that are recommended are identified with and
"A," while those corridors that are acceptable but not preferred are iden-
tified with a "C."Finally,those corridors that are considered unaccept-
able are identified with an "F."'
6.7 - Screening Results
Table 6.7 summarizes the comparisons of the 22 corridors studied in the
southern,central,and northern study areas.Environmental, economical,
and technical ratings are presented as well as a summary rating for each
corridor.Because of the critical importance of environmental considera-
tions,any corridor which received an F rating for environmental impacts
was assigned a summary rating of F.Thus,a corridor which may be excel-
lent from a technical and economic viewpoint was considered not acceptable
if the environmental rating was unacceptable.As discussed previously,the
same reasoning related to reliability was used to reject all corridors
which received an F technical rating.
6-9
Descriptions of the rationale for each corridor1s rating are presented
below.
(a) Southern Study Area
Three alternative corridors were evaluated in the southern study area.As
previously identified,two corridors connect Willow with Point ~lacKenzie.
The third corridor connects Willow with Anchorage.
(i)Corridor One (ABC I
)-Willow to Anchorage via Palmer
- Technical and Economical
This 73-mile corridor is the longest of the three being considered
for the southern area.As a consequence,there will be more clear-
ing of right-of-way required,more miles of line,and more towers.
Several highway and railway crossings will also be encountered,in-
cluding crossing of the Glenn Highway.The corridor is located in
a well-developed,inhabited area which will require easements on
private properties.There also could be a problem of radio and
television interference.
-Environmental
Several constraints were identified in evaluating this corridor,
chief among which were constraints under the land use category.
A new rlqnt-ot'-way woul o be required from ~~illow to a point in the
vicinity of Palmer. This would necessitate the development of a
pioneer access road and,since this area is wooded,attendant vege-
tation clearing and opening of a previously inaccessible area.The
corridor also bisects lands in the vicinity of Willow that have
been proposed for use as the new capital site.
Between Eklutna and Anchorage,this route parallels an existing
transmission line that now crosses extensively developed areas.
Paralleling existing corridors usually is the most appropriate
means of traversing developed areas.Because homes and associated
buildings abut the right-of-way,however,additional routes through
this developed area present problems,among which aesthetics is
most important.In addition,this corridor alternative crosses 5
rivers and 28 creeks,potentially affecting not only the rivers and
streams but also fish species inhabiting these water courses.From
the standpoint of aesthetics,a.transmission line in the vicinity
of Gooding Lake would negatively affect an existing bird-watching
area.Ho.wever,because this area is not heavily utilized and rout-
ing variations are available within the corridor,it is considered
environmentally acceptable.
Ratings:
Technical
C
Economi cal
C
6-10
Environmental
C
Summary
C
(ii)Corridor Two (AOFC)-Willow to Point MacKenzie via Red Shirt Lake
-Technical and Economical
Corridor ADFC crosses the fewest number of rivers and roads in the
southern study area.It has the advantage of paralleling an exist-
ing tractor trail for a good portion of its length,thereby reduc-
ing the need for new access roads.Easy access will allow mainten-
ance and repairs to be carried out in minimal time. This corridor
also occurs at low elevations and is approximately one-half the
length of Corridor One.
-Environmental
This corridor crosses extensive wetlands from Willow to Point Mac-
Kenzie.At higher elevations or in the better drained sites,ex-
tensive forest cover is encountered.Good agricultural soils have
been identified in the vicinity of this corridor;the state plans
an Agricultural Lands Sale for areas to be traversed by this corri-
dor.The corridor also crosses the Susitna Flats Game Refuge.The
presence of an existing tractor trail near considerable portions of
this corridor diminishes the significance of some of these con-
straints.Furthermore,its short length and the fact that it
crosses only one river and eight creek crossings increases its en-
vironmental acceptability.
Ratings:
Technical
A
Economical
A
Environmental
A
Summary
A
(iii)Corridor Three (AEFC)-Willow to Point MacKenzie via Lynx Lake
- Technical and Economical
This corridor has the same physical features as Corridor Two.80th
corridors have extensive wetlands.AEFC cuts across a developed
recreational area and hence will require special routing procedures
to circumvent some of the private property it will traverse.This
corridor is very accessible.Technically,because of its short
length and low elevati6n,it is a desirable corridor,but econom-
ically it would be costly to obtain easements and to route the line
through the several privately owned properties.
-Environmental
As with the previous corridor,this route crosses extensive wet-
lands requiring,in the better drained areas,extensive clearing of
associated forest.Just south of Willow,this route passes through
the Nancy Lakes recreation area.Substantial development of both
residential and recreational facilities has occurred in the past
and is continuing.These facilities would be affected by the pres-
ence of the transmission line,not only from a land use standpoint,
6-11
but also from an aesthetics standpoint.Because of this unavoid-
able land use conflict associated with this corridor,particularly
in the Nancy Lake area,it is not considerea to be environmentally
acceptab1e.
Ratings:
Techni cal
A
(b) Central Study Area
Economica 1
C
Environmental
F
Summary
F
Fifteen corridors utilizing different combinations of corridor segments
were identified in the central study area.These corridors connect the
damsites with the Intertie at four separate locations.These locations are
in the vicinity of Indian River near its confluence with the Susitna River
and near the communities of Chulitna,Summit,and Cantwell.
Because of the range in length of the corridors,those with long lengths
were assigned low economic ratings.These corridors,numbers Four
(ABCJHI),Five (ABECJHI),Seven (CEBAHI),Eight (CBAG),Nine (CEBAG),Ten
(CJAG),and Twelve (JACJHI),have lengths of 76 to 97 miles.In addition
to these,Corridors Four and Six (CBAHI)were assigned an F technical rat-
ing because they cross mountainous areas over 4,000 feet in elevation.
Corridors Four and Six were rated unacceptable technically and therefore
were eliminated because relia,bility cannot be compromised.The remaining
six corridors,although unacceptable economically (F rating),were evalu-
ated on an environmental basis.This was done to determine whether one of
these long corridors was much more acceptable environmentally than a
shorter one.
Therefore,environmental information is presented for the eight above-
mentioned corridors.This is followed by a discussion of the economic,
technical,and environmental features of the remaining seven corridors in
the central study area.
Corridors Techni cally and/or Economi cally Unacceptab 1e
(i)Corridor Four (ABCJHI)-Watana to Intertie via Devil Creek
Pass/East Fork Chulitna River
This corridor connects Devil Canyon with Watana and exits the Devil
Canyon project to the north following the drainages of Devil,
Portage,and Tsusena Creeks.To route this corridor to the Intertie
as required,the line crosses some mountain passes over 4,000 feet in
elevation with steep slopes and shallow bedrock areas (Corridor Seg-
ment CJHI).
The transmission line would interrupt the existing viewshed of the
recreation facility at High Lake.Existing patterns of land use in
the vicinity of High Lake may also be significantly disrupted by the
transmission line.Once on the north side of the river,this
6-12
corridor crosses 42 creeks between Devil Canyon and the connection
with the Interti e. Potenti al for stream degradation exi sts because
of the lack of existing access.Sensitive wildlife species,such as
caribou,wolves,and brown bear, as well as a golden eagle nest site,
could be potentially harmed by this corridor.
Ratings:
Techni cal
F
Economical
F
Environmental
F
Summary
F
(ii)Corridor Five (ABECJHI)-Watana to Intertie via Stephan Lake and
the East Fork Chulitna River
This corridor crosses areas of high elevations and shallow soils un-
derlain by bedrock.Land use constraints are encountered in the
vicinity of both High Lake and Stephan Lake,two significant recrea-
tion and lodge areas.Relatively important waterfowl and migrating
swan habitat woul d be affected,as woul d habitat for some of the
major big game species.In addition,this corridor makes 42 creek
crossings.Extensive vegetation clearing would be required,opening
areas to access.Because of the visual impacts and increased access,
this corridor received anF rating.
f<atings:
Technical
F
Economical
F
Env i ronmenta 1
F
Summary
F
(iii)Corridor Six (CBAHI)-Devil Canyon to the Intertie via Tsusena
Creek/Chulitna River
Reversing the sequence by which the damsites are connected, Corridor
Six extends from Devil Canyon to Watana (Corridor Segment CBA)and
from Watana north along Tsusena Creek to the point of connection with
the Intertie near Summit Lake (Corridor Segment AHI).Access roads
are presently absent along most of this corridor,and a pioneer route
would need to be established.This corridor also traverses eleva-
tions above 4,000 feet above sea level and encounters shallow soils
underlain by bedrock.Wetlands,extensive forest cover,and 32 creek
crossings also constrain the development of this corridor.Abald
eagle nest in the vicinity of Tsusena Butte, as well as the presence
of sensitive big game species such as caribou and sheep,present
additional constraints to the routing of the corridor.This corridor
was rated F,primarily because of increased access and potential neg-
ative impact on sensitive wildlife species.
Ratings:
Technical
F
Economi cal
C
Env i ronmenta 1
F
Summary
F
(lv)Corridor Seven (CE~AHI)-Devil Canyon to Intertie via Stephan
Lake and Chulitna River
The primary environmental constraints associated with this corridor
6-13
are the result of visual and increased access impacts.The corridor
crosses near residential and recreational facilities at Stephan Lake
and isin the viewshed of the Alaska range.Access road construction
would be necessary through wetlands and areas of heavy timber.
In addition,the corridor crosses 45 creeks,including some with
valuable spawning areas.It also crosses habitat for wolves and
bears,including Prairie Creek which is heavily used by brown bears
during salmon runs.This offers the potential for increased bear-
human contacts.
Again, because of potential for ~isual impacts and increased access,
this corridor received anF rating.
Ratings:
Technical
C
Economical
F
Environmental
F
Summary
F
(v)Corridor Eight (CBAG)- Devil Canyon to Intertie via Deadman/
Brushkana Creeks and Denali Highway
Constraints in the categories of lana use,aesthetics,and fish and
wildlife resources are present in this corridor.Among the longest
of corridors under cons ider atl on ,this route passes near recreation
areas,isolated cabins,lakes used by float planes,and land-based
airstrips.In traversing lands from the Watana Dam site to the point
of connection with the Intertie,the route also intrudes upon some
scenic areas.Along much of its length,the corridor crosses wood-
lands and,since a pioneer access road probably would need to be
developed,vegetation clearing would likely be extensive.Once north
of the Watana Dam site,the transmission line corridor makes 35 creek
crossings and traverses the habitat not only for a variety of sensi-
tive big game species but also for waterfowl and raptors.In addi-
tion,the line passes near the location of an active bald eagle nest
on Deadman Creek.
For these reasons,a rating of F was assigned.
Ratings:
Technical
C
Economi cal
F
Environmental
F
Summary
F
(vi)Corridor Nine (CEBAG)- Devil Canyon to Intertie via Stephan Lake
andUenali Highway
Corridor Nine is the longest under construction in the central study
area and, hence,would require disturbance of the largest land areas.
It also crosses areas of shallow bedrock, important waterfowl mi gra-
tory habitat at Stephan Lake,and 48 creeks,inclUding valuable
spawning areas.
The corridor passes near Stephan Lake,utilized heavily for recrea-
tion,and any line constructed in this area would be visible when
6-14
looking towards the Alaska range.Although one of the proposed ac-
cess roads to the damsites does occur in this area offering the po-
tential for parallel rights-of-way,the extreme length of this corri-
dor and the potential for unavoidable adverse land use and aesthetic
impacts result in its being unacceptable.Thus,an F rating w~s as-
signed.
Ratings:
Technical
C
Economica 1
F
Environmental
F
Summary
F
(vii)Corridor Ten (CJAG)-Devil Canyon to Intertie via North Shore,
Susitna River,and Penali Highway
This is the second longest of the corridors under investigation by
this study.Routing above 3,000 feet and its concomitant bedrock and
steep slopes are important restrictions of this corridor.It would
also encounter the land use constraints identified in Corridor Nine,
as well as several other drawbacks,most notable of which are in the
areas of aesthetics and fish and wildlife resources.Forty-seven
creek crossi ngswould be required by this corridor.
This corridor could also parallel one of the proposed access roads.
However,as with Corridor Nine,its long length,land use,and visual
impacts do not make it an acceptable corridor.
All of the above and particularly the aesthetic constraints result in
an F rating.
Ratings:
Technical
C
Economical
F
Environmenta 1
F
Summary
F
(viii)Corridor Twelve (JA-CJHI)-Devil Canyon -Watana to Intertie .via
Devil /Chulitna River
This corridor has a number of environmental constraints which to-
gether make it environmentally unacceptable.Land use conflicts
would likely occur, since much of the land crossed is privately
owned.The lack of existing rights-of-way and clearing of vegetation
would result in new access.In addition,aesthetic impacts would oc-
cur in the High Lakes area and because the corridor is in the view-
shed of the Alaska Range.Finally,the corridor crosses 40 creeks,
including valuable salmon-spawning grounds,and crosses near a golden
eagle nest.
This corridor,primarily because of impacts to access,private lands,
and aesthetics,received an F rating.
Ratings:
Technical
C
Economical
F
6-15
Environmenta 1
F
Summary
F
Corridors Technically and Economically Acceptable
Review of the environmental ratings for the eight corridors above
shows all of them to be environmentally unacceptable.Therefore,the
screening in the central study area process was continued with the
seven remaining corridors with lengths or elevations that did not
rule them out economically or technically.The results of this
screening for technical,economical,and environmental factors
follow.
(i)Corridor One (ABCD)~Watana to the Intertie via South Shore of the
Susitna River
- Technical and Economical
Corridor One is one of the shortest corridors considered,approxi-
mately 40 miles long,making it economically favorable.No techni-
cal restrictions were observed along the entire length of this
corri dor.
-Environmental
Because of its short length,environmental disturbance caused by
transmission line construction would be reduced.The more note-
worthy constraints are those identified under the categories of
land use and vegetation.Corridor One would require the develop-
ment of a new right-of-way between Watana and Devil Canyon with
some opportunity existing to utilize the CDE-developed road for ac-
cess between the Intertie and Devil Canyon.The potential does
exist in this corridor to use one of the proposed access roads cur-
rently under consideration.Wetlands and discontinuous forest
cover occur in the corridor,especially in the eastern third of the
route.Access road development,if required in this area,and the
associated vegetation clearing present additional constraints to
this corridor.
Ratings:
Technical
A
Economical
A
Environmental
A
Summary
A
(ii)Corridor Two (ABECD)-Watana to Intertie via Stephen Lake
- Technica]and Economical
This corridor is approximately five miles longer than Corridor One
and would require an additional five miles of access road for con-
struction purposes.The corridor will rise to a maximum elevation
of 3,600 feet,and also crosses wetlands and extensive forest
cover. This higher elevation,increased clearing,and longer
length result in a lower technical and economic rating than Corri-
dor One.
-Environmental
This corridor is identical to Corridor One with the exception of
6-16
Corridor Segment BEC.Because of this deviation,several addition-
al problems arise in this corridor as compared with Corridor One.
First,an access road about nine miles longer than that required
for the construction of Corridor One would be needed. A new road
may also have to be developed along most of this route,which would
also cross wetland and forested areas.Residential and recrea-
tional facilities at Stephan Lake and the much higher visibility of
the transmission facilities to the users of this recreation area
would be a major constraint posed by this corridor.
The corridor would also intrude upon habitat for wolves,bear,and
caribou,as well as for raptors and waterfowl.Of note,brown
bears utilizing the fish resources of Prairie Creek would likely
encounter this alternative corridor more frequently than they would
Corridor One,thus potentially bringing bears and people into close
contact.
These potential impacts to aesthetics and creation of new access
road result in this corridor being environmentally unacceptable.
Ratings:
Technical
C
Economical
C
Env i ronmenta 1
F
Summary
F
(iii)Corridor Three (AJCF)-Watana to Intertie via North Shore of the
Susitna River
-Technical and Economical
This corridor is similar in length to Corridor Two and shares the
same technical and economical considerations.There are no exist-
ing roads for nearly the entire length,and it does encounter some
steep slopes.These will reduce the reliability of the line and
add to the cost of construction.
-Environmental
Summary
C
Environmental
C
Economi cal
C
The corridor in this area would likely require a pioneer access
road. This route would also be impeded by the existence of recrea-
tion facilities in the vicinity of High Lake and,more signifi-
cantly,Otter Lake.The corridor is within sight of recreation
facilities at these lakes and may also interfere with the use of
High Lake by planes during certain weather conditions.The route
also crosses Indian River and Portage Creek;both streams support
significant salmon resources.Potential damage to spawning areas
could occur as a result of construction along this corridor.An
active golden eagle nest exists in the Devil Creek vicinity.This
species is sensitive to development activities and could be ad-
versely affected by Corridor Three.
Ratings:
Technical
C
6-17
(iv) Corridor Eleven (CJAHI)-Devil Canyon to the Intertie via Tsusena
Creek/Chulitna River
- Technical and Economical
This corridor has a disadvantage over the others discussed because
of its 70-mile length.New access roads and vegetative clearing
would be required for a considerable portion of the corridor,
thereby increasing costs of construction.
-Environmental
Corridor Segments CJA (part of Corridor Three)and AHI (part of
Corridor Six)comprise this alternative and, as such,have been
previously discussed.The long length of this corridor,its cross-
ing of 36 creeks,and development of a new right-of-way and land
use conflicts contribute to an unacceptable environmental rating.
Ratings:
Technical
C
Economica 1
C
Ell vi ronment a1
F
Summary
F
(v) Corridor Thirteen (A~CF)-Watana to Devil Canyon via South Shore,
Oevil Canyonto Intertie via North Shore,Susitna River
- Technical and Economical
This corridor,41 miles in length,is one of the shorter ones being
considered.Although it crosses deep ravines,and forest clearing
will be required over a considerable portion of its length,it is
rated high technically because of its short length and low eleva-
tion.
-Environmental
Since this corridor combines segments from Corridor One (ABC)and
Corridor Three (CF),the same constraints for those two routes
apply which have been previously described.This corridor presents
a few environmental problems.Conflicts with recreation near Otter
Lake can be resolved through careful selection of one final right-
of-way.
Ratings:
Technical
A
Economical
C
Environmental
A
Summary
A
(vi)Corridor Fourteen (AJCD)-Watana to Uevil Canyon vi.a North Shore,
Devil Canyon to Intertie via South Shore,Susitna River
- Technical and Economical
This corridor is also one of the shortest among the fifteen studied
in the central area.Some access roads will be required for this
corridor and some clearing necessary.Advantage will be taken of
the proposed project access road where possible to locate the
transmission line close by.
Corridor Fourteen is rated as recommended both economically and
technically,because of gentle relief,short length,and small
amounts of clearing.
-Environmental
This corridor reverses the routing between damsites and the Inter-
tie proposed by Corridor Thirteen.Constraints are,therefore,the
same as those presented for Corridors Three and One,and are not
great.However,the unavoidable conflict with land use at High
Lake results in a Crating.
Ratings:
Techni cal
A
Economical
A
Env i ronmenta 1
C
Summary
A
(vii)Corridor Fifteen (AtiECF)-Watana to Uevil Canyon via Stephan Lake,
Uevil.Canyon to Intertie via North Shor~,SusitnaRiver
- Technical and Economical
This corridor is approximately 45 miles long and would require con-
struction of new access roads and forest clearing for a~most its
entire length.These negative economical points contribute to the
low rating of this corridor.
-Environmental
This corridor combines segments from Corridor Two (ABEC)and Corri-
dor Three (CF).The constraints for these corridors have been pre-
sented under their respective discussions.Extensive new access
and detrimental visual impacts near Stephan Lake were the primary
constraints along the corridor segment from Corridor Two which re-
sulted in an unacceptable environmental rating.
Ratings:
Technical
C
(c)'Nor-thern Study Area
Economical
C
Envi ronmenta 1
F
Summary
F
Constraints appeared in the routing of all four corridors evaluated in the
northern study area.The shortest route was 85 miles and the longest was
115 miles.Topography and soils restrictions are constraints to eacn of
the corridors evaluated.In addition,the two eastern corridors of the
study area cross mountain slopes.Each of the corridors would be highly
visible in the floodplain of the Tanana River.Major highways skirt these
floodplains at some distance to the north,however;and only scattered,
6-19
isolated residential areas would be encountered by the corridors.Little
information has been collected concerning the cultural resources in the
vicinity of any of the four corridors of this study area.The Dry Creek
archaeologic site near Healy has been identified;however,the presence of
numerous sites in the foothills of the Alaska Range and in the vicinity of
the Tanana River are suspected.Additional constraints peculiar to the
four separate corridors are presented below.
(i)Corridor One (ABC)..Healy to Fairbanks via Parks Highway
- Technical and Economical
This corridor crosses the fewest water courses in the northern
study area.Although it is approximately four miles longer than
Corridor Two,it is technically favored because of the existence of
potential access roads for almost the entire length .
..Environmental
Because it parallels an existing transportation corridor for much
of its length,this corridor would permit line routing that would
avoid most visually sensitive areas.The three proposed road
crossings for this corridor (as opposed to the 19 road crossings of
the Healy-Fairbanks transmission line)could occur at points where
roadside development exists,'in areas of visual absorbtion capabil-
ity or in areas recommended to be opened to long-distance views
(D.N.R.1981).
Four rivers and 40 creeks are crossed by this corridor,with poten-
ti al for impacts.It crosses the fewest number of water courses of
any route under consideration in the northern study area.In addi-
tion,the inactive nest site of a pair of peregrine falcons occurs
within this proposed corridor.
As with visual impacts, land use,wildlife,and fishery resource
impacts can be lessened through careful route location and utiliza-
tion of existing access.Impacts on forest clearing can also be
lessened through the sharing of existing transmission line corri-
dors.
Ratings:
Technical
A
Economical
A
Envi ronmenta 1
A
Summary
A
(ii)Corridor Two (ASDCl - Healy to Fairbanks via Wood River Crossing
- Technical and Economical
This is the shortest corridor (86 miles)studied in this area.Al-
though comparable to Corridor One,it crosses additional wetlands,
increasing the technical difficulty of transmission line construc-
tion.Development of roads will also pose a major constraint.
6-20
-Environmental
Corridor Two is the shortest under consideration in the northern
study area.As it is a variation of Corridor One,many of the same
constraints apply here.The lack of existing rights-of-way is a
constraint throughout much of this route.Prior to crossing the
Tanana River,this corridor deviates farther to the northeast than
does Corridor One,thereby crossing additional wet soils;thus,
access-ro~d development poses a major constraint.Forest clearing
would be necessary in the broad floodplain of the Tanana River.
While it is the shortest route,this corridor still crosses 5
rivers and 44 creeks as well as prime habitat and important habitat
for peregrines and golden eagles.These constraints,and visual
and public land conflicts,result in a Crating.
Ratings:
Technical
C
Economi cal
A
Env i ronmental
C
Summary
C
(iii)Corridor Three (AEDC)-Healy to Fairbanks via Healy Creek and
Japan Hills
- Technical and Economical
This U5-mile corridor is the longest in the northern study area.
Its considerable length would contribute substantially to increased
costs of construction.The crossing of areas over 4,500 feet in
el evation results in the corridor I s bei ng technically unacceptable
for reasons discussed in Section 6.4.
-Environmental
This corridor crosses a high mountain pass and, in some locations,
encounters bedrock overlaid with shallow,wet soils.Access is a
problem because, except for the road into the Usibelli coal fields,
no rights-of-way exist along the route.Crossing the broad flood-
plain of the Tanana and Wood Rivers would require extensive forest
clearing and result in aesthetic impacts. In addition,this corri-
dor involves 3 river and 72 creek crossings.Prime habitat for
caribou,peregrine falcons,sheep,and waterfowl as well as import-
ant habitat for golden eagles and brown bear would be affected.
The increased length and increased visual impacts result in this
corridor's being environmentally unacceptable.
Ratings:
Technical
F
Economical
C
6-21
Environmental
F
Summary
F
(iv)Corridor Four (AEF)-Healy to Fairbanks via Wood River and Fort
Wainwright
- Technical and Economical
The technical and economical constraints associated with this cor-
ridor are the same as those in Corridor Three.The long distance
of this corridor (105 miles)and the crossing of areas over 4,500
feet in elevation reduce its attractiveness from a technical and
economical viewpoint.
-Environmental
Corridor Four is very similar to Corridor Three in that it paral-
lels Healy Creek drainage north.Therefore,impacts to this moun-
tainous region would be identical to those described for this cor-
ridor segment in Corridor Three.In the vicinity of Japan Hills,
however,the corridor parallels an existing sled road for part of
its length as it traverses the wet,heavily forested floodplain of
the Tanana and Wood Rivers.Clearing requirements might,there-
fore,be reduced, as would be the need for access roads in this
area.Important habitat or prime habitat for peregrine falcons,
bald eagles,sheep,caribou,and brown bear exists within this cor-
ridor.This corridor is unacceptable from a land use standpoint
because it is within the Blair Lake Air Force active bombing range,
precluding further consideration of this corridor.
Ratings;
Technical
F
Economical
C
6-22
Environmental
F
Summary
F
TABLE 6.1:ECONOMICAL AND TECHNICAL SCREENING
SOUTHERN STUDY AREA (WILLOW TO ANCHORAGE/POINT MACKENZIE)
(1)(2)(3)
ABC'~AEFC-
-Length (miles)73 38 39
-Max.Elev.(ft )1400 400 400
-Clearing (miles)=
Medium &Light 61 20 15
None 12 18 24
- Access (miles)=
New Roads 2U 0 12
4-Wheel 53 38 27
-Tower Construction*329 180 176
-Rating:
Economical C A C
Technical C A A
A =recommended corridor
C =acceptable but not preferred
F =unacceptable
*Approximate number of lowers required for this corridor,
assuming single-circuit line.
TABLE 6.2:ECONOl--IlCAL AND TECIINICAL SCREENING
CENTRAL STUDY AREA (DAM SITES TO INTfRTlE)
(1)(2)0)(4)(~)(6)(7)(8)(9)(10)(11 )(12)(1."S )(14)(1)
ABCD ABE CD AJCr ABCJHI ABECJHI CBAHI CEBAHI CBAG flBA§.CJAG CJAfH JACJHI ABCr AJCD ABECr-----------
-Length 40 4~41 77.82 68 7~90 9~91 69 70 41 41 4~
- Hax,Elevation;ft.2~OO 3600 3~00 4JOO 4JUO 4JOO J500 noo 3600 3500 3800 3900 2500 JSOO J600
-Clearing
Medium &Light 38 30 26 18 30 20 27 45 J7 40 55 17 39 26 J5
f\lone Z 15 15 59 50 48 46 45 60 51 14 53 2 15 10
-Access
New Roads 28 33 41 66 57 47 56 60 70 63 50 SO 41 29 45
4-Wheel 12 12 a 0 ·0 0 0 28 27 28 a 1~0 12 0
- Tower Construction*180 20.3 185 347 369 306 329 405 428 410 311 315 180 185 203
-Rating:
Economical A C C r r C f f F F C f C A C
Technical A C C F r r C C C C C C A A C
A =recommended
C =acceptable but not preferred
f =unacceptable
*Approximate number of towers required for this corridor;
assuming single-circuit line.
TABLE 6.3:ECONOMICAL AND TECHNICAL SCREENING
NORTHERN STUDY AREA (HEALY TO FAIRBANKS)
-Length
-Max.Elevation
-Clearing
Medium &Light
None
- Access
New Roads
4-Wheel
- Tower Construction*
-Rating:
Economical
Technical
(1)
ABC
90
1600
48
42
o
90
405
A
A
(2)
ABDC
86
1600
50
36
o
43
387
A
C
115
4500
40
75
'>4
42
518
C
F
1U5
45UO
')0
55
42
16
47.~
C
F
A =recommended
C =acceptable but not preferred
F =unacceptable
*Approximate number of towers required for this corridor,
assuming single-circuit line.
,I'
Table 6.4
Environmental Constraints - Southern Study Area (Uillow to Anchorage/Point MacKenz1e)
Corridor
1
(ABC')
2
(ADFC)
3
(AEFC)
Length
73
38
39
lopography/Soils
SOlne soils with
severe limitations
to off road travel;
some good agri-
cultural soHs
Host of route
potentially wet,
with severe
limitations to
off road travel;
some good agri-
cultural soHs
Same as Corridor 2
land Use
'ftoexfStliiglmlrin
AS;residential uses
near Palmer;proposed
capital site;much U.S.
I(Httary Wdl.,Private,
and Village Selection
land
Trail is only existing
ROW;residential and
recreational areas;
SusHna flats Game
Refuge;agricultural
land sale
No known existing ROW;
residential and recre-
ational use areas,
including Nancy lakes;
lakes used by float
planes;agricultural
land sale
Aesthetics
raUaroll,raH;
trail paralleling
Deception Ck.:
Gooding L.bfrd-
watching area;
5 crossings of
Glenn Jlwy,1
crlissing of
Parks Hwy
Susitna flats
Game Refuge;
Idttarod Tran;
1 crossing of
Parks Hwy
l.ake area south
of Willow;
Iditarod Trail;
1 crossing of
Parks Hwy
Cultural Resources a
Archeolog1c sites-
data void
Archeologic sites-
data void
Archeologic s1tes-
data void
Vegetation
IlCt lands a1(lng
Deception Ck.
and at Matanuska
River crossing;
extensive clearing
in upland,forested
areas needed
Extensive wetlands;
clearing needed in
forested areas
Extensive wetlands;
clearing needed in
forested areas
Fi shResources
5 river and 28
creek crossings;
valuable spawning
sites,especially
salmon:
Knik area
Matanuska area
data void
1 river and 8
creek crossings;
valuable spawning
sites,especially
salmon:
L Susttna R.
data void
1 river and 8
creek crossings;
valuable spawning
sites,especially
salmon:
l.Susitna R.
data void
UfldHfe Resources
Passes through or
near waterfowl and
shorebird nesting
and feeding areas,
and areas used by
brown bear
Passes through or
near waterfowl and
shorebird nesting,
feeding, and migra-
tion areas,and areas
used by furbearers
and brown bear
Same as Corridor 2
Environmental
Rating b-----C
A
F
a. Coastal area probably has many sites;available literature not
yet reviewed.
b.A = recoumendsd
C =acceptable but not reconmended
F =unacceptable
,I"
table 6.5
fl
Environmental Constraints - Central Study Area (Dam Sites to lntertie)
CorridQr
1
(ABeD)
Length
(Miles)
40
TQPographY/SQils
Crosses'several
deep ravines;
about 1000'
change in
elevation;
some wet SQ n s
land Use
little existing
ROW except Corps
rd.;mQstly
Village Selection
and Private lands
Aesthetics
Fog lakes;
Stephan lake;
prQpQsed access
road
Cultural Resources
Archeologic sites
near Watana dams1te,
Stephan lake and Fog
lakes;data void from
Gold Creek to Devil
Canyon;historic sites
near the conmunities of
Gold Creek and Canyon
Vegetation
Wetlands in
eastern third of
corridor;
extensive forest-
clearing needed
Fish ResQurces
1 river and 17 creek
crossings;valuable
spawning areas,
expecially grayling:
data void
Wildlife Resources
Unidentified raptor nest
located on trib.to
Susitna; passes through.
habUatfor:raptors,
furbearers.wolves.
wo Iver tne,brown bear.
caribou
Environmental
Ratinga
A
2
(ABE CD)
45 Crosses several
deep ravines;
abQut 2000'
change in elev.;
some steep
slQpes;some
wet SQl1s'
little existing Fog lakes;
ROW except Crops Stephan lake;
rd.and at 0;rec.proposed access
and resid.areas; road; hi9h
float plane areas; country (Prairie
mostly Village &Chulitna Ck.
Selection and drainages)and
Private Lands viewshed of
Al ash Range
Same as Corridor 1 Wetlands in
eastern half of
corridor;
extensive forest-
clearing needed
1 river and 17 creek
crossings;valuable
spawning areas.
especially graYling:
data void
Passes through habitat for:
raptors.waterfowl. migrat-
ing swans.furbearers.
caribou.wolves.wolverine.
brown bear
F
3
(AJCF)
4
(ABCJHI)
41
77
Crosses several
deep ravines;
about 2000'
change in
elevation;
some steep
slopes;some
wet sons
Crosses several
deep ravines;
>2000'change
in elevation;
rout ing above
4000';steep
slopes;some
wet soils;
shallow bed-
rock in mts.
No existing ROW
except at F;rec.
areas;float
plane areas;
mostly Village
Selection and
Private land;
resid.&rec.
development in
area of Otter L.
and old sled rd.
No existing ROW;
rec. areas and
isolated cabins;
lakes used by
float planes;
much Vi l1age
Selection Land
Viewshed of
Alaska Range &
JUgh Lake;pro-
posed access rd.
Fog lakes;
Stephan lake;
proposed access
rd;viewshed of
Alaska Range
Archeologic sites by
Watana dam site,&near
Portage Ck./Susitna R.
confluence; possible
sites along Susitna R.;
Historic sites near
communities of Gold
Ck.and Canyon
Archeologlc sites near
Watana dam site,
Stephan t.and fog
lakes;possible sites
along pass between
drainages; data void
between H and I
·forest-clearing
needed In western
half
Small wetland
areas in JA
area; extensive
forest-clearing
needed;data void
14 creek crossing;
valuable spawning
areas,especially
grayling and salmon:
Iridian River
Portage Creek
data void
1 river and 42 creek
crossings;valuable
spawning areas,
especially grayling
Golden eagle nest aloog
Devil Ck.near High l.;
active raven nest on Devil
Ck.; passes through habitat
for:raptors,furbearers.
wolves.brown bear
Golden eagle nest along
Devil Ck.near High l.;
caribou movement area;
passes through habitat
for:raptors,waterfowl.
furbearers,wolves.
wolverine.brown bear
C
C
a. A =recommended
C =acceptable but not reconnended
f =unacceptable
Table 6.5 (Cont'd)
Environmental Cons tra lnts - Central Study Area (Dam SHes to lntertie)
length
Corridor (Miles)
5 82
(ABECJHI)
,I'
Topography/Soils
Crosses several
deep ravines;
changes In
elevation >2000';
routing above
4000';steep
slopes;some wet
soils;shallow
bedrock In mts
land Use
Same as Corridor
4
Aesthetics
fog lakes;
Stephan lake;
High Lake;
proposed access
rd;viewshed at
AhskaRange
Cultural Resources
Same as Corridor 4
Veglltation
Wet lands In JA
and Stephan lake
areas; extensive
forest-clearing
needed
Fish Resources
42 creek crossings;
valuable spawning
areas,especially
grayling and salmon:
data void
Environmental
Wildlife Resources Rating
Same as Corridor 4 f
with Important waterfowl
and migrating swan habitat
at Stephan lake
6
(CRAIn)
68 Crosses several
deep ravines;
changes In
elevation of
about 1600';
routing above
4000';steep
slopes;some wet
soils;shallow
bedrock in mts.
No known existing fog lakes and
ROW;rec. areas Stephan lake;
and Isolated proposed access
cabins;float rd.;Tsusena
plane area; Butte;vlewshed
Susitna 'area and of Alaska Range
near I are Village
Seleet ion land
Archeologic sItes near
Watana dam site,fog
lakes and Stephan l.;
data void between H
and I
Extensive wet-
lands frcmB to
near Tsusena
Butte; extensive
forest-clearing
needed
32 creek crossings;
valuable spawning
areas,especially
grayling:
data void
Bald eagle nest s.e.of
Tsusena Butte; area of
caribou movement;passes
through habitat for:
raptors,waterfowl,fur-
bearers,wolves, wolverine,
brown bear
C
7
(tE6AHl)
8
(CBAG)
73
90
Crosses several
deep ravines;
change in
elevation of about
1600';routing
above 3000';
steep slopes;
some wet soils;
shallow bedrock
in mts.
Crosses sl'veral
deep ravines;
change In
elevat ion of about
1600';routing
above 3000';
steep slopes;
some wet soils;
sha11 ow bedrock
in mts.
Same as Corridor Fog Lakes and Same as Corridor 6 Extensive wet-45 creek crossing;Same as Corridor 6,with F
6 Stephan Lake;lands in stephan valuable spawning important waterfowl andproposedacessL,fog lakes,areas,especi ally migrating swan habitat
rd.;high Tsusena Butte grayling:at Stephanlake
country (Prairle-areas;extensive data void
Chunilna Cks);forest-clearing
Tsusena Butte;needed
viewshed of
Alaska Range
tlo existing ROW;fog Lakes; Archeologic sites near Wetlands between 1 river and 43 creek Important bald eagle
C
rec. areas and Stephan lake;Watana dam site,Fog 8 and 'mountains;crossings;valuable habitat by Denali Hwy.
isolated cabins;access rd;lakes,Stephan Lake extensive forest-spawning areas, and Deadman L.;unchecked
float plane seenIe area of and along Oeadman Ck.clearing needed expecially grayling:bald eagle nest near
areas;air strip Deadman Ck.;data void Tsusena Butte; passes
and airport;viewshed of through habitat for:
much Village Alaska Range raptors,furbearers,
Selection and wolves, wolverine,
federa 1 Land brown bear
,t'..
Table 6.5 (Cont'd)
Environmental Constraints - Central Study Area (Dam Sites to Intertie)
Length Environmental
Corridor (Miles}Topography/Soils Land Use Aesthetics Cultural Resources Vegetation Fish Resources Wildlife Resources Rating
9 95 Crosses several Same as Corridor Fog Lakes;Same as Corridor 8 Wetlands in 1 river and 48 creek Same as Corridor 8,F
(CEIlAG)deep ravines;8 Stephan Lake;Stephan LIFog crossings;valuable with important waterfowl
changes in proposed access Lakes areas;spawning areas,and migrating swan habitat
elevation of about rd;Mgh country extensive forest-expecially grayling: at Stephan Lake
1600'; rout in9 (Prairie and clearing needed data void
above 3000'; steep Chunl1na tks.);
slopes;some wet Deadman Ck.;
sons;Shallow viewshed of
bedrock in mts.Alaska Range
10 91 Same as Corridor No existing ROW;High Lakes area;Archeologfc sites SmaH wetlands 1 river and 47 creek Golden eagle nest along Devil C
(CJAG)8 rec. areas and proposed access near Watana dam stte. in JA area;crossings;valuable Ck.near High Lake;unchecked
isolated cabins;rd.;DeadmanCk.and along Deadman Ck.extensive forest-spawn iny areas, bald eagle nest near Tsusena
float plane drainage;view-clearing needed expecially grayling: Butte; area of caribou move-
areas;air strip shed at AI ash data void ment;passes through habitat
and airport;Range for:raptors,waterfowl,
mostly Village
furbearers,brown bear
Selection and
Federal Land
11 69 Crosses sever:tl No existing ROW;High Lakes area;Archeologlc sites Small wetland 36 creek crossings;Golden eagle nest along C
(CJAHI)deep IriIvinesi rec. areas and proposed access nEar Watana dam site areas in JA valuable spawning Devil Ck.near High Lake;
changes in isolated cabins;rd,;viewshed area;some areas,especially bald eagle nest s.e.of
elevation of float plane -of Alaska Range forest-clearing grayling and salmon:Tsusena Butte; passes
1000'; routing areas; mostly
needed data void through habitat for:
above 3000';Village Selection
raptors,furbearers,
steep slopes;some and Private Land brown bear
wet soils;
shaHow bedrock
in mts.
12 70 Same as Corridor No existing ROW;High lakes area;
Archeologlc site Small wetland 40 creek crossings;
Golden eagle nest along
F
(JA-CJIIJ )11 rec. areas and proposed access nEar Watana dam site;areas in JA valuable spawning Devil Ck.near High Lake;
isolated cabins;rd.;Tsusena possible sites along area;fairly areas,especially passes through habitat
float plane Butte;vtewshed pcss between drainages extensive grayling and salmon:for:raptors.furbearers,
area;mostly of Alaska Range forest clearing data void
wolves,bro~fl bear
Village Selection
needed
and Private Land
,.
Table 6.5 (Cont'd)
Environmental Constraints - Central Study Area (Dam Sites to Intertie)
length Environmental
Corridor (Miles)
Topography/Soils land Use Aesthetics Cultural Resources Vegetation fish Resources Wildlife Resources Rating
13 41 Crosses several No known existing fog lakes,Archeologic sites near Wetlands in 15creek crossings;UnidentiHed raptor nest A
(ABCF)deep ravines;ROW except at f; Stephan l.;Watana dam site,eastern third valuable spawning on tributary to Susitna;
about 1000'
rec,areas;float proposed access Portage Ck./Susitna R. of corri dor;areas,especially passes through habitat for:
change in plane areas;rd.·confluence; Stephan l.,extensive grayling and salmon:raptors,furbearers,wolves,
elevation;some resid.and rec.and Fog lakes;historic forest-clearing Indian River wolverine,brown bear,
wet sons use near Otter sites;near communities needed Portage Creek caribou
L and old sled of Canyon and Gold Ck.data void
rd.;isolated
cabins; mostly
Village Selection
land;some Private
land
14 41 Crosses deep
little existing Vlewshed of Archeologic sites by Forest-clearing 1 river and 16 creek Golden eagle nest in Devil A(AJCO)ravine at Devil ROil except old Alaska Range Watana dam site,needed in western crossings;valuable Ck./High lake area;active
Ck.;about 2000'Corps rd.and and High lake;possible sites along half spawn ing areas,raven nest on Devil Ck.;
change in at 0; rec. areas;proposed access SusUna R.;historic especially grayling:passes through habitat for:
elevation;routing Isolated cabins; road sites near communities data void raptors,furbearers,wolves,
above 3000';some much Village of Canyon and Gold Ck.brown bear, caribou
steep slopes;Selection land;
some wet soils some Private
land
15 45 Crosses several No known existing Fog lakes;Same as Corridor·13 Wetlands in 15 creek crossings;Important waterfowl and F
(A8ECF)deep ravines;ROW except at F;Stephan lake;eastern half valuable spawning migrating swan habitat
about 2000'change rec. areas;float proposed access of corridor;areas,especially at Stephan l.; passes
in elevation;plane areas;road;hit extensive forest-grayling and salmon:through habitat for:
some wet soHs resid.andrec.country Prairie clearing needed Indian River raptors,waterfowl,
use near Otter and Chunflna Cks.Portage Creek furbearers,wolve s,
L and old sled drainages);data void wolverine,brown bear,
rd.;IsoIated viewshed of caribou
cabins; mostly Alaska Range
Village Selection
land with some
Private land
.--_.,.-,---,......'-"......"""
Table 6.6
Environmental Constraints -Northern Study Area (Healy to Fairbanks)
length
Wildlife Resources a Envir-onmen;;,l
Corridor (Miles)Topography/Soils land Use Aesthetics Cultural Resources Vegetation Fish Resources Ilating
-1----go-Some wet solls Air strip.3 crossings of ArcheoJogic sites Extensive wetlands;4 river and 40 creek Passes through or A
(ABC)with severe residential areas Parks Hwy;probable since forest clearing needed uossings;valuable near prime habitat
limitations to and-isolated cabins.Nenana R.-there is a known mainly north of the spawning sites:for:peregrines,
off--road traffic some U.S.Military scenic area site nearby; data Tanana River Tanana River waterfowl,furbearers,
Withdraw]and Native void data void moose;
land passes through or
near important-
habitat for: pere-
grines,golden eagles
2 ·86 Severe limitations No existing ROW n.3 crossings of Dry Creek Probably extensive 5 river and 44 creek Passes through or C
(ABDe)to off-road traffic of Browne;Parks Ilwy;archeologic site wetlands between crossings;valuable near prime habitat
in wet soils of scattered residential bfghvisibil1ty near Ilealy;Wood and Tanana spawning sites:for:peregrines,
the flats and-isolated in open flats possible sites Rivers; extensive
Wood River waterfowl,furbearers;
cabins;airstrip;along river forest clearing data void passes through or
fort Wainwright crossings;data needed n. of
near important habitat
MHitary Reser-void Tanana River for: golden eagles,
vaUon other raptors
a. Source:VanBallenberghe personal cOlmlunicatfon.Prime habitat c
minimum amount of land necessary to provide a sustained yield
for a spedes;based upon knowledge of that species'needs from
experience of ADF&G personnel. Important habitat =land which
~Df&Gconsfders not as critfcal to a species as fs Prfme habitat,but is valuable. -
b. A =recomnended
C =acceptable but not preferred
f =unacceptable
3
(A£DC)
4
(AEF)
115
105
Change in elevation
of about 2500I;
steep slopes.
shallow bedrock in
mts.;severe limit-
atfons to off-road
traffic in the
flats
Same as Corridor 3
No existing 'ROW
beyond Healy/Cody
Ck.confluence;
isolated cabins;
airstrips;fOrt
~ainwright Military
Reservation
Airstrips.isolated
cabins;fort Wain-
wright Military
Reservation
1 crossing of
Parks Hwy;
high visibflfty
in open flats
High visibility
in open flats
try Creek
archeologic site
near Healy;
rossible sites
near Japan Hills
and in themts ••
data void
Archeologic sites
near Dry Creek and
Fort Wainwright;
possible sites near
Tanana River; data
void
IProbablyextens1 ve
wetlands between
Wood and Tanana
Rivers; extensive
forest clearing
needed n. of
Tanana Rfver;
data lad<lng for
southern part
Probably extensive
wetlands between
Wood and-Tanana
RIvers
3 rfver and 72 creek
crossings;valuable
spawning sHes:
Wood River
data void
3 rfver and 60 creek
crossings.valuable
spawning sites:
Wood River
data void
Passes through or-
near prime habitat
for:peregrines,
waterfowl,furbearers,
caribou,sheep;
passes through or near
important habitat for:
golden eagles,brown
bear
Passes through or
near prime habitat
for:peregrines.bald
eagles,waterfowl.
furbearers,caribou.
sheep;
passes through or
near important habitat
for: golden eagles,
brown bear
c
F
7 -CONCLUSIONS AND RECOMMENDATIONS
7.1 "Conclusions
(a) Previous Reports
The Interim Feasibility Report of the COE,together with the feasibility
report prepared by IECO/RWRA,have been thoroughly reviewed ..The COE dis-
cussed a number of alternative transmission line corridors in considerable
depth;however,no specific route was indicated.The IECO/RWRA report in-
dicated a specific route,but gave no detailed study on how a determination
had been reached.However,the report discussed in detail the economic
feasibility of alternative transmission voltage and system configurations.
The two reports provided excellent data and background for Acres'initial
studies.
(i)CO~1975Report
The COE report concluded that Segments 1, 3,7,8,9, 10, 13,and 16
(shown in Figure C.l)were the preferred corridors.Of these,only
Segments 1, 7,8,9,and 16 apply to Acres' area of study.The COE
preference resulted primarily from the fatt that the chosen corridors
fall within existing highway and rail corridors and likely present
the least construction impacts of all the alternatives they consid-
ered.While problems of scenic impact exist along these corridors,
these problems have the potential for mitigation because of existing
terrain features and vegetation and through careful tower placement
and access procedures.It should be noted that the preferred corri-
dors selected by the COE are general in nature with no definitiv~
boundaries.
(ii)IECO/RWRA,1979Report
The IECO/RWRA report presents a determination of the economic feasi-
b il ity for the Anchorage"Fairbanks transmission 1i nee In their re-
port,IECO/RWRA stated that alternative corridors were reviewed along
or near the railbelt region between Anchorage and Fairbanks.How-
ever,the report gave no details on the methods of corridor evalua-
tion used. In their evaluation,IECO/RWRA relied heavily on their
experience and knowledge of the railbelt area and their field visits
to specific sites.The preferred corridor selected by IECO/RWRA is
almost the same as the preferred corridor selected by the COE,except
here it is more defined.
(b)Acres Study
The APA decision to proceed with the Intertie has resulted in a split of
this study into three separate geographical entities;namely,the southern,
central,and northern areas.For each area,one corridor has been selected
as feasible and therefore recommended.These are:
7-1
- Southern Study Area:
- Central Study Area:
- Northern Study Area:
Corridor ADFC
Corridor ABCD
Corr i do;'ABC
Specifics of these corridors and reasons for rejection of others are
discussed below.
(i)Southern Study Area
In the southern study area,Corridor Segment AEF and, hence,Corridor
Three (AEFC)were determined unacceptable.This results primarily
from the routing of the segment through the relatively well-developed
and heavily utilized Nancy Lake state recreation area.Adjustments
to this route to make it more acceptable were attempted but no alter-
ations proved successful.Consequently,it was recommended this cor-
ridor be dropped from further consideration.
Corridor One (ABC')was identified as acceptable but not preferred,
thus given the C rating.Its great length,its traversing of resi-
dential and other developed lands,and the numerous creek crossings
and extensive forest clearing involved relegate this corridor to this
environmental rating.Economically and technically,this corridor
has more difficulties than the other two considered.This is a
longer line and crosses areas which may require easements in the area
north of Anchorage.
Corridor Two (ADFC)was identified as the candidate which would sat-
isfy most of the screening criteria.This corridor is shown in Fig-
ures 7.1 and 7.2,and stretches from an area north of Willow Creek to
Point MacKenzie in the south.The corridor is located east of the
lower Susitna River and crosses the Little Susitna kiver.The corri-
dor also crosses an Existing 138 kV line owned and operated by
Chugach Electric Association (CEA),which starts at Point MacKenzie
and extends to Teeland Substation.
Up to this point in the corridor selection study,Point MacKenzie has
been considered a terminal point for Susitna power.It was assumed
that an underwater cable crossing would be provided at this location.
Upon further study and data-gathering it has become known that the
existing crossing at Point MacKenzie has experienced power interrup-
tions caused by ship's anchors snagging the submarine cables.CEA,
which owns the submarine cables,required additional transmission
capacity to Anchorage.After thoroughly studying the matte}',it has I.
opted for a combined submarine/overhead cable transmission across I .
Knik Arm and onto Anchorage.This was the most desirable option to
CEA,both from the environmental and technical point of view.
The CEA crossing will be located approximately eight miles northeast
of Point MacKenzie on the west shore of the Knik Arm and across from
Elmendorf Air Force Base in the vicinity of Six Mile Creek. This
cross i ng is located northeast of the Ancnor eqe Harbor,away from the
heavy ship traffic,thereby reducing risk of anchor damage to the
cab 1e.
7-2
It is intended to terminate Corridor ADFC at this new crossing point
and extend the transmission corridor to Elemendorf Air Force Base and
beyond to Anchorage.
Although the crossing is approximately eight miles northeast of Point
MacKenzie,it does not influence the results of this corridor selec-
tion and screening process.The best corridor has been selected and
screened.During routing studies (see Section 7),minor deviations
outside the corridor will have to occur in order to terminate at the
revised crossing point.However,preliminary investigations indicate
it will be possible to select a technically,economically,and en-
vironmentally acceptab1e route,part icular ly si nee an exis t i ng trans-
mission line can likely be paralleled from the selected corridor to
the revised crossing point.Furthermore,CEA has received the neces-
sary permits and is constructing an underwater crossing at Knick Arm,
tnd lcat f nq acceptable levels of environmental impact.
(b) Central Study Area
In the central study area, several corridor segments and,hence,their as-
sociated corridors were determined to be unacceptable.The first of these,
Corridor Segment BEC,appears as part of Corridors Two (A~ECD),Five
(ABECJHI),Seven (CEJAHI),Nine (CEBAG),and Fifteen (ABECF).The reason
for rejecting this segment is primarily that the developed recreation area
around Stephan Lake would be needlessly harmed--needless because viable op-
tions exist to avoid intruding into this area.Again,modifying this route
to something more acceptable failed.Consequently,it is recommended that
these five corridors be dropped from further consideration.
Corridor Segment AS was also determined not to warrant further considera-
tion because of its approximate 6S-mile length,two-thirds of which would
possibly require a pioneer access road. Also,extensive areas of clearing
would be required,opening the corridor to view in some scenic locations.
Finally,the impacts on fish and wildlife habitats are potentially severe.
These preliminary findings,coupled with the fact that more viable options
to Segment AG exist,suggest that consideration of this corridor segment
and.therefore,Corridors Eight (CBAG)and Ten (CJAG)should be termin-
ated.
Corridors Eleven (CJAHI)and Twelve (JA-CJHI)were identified as accept-
able. This rating arose from the fact that,as shown in Environmental Con-
straint Table 6.5,numerous constraints affect this routing.Information
from recently completed field investigations suggest that these constraints
cannot be overcome and the routes should be rejected.Furthermore, the
technical and economical ratings preclude these corridors from further con-
sideration.
Corridor Segment HJ has been moved so that it no longer parallels the Devil
Creek drainage;the new location HC is selected to avoid both High Lake and
the Devil Creek drainage.It then follows the Portage Creek drainage to
7-3
the point of intersection with Corridor Segment JH,near the creek's head-
waters.Subsequent investigations have confirmed that this corridor seg-
ment is not viable and,consequently,Corridors Four and Five are elimin-
ated from further consideration.
Corridors Six intrudes on valuable wildlife habitat and would cross numer-
ous creeks,none of which are currently crossed by existing access roads.
In addition,a high mountain pass and its associated shallow soils,steep
slopes,and surficial bedrock constrain this routing.Finally,its cross-
ing of areas over 4,000 feet in elevation makes it technically unaccept-
able,so this corridor is dropped from further consideration.
Corridors Three (AJCF)and Fourteen (AJCD)have been identified as accept-
able but not recommended because of the CJ Corridor Segment.This corridor
segment intrudes upon an existing recreation area at High Lake and contra-
venes existing views of the Alaska Range;it also crosses valuable habitat
for sensitive big game species.
Corridor One (ABCD),as shown in Figure 5.2,was one of the three recom-
mended corridors.Constraints to this routing do exist,however,and will
need to be further evaluated before modifications to this corridor are sug-
gested.This corridor is one of the shortest in length (38 miles) of all
corridors considered in this area.It is recommended,therefore,because
of its technical and economical rating.
Corridor Thirteen (ABCF)is also an acceptable but not preferred corridor.
With the presence of the developed recreation area at Otter Lake,Corridor
Thirteen could require special attention in Segment CF.The technical rat-
ing for this corridor is attractive because of the short length of trans-
mission line and the fact that the lines could be constructed within a
reasonable distance to the access roads.Because of crossings of deep ra-
vines and forest clearing,this corridor is not recommended economically.
Figures 7.3 and 7.4 show the location of the recommended corridor in the
area from Watana to an area in the vicinity of Gold Creek,and it essen-
tially straddles the Upper Susitna River.The area of the corridor between
Watana and Devil Canyon may be extended to the north and is dependent on
the route the access road may take.Every effort wi 11 be made to coordi-
nate the transmission lines with the access road.
(c)Northern Study Area
Corridors Three (AEDC)and Four (AEF)were determined unacceptable because
of many constraints,and thus,rated F.They include:the lack of an
existing access road;problems in dealing with tower erection in shallow
bedrock zones; the need for extensive wetland crossings and forest clear-
ing; the 75 river or creek crossings involved;and the fact that prime hab~
itat for waterfowl,peregrine falcons,caribou,bighorn sheep, golden
eagle,and brown bear would be crossed.In addition,Corridor Four crosses
areas of significant land use constraints and elevations of over 4
,000
feet.
7-4
Corridor Two (ABOC)was identified as acceptable but not preferred,and
thus,rated C.Certain constraints identified for this corridor suggest
that an alternative is preferable.Compared with Corridor One,Corridor
Two crosses additional wetlands and requires the development of more access
roads and the clearing of additional forest lands.
Corridor One (ABC),shown in Figures 7.5 to 7.8,was the only recommended
corridor in the northern study area.While many constraints were identi-
fied under the various categories,it appears possible to select a route
within this corridor to minimize constraint influences.This corridor is
attractive economically, because it is ~lose to access roads and the Parks
Highway.The visual impact can De lessened by strategic placement of the
line.This line also best meets technical and economical requirements.
7.2 -Recommendations
As stated above,three general corridors were identified as the most recom-
mended.These corridors will be subjected to additional studies so that a
transmission line route of one-half-mile width can be identified.The fol-
lowing studies will be continued under Subtask 8.03.
(a)Techn ica 1
(i)Performance of photo interpretation and terrain analysis of the
transmission line corridors and the identification of adverse geolog-
ical features and geotechnical conditions that significantly affect
the design or construction.
(ii)Identification of the terrain and soil conditions such as wet marsh-
land and soft overburden to dry,sloping-rock hillsides.
(iii)The completion of surface and subsurface investigations to the extent
necessary to provide adequate data to confirm project feasibility and
for the submission of the FERC license application.
(iv)Identification of areas along the routes that appear to be underlain
by soils susceptable to seismically induced ground failure such as
liquifaction or land sliding.
(v)Collection of preliminary ground motion data for the transmission
lines and switching stations.
(b)Environmental
Subtask 7.09 will continue to analyze data pertinent to the avoidance rout-
ing scheme specified in the POS,and refine the corridor route location,
based upon environmental considerations.Following this,an environmental
impact assessment of the preferred route will be conducted.At the same
time,techniques to mitigate identified impacts will be developed.Mitiga-
tion techniques which can diminish the construction impact are described
below.
7-5
(i)Mitigation of Construct ton Impacts
Given the existence of routing~constraints in all corridors,the as-
signment of a C and an A environmental rating considers the potential
environmental impact in developing corridors so designated.In fact,
consideration of construction techniques as mitigative measures has
been a part of the evaluation process and, in some instances,such
construction methods have permitted a corridor to carry a Cor an A
rating.A consideration in the development of any corridor should be
the prescription of impact-mitigating construction techniques.These
techniques could include the following on a prescription basis.
-Use of winter construction in wetland,rather than developing road-
ways that would have undesirable direct and indirect impacts;
-Use of helicopter~based construction in particularly remote areas
or in areas judged too wet for summer access;
-Use of existing rights-of-way,wherever pbssible;
-Use of techniques that allow minimum vegetation clearing,such as
"featheringll of rights-of-way edges and topping rather than clear-
cutting tall-growing trees;and
Use of tower designs that will minimize conspicuousness in particu-
larly sensitive scenlc ar eas.
-Reseeding of areas disturbed by construction equipment.
By considering these and other impact mitigating measures, con-
straints to routing project transmission lines,regardless of the
route followed by the preferred corridor,can be diminished.
7.3 - Other
It is also recommended that appropriate state and federal agencies and the
general public be permitted to review and comment on this repor t and the
recommended corridors.
7~6
~~
\Q;/.."O~~,I~~~
Cl
D
~~
MATCHLINE A
o
i
SCALE IN MILES
25 50
SCALE IN MILES
LOCATION MAP
2
RECOMMENDED TRANSMISSION CORRI DOR
SOUTHERN STUDY AREA FIGURE 7.1
MATCHLINE A
(,
o
i
SCALE IN MILES
25 50
SCALE IN MILES
LOCATION MAP
2
RECOMMENDED TRANSMISSION CORRIDOR
SOUTHERN STUDY AREA FIGURE 7.2
LOCATION MAP
25 50
SCALE IN MILES
11
MATCHLINE B
o
i
2
SCALE IN MILES
RECOMMENDED TRANSMISSION CORRIDOR
CENTRAL STUDY AREA FIGURE 7.3
LOCATION MAP
25 50
SCALE IN MILES
MATCHLINE B I
I
I
I
I
~-
o
I
2
!
RECOMMENDED TRANSMISSION CORRIDOR
CENTRAL STUDY AREA
SCALE IN MILES
FIGURE 7.4 m
SCALE IN MILES
RECOMMENDED TRANSMISSION CORRIDOR
NORTHERN STUDY AREA
MATCHLINE C
LOCATION MAP
o 2
I
SCALE IN MILES
FIGURE 7.5
LOCATION MAP
2
FIGURE 7.6
o~i~~~
SCALE IN MILES
<<9
<"
i\
"V'trt.O /6'\\<c"
\\c \.\~'\
~~:f
I MATCHLINE D
/J>
//~",
~
RECOMMENDED TRANSMISSION CORRIDOR
NORTHERN STUDY AREA
I MATCHLINE
25 50
SCALE IN MILES
/
FIGURE 7.7
LOCATION MAP
2
!
SCALE IN MILES
o
i
/
MATCHLINE E ~/
/'
.>
"'0
RECOMMENDED TRANSMISSION CORRIDOR
NORTHERN STUDY AREA
MATCHLINE D
J
J
1/.>:
RECOMMENDED TRANSMISSION CORRIDOR
NORTHERN STUDY AREA
o
I
SCALE IN MilES
2
FIGURE 7.8
25 50
SCALE IN MILES
8 -BIBLIOGRAPHY AND AUTHORITIES CONTACTED
Al aska Agricultural Experiment Station.1980.-Susitna Hydroelectric Project
Environmental Studies,Annual Report (draft),Subtask 7.12, Plant Ecology.
Terrestrial Environmental Specialists,Inc.,Phoenix,New York.
Alaska Department of Fish and bame.1978a.Alaska's fisheries atlas.Volumes
I and II.Alaska Department of Fish and Game,Anchorage,Alaska.
Alaska Uepartment of Fish and Game.1978b.Habitat essential for fish and
wildlife on state lands.Alaska Department of Fish and Game,Anchorage,
A1ask a.
Alaska Department of Fi sh and Game.1978c.Pre1imi nary environmental
assessment of hydroelectric development on the Susitna River. Alaska
Department of Fish and Wildlife,Anchorage,Alaska.
Alaska Department of Fish and Game.1979.State game refuges,critical habitat
areas and g~ne sanctuaries.Alaska Department of Fish and Game,Habitat
Protection Section,Anchorage,Alaska.
Alaska Department of Natural Resources.1980.Susitna basin land
use/recreation atlas;planning background report.Land and Resource
Planning Section,Division of Research and Development,Alaska Department
of Natural Resources in cooperation with the United States Department of
Agriculture.
Alaska Department of Natural Resources.1981.Susitna basin planning back-
ground report,scenic reservoirs along the Parks Highway.Inventory and
Management Recommendation,Land and Resource Planning Section,Division of
Research and Development,Anchorage,Alaska.
Alaska Power Authority.December 1979.Anchorage,Fairbanks Transmission In-
tertie,Economic Feasibility Report.International Engineering Company,
Inc.,and Robert W.Retherford Associates.
Bacon,G.1978a.Archeology near the Watana d~site in the Upper Susitna
River basin.Alaska District Corps of Engineers,Anchorage,Alaska ..
Bacon,G.1978b.Archeology in the Upper Susitna River basin.Alaska District
Corps of Engineers,Anchorage,Alaska.
CIRl/Holmes and Narver.1980.Land status maps,Susitna Hydroelectric Project,
SUbtask 2.04.Acres American,Incorporated,Buffalo,New York.
Cowardin,L.M.,V.Carter,F.C.Golet,and E.T.LaRoe.1979.Classification
of wetlands and deep water habitats of the United States.United States
Department of the Inter ior , Fish and Wildlife Service,Office of Biological
Services,Washington,D.C.
8-1
Fr iese,N.V.1975.Pre-authori zat i on assessment of anadromous fi sh popul a-
tions of the Upper Susitna River watershed in the vicinity of the proposed
Devil Canyon Hydroelectric Project.Alaska Department of Fish and Game,
Division of Commercial Fisheries,Anchorage,Alaska.
Morrow,J.E.1980.The freshwater fishes of Alaska.Alaska No~thwest Pub-
lishing Co.,Anchorage,Alaska.
Murray,P.f.1979.Threatened and endangered plants of Alaska.U.S.Depart-
ment of Agriculture,Forest Service,Washington,D.C.
Riis,J.C.1975.Pre-authorization assessment of the Susitna River hydroelec-
tric projects:Preliminary investigations of water quality and aquatic
species composition.Alaska Department of Fish and Game,Sport Fish
Division,Anchorage,Alaska.
U.S.Department of Agri culture,Soil Conservati on Servi ceo 1979.Exp 1oratory
soil survey of Alaska.U.S.Department of Agriculture,Soil Conservation
Service,Washington,D.C.
U.S.Department of the Army.1975.Hydroelectric power and related purposes:
Southcentral Railbelt Area,Alaska, upper Susitna River bas i n >Interim
Feasibility Report,Appendix 1,Part 2.Alaska District Corps of Engi-
neers,Anchorage,Alaska.
U.S.Department of the Interior.1973.The endangered species act of 1973.
U.S.Department of the Interior,Fish and Wildlife Service,Washington,
D.C.
University of Al aska Museum.1980a.Susitna Hydroelectric Project t:nviron-
mental Studies,Semi-annual Report, Subtask 7.06,Cultural Resource Invest-
igation.Terrestrial Environmental Specialists,Inc.,Phoenix,New York.
University of Alaska Museum.1980b.Susitna Hydroelectric Project Environ-
mental Studies,Procedures Manual,Subtask 7.06,Cultural Resource Investi-
gation.Terrestrial Environmental Specialists,Inc.,Phoenix,New York.
8-2
AUTHORITIES CONTACTED
State Agencies
Alaska Department of Fish and Game
Anchorage,Alaska
Dimitri Bader
Received,during personal vist on January 21,1981,maps showing habitat
essential for fish and wildlife on state lands.
Alaska Department of Fish and Game
Fairbanks,Alaska
Francis Van Ballenberghe
Received information during a personal visit in January 1981,on habitat
data coveri ng an area from Fairbanks/Healy to Ester.
Fed~ral Agencies
U.S.Department of Agriculture,Soil Conservation Service
Anchorage,Alaska
Sterling Powell
Received,during personal visit on October 28,1980,soils information,
lower Susitna basin,and a copy of an Alaska Department of Natural
Resources publication,"Susitna Basin Land Use/Recreation Atlas Planning
Background Report."
U.S.Department of Engergy,Alaska Power Administration
Juneau,Alaska
Robert Cross
Received,during personal visit on November 4,1980,maps and information
on Alaska Power Administration Susitna Project transmission line studies.
Uti 1 Hies
Golden Valley Electric Association,Inc.,(GVEA)
Fairbanks,Alaska
Fairbanks Municipal Utilities System (FMUS)
Fairbanks,Alaska
Anchorage Municipal Light &Power (AML&P)
Anchorage,Alaska
Chugach Electric Association (CEA)
Anchorage,Alaska
Matanuska Electric Association (MEA)
Anchorage,Al aska
8-3
APPENDIX A
GENERIC PLAN FORMULATION ANO
SELECTION METHODOLOGY
APPENDIX A-GENERIC PLAN FORMULATION AND SELECTION METHODOLOGY
On numerous occasions during the feasibility studies for the Susitna Hydroelec-
tric Projects,it is necessary to make decisions in which a single or a small
number of courses of action are selected from a larger number of possible al-
ternatives.
This appendix presents a generalized framework for this decision-making process
that has been developed for the Susitna planning studies.It outlines,in gen-
eral terms, the approach to be used in screening a large multitude of options
and finally establishing the best option or plan. It is comprehensive in that
it takes into account not just economic aspects but also a broad range of envi-
ronmental and social factors.
The application of this generalized methodology is particularly relevant to the
following decisions to be made during the Susitna studies:
-Selection of alternative plans involving thermal and/or non-Susitna hydroelec-
tric developments in the primary assessment of th€economic feasibility of the
Susitna Basin development plan (Task 6).
-Selection of the preferred Susitna Basin hydroelectric development plan (i.e.,
identification of best combination of damsites to be developed)(Task 6).
-Selection of the preferred railbelt generation expansion plan (i.e.,compari-
son of railbelt plans with and without Susitna).
- Optimization of the selected Susitna Basin development plan (i.e.,determining
the best dam heights,installed capacities,and staging sequences)(Task 6).
-Selection of the preferred transmission line routes (Task 8).
-Selection of the preferred mode of access and access routes (Task 2).
-Selection of the preferred location and size of construction and operational
camp facilities (Task 2).
It is recognized that the above planning activities embrace a very diverse set
of decision-making processes.The generalized methodology outlined here has
been carefully developed to be flexible and readily adaptable to a range of ob-
jectives and data availability associated with each decision.
The following sections briefly outline the overall decision-making process and
discuss the guidelines to be used for establishing screening and evaluation cri-
teri a.
A.I - Plan Formulation and Selection Methodol0,9y
The methodology to be used in the decision process can generally be subdivided
into five basic steps (Figure A.I):
A-l
- Step 1:
- Step 2:
- Step 3:
- Step 4:
- Step 5:
Determine basic objectives of planned course of action.
Identify all feasible candidate courses of action.
Establish basis to be used and perform screening of candidates.
Formulate plans incorporating preferred alternatives.
Reestablish basis to be used,evaluate plans,and select preferred
plan.
Under Step 2,the candidate courses of action are identified so that they satis-
fy,either individually or in combinations, the stated objectives (Table A.l).
In Step 3,the basis of screening these candidates is established in items of
redefined,specific objectives;assumptions; data base criteria;and method~
ology. This process follows a subseries of seven steps as shown in Table A.2,
to produce a short list,ideally of no more than five or six preferred alterna-
tives.Plans are then formulated in Step 4 to incorporate single alternatives
or appropriate combinations of alternatives.These plans are then evaluated in
Step 5,using a further redefined set of objectives,criteria,and methodology
to arrive at a selected plan. This 6-step procedure is illustrated in Table
A.3. Tables A.2.and A.3 also indicate the review process that must accompany
the planning process.
It is important that within the plan formulation and selection methodology,the
objectives of each phase of the decision process be redefined as necessary.At
the outset,the obj ecti ves wi 11 be broad and somewhat gener ali n nature.As the
process continues,there will be at least two redefinitions of objectives.The
first will take place during Step 3 and the second during Step 5.As an exam-
ple,the basic objectives at Step 1 might be the development and application of
an appropriate procedure for selection of a single preferred course of action.
Step 2 might involve the selection of those candidates which are technically
feasible on the basis of a defined data base and set of assumptions.The objec-
tives at Step 3 might be the establishment and application of a defined set of
criteria for elimination of those candidates that are less acceptable from an
economical and environmental standpoint.This would be accomplished on the
basis of appropriately modified data base and assumptions.Having developed
under Step 4 a series of plans incorporating the remaining or preferred alterna~
tives,the objectives under Step 5 might be the selection of the single alterna-
tive which best satisfies an appropriately redefined set of criteria for eco-
nomic,environmental,and social acceptability.
A.2 - Guidelines for Establishing Screening and Evaluation Criteria
Definition of criteria for the screening and evaluation procedures will largely
depend on the precise nature of the alternatives under consideration.However,
in most cases comparison will be based on technical,economic,environmental and
socioeconomic factors which will usually involve some degree of trade-off in
making a preferred selection.It is usually not possible to adequately quantify
such trade-offs.
Additional criteria may also be separately considered in some cases,such as
safety or conservation of natural resources.Guidelines for consideration of
the more common overall factors are discussed in the following paragraphs.
A-2
(a) Technical Feasibility
Basically all options considered must be technically feasible,complete
within themselves,and ensure public safety.They must be adequately de-
signed to cope with all possible conditions including flood flows, seismic
events,and all other types of normal loading conditions.
(b)Economic Criteria
Incases where a specific economic objective can be met by various alterna-
tive plans,the criteria to be used is the least present-worth cost.For
example,this would apply to the evaluation of the various railbelt power
generation scenarios,optimizing Susitna Basin hydroelectric developments,
and selection of the best transmission and access routes.In cases where
screening of a large number of options is to be carried out,unit commodity
costs can De used as a basis of comparison.For instance,energy cost in
$/kwh would apply to screening a number of hydroelectric development sites
distributed throughout southern Alaska.Similarly,the screening of al-
ternative access or transmission line route segments would be based on a
$/mil~comparison.
As the Susitna Basin development is a state project,economic parameters
are to be used for all analyses.This implies the use of real (inflation-
adjusted)interest rates and only the differential escalation rates above
or below the rate of general price inflation.Intra-state transfer pay-
ments such as taxes and subsidies are excluded,and opportunity values (or
shadow prices)are used to establish parameters such as fuel and transpor-
tation costs.
Extensive use should also be made of sensitivity analyses to ensure that
the conclusions based on economics are valid for a range of the values of
parameters used.For example,some of the more common parameters consid-
ered in comparisons of alternative generation plans particularly lend them-
selves to sensitivity analyses.These may include:
-Load forecasts
-Fuel costs
-Fuel cost escalation rates
-Interest and discount rates
-Economic life of system components
- Capital cost of system components
(c)Environmental Criteria
Environmental criteria to be considered in comparisons of alternatives are
based on the FERC requirements for the preparation of the Exhibit E
"Environmental Report"to be submitted as part of the license application
for the project.These criteria include project impacts on:
- Physical resources:air,water,and land
A-3
-Biological resources:flora,fauna,and their associated habitats
-Historical and cultural resources
-Land use and aesthetic values
In addition to the above criteria which are used for comparing or ranking
alternatives,the following economic aspects should also be incorporated
into the basic alternatives being studied:
~In developing the alternative concepts of plans,measures should be ;n~
corporated to minimize or preclude the possibility of undesirable and ir-
reversible changes to the natural environment.
-Efforts should also be made to incorporate measures which enhance the
quality aspects of water, land,and aiT.
Care shQuld be taken when incorporating the above aspects into the alterna~
tives being screened or evaluated to ensure consistency among alternatives;
i.e.,that all alternatives incorporate the same degree of mitigation.As
an example,these measures could include reservoir operational constraints
to minimize environmental impact,incorporation of air quality control
measures for thermal generating stations,and adoption of access road and
transmission line design standards and construction techniques which mini-
mize impact on terrestrial and aquatic habitat.
(d)Socioeconomic Criteria
Similarly,based generally on FERC requirements,the project impact assess-
ment should be considered in terms of socioeconomic criteria which in-
clude:
-Impact on local communities and the availability of public facilities and
services;
-Impact of employment on tax and property values;
-Displacement of people,businesses,and farms;and
- Disruption of desirable community and regional growth.
A.3 - Plan Selection Procedure
As noted above,for each successive screening exercise,the criteria can be
refined or modified in order to reduce or increase the number of alterna-
tives being considered.As a general rule,no attempt will be made to as-
cribe numerical values to non-quantifiable attributes such as environmental
and social impacts in order to arrive at an overall numerical evaluation.
It is considered that such a process tends to mask the judgmental tradeoffs
that are made in arriving at the best plan.The adopted approach involves
utilizing combinations of both quantifiable and qualitative parameters in
the screening exercise without making tradeoffs.For example,the screen~
ing criteria used might be:
- II ••••alternatives will be excluded from further consideration if their
unit costs exceed Xand/or if they are judged to have a severe impact on
wildlife habitat ....11
A-4
This approach is preferable to criteria which might state:
- "....alternatives will be excluded if the sum of their unit cost index
plus the environmental impact index exceeds Y ...."
Nevertheless,it is recognized that under certain circumstances,particu-
larly where a relatively large number of very diverse alternatives must be
screened very quickly,the latter quantitative approach may have to be
used.
In the final plan evaluation stages,care will be taken to ensure that all
tradeoffs that have to be made between the different quantitative and qual-
itative parameters used are clearly highlighted.This will facilitate a
rapid focus on the key aspects in the decision-making process.
An example of such an evaluation result might be:
-".L.Plan A is superior to Plan B.It is $X more economical and this
be~efit is judged to outweigh the lower environmental impact associated
with Plan B ...."
Sufficient detailed information should be presented to allow a reviewer to':
make an independent assessment of the judgmental tradeoffs made.
The application of this procedure in the evaluation stage is facilitated by
performing the evaluations for paired alternatives only.For example,if
the short-list plans are A,B,and C,then in the evaluation,Plan A is
first evaluated against Plan B,and the better of these two is evaluated
against C to select the best overall plan.
A-5
TABL~A.1:STEP 2 -SELECT CANDIDATES
Step 2.1 -Identification of candidates:
-objectives
-assumptions
-data base
-selection criteria
-selection methodology
Step 2.2 ..List and describe candidates that will be used in Step 5.
TABLE A.2:STEP 3 -SCREENING PROCESS
Step J.1 -Establish:
-objectives
-assumptions
-data base
-screening criteria
-screening methodology
Step 3.2 -Screen candidates,using methodology established in Step 3.1 to
conduct screening of alternatives.
Step 3.3 -Identify any remaining individual alternatives (or combinations
of alternatives)that satisfy the objectives and meet the
criteria established in Step 3.1 under the assumptions mad~.
Step 3.4 -Determine Ylhether a sufficient number of alternatives remain to
formulate a limited number of plans.If not,additional
screening via Steps 3.1 through 3.3 is required.
Step 3.5 -Prepare interim report.
Step 3.6 -Review screening process via (as appropriate):
- Acres
-APA
-External groups
Step 3.7 - Revise interim report.
TABLE A.3:STEP 5 -PLAN EVALUATION AND SELECTION
Step 5.1 -Establish:
-objectives
-evaluation criteria
-evaluation methodology
Step 5.2 -Establish data requirements and develop data base.
Step 5.3 -Proceed with the plan evaluation and selection process as
follows:
-Identify plan modifications to improve alternative plans
Based on the established data base and the selection criteria,
use a paired comparison technique to rank the plans as (1)the
preferred plan,(2)the second best plan,and (3)other plans;
Step .5.4 -Prepare draft plan selection report.
Step 5.5 - Review plan selection process via (as appropriate):
-Acres
-APA
-External groups
Step 5.6 -Prepare final plan selection report.
kJ w ~~!J ~W ~~u ~u U 1ai;..J ~,'.'W ~W W w.w.;I,~
INPUT FROM AVAILABLE SOURCES -PREVIOUS AND CURRENT STUDIES
DEFINE
OBJECTIVES
SELECT
CANDIDATES SCREEN
FEEDBACK
FEEDBACK
LEGEND
--J\STEP NUMBER IN
4 STANDARD PROCESS
(APPENDIX A )
PLAN FORMULATION AND SELECTION METHODOLOGY
FtGUREA,tm
APPENDIX B
SOILS INFORMATION
APPENDIX TABLE B.l
SOIL ASSOCIATIONS WITHIN THE PROPOSED TRANSMISSION CORRIDORS -
GENERAL DESCRIPTION,OFFROAD TRAFFICA~ILITY LI~IITATIUNS (ORTL),AND
COMMON CRUP SUITABILITY (CCS)a
EFl -Typic Gyofluvents -Typic Cryaquepts,loamy,nearly level
-Dominant soils of this association consist of well-drained,stratified,
waterlaid sediment of variable thickness over a substratum of gravel,
sand,and cobblestones.Water table is high in other soils,including
the scattered muskegs.ORTL:Slight - Severe (wet;subject to flood-
ing);CCS:Good -Poor (low soil temperature throughout growing season).
EOl -Typic Cryorthents,loamy,nearly level to rolling
- This association occupies broad terraces and moraines;most of the bed-
rock is under thick deposits of very gravelly and sandy glacial drift,
capped with loess blown from barren areas of nearby floodplains.Well-
drained,these soils are the most highly developed agricultural lands in
Alaska.ORTL:Slight;CCS:Good - Poor.
IQ2 -Histic Pergelic Cryaquepts -loamy,nearly level to rolling
-The dominant soils in this association are poorly drained,developed in
silty material of variable thickness over very gravelly glacial drift.
Most soils have a shallow permafrost table,but in some of the very
gravelly,well-drained soils,permafrost is deep or absent.ORTL:
Severe -Wet;CCS:Poor
IQ3 -Histic Pergelic Cryaquepts -Typic Cryofluvents,loamy,nearly level
- Soils of this association located in low areas and meander scars of
floodplains are poorly drained silt loam or sandy loam;these are usually
saturated above a shallow permarfrost table.Soils on the natural levees
along existing and former channels are well-drained,stratified silt loam
and fine sand; permafrost may occur.ORTL:Severe (wet);CCS:Unsuit-
ab 1e (1ow temperature duri ng growi ng season;wet)-Good (but subject to
flooding).
IQ25 -Pergelic Cryaquepts -Pergelic Cryochrepts, very gravelly,hilly to steep
-Soils of this association occupying broad ridgetops,hillsides,and
a. Source:U.S.Department of Agriculture,Soil Conservation Service 1979.
See Appendix Table B.2 for definitions for Offroad Trafficability
Limitations and Common Crop Suitability.
APPENDIX TABLE B.1 (Cont'd)
valley bottoms at high elevation are poorly drained,consisting of a few
inches of organic matter,a thin layer of silt loam,under which is very
gravelly silt loam;permafrost table is at a depth greater than 2 feet.
In locations of hills and ridges above tree line these soils are well-
drained.ORTL:Severe (wet)steep slopes);CCS:Unsuitable (wet;low
soil temperature;short,frost-free period).
IR1 -Typic Cryochrepts,loamy,nearly level to rolling
-On terraces and outwash plains,these soils are well-drained,having a
thin mat of course organic mat t er over gray silt loam.In slight depres-
sions and former drainage ways)these are moderately well-drained soils,
having a thin organic mat over silt loam,with a sand or gravelly sub-
stratum.ORTL:Slight-Moderate;CCS:Good.
IR10 -Typic Cryochrepts,very gravelly,nearly level to rolling - Aeric Crya-
quepts,loamy,nearly level to rolling
- Generally well-to moderately well-drainea soils of terraces,outwash
plains,and low moraines.Typically, these soils have a silt loam upper
layer over gravelly soils.Pockets of poorly drained soils with a shal-
low permafrost table occupy irregular depressions.ORTL:Moderate-
Severe (wet);CCS:GOOd -Poor (wet;low soil temperature throughout
growing seasen;short,frost-free period).
IR14 -Alfic Cryochrepts,loamy,hilly to steep -Histic Pergelic Cryaquepts,
loamy,nearly level to rolling
-On mid-slopes,these soils are well drained,of micaceous loess ranging
to many feet thick over shattered bedrock of mica schist.Bottomland
areas are poorly drained with a relatively thick surface of peatmoss. In
these soils,permafrost ranges from 5-30 inches in depth.ORTL:
Moderate - Severe (steep slope;wet);CCS:Poor (steep slopes;highly
susceptible to erosion).
IU3 -Pergelic Cryumbrepts,very gravelly,hilly to steep -rough mountainous
1and
-On high alpine slopes and ridges close to mountain peaks,these soils
have a thin surface mat of organic material beneath which is an 8 to 12-
inch-thick,dark brown horizon formed in very gravelly or stony loam.
This association also includes areas of bare rock and stony rubble on
mountain peaks.ORTL:Severe (short,frost-free periOd)-Very Severe
(steep slope);CCS~Unsuitable (short,frost-free period;shallow
bedrock).
RM1 -Rough Mountainous Land
-Rough,mountainous land composed of steep,rocky slopes;icefields;and
APPENDIX TABLE B.l(Cont'd)
glaciers.Soils on lower slopes are stony and shallow over bedrock.Un-
suitable for agriculture.Roads feasible only in major valleys.
SOl -Typic Cryorthods,loamy,nearly level to rolling -Sphagnic Borofibrists,
nearly level
-Low hills,terraces,and outwash plains have well-drained soils formed in
silty loess or ash, over gravelly glacial till.Depressions have poorly
drained,fibrous organic soils.UKTL:Slight -Very Severe;CCS:Good
(on well-drained soils)- Unsuitable (wet organic soil).
S04 -Typic Cryorthods, very gravelly,nearly level to rolling -Sphagnic
Borofibrists,nearly level
-Soils of nearly level to undulating outwash plains are well-drained to
excessively well-drained,formed in a mantel of silty loess over very
gravelly glacial till.Soils of the association located in depressions
are very poorly drained,organic soils.ORTL:Slight -Very Severe;
CCS:Good - Unsuitable (wet,organic).
S05 -Typic Cryorthods, very gravelly,hilly to steep -Sphagnic Borofibrists,
nearly level
-On the hills and plains,these soils,formed in a thin metal of silty
loess over very gravelly and stony glacial drift,are well drained and
strongly acid.In muskegs,most of these soils consist of fibrous peat.
ORTL:Severe (steep slope);CCS:Unsuitable (steep slopes;stones and
boulders;short,frost-free season).
SOlO -Humic Cryorthods, very gravelly,hilly to ~teep
- Generally,these are well-drained soils of foothills and deep mountain
valleys,formed in very gravelly drift with a thin mantel of silty loess
or mixture of loess and volcanic ash.These soils are characteristically
free of permafrost except in the highest elevation.ORTL:Severe (steep
slope);CCS:Poor - Unsuitable (low soil temperature throughout growing
season;steep slopes).
S015 -Pergelic Cryorthods -~istic Pergelic Cryaquepts, very gravelly,nearly
level to rolling
-On low moraine hills,these soils are well drained,formed in 10 to 20
inches of loamy material over very gravelly glacial drifts.On foot
slopes and valleys,these soils tend to be poorly drained,with shallow
permafrost table.ORTL:Slight -Severe (wet);CCS:Unsuitable (short,
frost-free periud;wet; stones and boulders).
APPENDIX TABLE 8.1 (Cont'd)
S016 -Pergelic Cryorthods very gravelly,hilly to steep -Histic
Pergelic Cryaquepts,loamy,nearly level
-On hilly moraines these soils are well-drained;beneath a thin surface of
partially decomposed organic matter,the soils havespodic horizons
developed in shallow silt loam over very gravelly or sandy loam. In
valleys and long foot slopes,these are poorly drained soils,with a
thick,peaty layer over a frost-churned loam or silt loam. Here, depth
of permafrost is usually less than 20 inches below surface mat.ORTL:
Severe (steep slope;wet);CCS:Unsuitable (short,frost-free period)-
Poor (wet;low soil temperature)..
APPENDIX TABLE B.2
DEFINITIONS FOR OFFROAD TRAFFICABILITY LIMITATIONS AND
COMMON CROP SUITABILITY OF SOIL ASSOCIATIONSa
OFFROAD TRAFFICABILITY LIMITATIONS (ORTL)
Offroad Trafficability refers to cross-country movement of conventional wheeled
and tracked vehicles,including construction equipment. Soil limitations for
Offroad Trafficability (based on features of undisturbed soils)were rated
Slight,Moderate,Severe,and Very Severe on the following bases:
-Slight
Soil limitations,if any,do not restrict the movement of cross-country
vehicles.
-Moderate
Soil limitations need to be recognized but can generally be overcome with
careful route planning.Some special equipment may be required.
- Severe
Soi1 1imitations are difficult to overcome,and special equipment and careful
route planning are required.These soils should be avoided if possible.
-Very Severe
Soil limitations are generally too difficult to overcome.Generally,these
soils are unsuitable for conventional offroad vehicles.
Common Cropb
Suitability (CCS)
Soils were rated as Unsuitable,Good,Fair,and Poor for the production of com-
mon crops on the following bases:
- Unsuitable
Sailor climate limitations are generally too severe to be overcome.None of
the common crops can be grown successfully in most years,or there is danger
of excessive damage to soils by erosion if cultivation is attempted.
a. Source:U.S.Department of Agriculture,Soil Conservation Service 1979.
b.The principal crops grown in Alaska--barley,oats,grasses for hay and
silage,and potatoes--were considered in preparing ratings.Although only
these crops were used,it is assumed that the ratings are also valid for
vegetables and other crops suited to Alaskan soils.
APPENDIX TABLE B.2 (Cont'd)
-Good
Sailor climate limitations,if any, are easily overcome,and all of the com-
mon Alaskan crops can be grown under ordinary management practices.On soils
of this group --
(a)Loamy texture extends to a depth of at least 18 inches (45 cm).
(b)Crop growth is not impeded by excessive soil moisture during the growing
seasons.
(c)Damage by flooding occurs no more frequently than 1 year in 10.
(d) Slopes are dominantly less than 7 percent.
(e) Periods of soil moisture deficiency are rare,or irrigation is econom-
ically feasible.
(f)Damage to crops as a result of early frost can be expected no more fre-
quently than 2 years in 10.
(g)The hazard of wind erosion is estimated to be slight.
-Fair
Soils or climate limitations need to be recognized but can be overcome.Com-
mon crops can be grown,but careful management and special practices may be
required.On soils of this group --
(a)Loamy texture extends to a depth of at least 10 inches (25 cm).
(b) Periods of excessive soil moisture,which can impede crop growth during
the growing season,do not exceed a total of 2 weeks.
(c)Damage by flooding occurs no more frequently than 2 years in 10.
(d) Slopes are dominantly less than 12 percent.
(e) Periods of soil moisture deficiency are infrequent.
(f)Damage to crops as a result of early frost can be expected no more fre-
quently than 3 years in 10.
(g)There is no more than a moderate hazard of wind erosion.
-Poor
Soils or climate limitations are difficult to overcome and are severe enough
APPENDIX TABLE B.2 (Cont1d)
to make the use questionable.The choice of crops is narrow,and special
treatment or managment practices are required.In some places,overcoming the
limitations may not be feasible.On soils of this group --
(a)Loamy texture extends to a depth of at least 5 inches (12 cm).
(b) Periods of excessive soil moisture during the growing season do not ex-
ceed a total of 3 weeks.
(c)Damage by flooding occurs no more frequently than 3 years in 10.
(d)Slopes are dominantly less than 20 percent.
(e) Periods of soil moisture deficiency are frequent enough to severely dam-
age crops.
(f)Climatic conditions permit at least one of the common crops,usually
grasses,to be grown successfully in most years.
APPENDIX C
REVIEW OF PREVIOUS STUDIES
APPENDIX C -REVIEW OF PREVIOUS STUDIES
-The U.S.Army Corps of Engineers (CaE)Study
The CUE study was contained in a report entitled "South-Central Railbelt Area,
Alaska Upper Susitna River Basin, Interim Feasibility Report,Hydroelectric
Power and Related Purposes"dated December 1975.Section H and Section I of
Appendix 1 of the CaE report deal with the transmission system which would in-
terconnect the communities of Anchorage and Fairbanks and transmit power from
the project to these load centers.These two sections were originally pre-
pared as reports to the CUE by the Alaska Power Administration of the United
States Department of the Interior.Each section of the following text con-
sists of a brief summary of certain aspects of the CUE's feasibility studies
followed by a critical review of the CUE's approach and conclusions.This re-
view was prepared with a consideration of changes that have occurred since the
CaE study was performed and under the assumption that the Alaska Power Author-
ity would begin construction of the Intertie program (Willow to Healy)prior
to Susitna transmission line construction.
This section was prepared in conjunction with Terrestrial Environmental
Specialists,Inc.(TES).
(a)Methods of Evaluation
The evaluation process presented in the CaE report,concerning selection
of a preferred corridor for the project,involved several steps.The
first step required interpretation of large-scale topographic maps and
aerial photo mosaics.The next step involved an aerial reconnaissance to
determine which of the mountain passes could accommodate transmission
line construction and to review potential corridors.During this over-
flight,several corridors were found to have constraints that would pre-
clude their use for transmission facilities.
The corridors surviving this review process were then subjected to more
detailed analysis.The result of this process was the identification of
twenty-two individual corridor segments located within the study area.
These corridor segments were then inventoried and environmental impact
analysis performed for each alternative corridor.Inventory and impact
information was presented in both a tabular and textual format,and was
based upon then available information.The selected corridors were
Susitna 1 (comprising Corridor Segments 7, 8,and 9)and Nenana 1 (com-
prising Corridor Segments 7,8;9,10, 13,and 16). (See Figure C.1
which is taken directly from the CaE report.)
The use of inventory tables proved very workable in the CaE study.while
other corridor selection methodologies could have been utilized,the in-
ventory method proved to be a useful mechanism in defining transmission
line corridors,as evidenced by the fact that very few letters to the COE
(which were subsequently in the Environmental Impact Statement)were
critical of the selected corridor.
C-l
APPENDIX TABLE C.1:CORRIDOR ANALYSIS -PROJECT POWER TO
ANCHORAGE/COOK INLET AREA
166 170 1~9 164 2~8 385
2,100 2,100 3,800 2,200 3,000 4,000
1*i 2 1 3 4
Analysis factor:
length,miles
Max.elevation,feet
Ranking
S-..:,
Susitna Corridors
S - 2 5 -J 5 - 4
Mantanuska Corridors
M - 1 M - 2----
Environmental Impacts
Soils
Vegetation
Wildlife
Existing developments
Scenic quality/recreation:
Developed areas
Remote areas
Ranking
Costs
-----Construction
Operation and maintenance
Ranking
Reliability
Exposure to hazards
Ease of repair
Ranking
Summary Ranking
*1 =least impact
4 =most impact
1 2 1 1 2 2
2 3 1 3 4 ~
1 2 .3 3 4 3
J 3 2 1 J 3
3 3 2 1 3 3
1 2 3 4 4 3
1 3 i 5 4 4
1 1 2 1 3 4
1 1 2 1 3 3
1 1 2 1 3 4
1 1 2 1 2 3
1 2 2 2 3 3
1 2 3 2 4 4
1 2 3 2 4 4
(preferred
corridor)
APPENDIX TABLE C.2:CORRIDOR ANALYSIS -PROJECT POWER TO
FAIRBANKS/TANANA AREA
Ana lysis factor:
Nenana Corridors
N~--N -...-t----N "'-r N -4"N"'5
Delta Corridor
D
Length,miles
Max.elevation,feet
Ranking
228 250 261 223 212 2aO
2,400 4,300 4,000 4,000 4,300 4,000
1*3 3 2 3 3
1 3 3 2 1 J
32211 3
1 3 2 2 3 2
Environmental Impacts
Soils
Vegetation
IHldlife
Existing developments
Scenic quality/recreation:
Del/eloped areas
Remote areas
Ranking
1
2
1
3
3
2
3
2
2
3
2
2
2
2
3
2
3
1
3
1
3
3
3
2
Costs
-----Construction
Operation and maintenance
Ranking
1
1
1
4
4
4
2
2
2
3 5 6
3 5 3
~-5-~~·~··-·---Ii
Reliability
Exposure to hazards
Ease of repair
Ranking
1 4 3 2 4 4
1 4 2 3 4 3
1 .3 2 2 3 J
Summary Ranking
*1 =least impact
4 =most impact
1
(preferred
corridor)
4 2 2 3 4
100 125
A.PA,Morch 1975
75=50
DEVI L CANYON PROJECT
TRANSMISSION
CORRIDOR SEGMENTS
Scale in rn i le s
--:-
UNITEO STATES DEPARTMENT OF THE INTERIOR
ALASKA POwER ADMINISTRATION
,-"
FIGURE C.I
APPENDIX D
RECORD OF EVENTS
APPENDIX 0 -RECORD OF EVENTS
A number of events took place in 1980 which had a significant impact on the sub-
task activities.The major events are summarized below:
(a)May 13,1980
Acres American Incorporated (Acres)received a letter from APA informing
Acres that the Alaska Legislature has appropriated $3.8 million to APA for
preconstruction activities related to transmission interconnection between
the Anchorage and Fairbanks systems.APA was considering a separate
Architectural/Engineering (A/E)contract for the Intertie and requested
Acres to identify any activity that is critical to the early route selec-
~ion study.These activities were to proceed immediately but would require
prior APA approval.
(b)May 20,1980
A meeting was arranged in Anchorage between APA and Acres.APA informed
Acres that it has definitely been decided to engage a separate A/E firm to
study the Intertie from Healy to Willow.This line will be built to
Susitna Project requirements but operated initially at 138 kV.Discussions
took place on the best way to coordinate efforts with the new A/E firm and
to identify the activities that must be completed to meet the Intertie
schedule.
(c)May 19 -21,1980
Several meetings were held with IECO/RWRA to clarify the IECO/RWRA proposal
of May 8,1980,to render engineering services to Acres for the Susitna
transmission line studies.
(d)June 26,1980
Acres submitted to APA a letter recommending the following procedures for
Intertie coordination:
(i)Acres should proceed with authorization under Subtask 2.08 of the
aerial photography of an identified corridor from Healy to Willow.
Acres assumed that the aerial photography would be restricted to the
corridor selected by IECO/RWRA in their Intertie report.
(ii)Acres should also proceed with authorization under Subtask 2.04 of
the land status research for the selected corridor.
(iii)Acres should proceed as soon as possible with the electrical system
power studies which will be based on scenarios from 1994 onwards.
The studies will determine the recommended voltage and electrical
characteristics of the Susitna tranmission lines.
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(iv)Acres will also proceed with the remainder of the feasibility study
of the transmission line from the project site to the Intertie from
Anchorage to Willow and Healy to Fairbanks,in accordance with the
schedule contained in the current POSe
(e) June 27,1980
Commonwealth Associates Incorporated (CAl)contacted Acres to notify them
that it has been chosen as the AlE firm for the Intertie contract.Ameet-
ing was scheduled at Jackson,Michigan.
(f)July 10,1980
Ameeting was held with CAl.Susitna Project information was supplied,and
a coordinated approach for obtaining system data was agreed upon.Other
subjects were discussed such as climatic data and Institute of Social and
Economic Reserves forecast.Aerial ~hotography was discussed,and CAl pro-
posed to notify Acres of the exact route at a later date.
(g)July 28,1980
Acres received notification from APA to proceed with the recommended pro-
cedure descri bed in Acres I 1etter of June 26,1980.
(h)August 18,1980
Copies of reduced quadrangle maps were received from CAl showing the area
that required photographing for the Intertie corridor.
(i)October,19BO
Utilities system data were received in the early part of the month,but
final Chugach Electric Association data were not received until October 15,
1980.This information was passed on to APA for transmittal to CAl.
(j)October 13~19BO
APA notified Acres via a copy of a letter from CAl that the Alaska state
authorities would permit only one rig.ht-of ..way for both the Intertie and
the Susitna transmission lines.
(k)November 18,1980
Ameeting with APA and CAl was held in Jackson,Michigan,to discuss ways
of coordinating and exchanging information between CAl and Acres.
It was agreed that the Intertie between Willow and Healy would be selected
in cooperation with Acres in order to consider any Susitna impacts upon the
selected Intertie corridor.
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