HomeMy WebLinkAboutAPA2921dSUSITNA HYDROELECTRIC PROJECT
AQUATIC MITIGATION REPORT SERIES
ACCESS,CONSTRUCTION AND TRANSMISSION
AQUATIC MITIGATION PLAN
Draft Mitigation Report No.
May 1985
Prepared By:
Woodward-Clyde Consultants
701 Sesame Street
Anchorage,Alaska 99503
In Association With:
Entrix,Inc.
4794 Business Park Boulevard
Anchorage,Alaska 99503
Submitted To:
Harza-Ebasco Susitna Joint Venture
711 H Street
Anchorage.Alaska 99501
For:
The Alaska Power Authority
327 W.5th Avenue.2nd Floor
Anchorage.Alaska 99501
I"i 4......,
Preface
This report represents one volume of a three volume report series on aquatic
mitigation planning for the proposed Susitna Hydroelectric Project.These volumes
are:
1.Access,Construction and Transmission Aquatic Mitigation Plan
2.Impoundment Area Fish Mitigation Plan
3.Middle River Fish Mitigation Plan
A primary goal of the Alaska Power Authority's mitigation policy is to maintain
the productivity of natural reproducing populations,where possible.The planning
process follows procedures set forth in the Alaska Power Authority Mitigation
Policy for the Susitna Hydroelectric Project (APA 1982),which is based on the
U.S.Fish and Wildlife Service and Alaska Department of Fish and Game mitigation
policies.Mitigation planning is a continuing process,which evolves with
advances in the design of the project,increased understanding of fish populations
and habitats in the basin and analysis of potential impacts.An important element
of this evolution is frequent consultation with the public and regulatory agencies
to evaluate the adequacy of the planning process.Aquatic mitigation planning
began during preparation of the Susitna Hydroelectric Project Feasibility Report
(1981)and was further developed in the FERe License Application (1983).A
detailed presentation of potential mitigation measures to mitigate impacts to chum
salmon that spawn in side sloughs was prepared in November 1984.It is expected
that the three reports in the present report series will also continue to evolve
as the understanding of project effects is refined.
TABU:OF cx:.mmrs
Title Page •
Preface.
Table of COntents.
List of Figures.
List of Tables
•
• •
•
••
•
•
•
•
~
i
iii
iv
vi
ix
•1 -nm:axJC'I'Iaf •
1.1 General Description •
1.2 IlIpact Assessments.
1.3 Miti,.gation Plan •
1.4 }qercy Reo "'''en:3ations.
•
• •
•
•
•
• •
1
1
3
3
5
7
B
B
20
23
24
26
27
33
•
•
• •
•
•
2.2
2 -NX'ESS ~
2.1 Impact Analysis
2.1.1 cantwell to watana
2.1.2 watana to Devil cartya\•
2.1.3 ~Roads.
2.1.4 Railroad fran Gold creek to Devil canyon •
Aooess Mitigation •
2.2.1 IJIp!ct Med1anisms am Mitigation Measures.
2.2.2 Marltorin]••
3 -aH;'IR]C'I'Iaf •
3.1 Impact Analysis
3.1.1 watana o:un and Facilities.
3.1.2 Devil Canyon O!ml am Facilities.
3.2 Constn1ction Mitigation •
3.2.1 Impact Mechanisms am Mitigation Measures.
3.2.2 MonitorinJ.
36
36
36
54
61
62
67
4 -'IRANSMISSIClN LINE CXlRRIJ:X)RS.
4.1 Iilp.ct Analysis
69
69
4.1.1
4.1.2
4.1.3
4.2
TABlE OF a:NI'ENIS (oontinued)
Watana to Gold creek •
Devil canyon to Gold creek •
WilleM to Healy.
4.1.4 Healy to Ester •
4.1.5 Wil1 eM to Anchorage.
Transmission Line Mitigation.
4.2.1 I:npact Mechanisms am Mitigation •
4.2.2 Monitorin].
~
69
73
74
76
77
79
80
83
5-~
6 -'REF'E:RENCES
Appen:lix A -Letailed Mitigation and Monitoring Costs
84
85
LIST OF FIGUR ES
Figure 1 The Susitna River basin and the proposed sites of the Watana
and Devil Canyon dams
Figure 2 Mitigation plan development and implementation
Figure 3 Option Analysis
Figure 4 The vicinity of the dam sites,access corridors and
transmission line corridors
Figure S Migration and spawning periods for Arctic grayling and
Dolly Varden in tributaries
Figure 6 Schedule for the construction of the Watana dam and related
facilities
Figure 7 Plan view of potential Watana borrow sites
Figure 8 Plan view of the Watana dam,cofferdams,related facilities
and disposal areas
Figure 9 Sensitive aquatic habitat along the northern section of the
Watana access corridor
Figure 10 Sensitive aquatic habitat along the central section of the
Watana access corridor
Figure 11 Restricted periods of instream activity for streams crossed
by the access corridor from the Denali Highway to the Watana
dam site
vi
Figure 12 Schedule for the construction of the Devil Canyon dam and
related facilities
Figure 13 Sensitive aquatic habitat along the Watana and Devil Canyon
access corridors
Figure 14 Sensitive aquatic habitat along the western section of the Devil
Canyon access corridor
Figure IS Restricted periods of instream activity for streams crossed
by the access and transmission line corridors to the Devil
Canyon dam site
Figure 16 Plan view of the Devil Canyon dam,cofferdams and disposal
areas
Figure 17 Plan view of potential Devil Canyon borrow sites
Figure 18 Stages I and 3 of the Watana dam
Figure 19 Borrow Site E
Figure 20 Plan view of the Devil Canyon dam and related facilities
Figure 21 Rehabilitated Borrow Site E
Figure 22 Staged construction of transmission lines
Figure 23 Transmission line corridor from the Watana dam site to Gold
Creek
Figure 24 The southern section of the Anchorage-Fairbanks Inter tie
Figure 2S The central section of the Anchorage-Fairbanks Intertie
vii
Figure 26 The northern section of the Anchorage-Fairbanks Intertie
Figure 27 The transmission line corridor from Anchorage to Willow
Figure 28 The southern section of the transmission line from Healy
to Ester
Figure 29 The northern section of the transmission line from Healy
to Ester
viii
LIST OF TABLES
Table J Access.construction and transmission line impact mechanisms
and associated mitigation.
Table 2 Summary of comments from the resource management agencies
pertaining to access,construction and transmission lines.
Table 3 Streams to be crossed by the Denali Highway between Cantwell
and the Watana access road junction.
Table 4 Streams to be crossed by the Watana access road (Denali Highway
to the Watana dam).
Table 5 ADF&G standards for passing Arctic grayling to be used on the
Susitna Hydroelectric Project stream crossings.
Table 6 ADF&G temporary stream diversion standards.
Table 7 Streams to be crossed by the Devil Canyon access road and
railroad spur from Gold Creek.
Table 8 Costs associated with the access,construction and transmission
line mitigation and monitoring.
Table 9 ADF&G standards for blasting near an anadromous fish stream.
Table 10 Streams crossed by the Anchorage-Fairbanks Intertie.
Table II Streams crossed by the transmission line corridor from Healy to
Ester.
Table 12 Streams crossed by the transmission line corridor from Willow to
Anchorage.
ix
1.INTRODUCTION
The Access,Construction and Transmission Aquatic Mitigation Plan (ACT)is a
component of the fisheries mitigation plan for the Susitna Hydroelectric Project
proposed by the Alaska Power Authority (APA).The ACT contains an evaluation of
the aquatic impacts associated with the construction and operation of the access
roads and transmission lines.Potential impacts on the aquatic environment from
the construction of the proposed Watana and Devil Canyon dams and related
f'acil ities are also identified.The impacts discussed for mitigation planning in
this volume are based on information presented for the three stage development of
the proposed Susitna Hydroelectric Project.Stage 1 involves construction of the
Watana dam.access roads and related facilities;during Stage 2,the Devil Canyon
dam and faciJities will be built.Stage 3 construction will increase the crest
elevation of the Watana dam.The ACT presents the mitigation measures which will
be utilized during and after the construction of the access roads.transmission
lines,dams and related facilities to maintain the productivity of the aquatic
populations.The APA intends to incorporate the final mitigation documents in the
specifications for bids and the contract documents.
1.1 General Description
The proposed Watana and Devil Canyon dams are located approximately 140 miles (225
km)north of Anchorage in the upper Susitna River Basin.The basin is bounded by
the Talkeetna Mountains to the southeast and the Alaska Range to the north and
west (Figure I).The Watana dam will be sited between River Mile (RM) 184 and RM
185;the Devil Canyon dam will be built 32 miles (53 km)downstream at
approximately RM 152 of the Susitna River.
The proposed dams are in the northern portion of Southcentral Alaska.The climate
is typical of the transition zone,with annual temperatures averaging about 3SoF.
Winter extends from October to May with temperatures occasionally dropping below
-SOoF.Summers are correspondingly short and frequently rainy.Tundra is the
dominant vegetation although stands of coniferous and deciduous trees exist in
areas protected from wind and at lower elevations.Isolated areas of permafrost
occur near the dam sites.
The hydrologic resources in the vicinity of the dams include small.clearwater
streams,lakes and the Susitna River.a large,glacial-fed river.The Susitna
River is similar to many unregulated northern glacial rivers with high,turbid
summer flows and low,clearer winter flow.In the spring.runoff from snowmelt
and increased glacial contributions cause a rapid increase in flow and suspended
sediment concentration.Turbidity in the mainstem is reduced in the fall when
glacial contributions to the headwaters of the Susitna River decrease.The
surface waters in the basin are predominantly of the calcium bicarbonate type with
low dissolved solids concentrations;the water is chemically acceptable for most
uses (Balding 1976).Clearwater streams are prevalent on the bluffs bordering the
Susitna River.The hydrologic regimes of the streams are typical of the
subarctic.snow-dominated flow regime,in which a snowmelt flood in spring is
followed by generally moderate flow through the summer.with flows peaking after
rainstorm events.From October to April,low flows occur when freezing
temperatures reduce surface water contributions.A general overview of the
chemical characteristics of streams in the project provided measurements of pH
ranging from 6.0 to 7.S and percent dissolved oxygen saturation ranging from 72
percent to 99 percent (Sautner and Stratton 1984). Most of the lakes in the basin
are small and shallow although a few larger and deeper lakes exist.The lakes
generally have higher summer water temperatures than the streams;lake-water
temperatures may reach 6SoF (Balding 1976).
The aquatic resources are varied in the general area of the dams and
transportation corridors.The numerous clearwater streams and lakes support an
abundant fish population.The fish species in close proximity to the access and
transmission line corridors and dam sites have been studied since 1981 (ADF&G
1981. 1983,Sautner and Stratton 1984).Arctic grayling.Dolly Varden and sculpin
are known to inhabit many of the clearwater streams (Sautner and Stratton 1984).
In larger streams.whitefish,longnose sucker and burbot have been observed
(Sautner and Stratton 1984).Populations of Arctic grayling and Dolly Varden in
selected streams in the vicinity have been estimated (ADF&G 1981. 1983,Sautner
and Stratton 1984).The fish species observed within nearby lakes include Arctic
grayling.Dolly Varden,burbot and lake trout (Sautner and Stratton 1984).The
Susitna River in the vicinity of the damsites provides overwintering habitat for
many fish species such as Arctic grayling and Dolly Varden and is used as a
2
migration corridor by resident and anadromous fish (ADF&G 1983). A few chinook
salmon migrate upstream within Devil Canyon to spawn in tributary mouths (Barrett
et a1.1985).However.Devil Canyon blocks the upstream passage of other fish
species.
1.2 Impact Assessments
Although details of construction activities for the three stage development of the
proposed Susitna Hydroelectric Project have not been prepared.the general type
and schedule of activities which will occur during construction and operation of
the dams are assumed to be similar to those identified in the FERC License
Application (APA 1983a);therefore.the potential effects of these activities upon
the aquatic environment can be assessed.Potential aquatic impacts consist of
changes to habitat and/or direct effects on aquatic organisms.Arctic grayling
and Dolly Varden were selected as the evaluation species for potential
construction impacts (APA 1983b). All life stages of these species are abundant
in the habitats in the clearwater streams and lakes in the vicinity of the access
and transmission corridors and dam facility sites (Sautner and Stratton 1984).
Arctic grayling have high human use value as sport fish and both species are
sensitive to water quality degradations and instream disturbances.Mitigation
plans focusing on the potential impacts which are identified for the evaluation
species are expected to maintain the integrity of aquatic habitats and the natural
productivity of other aquatic species that utilize similar habitats.Table 1
summarizes the anticipated impacts.
1.3 Mitigation Plan
The mitigation plan reflects the intent of the APA to maintain the productivity of
the natural aquatic population (APA 1982).The policies of the U.S.Fish and
Wildlife Service (USFWS)and the Alaska Department of Fish and Game (ADF&G)were
used to develop this approach to mitigation (USFWS 1981.ADF&G 1982).The
mitigation plan will be developed and implemented in stages as shown in Figure 2.
APA projects will avoid potential impacts where feasible .If unavoided,impacts
will be minimized.rectified.reduced or compensated.These mitigation options
will be analyzed in the hierarchical scheme depicted in Figure 3.
3
During construction of the access roads,transmission Jines,dams and facilities,
many potential impacts will be avoided or minimized by adherence to the APA's Best
Management Practices Manuals (BMPM's).These manuals have been prepared in
coordination with the resource management agencies to provide guidelines and
recommendations for environmentally acceptable construction practices.Federal
and state regulations have been identified within the BMPM's .The BMPM's will be
included in the bid specifications for the design and construction of the Susitna
Hydroelectric Project.Contractual documents will specify that construction
activities conform with the BMPM's.
The BMP manual on Erosion and Sedimentation Control (APA 1985a)provides
guidelines and techniques to avoid or minimize potential construction impacts on
the aquatic environment.Construction activities which may result in erosion or
sedimentation impacts,such as vegetation clearing and borrow excavations,are
discussed and general guidelines are presented for the planning,design,
construction and maintenance phases of a project.The manual describes
alternative site-specific methods to reduce erosion and sedimentation and prevent
water quality degradations.
The potential aquatic impacts associated with appropr iaring water will be avoided
or minimized by adherence to the BMP manual on Water Supply (APA 1985b).Although
the actual plans,designs and installations will be dictated by site-specif'ic
conditions,the manual depicts the environmental guidelines and regulatory
requirements for water withdrawal.
The BMP manual on Liquid and Solid Waste (APA 1985c)will be utilized to avoid or
minimize potential impacts from waste disposal on aquatic organisms.The manual
presents various waste management techniques.The collection,treatment and
disposal of liquid wastes at project sites will conform to techniques described in
the manual to avoid or minimize water quality degradations.Solid wastes will be
handled ,stored and disposed according to manual guidelines to minimize
environmental impacts.
The BMP manual entitled-Fuel and Hazardous Materials (APA 1985d)contains
guidelines to a void or minimize potential aquatic impacts from such materials.
4
These materials have the potential to cause significant adverse effects on the
aquatic environment.Regulation requirements and management strategies described
in the BMPM will be utilized to safely handle and store these materials with a
minimum of adverse effect.
Potential impacts from spill accidents will be minimized through the use of the
Oil Spill Contingency Planning BMP manual (APA 1985e).Adverse impacts from
spills of petroleum products will be minimized by site-specific spill contingency
plans specifying procedures to detect and contain spills.The cleansing and
restoration of contaminated areas are also described in the manual.The manual
confirms the APA's intent to notify and cooperate with the applicable regulatory
agencies in the event of a spill.
Potential impacts associated with most construction,access and transmission line
activities will be avoided or minimized through adherence to the BMPM's;residual
impacts will be rectified,reduced or compensated.The APA is committed to
restoring or rectifying affected aquatic habitat if possible.Monitoring
activities will verify the reductions in aquatic impacts over the duration of the
project.Compensation measures have not been proposed.Table 1 presents the
mitigation measures which will avoid,minimize,reduce or rectify potential
impacts.
Monitoring and maintenance are integral features of the mitigation process.
Monitoring will increase the flexibility of the mitigation plan and verify that
the expected level of mitigation has been achieved .Unrecognized aquatic impacts
and inadequate mitigation measures may be identified and corrected through
monitoring and maintenance activities.Construction monitoring,conducted by an
on-site Environmental Field Officer (EFO),will assure conformance with the
BMPM's.regulatory permits and license stipulations.Operational monitoring will
verify that long-term impacts do not cause significant degradation in the aquatic
resources of the region.
1.4 Agency Recommendations
The mitigation plan is intended to be responsive to resource management agency
5
recommendations.Recommendations have been identified from agency comments on the
License Application (APA 1983b, 1983c)and from the APA's Responses to Comments on
the License Application (APA 1984).The ACT plan reflects these recommendations,
which emphasize avoidance and minimization of potential aquatic impacts.Table 2
summarizes the comments including the dates and reasons for the comment submittal
from each agency.All comments pertaining to the construction and maintenance of
the access and transmission line corridors and the dams and related facilities are
addressed within the plan.
Additional comments from the resource management agencies are expected following
circulation of the draft ACT Plan.These comments and recommendations will be
discussed with agency representatives and used to develop the continuing project
mitigation plan.
6
2 -ACCESS CORRIDORS
Access to the sites of the Watana and Devil Canyon dams is needed for construction
and maintenance activities.Figure 4 depicts the access corridors to the Watana
and Devil Canyon dam sites.The Watana dam site will be accessed by road from the
Denali Highway.During Stage I construction.the closest railroad facility will
be located in Cantwell at the junction of the Denali and Parks highways.
approximately 60 miles (97 km)from the Watana dam site.During Stage 2.the
Devil Canyon dam site is anticipated to be accessed by a combination of railroad
and road .The Devil Canyon road will be built from the Watana access road to the
Devil Canyon dam site.A railroad spur and terminal facility is expected to be
constructed from Gold Creek.Secondary roads will be constructed to access the
construction camps,villages.related facilities.borrow and disposal sites.The
Stage 3 development or the Watana dam will utilize access corridors established
during the previous stages of construction.
Construction and maintenance of the access road network will impact the aquatic
resources of the region.Many of these impacts are expected to be relatively
short in duration .Construction activities such as clearing and culvert
installation may temporarily decrease water quality in streams and disrupt
existing habitat.Long-term aquatic impacts will also occur during access
construction and operation.A minor loss of aquatic habitat will occur at the
site of culverts and low water stream crossings.Unrestrained instream activities
could block fish migrations resulting in a long-term impact to the aquatic
resources.The most significant impact anticipated is increased sport fishing
pressure on unexploited fish populations as the access corridors will increase the
accessibility of water bodies in the vicinity.
Mitigation will avoid.minimize,rectify.and reduce the potential aquatic impacts
identified for access construction and operation (Figure 3).Many adverse impacts
associated with construction activities can be avoided or minimized through
environmentally careful construction practices.Best Management Practices Manuals
(BMPM's)have been prepared by the APA to ensure that environmentally acceptable
construction methods are utilized by their contractors.The BMPM's provide
guidelines to minimize erosion.maintain water Quality.avoid oil contamination.
7
and manage liquid and solid wastes.Instream construction will be restricted
during the sensitive periods of Arctic grayling and Dolly Varden spawning (Figure
S).Management policies may minimize the impacts from increased sport fishing
pressure.Monitoring activities throughout construction and during maintenance of
the access roads will verify that activities are conducted with a minimum of
adverse environmental impacts.Compensation for aquatic impacts will not be
necessary unless a major oil spill occurs.
2.1 -Imoact Analysis
2.1.1 'antwell to Watana
(a)pescriotion
The section of the Denali Highway from Cantwell to the intersection with the
Watana access road,a distance of 21.3 miles (35.5 km),will be upgraded by
improving one bridge,topping the road with more gravel,and straightening road
curves.Any needed realignment should be possible within the existing easement.
In addition,6 miles (10 km)of the road will be paved from the railhead facility
at Cantwell to a point 4 miles (7 km)east of the junction of the Parks and Denali
highways.Paving will avoid the problem of excessive dust and flying stones in
the community of Cantwell.
Within the section to be upgraded,the Denali Highway crosses several small
tributaries of the Nenana River including Edmonds Creek and tributaries to the
Jack River.The Jack River system contains Arctic grayling and the Nenana River
system in this region supports several other species of resident fish (Table 3).
The Watana dam site will have road access from Milepost 114.5 of the Denali
Highway (APA 1983a).The road will run approximately 44 miles (73 km)south to
the dam and construction campsites (Figure 4).The northern portion of the route
will traverse 19 miles (31 km)of high,rolling,tundra-covered hills.The road
will cross small streams including Lily Creek,Seattle Creek,Brushkana Creek,and
additional unnamed creeks (Table 4).These northern streams,which are part of
the Nenana River drainage,contain Arctic
8
grayling.Dolly Varden,sculpins,and probably other resident species.The
southern 25 miles (40 km)of the road will cross and parallel Deadman Creek,a
tributary of the Susitna River.Deadman Creek contains Arctic grayling.Dolly
Varden,and other resident species (Table 4).The Arctic grayling population of
Deadman Creek is estimated at 510 fish per mile reach near the access corridor
(Sautner and Stratton 1984).The access corridor lies within I mile (1.6 km)of
Deadman Lake which contains Arctic grayling.Dolly Varden,lake trout,humpback
whitefish,round whitefish.burbot,and sculpin (Sautner and Stratton 1984).
Arctic grayling appear to dominate in numbers.
Watana access construction is scheduled to begin in early spring of 1990 and
continue until late fall of 1991 (Figure 6).A snow and ice road may be
constructed during the winter of 1989-90 for heavy equipment access to permit
construction to proceed from both ends of the access road.Instream activities,
including the installation of O.idges and culverts.are expected to occur in the
open wa ter season of 1990.
Prior to actual road construction.the corridor will be cleared;min imal impacts
at stream margins will be assured by adherence to the BMPM (APA 1985a).The
Watana access corridor will not require extensive clearing activity until heavily
vegetated terrain is encountered within 3 miles (5 km)of the construction
campsite;thick brush will be removed at the crossings of the three Deadman Creek
tributaries nearest the Susitna River.Trees and large brush impeding overburden
removal will be cleared by equipment ranging from hand-held chainsa ws to
hydro-axes.Trees and brush will be felled into the access corridor and away from
waterbodies.Overburden and cleared material will be stockpiled at specific
disposal sites.left in place or burned.Coniferous vegetation may be chopped by
hydro-axes and broadcast;piles of coniferous slash will be burned within the
first year after cutting.Deciduous vegetation may be piled at corridor margins.
The length of haul of substandard materials will be minimized by allowing
overburden and cleared vegetation to be disposed in side borrow excavation
trenches.Clearing near the impoundment area may utilize disposal sites within
the permanent inundation area.The amounts of cleared vegetation are expected to
be small and are not J ikely to raise hydrogen sulfide concentrations in the
reservoir.Additional disposal sites,if necessary.will be located away
9
from floodplains and wetlands and the disposal sites will be bermed to avoid
increased sediment and organic contributions to nearby watersheds.
The Watana access road will be constructed of gravel and have a crown width of 24
f'cet (7.3 m).Road construction will predominantly use side borrow techniques in
which needed borrow material will be excavated by scraping trenches directly
alongside the road.Thus,construction activity will generally be confined to a
narrow strip,50 ft (15m)to 70 ft (21 m)each side of the road centerline.This
technique will minimize the requirements and associated impacts of large borrow
pit excavations.The majority of the borrow material for the access roads is
estimated to be available from side borrows:the remainder is expected to be
obtained from borrow sites 0 and E (Figure 7).These borrow areas will be
utilized predominantly for camp.village and dam construction (Section 3.1.1).A
mining plan,as required by 43 CFR Part 23 will be prepared for each site prior to
the removal of material.A permit application for activities at Borrow Site E
will be submitted to the ADF&G (AS 16.05.870).
The access road stream crossings will be located perpendicular to the stream,
preferably in a straight stretch (Lauman 1976)with low gradient and narrow,
Stall.banks that do not require cutting or excessive stabilization.Vehicle
barriers u guardrails will be installed at sites where there appears to be a
greater risk of accidents.
Stream crossings will require the installation of culverts or bridges.Prior to
the commencement of construction activities,permit applications for stream
crossing structures will be submitted to the ADF&G as required by AS 16.05.870.
Culverts will be designed in adherence to the Drainage Structure and Waterway
Design Guidelines (Harza-Ebasco 1985a)and the ADF&G velocity criteria to allow
fish pas sage during flood flows and critically low flows.For a specified length
of culvert,the water velocity criteria (Table 5)dictates the size of culvert.
Drainage structures will be routinely maintained to ensure fish passage .
Accumulated debris at culvert openings will be removed.Appropriate cc ntrol
measures will be undertaken as a part of routine maintenance to ensure that beaver
dams do not interfere with fish passage needs.
10
Construction activities will utilize water for gravel washing,fill compaction and
dust control.Water will be withdrawn from available sources along the access
corridor.Streams or lakes not supporting fish will be utilized preferentially.
Prior to water withdrawal,the ADF&:G and ADNR will be consulted for approval and
permitting of water removal sites.Water intakes will be screened as described in
the BMPM on Water Supply (APA 1985b).Water will hi:treated to conform to
ADEC/USEPA standards prior to discharge.Water utilized for gravel washing will
be channeled through settling ponds.
(b)Potential Impacts
Potential impacts on fisheries resources may result from alterations in the
physical characteristics of the aquatic habitat and/or direct effects on aquatic
organisms.Impacts identified for access road construction and maintenance are
presented in the anticipated order of occurrence and consider both types of
potential effects.
o Clearing
Potential impacts from the clearing phase of construction include minor
water quality degradations and some loss of aquatic habitat at stream
crossings.Degradations of fish and aquatic habitat will be avoided by
adherence to the following guidelines (APA 1985a):
Vegetated buffer zones will be retained at stream margins until
instream construction is necessary;
Cleared areas near streams and lakes will be stabifized to prevent
soil erosion into the water body;
Cleared material will be removed from water bodies to prevent
blockage of fish movements,deposition of organics on substrates,
and increased localized erosion;
11
Clearing of streamside vegetation will be minimized to prevent loss
of fish habitat,reduction in availability of food organisms,and
instream temperature variations;and
Stream banks will be promptly graded,mulched,and revegetated to
minimize erosion.
Cleared material will be treated in accordance with BMPM guidelines on
Liquid and Solid Waste Management (APA 1985c).Cleared material will be
removed from the streams to approved construction disposal sites and
salvaged,or burned onsite.Coniferous vegetation may be cut by
hydro-axes and strewn on the corridor margins.Piled coniferous slash
will be burned within one year.Deciduous slash in small quantities may
be left at the margins of the corridor.
Construction disposal sites that contain cleared slash and substandard
materials (overburden)will be located in the reservoir permanent
inundation area or in excavated side borrows away from waterbodies.
Additional disposal sites are not expected to be necessary.Disposal
sites will be located and configured so that neither high streamflows
during breakup nor rainfall runoff will wash silty material into
streams.Large disposal sites in the reservoir area will entail
constructing runoff control structures,surrounding the disposal site
with berms,or channeling runoff through containment and settling ponds.
Disposal sites are discussed in greater detail in Section 3.1.1.Figure
8 illustrates the locations of the disposal sites in the reservoir
impoundment zone.Incremental impacts from access corridor cleared
debris disposal are expected to be negligible.
Some loss of habitat due to cover removal is expected to occur in the 44
ft (12.9 m)wide road corridor at stream crossings.Changes of this
magnitude are not great enough to adversely affect fish and other
aquatic organism populations in the streams.Mitigation beyond
adherence to the specified BMPM's (APA 1985a, 1985c) is not likely to be
necessary.
12
o Stream Crossings and Encroachments
Adverse impacts associated with stream crossings during road
construction will be avoided or minimized through adherence to the BMPM
guidelines presented in the manual on Erosion and Sedimentation Control
(APA 1985a). Some permanent loss of habitat will occur in the immediate
vicinity of the stream crossing.Temporary impacts on aquatic organisms
from water quality degradations and substrate alterations due to stream
crossing activities are expected to be generally short in duration.
Potential migration barriers will be avoided by scheduling instream
activities during non-sensitive aquatic periods.
Any instream activity associated with upgrading of the Denali Highway
will have potential impacts similar to those resulting from new
construction.The BMPM techniques (APA 1985a)will be followed to
minimize temporary impacts from culvert extensions,bridge work or road
straightening.
Fish may avoid habitat experiencing excess suspended sediment levels.
The drainages crossed by the access road arc clearwater streams
inhabited primarily by Arctic grayling and Dolly Varden .Water quality
in these streams will be sensitive to increases in turbidity and
suspended sediments.The BMPM (APA 1984a)techniques and the ADF&G
guidelines will be followed to minimize aquatic impacts from substrate
alteration and local turbidity and suspended sediment increases
downstream of points of entry for heavy equipment.Residual losses
associated with substrate alteration in the stream crossings are
anticipated to be minor relative to the magnitude of the remaining
unaffected substrate.Residual impacts may include the short-term
deposition of small amounts of silt over spawning areas and benthic
production areas.Subsequent high water events are expected to remove
any deposition.Displaced aquatic organisms are expected to return to
previously utilized habitat when suspended sediment levels revert to
natural levels upon cessation of instream activity .
13
Instream use of equipment will be limited to the installation of stream
crossing structures and vehicles will be maintained to avoid water
quality degradations from fuel.hydraulic fluid,or antifreeze leakages.
Water degradations from vehicle leakages are not expected to be
significant if activities are conducted as described.
Stream crossings at streams having documented fish or fish habitat at,
or upstream from,the construction site will be designed to pass fish.
Figures 9 and 10 illustrate the locations of sensitive fish habitat that
may be effected by construction of the Watana access road along the
planned alignment.The evaluation species used in developing design
criteria for stream crossings in the project area is Arctic grayling.
At stream crossings where fish passage will be maintained,bridges or
large culverts may be constructed.
Bridges will be installed where streamflows are large.Bridges are
expected to be located at stream crossings 5.8, 12.0, 13.7,and 27.5
miles from the Denali Highway.On smaller systems where fish passage IS
required,open-bottom arch,multi plate elliptical or oversized circular
culverts will be installed to maintain the natural streambed (Joyce et
al. 1980a;Lauman 1976).Multiplate elliptical and oversized circular
culvert inverts will be set below the streambed elevation to a depth of
at least one-fifth their diameter to avoid perching.Culverts will be
armored to minimize erosion at the outlet.Natural stream substrate
will be placed over the entire bottom length of the culverts.
Open-bottom arch culverts will be preferentially utilized to maintain
natural substrate (APA 1985a).Permanent aquatic habitat alteration is
expected at the stream crossing where culverts are installed.However,
the alteration is Dot expected to significantly affect stream aquatic
populations if installation proceeds as described above.
Only at those stream crossing sites without fish or fish habitat at, or
upstream from,will the design of the crossing be based solely on
hydrologic and hydraulic criteria.From this figure,only the streams
14
crossed at corridor miles (eM's)10.7,11.7, 18.0,23.0,23.7, 24.8,
28.5, 37.2 and 37.8, as measured from the Denali Highway (Table 4), do
not appear to have fish or fish habitat upstream from the crossing site.
Stream diversions may be needed during construction.Open-bottom arch
culverts can be installed without stream diversions.When culverts
other than open-bottom arches are used,streams will be diverted around
the work area and back into the natural stream channel until the
crossing is completed.On small systems.the stream may be flumed.
Diversion or fluming will reduce the amount of siltation downstream from
the construction area.Diversion will be accomplished in accordance
with AOF&G criteria (Table 6).Channel stabilization will proceed
immediately after the resumption of normal flow to shorten the duration
of turbidity impacts in accordance with the BMPM entitled Erosion and
Sedimentation Control (APA 1985a).
Arctic grayling and Dolly Varden migrations to spawning areas could be
impacted by instream disturbances.Arctic grayling likely migrate from
overwintering habitats.such as Deadman Lake,to spawning habitat in
tributaries following spring breakup.Stream-resident Dolly Varden feed
predominantly during the summer months in small headwater streams and
are believed to remain in these streams for spawning in late August to
October.Dolly Varden are expected to migrate to lakes or deeper pools
for overwintering.Figure 5 presents the migration and spawning
periods;instream activities during the spring and late fall could alter
or block these migrations.Instrearn activities will be restricted
during Arctic grayling and Dolly Varden spawning.Figure 11 illustrates
the restricted periods for streams crossed by the Watana access road.
o Fill Placement
The potential impacts of fill placement on aquatic habitats will be
minimized through the proper construction techniques detailed in the
BMPM (APA 1985a).Potential impacts include habitat loss through fill
placement and increased suspended sediment levels.Residual impacts of
15
fill placement are expected to be negligible.
Fill utilized in stream crossing construction is not expected to cover
significant amounts of habitat previously used by fish.The access road
is aligned outside the flood plain except at the site of stream
crossings.'The impact on aquatic habitat will therefore be minor.
Sheet flow blockages,resulting in ponding on one side of the access
road and drying on the other side,will be prevented.Culverts and
drainage structures will be installed under the fill to maintain the
integrity of the road and the water drainage patterns which contribute
to wetlands along Deadman Creek.
Proper stabilization techniques as outlined in the BMPM (APA 1985a)will
be observed to minimize erosion and reduce suspended sediment and
turbidity contributions to waterbodies.Fill with high organic and/or
fines content will not be utilized.Fills and cuts will be stabilized
to prevent erosion and revegetated as construction is completed.
a Borrow Sites
Few impacts are anticipated from borrow excavations as the construction
techniques presented in the BMP manual on Erosion and Sedimentation
Control (APA 1985a)will be followed to avoid sheet flow blockages and
increased sediment and petroleum contamination.The majority of the
fill material for road construction will be obtained using side borrow
techniques.The remainder of the material will be excavated from borrow
sites 0 and E .(Figur:7).
Borrow excavations will adhere to the 9MPM (APA 1985a)in order to
minimize sediment and petroleum product contributions to waterbodies
within the drainage.Buffer zones will be maintained at stream margins.
Runoff control structures will be installed at borrow sites and turbid
water will be channeled through stilling ponds prior to discharge in
adherence to BMPM guidelines (APA 1985a).Flocculants will be used.if
16
necessary.to settle fine sediments.Discharged water will conform to
water quality standards of the ADEC (18 AAC 70)and the USEPA.Erosion
will also be minimized by excavating material according to the gravel
removal guidelines of the USFWS (Joyce er al.1980b).Residual impacts
are discussed in grea ter detail in Section 3.1.1 and include the
conversion of riparian and upland habitat to lake habitat at Borrow Site
E.
Borrow Site D is located on a sloped bench.approximately 1500 ft above
the Susitna River at the proposed site of the Watana construction
facilities at an elevation of 2300 ft (700 m).Borrow activities,
conducted in accordance with the BMPM techniques (APA 1985a),at this
site are not expected to impact aquatic resources in the vicinity.
Runoff control structures such as berms and settling ponds will minimize
turbidity increases to Tsusena and Deadman creeks.
Borrow Site E is located in the floodplain of the Susitna River at the
mouth of Tsusena Creek.Removal of gravel is expected to be confined to
the inactive channel floodplain;instrcam activities are expected to be
restricted to a crossing of Tsusena Creek.Berms will be
constructed to prevent turbid water contributions to Tsusena Creek.
Buffers will border Tsusena Creek and the Susitna River.Surface runoff
and water used in material washing will be circulated through sediment
settling ponds and reused in material washing.Excavations will occur
in aliquots and rehabilitation by contouring and removing man-made
objects will follow cessation of activities in each aliquot.Potential
impacts on aquatic organisms will include temporary degradations of
habitat due to increases in turbidity and noise disturbances.A
long-term impact is expected as a deep pit will be excavated during
gra vel removal.Section 3.1.J details anticipated impacts;mitigative
measures are described in Section 3.2.1.
o Water Removal
The BMPM guidelines for Water Supply (APA 1985b)and the ADF&G water
17
removal criteria will be followed to avoid or minimize potential impacts
including fish entrainment,habitat dewatering and increases in
suspended sediment levels.BMPM adherence will insure that minimal
residual impacts are incurred.
Water removal along the access corridor will pref'erentia lly utilize
shallow lakes without fish such as the lakes located at 13 and 40
miles (21 and 64 km)from the Denali Highway;in streams,no more than
20 percent of the instantaneous flow will be removed at any time.Under
frozen conditions or in cases where the average annual stream flow is
unknown,10 percent of the flow at the time of water removal wili be
used as the maximum withdrawal flow.All water intakes will be screened
and sized according to ADF&G intake design criteria to prevent fish
entrapment,entrainment.and impingement (APA 1985b).
The ADF&G criteria state that:(I)all intakes should be screened;(2)
openings in the screen should not exceed 0.04 sq in;and (3)water
velocity at the screen should not exceed 0.1 f'r/sec (0.03 m/sec)in
anadromous fish streams or .5 f't/sec (.15 m/s)in non-anadromous fish
supporting streams or lakes.
o Operation and Maintenance Activities
During road construction and operation,impacts to the aquatic habitat
from accidents involving transport vehicles,including those carrying
petroleum products,will be avoided if possible.The access road will
be designed without hazardous curves and hills.Traffic control signs
and guardrails will be installed where needed.Dust will be controlled
in summer and ice will be sanded in winter.
An Oil Spill Contingency Plan will be developed prior to the beginning
of construction activities in accordance with the BMP manual on Oil
Spill Contingency Planning (APA 1985c) to minimize water quality impacts
should a spill occur.Residual impacts from an accidental fuel spill
may cause short-term reductions in water quality within the watershed
18
as small amounts of petroleum products are expected to enter the water.
An accidental spill,if located adjacent to fish habitat,would likely
severely injure or kill fish directly impacted by the petroleum
products.Following a major spill.an assessment of the aquatic losses
would be conducted by the Environmental Field Officer (EFO)described in
Section 2.2.2.Appropriate site-specific mitigative measures would be
negotiated in consultation with the resource management agencies.
The BMP manual on Fuel and Hazardous Materials (APA 1985b)provides
guidelines to prevent petroleum products from contaminating water in the
area during refueling or storage.Activities associated with petroleum
storage or transfer will only be allowed in bermed areas.Spillage will
be transported by local runoff to a collection area and treated prior to
release into water bodies.
The access road will be properly maintained so that road operation
impacts on aquatic habitats will be minor.Gravel displaced during road
operation or maintenance activities will be removed from wetlands.
Maintenance will include removal of culvert and bridge debris to
maintain fish passage.
The greatest long term source of adverse impacts upon fish populations
is likely to be increased fishing pressure resulting from improved
access to streams and lakes.As stated in Section 2.1.1.the Watana
access road will cross Brushkana,Lily.Seattle.and Deadman creeks as
well as other small,unnamed streams.These clearwater streams are
inhabited by Arctic grayling and Dolly Varden.Deadman Creek,in
~articular,is known for its large and abundant population of Arctic
grayling.The reach of Deadman Creek between the falls and Deadman Lake
is considered prime Arctic grayling habitat.By subjecting this stream
to increased fishing pressure,many of the larger.older fish will be
removed from the population,altering the age structure and possibly
reducing reproductive potential (Schmidt and Stratton 1984). A similar
impact may occur in other grayling streams.
19
During road construction,several thousand workers will be in the area
between the Denali Highway and the Watana damsite (Section 3.1). A
survey of construction workers On the Terror Lake Hydroelectric Project
indicates that workers lack sufficient leisure time to participate
frequently in recreational activities such as fishing (Harza-Ebasco
1985b).During construction at Terror Lake from 1983 to 1984, 57
percent of the project personnel had not fished within ten miles of the
project site.23 percent reported fishing less than 10 times and 8
percent had fished more than 25 times.10 percent of the project
personnel did not respond to the survey evaluating recreational usage of
areas near the project site.However,access will be opened to the
public following the completion of construction of the Susitna dams.
Although this area has been a recreational area in past years,it has
not experienced a large influx of people.Unless controlled,this
influx will increase fishing pressure on the streams and lakes in the
area.The effects of such an increase in pressure were modeled by
Schmidt and Stratton (1984).The finding was that the trophy-sized
Arctic grayling presently in the creek could only be maintained if a
catch-and-release policy was implemented.Allowing a harvest would lead
to a population dominated by smaller fish.Alternative management
policies may be the only method to lessen these effects of increased
pressure.These policies are the jurisdiction of the Alaska State Board
of Fisheries (AS 16.05.251);however,APA will provide the Board with
project information needed to formulate policy decisions.
2.1.2 -Watana to Devil Canyon
(a)Descriotion
The planned Devil Canyon access road will traverse high tundra throughout most of
its length.Dense shrub vegetation and trees are encountered downstream of Devil
Canyon when the access road approaches th.e Susitna River crossing.The terrain
has gentle to moderate slopes allowing road construction without deep cuts except
i n the case of several stream crossings.Access construction and maintenance will
be conducted in the same manner as the Watana access road (Section 2.1.1).
20
------- -- - - - - - -
Construction will begin and is expected to finish in 1995 as shown in Figure 12.
The Susitna River will be crossed by a high level suspension bridge with an
overall length of 1.190 ft (550 m)at approximately RM ISO.The Susitna River
crossing will link the rail spur from Gold Creek to the construction camps.
Bridges are also expected to be installed at streams located 2.2. 8.0.15.7 and
22.4 miles from the junction with the Watana access road.
The Devil Canyon access road is planned to depart from the Watana access road at
mile 38.5 and cross Tsusena Creek 2.2 miles (3.5 km)and Devil Creek 22.4 miles
(35.5 km)from the Watana access road junction (Figure 4).The road will cross
numerous small streams between Tsusena and Devil creeks and parallel Swimming Bear
Creek for approximately 6 miles (9.5 km).Tsusena Creek contains Arctic grayling.
Dolly Varden.sculpin and other species;Devil Creek contains sculpin and Dolly
Varden (Sautner and Stratton 1984).The road will approach within 1300 ft (400 m)
of Swimming Bear Lake.which supports a population of Dolly Varden (Sautner and
Stratton 1984)and cross the Devil Creek tributary draining from Swimming Bear
Lake.This tributary is used by Dolly Varden for spawning and rearing during the
open water season (Sautner and Stratton 1984).The access road will encroach on
the Devil Creek flood plain for almost I mile (1.6 km)and parallel Devil Creek
for 5 miles (8 km).Between the Devil Creek crossing and the Susitna River.the
road will cross three tributaries to Devil Creek that provide habitat for Dolly
Varden and sculpin (Table 7).The access corridor encounters the High Lake
Complex approximately 28 miles (45 km)from the Watana junction.These lakes
contain rainbow trout,Dolly Varden and sculpin (Sautner and Stratton 1984).
Figures 13 and 14 illustrate the sensitive aquatic habitat encountered by the
Devil Canyon access corridor.
(b)Potential Impacts
Potential impacts identified for the Denali Highway to Watana access road (Section
2.1.1)are also applicable to the Devil Canyon access road.Additional impacts
arc discussed further .
21
a Clearing
The Devil Canyon access corridor will encounter dense brush and trees
and will require more vegetation clearing with chainsaws and hydro-axes
than the Watana access corridor.Similar measures will be undertaken to
prevent increased erosion.A need for additional mitigation is not
anticipated if clearing proceeds according to the BMPM techniques (APA
1985a).
o Stream CrQssings and Encroachments
All construction will adhere to tbe BMPM techniques (APA 1985a) to avoid
or minimize aquatic impacts from access road stream crossings and
encroachments.Surface runoff along the Devil Canyon access road
encroachment on the Devil Creek floodplain will be drained through
culverts designed to maintain surface water contributious to wetland
habitat (Harza-Ebasco 1985a).Additional impacts arc not expected due
to the encroachment.
The access road will cross the Devil Creek tributary draining from
Swimming Bear Lake.This tributary provides the only documented
spawning and rearing habitat for the lake population of relatively
large Dolly Varden,up to 375 mm in length,which are believed to
overwinter in Swimming Bear Lake (Sautner and Stratton 1984).Instream
activities during the fall may disturb Dolly Varden spawning and impact
the lake population.The deposition of silt,due to instream
activities,onto gravel containing embryos could reduce embryo survival
with a subsequent reduction in year class strength.Instream activities
will be restricted during sensitive periods for streams supporting
Arctic grayling and/or Dolly Varden as shown in Figure 15.
a Fill Placement
Fill placement in the Devil Creek floodplain will follow BMPM techniques
(APA 1985a) to prevent draining wetlands.
22
Revegetation will proceed as fill is stabilized.Residual impacts are
expected to be negligible.
a Borrow Sites
Fill for the Devil Canyon access road will be obtained predominantly
through side borrow techniques.Borrow Sites D and E may also be used;
the potential impacts are described in Section 2.1.1.
o Operation and Maintenance Activities
Increased fishing pressure on lakes and streams in the vicinity of the
access road is expected to be the greatest long term adverse impact on
the fisheries resources.Swimmiug Bear and Devil creeks contain
numerous Arctic grayling and Dolly Varden.The High Lake complex also
contains rainbow trout.The population composition is expected to be
altered by the reduction or elimination of older-age classes (Sautner
and Stratton 1984).
2.1 .3 -Secondary Roads
•
(a)Description
The secondary roads are anticipated to be short in length and not require stream
crossings.Short spur roads will be needed to reach the material borrow and
disposal sites which are not located adjacent to the access corridors.Access to
and within the construction camps and villages will also require the construction
of secondary roads.The locations and alignments of these auxiliary access roads
are illustrated in Figures 8 and 16.
(b)Potential Impacts
Potential impacts on aquatic habitats from the construction,operation and
maintenance of the secondary roads are not expected to be significant as stream
crossings or encroachments are not expected,The BMPM techniques (APA 1985a)will
23
-_.-_.._----- - - - -
be applied to avoid or minimize potential aquatic impacts.Erosional and clearing
impacts identified for the Watana access road (Section 2.1.1)are relevant for
secondary roads.
2.1.4 RailrQad frQm GQld Creek to Devil CanYQn
(a)pescriptiQn
A ra ilroad spur of the Alaska Railroad is planned f'rom Gold Creek to Devil Canyon
for Stage 2 development.The railroad access corridor will depart from the
existing railroad at Gold Creek and proceed north and east to the construction
campsite.It will remain on the south side of the Susitna River.The railroad
will crQSS Gold Creek,which contains excellent fish habitat (Sautner and Stratton
1984)and is known to support pink and chinook salmon (ADF&G 1981, 1983;Barrett
et al.1984».Several tributaries that enter the Susitna River between Gold
Creek and Jack Loog Creek will be crossed;the tributaries contain Arctic
grayling,chinook salmon,and sculpin (Sautner and Stratton 1984)(Table 7).
These tributaries may be an important source of clear water for Slough 19,which
is a spawning area for salmon.The access corridor closely parallels Slough 20
which is utilized by adult pink,chum and chinook salmon (ADF&G 1981, 1983,
Barrett et a1.1984).The railroad will then parallel Jack Long Creek fQr
approximately 4 miles (6 .S km).The railroad will be located within the
floodplain and crQSS three tributaries of Jack Long Creek.Jack Long Creek
contains small numbers of pink,coho,chinook,and chum salmon,rainbow trout,
Arctic grayling and sculpin (ADF&G 1981, 1983;Barrett et al. 1984;Sautner and
Stratton 1984).One of the tributaries appears to be accessible to fish and may
be utilized by adult or juvenile salmon (Sautner and Stratton 1984).The ra il road
terminus and turnaround at Devil Canyon will be located adjacent to the upper
reaches of Jack Long Creek.
(b)Potential Impact<:;
Potential impacts resulting from the railroad access construction,operation and
maintenance will be similar to those impacts identified for the Watana access road
(Section 2.1.1).Add itiona l site specific impacts are discussed further.
24
o Clearing
Construction of the railroad access corridor will require extensive
hardwood tree clearing.BMPM clearing techniques (APA 1985a)will be
utilized to avoid or minimize impacts on the aquatic resources from
turbidity and siltation increases.Ma terial will be removed from
streams to prevent fish blockages.
o Stream Crossings or Encroachment
Bridges and culverts will be installed according to BMPM guidelines (APA
1985a)to maintain fish passage and to prevent turbidity and
sedimentation impacts on sloughs and clearwater streams.Large volume
streams,such as Gold Creek,will require bridges.Encroachments into
floodplains will occur along Slough 20 and Jack Long Creek.As
described in Section 2.1.1,culverts will be installed to continue
surface runoff contributions to wetlands.
Instream activity Juring summer and fall may cause salmon to avoid
spawning habitat in Gold and Jack Long creeks.Instream activities will
predominantly be restricted to early or midsummer to avoid resident and
anadromous spawning periods (Figure 15) as explained in Section 2.1.1.
o Fill Placement
The BMPM (APA 1985a)techniques will be utilized to avoid detrimental
impacts on the aquatic resources associated with fill placement near
sloughs and streams.Along Slough 20 and Jack Long Creek,fill will be
stabilized to prevent sediment influx to the clear water.Temporary
increases in suspended sediments may impact sight feeding fish,such as
Arctic grayling.However,Arctic grayling successfully migrate through
the turbid mainstem during summer months (ADF&G 1983).Residual impacts
from fill placement are expected to be negligible so long as suspended
sediment increases are short in duration .
2S
o Borrow Sites
Borrow material for railroad fill will be obtained from Borrow Site G.
Borrow Site G will be extensively used for the Devil Canyon dam
construction and will be located at the confluence of Cheechako Creek
and the Susitna River upstream of the Devil Canyon dam site (Figure
(7).Gra vel removal is expected to be confined to the channel margins.
The USFWS Gravel Removal Guidelines (Joyce et al,1980b)and the 8MP
Manual on Erosion and Sedimentation Control (APA 1985a) will be b.::,plied
to excavation activities.Buffers will isolate the excavation from
Cheechako Creek and the Susitna River.Aggregate washing water will be
channeled through settling ponds and reused.As the borrow site will be
permanently inundated by the Devil Canyon reservoir,rehabilitation will
not be necessary.Borrow Site G is discussed in greater detail in
Section 3.1.2.Incremental impacts from excavations for railroad
access construction will be negligible.
o Ooeration and Maintenance Activities
The railroad access corridor may allow increased fishing pressure on
southside streams and sloughs between Gold Creek and Devil Canyon.
The populations in these streams are small,however,and arc not
expected to attract significant pressure.
2.2 - Access Mitigation
Mitigation of potential impacts during access roads and railroad construction will
be achieved primarily by adherence to the BMPM construction techniques (APA
1985a).Erosion will be minimized by utilizing proper clearing and soil
stabilization procedures as outlined in the BMPM on Erosion and Sedimentation
Control (APA 1985a).Revegetation will be scheduled to proceed in segments
immediately after portions of the roads or railroad are completed.Streams will
be crossed following BMPM guidelines (APA 1985a) in order to minimize impacts.
26
---_.--.------
Scheduling of construction activities is another means of mitigation that would
avoid or minimize adverse impacts to fish and aquatic habitats.Movements of
vehicles through streams during periods of peak Arctic grayling and Dolly Varden
migration will be avoided.Figure 5 illustrates these migration periods.
Instream and streambank construction will be minimized at streams containing
sensitive habitat during peak migration periods to allow successful passage of the
majority of the population to spawning or overwintering habitat.Figures II and
IS present the restricted periods for the streams crossed by the access corridors.
Potential impacts were identified in Section 2.1;Section 2.2.1 discusses these
impact mechanisms and the mitigation measures that will be applied during and
after access construction.Those sources of impact considered to have greatest
potential for adverse effects to the aquatic environment are given highest
priority.Measures to avoid,minimize,rectify and reduce impacts ate discussed.
Continued monitoring of the construction facilities and activities will ensure
that impacts to the aquatic environment are avoided or minimized.Monitoring
(Section 2.2.2)can identify areas that may need rehabilitation or increased
maintenance efforts and areas where previous mitigation measures are inadequate
and remedial action must be taken.Costs associated with all phases of
maintenance and monitoring arc outlined in Table 8.
2.2.1 Impact Mechanisms and Mitigation Measures
(a)Increased Fishing Pressure
(i)Impact Mechanism
The sport fishing pressure on the local streams and lakes
will substantially increase.The access roads will allow
fishermen to reach areas previously unexploited .
(ii)Mitigation
During the construction phase,access to the streams will be
limited by closing roads to unauthorized project personnel and
27
the general public.The Alaska Board of Fisheries will be
provided information needed to develop management policies.
Some watersheds,such as the Deadman Creek/Deadman Lake
system,are expected to require special management
considerations if current stocks are to be maintained (Schmidt
and Stratton 1984).These regulations may take the form of
reduced seasons or catch limits,imposition of maximum or slot
.ze limits,or control of fishing methods.Since public
health regulations will not allow sport-caught fish to be
stored or prepared at public food service facilities,the
project policy will be that all fishing done by project
personnel and contractors be restricted to catch-and-release.
(b)Stream Crossings and Encroachments
(i)Impact Mechanism
During construction,fish are likely to avoid areas disturbed
by equipment operated in or near streams.Spawning and
overwintering migrations may be interrupted.
(ii)Mitigation
Construction activities in streams supporting fish populations
will be scheduled,if possible,to avoid fish migration
periods (Figures II and 15).Access road construction will
continue for approximately 1.5 years at Watana and year at
Devil Canyon (Figures 6 and 12).However,during these
time periods,instream activities near utilized fish habitat
will be coordinated to minimize conflict with identified
migration periods.
Spawning migrations and movements to and from overwintering
areas by evaluation species occur during several time periods
throughout ~h e year (Figure 5).Arctic grayling migrate
28
from lake overwintering habitat to spawning habitats following
spring breakup.Spawning appears to end in mid June.Arctic
grayling feed in streams and lakes during the summer prior to
migrating to lakes in the late fall for overwintering.
Stream-resident Dolly Varden predor.rinantly feed in small
headwater streams during summer and remain in these streams
for spawning in late August to October.Dolly Varden may
migrate to lakes for overwintering.By restricting instream
activities during fish migrations,impacts to the fish
resources in the region can be minimized .Bridges,culverts,
and other drainage structures will be installed during the
summer months before,between and after Arctic grayling and
Dolly Varden spawning periods.Activities not involving
instream construction will continue throughout the year.
Figures II and 15 present the periods during which instream
activities will be restricted for specified streams along the
access corridor.
The USFWS recommended scheduling clearing activities during
winter to minimize aquatic impacts.Because of the
difficulties inherent in wintertime construction,current
plans do not limit clearing to the winter.However,
restricting instream construction during aquatic
environmentally sensitive periods is expected to minimize
aquatic impacts.
(c)Water Quality
(i)Impact Mechanism
Temporary degradations in water quality caused by increas-d
turbidity,sedimentation and petroleum contamination may
change the species composition and reduce the productivity of
the system (Bell 1973,Alyeska Pipeline Service Company 1974).
29
(ii)Mitigation
The primary mitigation measures that will be used to minimize
degradations in water quality are:(I)erosion control
measures such as runoff control,stilling basins and
revegetation will be employed as outlined in the BMP Manual on
Erosion and Sedimentation Control (APA 1985a);and (2)the
time period of the construction activity will be minimized so
that degradation in water quality is a short-term,
non-reoccurring problem .Therefore,water quality
degradations from access construction and operation are not
expected to significantly impact the fisheries resources.
Further mitigation is not expected to be required.
(d)Oil and Hnardous Material Spills
(i)Impact Mechanism
Spills of oil and other hazardous substances into streams can
be toxic to fish and their food organisms.
(ii)Mitigation
A Spill Prevention Containment and Countermeasure Plan (SPCC )
will be developed as required by EPA (40 CFR 112.7)prior to
the initiation of construction .The BMP manual on Oil Spill
Contingency Planning (APA 1985c)will be used to avoid
potential impacts.
Equipment refueling or repair will not be allowed to take
place in or near floodplains unless adequate provisions have
been made to contain petroleum products.Waste oil will be
removed from the site and disposed using ADECjUSEPA-approved
procedures.Fuel storage tanks will be located away f'r orn
waterbod ies and within lined and bermed areas capable of
30
containing 110 percent of the tank volume.Fuel tanks will be
metered to account for all outflow of fuel.All fuel lines
will be located in aboveground or ground surface ut ilidors to
facilitate location of ruptured or sheared fuel lines.
Vehicle accidents,although impossible to totally prevent,
can be minimized by constructing the roads with properly
designed curves to accommodate winter driving conditions.The
roads will have adequate traffic signs and guardrails.During
the winter,difficult stretches will be regularly cleared and
sanded.In summer,dust will be controlled with water .
State law requires that all spills.no matter how small,be
reported to ADEC (18 AAC 70.080).Personnel will be assigned
to monitor storage and transfer of oil and fuel and to
identify and clean up spilled oil and other hazardous
material.
All personnel employed on the project,especially field
personnel ,will be trained to respond to fuel spills in
accordance with an approved oil spill contingency plan.The
BMPM Oil Spill Contingency Plan includes:
Guidelines to follow for a training program for involved
personnel.
Actions to take as a first line of defense In the event of
a fuel spill.
Persons to contact in the construction organization and in
state agencies.
Records to keep during an oil spill and cleanup operation.
Oil spill containment equipment will be located onsite and
31
adequate to handle the largest potential spill.Personnel
will be trained m the operation of the equipment.and the
equipment will be inventoried and tested regularly to make
sure it is in proper working order in the event of an
emergency (Bohme and Brushett 1979;Lindstedt-Sivi,1979).
Impacts from an unavoidable major spill will be assessed by
the Environmental Field Of'f icer (EFO).Appropriate
site-specific mitigation measures will be negotiated in
consultation with the involved resource management agencies.
(e)Borrow Sites
(i)Impact Mechanism
Removal of material may result in erosion.siltation and
increased turbidity .Borrow sites located in floodplains may
impact waterbodies through increased ice buildup from
groundwater overflow and alteration of fish habitat.Fish may
become trapped in excavations within the floodplain.
(ii)Mitigation
Adverse impacts on aquatic habitats will be avoided or
minimized by application of the BMPM guidelines.The
predominant source of borrow material will be alongside the
access road.Minimal impacts to the aquatic resources are
expected from side-borrow activities.
Borrow Site 0 (Figure 17)will be used predominantly for the
access road construction.Overburden at the site will be
stockpiled for later use in contouring and replanting the
borrow area.Berms or dikes will contain surface runoff to
reduce the discharge of highly turbid water into Deadman
Creek.Turbid water will be channeled through settling ponds.
32
Soil stabilization measures will be undertaken to limit
erosion of exposed slopes as described in the BMP manual on
Erosion and Sedimentation Control (APA 1985a).
Borrow Site E is located at the confluence of Tsusena Creek
and the Susitna River.Small amounts of borrow for access
road construction will be excavated from Borrow Site E.
Impacts associated with Site E will be minimized by adherence
to the BMPM and as explained in section 3.1.1.Erosion will
be reduced by stockpiling materials outside the floodplain and
retaining buffers between the excavations and the active
channels.Dragline operations in the active channel will be
avoided if possible.
Material washing operations will use recycled water.This
water will not be discharged 'into adjacent streams or lakes
unless the effluent conforms to ADEC and USEPA standards for
turbidity and suspended solids (18 AAC 70.020).Settling
ponds and stilling basins will be used to improve water
Quality.
The borrow sites will be rehabilitated after excavations have
ceased .The sites will be revegetatcd to reduce erosion.
Borrow Site E will be shaped and contoured to enhance fish
habitat as described in Section 3.2.1.Man-made objects will
be removed from the sites to the greatest extent possible.
Rehabilitated areas will be monitored to verify the
effectiveness of grading,revegetation and other mitigative
measures.
2.2.2 Monitoring
Monitoring is recognized as an essential project mitigation feature that will
provide for a reduction of impacts over time.Monitoring will be conducted during
33
project construction and operation:
To insure that environmentally acceptable construction practices.as defined by
the bid specifications,required permits and the BMPM's,are being employed on
the project
To evaluate the effectiveness of the operation and maintenance of mitigation
features
To recommend changes in construction practices or mitigation features to
further avoid,minimize,or reduce impacts
Monitoring of the access road construction will verify that proper construction
practices,as detailed in the BMP manuals,are being followed .This monitoring
activity will cover all aspects of the access road construction and maintenance.
Construction of tile Watana access road is presently scheduled to begin in January
1989.From that time until completion of all access roads,an Environmental Field
Officer (EFO)will be present at the sites.On a daily basis,the EFO will visit
areas where constr v -ition is occurring.The EFO will be responsible for compliance
with regulatory requirements and permits.The EFO will be a member of the APA
staff and will report to the APA's resident engineer and construction manager.
Once construction has begun,onsite changes in permit stipulations may be needed
because of accidents or changes in construction techniques.If a variation is
required,the EFO will notify APA's construction manager who will contact
regulatory agencies to amend permits or authorize field actions that were 11(1'.
specified in the permits.The construction manager will report permit violations,
issue monthly status reports to the resource agencies.The construction manager
will also be responsible for notifying the appropriate agencies prior to the
commencement of a major construction activity so that the regulatory agency may
request a site inspection .
Long-term operational monitoring will be conducred to evaluate the effectiveness
of the mitigation plan.Arctic grayling populations will be studied (Harza-Ebasco
34
1985c) to evaluate the effectiveness of management plan designed to minimize the
impact caused by increased fis;ling pressure in lakes and streams.The access road
will be periodically monitored as part of the maintenance schedule.Chronic
erosion sites will be identified and corrected;culverts will be inspected for
debris blockages that could prevent fish passage.
The monitoring program costs outlined for the project are estimated in Table 8.
35
3 -CONSTRUCTION
The proposed three-stage development of the Susitna Hydroelectric Project will
entail construction at two dam sites.Construction on the Stage I development of
the Watana dam is scheduled to begin in 1990 (Figure 6).Site preparation is
expected to start in 1989 and will include camp and village development.The four
turbines are scheduled to be on-line for power production in 1997.The Stage 2
development,to be initiated in 1995,will involve the construction of the Devil
Canyon dam and temporary camp facilities.In 2002,Stage 3 construction will
raise the crest elevation and increase the generating power of the Watana dam.
The additional two turbines in the Watana dam are expected to be on-line in 2008
(Figure 6).
The construction activities will affect the aquatic resources in the vicinity of
the sites.Changes in nearby water bodies and fish habitat will result;a loss of
habitat will occur at the dam sites.Borrow site excavations will disturb aquatic
habitat at the mouths of Tsusena and Cheechako creeks.Water quality
degradations,including increased sediment levels,hydrocarbons and wastewater
effluent contributions may temporarily decrease aquatic habitat quality .Fish
will be directly affected as migration barriers will be created by dam
construction.
Mitigation of these impacts in order to preserve the aquatic resources will be
primarily accomplished by proper adherence to the construction techniques
presented in the BMPM (APA 1985a,1985b.1985c,1985d.1985e).Additional
mitigative measures,such as borrow site rehabilitation,will rectify the impacts
associated with dam and camp construction.Monitoring will verif y that
construction activities Follow the BMPM and that water quality is not
significantly degraded.
3.1 -Imoact Analysis
3.1.1 Watana Dam and Facilities
The proposed Watana dam and related fac ilities will be constructed at RM 184
36
on the Susitna River between Deadman Creek (RM 187)and Tsusena Creek (RM
182)(Figure 4).The Susitna River is a large glacier fed river,turbid
during summer and clear during winter .The dam site is probably occupied by
burbot,sculpins,and longnose sucker during the open water season and by
these species and Arctic grayling during winter (ADF&G 1981,1983).
Tsusena Creek is a clearwater stream with a drainage area of 144 square miles
(373 km 2).A waterfall approximately 3 miles upstream of the confluence with
the Susitna River blocks upstream fish passage.Dolly Varden and sculpin are
present above the falls on Tsusena Creek (Sautner and Stratton 1984).Arctic
grayling,Dolly Varden,and sculpin utilize the habitat available in lower
Tsusena Creek (Sautner and Stratton 1984)and burbot and round whitefish
have been observed near its confluence with the Susitna River (ADF&G 1981,
1983).The Arctic grayling population in the mouth of Tsusena Creek and in
the clearwater plume which extends into the Susitna River was estimated at
1,000 fish (ADF&G 1981).Although excellent habitat is present within the
lower reaches of the creek,few Arctic grayling appear to utilize this area
for summer rearing (ADF&G 1983).
Deadman Creek,a meandering,clearwater tributary of the Susitna
River,supports Arctic grayling of trophy size,Dolly Varden and sculpin
(Sautner and Stratton 1984).A turbulent section prevents upstream fish
passage approximately 0.6 miles (I km)from the mouth of Deadman Creek.In
1981 and 1982,approximately 980 and 730 Arctic grayling were estimated to
inhabit the reach downstream from the fish barrier during summer (ADF&G 1981,
1983).Burbot and longnose sucker have been observed near the creek mouth
(ADF&G 1981).The creek has a drainage basin area of 175 square miles (453
2km ).
(a)Description
The Watana dam will be an earthfill structure located between RM 184 and
RM 185 of the Susitna River .The Stage I development of the Watana dam
will be built to a crest elevation of 2025 ft (617 00)with a maximum normal
reservoir elevation of 2000 f t (610 00).One outlet facility structure and
37
two power intakes will be designed to discharge a 50-year flood before the
spillway overflows (Figure 8).The powerhouse will have four power
generating units.
During Stage 3,the Watana dam will be raised to a crest elevation of
2205 ft (672 m)(Figure 18).The maximum normal reservoir elevation will be
increased to 2185 ft (666 m).The concrete spillway,outlet facility
structure and the two power intakes will be raised.A third power intake and
two additional power generating units will be constructed.Upon completion
of the Stage 3 development,the dam will be approximately 0.75 mile (1.3 km)
wide,0.75 (1.3 km)mile long and 885 feet (267 m)high.Over 62 million
cubic yards (47,500,000 m 3)of material will be used to construct the dam.
Clearing will be necessary at the dam site and in the impoundment area.
Cover vegetation will be removed at the site of the dam and construction camp
and village facilities.In the reservoir area,trees will be cleared
annually to the expected water level of inundation to reduce debris
accumulation at the dam water intakes.Cleared material will be stockpiled
or burned at specified disposal sites upstream of the Watana dam site (Figure
8)that will be subsequently inundated.
Prior to construction of the Stage I main fill structure,the diversion
tunnels and cofferdams will be completed and the river diverted through the
tunnels.Heavy equipment will be brought to the cleared site.Construction
material will be stockpiled in the project area .Fill material from the
borrow pit sites and usable material from excavation of the diversion tunnels
will also be stockpiled.Blasting will be necessary during diversion tunnel
construction and borrow excavations.During Stage I construction,rockfill
for the dam will be obtained from tunnel and channel excavations.Water
required for construction purposes will be withdrawn from the Susitna River.
The two cofferdams Will dewater the construction area of the main dam .One
cofferdam will be built upstream from the darnsite and the other downstream
(Figure 8).The upstream cofferdam will be approximately 800 feet (242 m)
long and 450 feet (136 m)wide;the downstream cofferdam will be 400 feet
38
(121 m)long and 200 feet (60 m)wide.Water blocked by the upstream
cofferdam will be diverted into two 38 foot (11.5 m)diameter concrete-line:
tunnels about 4100 feet (1240 m)long.The cofferdams will be constructed
during a two-year period (1990-1991)and will remain in use until reservoir
filling begins.At that time,the downstream cofferdam will partially be
removed;the upstream cofferdam will be inundated by the reservoir.
Gravel mining and material sorting will be required for construction of
the dam and related facilities.During Stage 1 development,approximately
10 million cubic yards (7.5 million m 3)of material will be excavated from
Borrow Site E between RM 180 and RM 182 along the north bank of the S i m a
River at the confluence of Tsusena Creek (Figure 7).Material around Tsus 1
Creek and the mainstem of the Susitna River will be removed.Depending
material quality and quantity,the borrow sites will be scraped or pit
excavated.Prior to material removal,a mining plan will be formulated in
accordance with 43 CFR Part 23;review and approval by concerned state a
federal resource managing agencies will be required.A pit excavation is
expected at Tsusena Creek.Gravel will be excavated,washed,and stockpile
during spring,summer and fall.Winter excavation is not proposed .The
gravel will be washed at the borrow sites;wash water will be channeled
through settling ponds and reused.Effluent from the settling ponds will
conform to the ADEC/lJSEPA standards.
Excavation of I million cubic yards (0 .75 million m 3)of gravel material wi
be needed for the Stage 3 development of the Watana dam.The upstream
regions of Borrow Site E (Figure 19)are not expected to be inundated by t
Devil Canyon reservoir,which has a normal operating elevation of 1455 ft
(443 m) to 1405 ft (428 rn),with the drawdown occurring from June to Au !l.
Additional gravel material in the downstream area of the borrow site will t
exposed during drawdown and will be available for excavation during
construction of the Stage 3 raising of the Watana dam.Excavation to remo
the needed amounts of material may necessitate the use of cofferdam
structures and/or dragline operations.
39
Overburden,vegetation and unusable material from construction sites will be
removed to selected disposal sites upstream from the dam site with in the area
of permanent inundation (Figure 8).Haul roads will be constructed to
these sites (Section 2.4.1).The reservoir area will be cleared of large
trees pr ior to inundation.
Housing of project personnel will be needed at the Watana site.During Stage
1 construction of the Watana dam.facilities to house a maximum of 2625
people are anticipated .The facilities will be located adjacent to the
construction site to simplify transportation to and from the camps.Two
campsites have been selected:the construction camp near Deadman Creek will
be located approximately 2 miles from the dam,and the construction village
will be within a mile of the site.Each development will occupy
approximately 170 acres (68 hal.Approximately 1510 people are expected to
be housed in the Watana construction camp and village during Stage 3
development.A permanent townsite encircling a 25 acre (10 hal lake (Figure
8)will be developed at the construction village site for personnel who will
operate and maintain the dam while the construction camp will be dismantled
and the site restored.
The construction camp will contain the management offices,hospital,
recreation hall,warehouses,communications center,bachelor dormitories,and
other necessary facilities.The wastewater treatment plant will be located
within the camp boundaries approximately 2,000 ft (610 m)from Deadman Creek .
It is anticipated that the camp,excluding the treatment plant.will be
dismantled,at the end of the Stage I development of the Watana dam
construction.The camp will be rebuilt and utilized during the Stage 2
construction at the Devil Canyon Dam site.Upon completion of the Devil
Canyon dam,the Watana construction camp will be reassembled for the Stage
3 development.
The construction village will be built during the Stage I development and
will be upgraded to a permanent town.The construction village will be maue
up of 320 temporary housing units and an additional 240 lots with utilities
furnished.The temporary housing units will be used primarily for workers
40
who are accompanied by families and will be removed to the Devil Canyon site
when construction of Stage 1 Watana is complete.The permanent town will be
built to house the families of employees who will form the operation and
maintenance team for Watana.The town will contain a hospital,a school,gas
station,fire station,store.recreation center.and offices,as well as
residences.
Construction uses for water will require withdrawal from waterbodies in the
vicinity of construction activities.The Susitna River will be the source
for water to be utilized in dam construction.Water will be utilized
throughout the construction process in activities such as concrete
production,aggregate washing and dust control.Concrete batching and
wastewater generated by the production of concrete for the tunnel lining.
spillway and powerhouse construction and grouting will be collected and
treated in settling ponds prior to discharge.Concrete wastewater pH levels
are high (10 +)and will be neutralized prior to discharge.A water
appropriation permit application will be filed with the ADNR as required by
AS 46 .15.070.In addition,the ADF&G and the ADEC will be consulted for
approval and permittn.g of water withdrawal.
Water for camp and village use will be withdrawn from Tsusena Creek and
wastewater will be piped to the treatment plant near Deadman Creek.
The Tsusena Creek intake will be located 6 miles (10 km)upstream from its
confluence with the Susitna River.The water will be treated to conform with
the primary and secondary requirements of the ADECjUSEPA for domestic use in
the construction camp and village.An estimated 1.5 cfs will be needed
during peak demand periods.Wastewater will receive secondary treatment
prior to discharge into Deadman Creek.The wastewater outfall will be
located in a turbulent section of Deadman Creek approximately 1.5 miles (7.5
km)upstream of its confluence with the Susitna River;thorough mixing is
expected rapidly.The sewage treatment system will serve both the
construction camp and village and will later be used for the permanent town.
The sewage treatment plant will include a biological treatment lagoon to
provide secondary treatment.A mechanical aerator will maintain biological
activity in the lagoon during the winter.Solid wastes will be disposed in a
41
lined.bermed and capped sanitary landfill situated between the camp and
village.
Hazardous wastes will be temporarily stored onsite in a bermed and lined
area and then removed for disposal.Waste oils containing trace metals
require handling as a hazardous waste under 40 CFR 261-265 .Solvents and
other chemicals of concern.including antifreeze,hydraulic oil.grease and
paints.are also toxic to aquatic life and will be stored in the hazardous
waste area.Vehicles will be maintained to prevent antifreeze,hydraulic
fluid and fuel from contaminating nearby water.Fuel will be stored and used
in large quantities during construction.Fuel tanks will be surrounded by
containment dikes capable of containing 110 percent of the tank capacity.
Fuel storage areas will be lined with impermeable materials to prevent fuel
contamination of groundwater.Vehicle fueling will be restricted to areas
where runoff will be collected.Oily water runoff from the dam site and
surface runoff at the vehicle maintenance areas,shops and related facilities
will be collected and treated.All fuel spills will be reported to the ADEC
as required by law.The contractor's Spill Prevention,Containment and
Countermeasure plan (SPCC)will be developed and personnel trained prior to
the initiation of construction as described in Section 2.1.1.
A 2500 foot (758 m)temporary airstrip will be built approximately I mile
(1.6 km)from the damsite at the 2200-2300 foot (667-697 m)level.The
airstrip will later be upgraded to a permanent airstrip which will be 6000
feet (1818 m) long.
(b)Potential Impacts
The construction of the Watana dam and camps will have a number of effects on
the Susitna River,nearby tributaries and their biota.Some effects will be
the direct result of construction activities,while other effects will result
from alteration of the river environment during construction.Impacts will
vary in duration and overall extent,some being temporary or localized while
others will be permanent or more widespread .
42
o Cofferdams and Diversion Tunnels
The first major phase of Stage I dam construction involves placement
of the two cofferdams and the permanent dewatering of 0.75 mile (1.3 km)
of riverbed at the damsite.Fish normally using this stretch are
anticipated to move into adjacent habitats.The effects on population
size are expected to be minor.The dcwatered area will eventually be
totally covered by the Stage 3 Watana dam;thus,the effect will be
a permanent but relatively minor loss of aquatic habitat.The Stage
dam will cover approximately 300 ft (91 m) less riverbed on the
downstream side (Figure 18),than the Stage 3 dam.
Upstream fish movements through this reach will be permanently blocked
when the Stage 1 development occurs.Arctic grayling seem to
predominantly return to the stream utilized in previous migrations from
the mainstem (ADF&G 1983).However,some Arctic grayling are expected
to migrate to other streams upstream and downstream along the Susitna
River (ADF&G 1983).For example,Arctic grayling tagged at Deadman
Creek have been recaptured at Tsusena and Fog creeks (ADF&G 1981, 1983).
The permanent upstream fish passage blockage between Deadman and Tsusena
creeks is not expected to cause major degradation in the aquatic
resources as migration appears to occur in both the upstream and
downstream directions.Interstream movements from Deadman Creek will
remain possible in the upstream direction;from Tsusena Creek,
interstream movements will remain possible downstream.
The cofferdams will impound water and raise water levels upstream
from the damsite.During the summer,a flood event equal to the
once-in-50-year flood will cause a water level of 1536 feet (465 m),
thus causing backwater effects for several miles upstream.To avoid ice
problems in the diversion tunnel during the winter.a control gate will
be partially closed to create a head pond approximately 50 feet (15 m)
deep.The water will be ponded to an elevation of 1470 feet (445 m)
affecting about 0.5 mile (0 .8 km)of river upstream from the cofferdam.
This backwater impoundment will provide additional mainstem hab itat
43
which is expected to be used by overwintering resident species.
The tunnel diversions during the Stage I dam construction will impact
fish in the vicinity.Arctic grayling and other resident fish
overwinter in mainstem habitat,and physical conditions within the head
pond will provide substantial overwintering habitat.Fish residing in
the impoundment upstream from the tunnels may be entrained into the flow
and transported downstream from the darnsire.If river transport
mechanisms move rocks and other materials into the tunnels,or if the
tunnel walls are not smooth,fish may be damaged through abrasion while
being transported downstream.Water velocities within the tunnels
witJ act as a barrier to upstream fish passage.
Experiments with fish transport indicate that fish are adversely
affected when exposed to velocities in excess of 9.0 f'r/sec (2.7 m/sec)
(Taft et al. 1977).Tunnel velocities are expected to exceed 18 f't/sec
(S.4 m/sec)during much of the summer (APA 1983c).However,little
impact on populations is expected since relatively few resident fish are
believed to occupy the mainstem area immediately upstream from the
tunnels during the summer.As water levels increase during the winter
months,entrance velocities into the tunnels are expected to be in
excess of 20 f't/sec (6 m/sec)(APA 1983c).Overwintering fish in the
head pond are likely to be entrained into the tunnels,and would likely
result in fish mortality.
Several agencies (ADF&G and TJSFWS)suggested that a grating at the
intake of the diversion tunnels would a void fish entrainment.However,
the installation of a fish screen would have temporary value since the
habitat within the impoundment is expected to be poor and most fish are
likely to seek alternative habitat.The cost associated with the
construction and maintenance of a screen does not appear justifiable
relative to the small number of fish potentially transported downstream.
Habitat immediately downstream of the diversion tunnels will be impacted
by the high discharge velocities at the downstream end of the tunnels.
44
The high velocities will deter f'ish from using the area immediately
downstream from the tunnels (Bates and Vanderwalker 1964;Stone and
Webster 1976)during dam construction and operation.Gravels,sands and
silts will be scoured from the immediate area of the tunnel outlet,and
suspended sediment levels will initially increase.This increase is
expected to be negligible relative to the.naturally turbid summertime
water conditions of the mainstem.However,during the winter,sediment
transport is anticipated to increase above natural winter levels.
Scouring of the glacial till in the channel bed would predominantly
cause an increase in bed load and the turbidity of the river is expected
to remain low.
o Borrow Activities
Impacts associated with borrow activities include habitat alterations
and temporary reductions in habitat quality from water quality
degradations caused by increases in suspended sediments and
hydrocarbons.A long-term aquatic impact is expected due to the
excavation in the vicinity of the mouth of Tsusena Creek.The volume of
material to be removed will result in a large pit that will become
filled with water.This pit will be rehabilitated to produce increased
lentic habitat replacing lost riparian and upland habitat as described
in Section 3.2.1.Other aquatic impacts from gravel removal operations
may be avoided or minimized by adherence to the BMPM on Erosion and
Sedimentation Control (APA 1985a).Gravel removal activities will
conform to the Gravel Removal Guidelines of the USFWS (Joyce et al.
1980b).
At Borrow Site E.the installation of a stream crossing structure at
Tsusena Creek will introduce small amounts of hydrocarbons and suspended
sediments into the creek.To avoid or minimize hydrocarbon
contamination,fuel utilized in borrow activities will be stored and
equipment refueled in a bermed and lined area.Accidental petroleum
spills will be avoided or contained according to the BMP Oil Spill Plan
detailed in Section 2.1.1 (APA 1985e).
4S
The Stage 2 development will change the quality of the aquatic habitats
with the rehabilitated Borrow Site E.The operation of the Devil Canyon
dam will impound a reservoir to a maximum normal operating elevation of
1455 ft (443 m).The reservoir wilt partially inundate Borrow Site E as
shown in Figure 19.Following inundation,the water quality of the
rehabilitated pit will reflect the reservoir water quality
characteristics.The productivity in the Devil Canyon reservoir is
expected to be poor because of high turbidity levels,cool temperatures
and low nitrogen and phosphorus nutrient levels.However.fish
utilization around the areas of tributary inflow.such as at the mouth
of Tsusena Creek,is expected to be higher than elsewhere in the
reservoir .A detailed description of the water quality and habitat
availability in the reservoir is contained in Exhibit E.Chapter 2 of
the License Application (APA 1983c).
During the Stage 3 development of Borrow Site E,temporary increases
in suspended sediment levels and instream disturbances may cause fish to
avoid habitat in the vicinity of the mouth of Tsusena Creek.The
additional gravel excavations,even though conducted in accordance with
the BMPM (APA 1985c)and the USFWS Gravel Removal Guidelines (Joyce et
al.1980b).may increase suspended sediment levels in the Devil Canyon
reservoir;relative to the expected reservoir turbidities,the sediment
contribution is not expected to significantly degrade the water quality .
Borrow activities may temporarily disturb fish utilizing habitat at the
mouth of Tsusena Creek.The sites of gravel excavation will be
rehabilitated following the cessation of material removal.
Excavation.in accordance with the BMPM on Erosion and Sedimentation
Control (APA 1985a),is not expected to have significant aquatic impacts
at upland sites such as Borrow Site D and Quarry Site A.Suspended
sediment increases at all borrow sites will be avoided or minimized by
retaining buffers at stream margins,collecting runoff and monitoring
settling pond effluents.Buffer zones of uncleared vegetation or
overburden will reduce sediment contributions to streams and lakes.
Runoff will be channeled away from waterbodies providing aquatic habitat
46
to minimize erosional impacts.The effluent discharged from the
settling ponds will be monitored and the ponds will be dredged when the
water Quality approaches the ADEC/USEPA standards.
o Fill Placement
The movement and usage of fill materials for the cofferdams and the main
dams will be conducted according to BMPM guidelines (APA 1985a)to avoid
or minimize turbidity and siltation impacts at the dam site and
construction camps.During the transport,storage and placement of the
fill material used in construction,material spills will be avoided to
prevent impacts to adjacent water bodies including the mainstem Susitna
River.Runoff control str uctures will be installed to channel surface
runoff into settling ponds prior to discharge to the Susitna River.The
placement of fill material during cofferdam construction will raise
suspended sediment levels downstream.However,the cofferdams will be
constructed during the summer and the resulting increase in suspended
sediments relative to the natural summer conditions is not expected to
significantly affect the aquatic resources downstream.Residual
increases in mainstem turbidity are expected to be negligible.
o Water Removal
All water removal operations will adhere to the BMPM guidelines (APA
1985b)in order to avoid or minimize potential impacts.All water
intakes will be screened and sized according to the ADF&G intake design
criteria to prevent fish entrapment,entrainment or impingement.Since
low volume pumps equipped with proper intake screens will be used,it is
expected that the number of affected fish will be low.
In accordance with the BMPM (APA 19~5h),a maximum of 370 cfs will be
withdrawn from the Susitna River during the open water season;under
frozen conditions.10 percent of the flow at the time of withdrawal,an
expected volume of 200 cfs,will limit the withdrawal quantities.These
47
maximum withdrawal quantities are expected to exceed the volumes
required for construction.The potential for dewatering of habitat in
the Susitna River is negligible.
The estimated I.S cfs which will be needed to meet peak domestic use
demands in both the construction camp and construction village presents
less than a one percent reduction in Tsusena Creek flow during the
average open-water season,and little impact is expected to result from
decreases of this magnitude.A maximum reduction of approximately 8
percent is expected during the winter period;overwintering Dolly
Varden,Arctic grayling and sculpin which may be present in deep pools
downstream of the intake are not likely to be adversely affected by the
water withdrawal.
Installation of the water withdrawal structure will follow the BMPM
guidelines (APA 1985b).Turbidity and suspended sediment levels will
increase temporarily during installation of the water intake system.
Impacts associated with this instream activity will be short in duration
and will cause negligible impacts to the aquatic resources if proper
construction practices are used.
o LiQuid and Solid Waste Management
Liquid and solid wastes will be managed in accordance with the BMP
techniques outlined in the manual on Liquid and Solid Waste Management
(APA 1985c) to minimize water Quality degradations.Wastewater from
construction and domestic activities will be monitored to verify
conformance with ADEC/USEPA standards and the wastewater disposal
permits.Potential aquatic impacts are not expected from the collection
and disposal of solid wastes in conformance with the BMPM (APA 1985c).
Residual impacts from waste disposal will not significantly affect the
aquatic habitat or the productivity of the aquatic system.All
necessary permit applications for discharge will be obtained from the
ADEC,USEPA,ADNR and PHS and include the ADEC wastewater and waste
disposal permits,a Federal Water Quality Certification and a National
48
Pollutant Discharge and Elimination System Permit.
Aquatic impacts on the Susitna River from wastewater generated during
construction activities are not expected .The wastewater will be
treated and neutralized prior to discharge.During the Stage
development,the construction wastewater will be discharged into the
Susitna River;mixing is expected to occur rapidly in the large,swift
river.During the Stage 3 development,the effluent discharged into
the river will be introduced into the Devil Canyon reservoir.The
effluent quantities will be insignificant relative to the reservoir
volume.
The BMP manual on Liquid and Solid Waste Management (APA 1985c)will be
applied to avoid impacts on fish habitat located downstream from the
effluent outlet into Deadman Creek.Secondary treatment will avoid
many of the problems associated with primary treatment.such as
decreased dissolved oxygen and increased biochemical oxygen demand (BOD)
and bacterial counts (Warren 1971).If disinfection is required,an
additional lagoon will be needed to provide the residence time to reduce
the total residual chlorine to the USEPA Chlorine standard of 2 mg/)for
salmonids.Arctic grayling,the primary species in Deadman Creek,are
considered to be very sensitive to alterations in water quality.The
effluent BOD and the concentration of total suspended solids (TSS)are
both estimated to be 30 mg/I,levels which conform to water quality
standards set by the Clean Water Act (USEPA)and the ADEC Wastewater
Disposal regulations (18 AAC 72).The treated wastewater will introduce
increased levels of phosphorus and nitrogen into Deadman Creek.A large
increase in production in Deadman Creek is not expected as the
wastewater outfall in Deadman Creek will be located in a turbulent
secti-.n and thorough mixing is expected rapidly.The maximum effluent
discharge from Watana camp is expected to be 1.5 cfs;the I in 20 year,
3D-day low flow for Deadman Creek is estimated to be 27 cfs (APA 1983c).
Following mixing,at this low flow,the BOD and TSS levels in the
effluent will be diluted to approximately 2 mg/1.
49
Nitrogen and phosphorus loadings will be similarly diluted.The water
Quality in Deadman Creek is thus not expected to be signif'icantly
degraded by the effluent contributions.
The diluted effluent is not expected to degrade the water quality in the
Watana reservoir by a measurable amount.During Stage 1 dam
construction,the effluent from the wastewater treatment plant will
rapidly become mixed with the water in Deadman Creek;maximum dilution
is expected before Deadman Creek enters the impoundment created behind
the cofferdams.During the Stage I operation,the maximum normal
reservoir elevation will be 2000 ft (610 m).The outfall will be
approximately 100 ft (30 m)upstream along Deadman Creek from the
reservoir at this elevation.Although complete mixing of the effluent
may not occur in the 100 ft (30 m)reach of creek,the large
volume of the reservoir is likely to assimilate the effluent completely
and water quality degradations in the impoundment are expected to be
undetectable.The effluent outlet will be inundated during the Stage
3 operation of the Watana dam.The effluent is not expected to
significantly degrade the water quality in the Stage 3 Watana reservoir.
o Disposal Sites
Adherence to the BMPM guidelines (APA 1985a)for disposal of material
will avoid or minimize adverse impacts on the aquatic resources.Runoff
control berms will minimize turbid water contributions to nearby streams
and lakes.Disposed material will be covered with a layer of coarse
gravel or shot rock to minimize erosion.Suspended sediment increases
will be temporary.Residual aquatic impacts are not expected.
The disposal sites will be partially inundated upon Stage I Watana
reservoir filling.Turbidity may increase locally during inundation;
however,relative to the large volume of water in the reservoir,
turbidity increases will be insignificant.
50
During the Stage 3 development of the Watana dam,overburden,vegetation
and unusable material from the dam site will be stockpiled until
disposal in the specified disposal area on the north bank of the Susitna
River (Figure 8).Disposal will take place during the drawdown cycle of
the Stage 1 reservoir;the reservoir will reach a minimum normal
elevation of 1850 f t (564 m)approximately in April.Quantities of
disposal material for the Stage 3 development will be less than
Quantities from the Stage I development.Residual aquatic impacts are
not expected if activities conform to the BMPM on Erosion and
Sedimentation Control (APA 1985a).
o Clearing
Clearing of vegetation will utilize the BMPM techniques (APA 1985a)to
minimize erosional impacts on nearby waterbodies.Increases in local
runoff may occur due to clearing activities and cause erosion,increased
turbidity,and increased dissolved solids (Likens et a1. 1970;Bormann
et at. 1970;Pierce et al. 1970).Residual aquatic impacts from
clearing activities will not require additional mitigation beyond
adherence to the BMPM (APA 1985a).
Increases in suspended sediment contributions to nearby waterbodies will
be avoided or minimized.Vegetation at stream margins will be hand
cleared.Vegetated buffer zones will be maintained to the greatest
extent practicable as the removal of bank cover will reduce fish
habitat,may increase the exposure of fish to predators,and lead to a
decrease in fish populations (Joyce et al.1980a).Suspended solids and
siltation increases will be minimized through soil stabilization
procedures.Increased turbidity generally reduces visibility and
decreases the ability of sight-feeding fish such as Arctic grayling and
Dolly Varden to obtain food (Hynes 1966),thus effectively reducing
feeding habitat.There is a considerable amount of literature that
deals with the effects of siltation on fish (Shaw and Maga 1943,Cordone
and Kelly 1961;~w a m o t o et al. 1978),particularly the effect on
spawning and incubation.A general conclusion reached by a review of
51
the literature (Dehoney and Mancini 1982) is that the greatest adverse
impact of siltation is on immobile eggs and on relatively immobile
larval fish.In general.siltation can cause significant losses of
incubating eggs and fry in redds,particularly by interfering with
oxygen exchange and waste removal.Areas of ground water upwelling flow
would likely be affected to a lesser extent than other areas because
silt would tend to be prevented from settling.Resident fish in the
vicinity of Watana Dam.including Dolly Varden.Arctic grayling.and
round whitefish.may be affected by siltation.However.increases in
suspended sediments are anticipated to be temporary;suspended sediment
levels will return to natural levels following cessation of construction
activities in accordance with the BMPM techniques (APA 1985a).
o Fuel and Hazardous Materials
The BMP manual on Fuel and Hazardous Materials (APA 1985d)outlines
handling and storage requirements to a void hazardous waste impacts.
Accidental oil spills will be avoided or contained by adherence to The
BMP manual on Oil Spill Contingency Planning (APA 1985e).Adherence to
these guidelines will avoid or minimize potential impacts associated
with fuel and hazardous material usage as described in Section 2.2.1.
Residual aquatic impacts are expected to be minor during typical
construction activities;accidental spills of material will have greater
impacts on the aquatic environment and require additional mitigation .
Waterbodies in close proximity to the construction sites may receive
small amounts of hydrocarbons.By providing proper drainage facilities.
ponding areas.and if necessary.pump stations to pump contaminated
water to the treatment facility.most oily and silty water will be
prevented from reaching Tsusena and Deadman creeks.The lake at the
village site will be more susceptible to intrusions of oily water.
Runoff control measures such as trenches alongside road ways will collect
runoff to avoid impacts to the lake.The water quality is not expected
to be detectably impacted by the hydrocarbons in such small quantities.
52
An accidental spill.however.would severely affect the aquatic biota in
nearby creeks and lakes.
a Blasting
Current construction plans do not require instream blasting.Blasting
is planned for areas 500 feet (150 m) or more from streams.A review of
the effects of blasting on aquatic life (Joyce et at.1980a.Teleki et
al.)indicates that effects from such blasting would probably not be
lethal to aquatic organisms (at least with charges of less than 200 kg
of TNT).The transmitted shock waves from the blasting may disturb fish
and perhaps temporarily displace them from areas near blasting activity.
This type of behavior is well documented for a variety of noise sources
(Vanderwalker 1967;Latvaitis et at. 1977;USEPA 1976).Secondary
effects of blasting.including increased turbidity and siltation caused
by loosened soils and dust.will be avoided by adherence to the BMPM
(APA 1985a).Instream blasting will adhere to the ADF&G standards
(Table 9)for the Susitna River.The location and amount of blasting
planned during the Watana dam construction is not expected to
significantly impact fish.Quarry activities are expected to be distant
enough to have negligible impacts.
a Recreational Impacts
Construction and operation of the dam and camps will result in
increased access to an area previously exposed to minimal fishing
pressure.The areas expected to sustain the heaviest harvest pressure
would be those stretches of Deadman and Tsusena Creeks and the Susitna
River that are easily accessible from the camps and the damsite.The
resident fish populations are thought to be at their maximum level.
i.e.•they are at their carrying capacity (ADF&G 1981).Studies to
date have indicated a relatively high percentage of "older"age group
fish (up to 9 years)(Sautner and Stratton 1984).Sportfishing will
inflict heaviest impacts upon larger,older fish and would likely result
in a change in the age distribution of the population (Schmidt and
Stratton 1984).However,increased fishing pressure is likely to result
from the construction of the access road (Section 2.2.1)and
construction of the dam will not incrementally increase fishing pressure
significantly.
3.1.2 Devil Canyon Dam and Facilities
The Devil Canyon dam will be situated on the Susitna River at RM 152 approximately
2 miles (3 km)downstream from the Cheechako Creek confluence (RM 154)and
represents Stage 2 of the Susitna Hydroelectric Project.The high velocities in
the Susitna River are believed to deter fish from utilizing habitat at the dam
site (ADF&G"1981).Fish are usually prevented from migrating upstream of Devil
Canyon because of the high water velocity.However,a relatively small number of
chinook salmon have been observed upstream of the Devil Canyon dam site (ADF&G
1981, 1983,Barrett er al. 1985). A maximum of 46 chinook salmon per year were
observed upstream of the Devil Canyon dam site between 1981 and 1984 (ADF&G 1981,
1983;Barrett et a1. 1985).
Cheechako Creek is a clearwater stream supporting Arctic grayling,Dolly Varden
and probably sculpin (Barrett et al. 1984). A few chinook salmon are known to
utilize the lower reaches of Cheechako Creek;between 1981 and 1984, a maximum of
29 chinook salmon were observed in Cheechako Creek (ADF&G 1981, 1983,Barrett et
al. 1985).During the low summer flows associated with the operation of Watana
dam,chinook salmon are likely to pass the Devil Canyon dam site.
(a)Description
The Devil Canyon dam will be located at RM 152 of the Susitna River,
approximately 32 miles (53 km)downstream from the Watana dam site.At the
Devil Canyon dam site,the Susitna River is confined to a canyon
approximately 600 feet (180 m)deep and 200 to 400 feet (60 to 120 m)wide at
river level.During the Stage 2 development of the Susitna Hydroelectric
Project,a thin concrete arch dam will be built at the downstream end of
Devil Canyon and connect to an earth/rockf ill saddle dam that will be
constructed at the south end of the arch dam to provide closure of a low area
54
at the south abutment.The dam foundation will cover about 90 ft (27 m)of
river bottom.Construction of the dam will require excavation in the river
channel.The reservoir behind Devil Canyon will cover 7800 acres (3120 ha)
and will be about 32 miles (53 km)long and not more than 0.5 mile (0 .8 km)
wide.
The concrete dam and foundation will be 646 feet (195 m)high with a crest
elevation of 1463 ft (446 m)and a crest length of 1650 feet (500 m).An
estimated 2.7 million cubic yards (2.052.000 m 3)of concrete will be needed
to construct the arch dam.The saddle dam will be 950 feet (287 m)across
and 245 feet (74 m)high with a crest elevation of 1472 ft (449 m)and will
require about 1.2 million cubic yards (912,000 m)of earth and rockfill
material.Gravel for filler material and for concrete aggregate will be
required.
Material for filter material and for concrete aggregate will be obtained from
the Susitna River at the dewatered dam site,Borrow Site G and Quarry Site K.
Borrow Site G is located at the confluence of Cheecha ko Creek and the Susi tna
River.A pit excavation is expected at Borrow Site G.Quarry Site K is
approximately 400 ft higher in elevation and 1.5 miles (2 km)upstream from
the mouth of Cheechako Creek.The locations of sites G and K are shown In
Figure 17;other borrow sites may be utilized if material quantities are not
adequate at sites G and K .
As with the Watana dam,the Devil Canyon dam will have an underground
powerhouse,intake structure,outlet works,and main and emergency spillways.
A 39 foot (11.8 m)diameter tailrace tunnel will convey t he turbine discharge
approximately 1.3 miles (2.2 km)downstream from the arch dam.
During construction of the dam,the river will be blocked above and below the
construction site by cofferdams.The flow will be diverted into a 30 foot
(9 m)diameter horseshoe tunnel,1490 feet (451 m)long,and discharged back
into the river channel.The upstream and downstream cofferdams will be about
400 feet (120 m)long and 200 to 4,')0 feet (60 to 120 m)wide (Figure 16).
55
During construction of the Devil Canyon dam,housing will be required for
1900 persons.The construction camp and construction village will be located
between 1.7 and 3.4 miles (2.8 and 5.6 km)southwest of the dam site (Figure
20).The camp will include bachelor dormitories,cafeteria,warehouses,
offices,hospital,and recreational buildings.The village will contain
housing for 170 families and will include a school,stores,and a recreation
area.The camp will be approximately 0.5 mile (0.8 km)from the village.
Both developments will be more than 700 feet (210 m)above the Susitna River
and more than 4000 feet (1200 m)from the edge of the canyon.Water,sewage.
and solid waste disposal facilities will be shared by both developments.
Water will be withdrawn from the Susitna River and effluent from a secondary
treatment system will be discharged into the Susitna River downstream of the
water intake.
The southern boundary of the camp and the village approach within 200 ft (60
m)of the upper reaches of Jack Long Creek.Arctic grayling,rainbow trout.
slimy sculpin,chinook,pink.chum and coho salmon are known to utilize Jack
Long Creek (Sautner and Stratton 1984). A small unnamed creek.which enters
the Susirna at RM 150.drains a series of lakes 3000 feet (90"0 m) to the east
of the camp.The creek is paralleled by the sewage outfall line for 1000
feet (300 m)or about 20 percent of its length.The unnamed creek and lakes
appear to provide Arctic grayling habitat.A few chinook salmon.Arctic
grayling.and Dolly Varden are found in the lower reaches of Cheechako Creek
(ADF&G 1983).
As at the Watana dam (Section 3.1.1),fuel and hazardous materials will be
stored and utilized onsitc.The fuel storage area will be located in a lined
and diked area on the south side of the construction camp approximately 300
feet (91 m)higher in elevation and 1500 ft (460 m)away from Jack Long
Creek.
Both the camps and the village are temporary developments to be dismantled
and removed when the Stage 2 construction of the Devil Canyon dam is
completed.Permanent personnel responsible for operations of the Devil
Canyon dam will live at the Watana town.No a irstr ip will be built;air
56
access will be provided by the permanent runway at Watana.
(b)Potenti;ll rmoacts
The adverse impacts upon the aquatic resources at the Devil Canyon dam site
arc expected to be similar,but of lesser magnitude,to those at the Watana
site (Section 3.1.1).Impacts from construction at Devil Canyon will be
primarily restricted to the dam site.Temporary impacts resulting from the
camp and village construction and operations are expected to be limited to
the area immediately surrounding the construction site.
o Cofferdams and Diversion Tunnel
"
Upon completion of the cofferdams and diversion tunnel,the dam site
will be dewatered as at the Watana darn (Section 3.1.1).Because the
turbulence at the site is believed to deter fish from utilizing the
aquatic habitat in the canyon,dewatering will likely have a minor
impact upon availability of suitable aquatic habitat.
The cofferdams will create a permanent upstream migration barrier to
fish in Devil Canyon.Under natural conditions,most fish species are
unable to migrate upstream through the canyon due to high water
velocities.In 1981 through 1984,chinook salmon were observed spawning
in four tributaries and tributary mouths upstream of the dam site.
However,few chinook salmon utilize this reach of river (21 to 46 fish
observed per year)(ADF&G 1981, 1983,Barrett ct al.1985)and
therefore the loss of chinook salmon spawning habitat upstream of the
darnsite is expected to be minor.
Fish migrations downstream will remain possible although high mortality
is likely if fish are abraided by the tunnel walls.Under natural
conditions,fish may migrate downstream though Devil Canyon.The extent
of downstream fish migration is assumed to be small.Fish migrating
downstream after construction of the cofferdams may be entrained into
the diversion tunnel.Entrained fish are likely to be damaged by
57 '
contact with tunnel walls.
During the winter the division tunnel will be partially closed to
impound a head pond to prevent ice problems;the impoundment may provide
overwintering habitat for Arctic grayling.However,overwintering fish
are likely to become entrained into the tunnel and transported
downstream .The impoundment is not expected to provide substantial fish
habitat.
o B0rrow Sites
The greatest impacts during construction of the dam and related
facilities are likely to be associated with gravel mining and processing
in Borrow Site G.However,all borrow activities will be conducted in
accordance with the BMPM techniques (APA 1985a)to avoid or minimize
potential aquatic impacts.Suspended sediment contributions to the
Susitna River from gravel mining will be controlled in order to minimize
adverse impacts to fish.The effects of gravel mining on aquatic
systems ha ve been discussed in Section 3.1.1.Poten t ial migration
barriers to fish in Cheechako Creek will be avoided.Residual impacts
due to borrow or quarry activities are not expected to cause a long term
degradation in the aquatic populations.
Vegetated buffer zones will be maintained around water bodies in the
vicinity.The sites will be bermed,Turbid runoff will be collected
and circulated through sediment ponds prior to release into clearwater
streams.Blasting in the quarry site is not expected to adversely
affect the aquatic resources of the region .Fish passage will be
maintained through Cheechako Creek and instream activities will be
restricted during the migration and spawning periods of Arctic grayling
and Dolly Varden as shown in Figure 5.Borrow Site G will be
permanently inundated by the Devil Canyon reservoir.
58
o Disposal Sites
Disposal sites will be located in accordance with the BMPM guidelines
(APA 1985a)to avoid or minimize impacts on the aquatic organisms as
described in Section 3.1.1.Runoff control structures will be installed
to avoid increases in turbidity or organic contributions to waterbodies
in the vicinity.Disposal sites will be situated upstream from the dam
site (Figure 16)and will be permanently inundated during reservoir
filling.Prior to inundation,disposed material will be stabilized with
a r iprap cover to minimize erosional impacts.Residual impacts on the
aquatic resources of the area from operation or inundation of the
disposal sites are expected to be negligible due to the large volume of
the reservoir.
o Water Removal
Water removal will be conducted as described in Section 3.1.1 to avoid
impacts to fish.Water for construction and camp use will be withdrawn
from the Susitna River.Required withdrawal discharges are expected to
be insignificant relative to the Susitna River discharge.
o Liquid and Solid Waste Management
To minimize water quality degradations,all process waters will be
treated prior to discharge to the Susitna River.Wastcwater from the
construction camp will be collected and treated in the Devil Canyon
sewage treatment plant.The treated effluent,less than I cfs,will not
significantly degrade the waste assimilative capacity of the Susitna
River and is expected to have no significant effect on the aquatic
environment.Water used in the concrete batch ing process,storm
drainage,and oily water runoff from the construction camp will be
collected and treated in settling ponds prior to discharge.Required
drainage facilities and retention ponds,as specified in the BMP manual
on Water Supply (APA 1985b),are expected to avoid impacts to Jack Long
Creek from uncontrolled runoff from the camp area.Residual increases
S9
in sediment levels are not expected to adversely affect spawning
habitats in Jack Long Creek or the unnamed creek nearby .
o Fuel and Hazardous Materials
Impacts associated with the handling and storage of fuel and hazardous
materials were described in Section 3.1.1.The BMP manual on Fuel and
Hazardous Materials (APA 1985d)will be followed to avoid adverse
impacts on the aquatic organisms in Jack Long Creek and other nearby
waterbodies.The BMP Oil Spill Contingency Planning manual (APA 1985e)
will be utilized to avoid or contain accidental petroleum spills.
a Blasting
Construction of the arch dam and the saddle dam will require excavation
in the dewatered river channel at the damsite,Excavation by blasting
or by mechanical means may result in the introduction of materials into
the Susima River that would be carried downstream.It is unlikely that
the damsite itself is located in a stretch of the Susitna regularly
inhabited by fish;therefore,it is expected that the excavation and
blasting required at the damsite would not disrupt fish populations.
However,the ADF&G blasting guidelines (Table 9)will be applied .
o Recre:ltional Impacts
As with the Watana dam,the most significant long-term impact associated
with the Devil Canyon dam will be the increase in fishing pressure.The
camp and village at the Devil Canyon site will house 1900 workers for
several years.As a result of the improved access and higher
population,streams and lakes in the vicinity will be subjected to
increased fishing pressure as described in Section 2.1.1.This area
has not been heavily utilized for sport fishing in the past.
The habitats most likely to be affected by increased fishing include
60
Cheechako Creek,unnamed creeks and lakes,Jack Long Creek,and to a
lesser extent,the Susitna River and Portage Creek,which enters the
Susitna River on the opposite side of the Susitna River from the camp
and village.
3.2 -Construction Mitigation
Mitigation of potential impacts associated with the construction of the Watana and
Devil Canyon dams and facilities will be achieved primarily by adherence to the
BMPM construction practices.The BMP described in the Erosion &Sedimentation
Control Manual (APA 1985a)will be followed to minimize turbidity and siltation
impacts.The BMP manual on Water Supply (APA 1985b)will be utilized to minimize
impacts associated with water withdrawal.Activities involving wastewater,
petroleum products and hazardous materials will conform to the relevant 'BMPM
(APA 1985c,1985d,1985e)to avoid or minimize potential impacts on the aquatic
resources in the vicinity.
Potential impacts are identified in Section 3.1.Section 3.2.1 contains a
discussion of the impact mechanisms and the mitigation measures that will be
applied during and after construction.Those mechanisms considered to have the
greatest potential for adverse impact to the aquatic envircnmen t are discussed
first.Avoidance,minimization,rectification and reduction of impacts are
discussed.Costs associated with the rehabilitation of Borrow Site E are
presented In Table 8; no 'other direct mitigation costs have been evaluated as
adherence to the BMPM (APA 1985a,1985b,1985c,1985d.1985e)is the primary means
of mitigation .
Continued monitoring of the construction facilities and activities will ensure
that impacts to the aquatic environment are avoided or minimized.Monitoring can
identify areas that may need rehabilitation or maintenance and areas where
previous mitigation measures are proved inadequate and remedial action is
necessary.Monitoring of construction is discussed 10 Section 3.2.2.Costs
associated with construction monitoring are outlined in Table 8.
61
3.2.1 Impact Mechanisms and Mitigation Measures
(a)Borrow Sites
(i)Impact Mech;tnism
Removal of floodplain gravel at Borrow Sites E, G and other
potential sites (Figures 7 and 17)can cause increased erosion,
siltation,increased turbidity,increased ice buildup caused by
ground water overflow,fish entrapment,and alteration of fish
habitat.
Oi)Mitigation
Gravel removal in the f'Ioodpla.ns of the Susitna River will be
conducted in accordance with the USFWS Gravel Removal guidelines
(Joyce et al.1980b)and the BMPM on Erosion and Sedimentation (APA
1985a).Buffers will be retained between the sites and any active
channels.The buffers will consist of vegetated strips and/or
dikes designed to prevent erosion and subsequent increases in
turbidity.At Tsusena and Cheechako creeks,buffers will be
maintained between the active channel and the excavations.Fish
passage will be maintained through Tsusena.Checch ako and all other
fish supporting creeks affected by borrow activities.The borrow
areas will be subdivided into aliquots;each aliquot will be
cleared and excavated prior to the commencement of borrow
activities in adjacent aliquots.Rehabilitation of the disturbed
aliquot will proceed concurrently with borrow activities in
adjacent a liquots.Rapid rehabilitation will assist in reducing
erosional impacts to the aquar.c resources.
Material washing operations will use recycled water and will not
discharge into adjacent clearwater streams.Water containing
suspended sediments will be circulated through settling ponds and
reused.Settling ponds may be maintained by dredging fine
62
materials which will be removed from the floodplain and used in
site renovation.Settling ponds will be cleared when the effluent
approaches the ADECjUSEPA standards.Upon closure of the borrow
site,the water will be discharged from the settling ponds into the
Susitna River.All effluents will conform to ADECjUSEPA standards
(AS 46.03.100;18 AAC 70.020; 18 AAC 72.010).
Overburden and unsuitable material will be stockpiled for return to
the removal area for contouring and revcgation efforts.Material
will be stockpiled outside the floodplain to avoid impounding flow
at higher stages resulting in material erosion.If insufficient
space exists away from the floodplain,material may be stockpiled
and armored to prevent erosion.
Rehabilitation at Tsusena and Cheechako creeks will proceed both
concurrently with borrow activities and following closure of the
site.Stockpiled overburden will be replaced at upland aliquots.
Exposed slopes will be stabilized and contoured to blend with
surrounding features and topography.Revegetation and
fertilization of the disturbed areas will assist in minimizing
erosion.All man-made objects will be removed following site
closure.Settling ponds will be dewatered of the clear surface
water and silt will be broadcast,removed to approved disposal
sites,left in place with a r iprap covering or piled in the
non flooded sections of the site.
The pit excavation at Borrow Site E will be rehabilitated to
provide fish habitat.A rehabilitated borrow pit can provide fish
rearing and overwintering and increase the availability of Arctic
grayling and Dolly Varden (Joyce et a1.1980a).Spoil materials
will be used to provide a diversity of water depths and bank slopes
to create a variety of fish habitats.A mean depth of 8 ft (2 .5 m)
or greater will be needed to assure survival of overwintering fish .
The pit will have a relatively long and narrow shape with an
irregular shoreline aligned longitudinally in the floodplain.
63
Spoil and overburden will be used to construct islands and
peninsulas.An outlet channel will be provided at the downstream
end of the pit to enable fish movement between the mainstem and the
p:t and the unnamed creek will contribute directly to the pit.
Tsusena Creek will remain independent of the pit by maintaining a
buffer of vegetation between the excavation and the active channel
of the creek.Figure 21 details a rehabilitated pit excavation
that may be appropriate for Tsusena Creek.
Borrow site G will be inundated following dam completion;
rehabilitation wiJl consist of stabilizing slopes to minimize
erosion and removing man-made objects.Revegetation will not be
necessary.Settling ponds will not be dewatered.
(b)Water Quality
(i)Impact Mel.'hanism
Temporary degradations in water quality caused by increased
turbidity,sedimentation and petroleum contamination may
change the species composition and reduce the productivity of
the system (Bell 1973,Alyeska Pipeline Service Company 1974).
Discharge of camp effluents may result in increased nutrient
loading.Concrete batching plants produce highly alkaline
eff'iuents.Wastewater may have a higher temperature than
natural waters.
(ii)Mitigation
The primary mitigation measures that will be used to minimize
degradations in water quality are:(l)employing BMPM erosion
control measures including runoff control,stilling basins and
revegetation (APA 1985a);and (2)maintaining vegetated buffer
zones.
64
Disposal sites will be constructed so that neither runoff
during breakup nor rainfall will wash silty material into
streams.This may entail runoff control structures.
surrounding the disposal site with berms,or channeling runoff
through containment ponds.Prior to site inundation,the
overburden and slash will be stabilized with gravel or r iprap
fill.Turbidity increases.water quality degradations,and
other impacts are not expected due to disposal site inundation
(Section 3.1.1).
The natural vegetation is a major factor in preventing erosion
(Alyeska Pipeline Service Company 1974).Clearing will be
confined to the minimum area and level necessary.Cleared
material will be removed to approved disposal sites,salvaged,
or burned onsite.Revegetation of cleared areas will proceed
as rapidly as possible following the termination of
construction activities.
All wastewater wilt be treated to comply with ADECjUSEFA
effluent standards (AS 46.03 .100;18 AAC 70.020;18 AAC
72.010).The concrete batching effluent will be neutralized
and treated prior to discharge into the Susitna River to avoid
impacts related to pH and toxic substances.Secondary
treatment will be utilized to reduce the concentration of
suspended solids and biochemical oxygen demand (BOD)of the
wastewater.The effluent will retain relatively high
concentrations of nitrogen and phosphorus.Wastewater will be
retained in settling ponds until effluent temperatures
approximate instream temperatures.
(c)Susitna River Diversions
(i)Impact Mechanism
The diversion tunnels and the dams will act as barriers to
successful fish migration.Chinook salmon will not be able to
utilize spawning habitat upstream of the dam site.Fish passing
downstream through the diversion tunnels are expected to be lost
because of impacts with tunnel walls.During summer,relatively
few fish are present in the vicinity of the tunnel entrance.
During winter,resident fish are expected to be entrained into the
intake and passed downstream.
(ii)Mitigation
Due to the relatively small impact on the aquatic resources,no
direct mitigation is proposed.The loss will be included in the
compensation for lost reservoir habitat that will take the form of
acquiring public access and undertaking habitat improvement outside
the project area (Jennings and Moulton 1985).
(d)Ojl and Hazardous Material Spills
(i)Impact Mechanism
Spills of oil and other hazardous substances into streams are toxic
to fish and their food organisms.
(i i)Mitigation
Mitigation for oil and hazardous material spills is described in
Section 2.2.1 and will be conducted in accordance with the BMPM on
Oil Spill Contingency Planning (APA 1985e)~compensation for a
major spill will be determined following consultation with the
resource management agencies.
(e)Clearing the Impoundment Area
(i)Impact Mechanism
66
Impoundment area clearing may accelerate erosional contributions to
the Susitna River.
(ii)Mitigation
Clearing will be scheduled annually as close to reservoir filling
as is feasible.Vegetation will be cleared to the elevation of the
high water level anticipated for each year of filling.Disturbance
to the vegetative mat will be avoided.Erosion control methods
described in the BMP manual on Erosion and Sedimentation Control
(APA 1985a)will be employed wherever needed to minimize erosion.
No additional mitigation will be required.
(f)Increased Fishing Pressure
(i)Impact Mechanism
The sport fishing pressure on the local streams and lakes will
increase due to the presence of the construction workers.
(ii)Mitigatjon
The mitigation of the aquatic impact from increased fishing
pressure has been previously discussed in Section 2.2.1.
Variations are not expected.
3.2.2 -Monitoring
Monitoring is recognized as an essential project mitigation feature that will
provide for a reduction of impacts over time.Monitoring will be conducted
throughout project construction:
To insure that the environmentally careful construction practices detailed in
the BMPM's (APA 1985a,1985b,1985c,1985d,1985e)are being employed on the
project to avoid or minimize impacts;
67
To verify and evaluate the effectiveness of the operation and maintenance of
mitigation features;and
To recommend changes in construction practices or mitigation features to
further avoid.minimize,or reduce impacts.
Construction monitoring will consist of monitoring construction activities to
verify that proper construction practices are being followed and that project
facilities are being properly maintained.This monitoring activity will cover all
project facilities,including camp and village construction,material removal,
washing operations for dam construction,reservoir clearing.abandonment,and
rehabilitation activities.
As described in Section 2.2.2.the APA will assign at least one member of its
staff to be an Environmental Field Officer (EFO)responsible for compliance with
regulatory requirements and permits.During and after construction activities,
the EFO will review the designs and verify that the activity is in compliance with
the BMPM's permit and license stipulations.If a discrepancy with existing
stipulations is observed and if a variance was not requested prior to implementing
the activity,a certificate of non-compliance will be issued and all responsible
parties will be notified.
The monitoring program wilt include water quality and borrow site monitoring.
Deadman Creek will be monitored to detect degradations in water Quality from
increased phosphorous or nitrogen (Harza-Ebasco 1985c).The water Quality
monitoring program will also investigate dissolved oxygen levels downstream of the
effluent outlet (Harza-Ebasco 1985c).Borrow sites will be monitored during
construction and after rehabilitation.Settling pond effluents will be monitored
to assure compliance with ADEC/USEPA standards.Tsusena and Cheechako creeks will
be monitored for fish blockages.Impacts identified through the monitoring
program will be assessed and rectified following negotiation with the resource
agencies.
68
4 -TRANSMISSION LINES
Power generated at the Watana dam and the Devil Canyon dam will be delivered to
power utilization regions by transmission lines.Construction will occur
throughout the three stages of development (Figure 22).The transmission lines
will be built from the Watana dam along the access road to the Devil Canyon dam
site and continue along the railroad spur from Gold Creek (Figure 23).At Gold
Creek,the transmission lines are planned to converge with the Anchorage-Fairbanks
Interrie currently extending from Willow to Healy (Figures 24.2S and 26).The
route south of Willow will be extended to Point MacKenzie where a submarine cable
will cross the Knik Arm.The terminus of the southern section will be the
University substation in Anchorage (Figure 27).The northern section will be
extended from Healy to Ester near Fairbanks (Figures 28 and 29).The transmission
corridor from Anchorage to Fairbanks will be 330 miles (530 km)long.
Potential aquatic impacts associated with the transmission line construction and
maintenance will be similar to those identified for the access corridor (Section
2.1).In general,impacts are anticipated to be short in duration and confined to
the construction phase.Short-term aquatic impacts will occur where the
transmission lines cross resident and anadromous fish streams.The transmission
line corridor will increase the accessibility of these streams and nearby lakes
and may lead to increased fishing pressure;this long-term impact is probably the
most significant potential aquatic impact associated with transmission line
construction.
Mitigation of potential transmission line impacts will also be similar to the
mitigation of the access road impacts (Section 2.2).Mitigat io n v"short-term
potential impacts during construction will be accomplished primarily by adherence
to the construction practices presented in the APA BMP manuals (APA 1985a,1985b,
1985c.1985d.1985e).Mitigation of impacts resulting from increased
accessibility may include restricting usage of the maintenance road.
4.1 -Impact Analysis
4.1.1 -Watana to Gold Creek
69
(a)Description
From the Watana dam site to Gold Creek,a distance of 37 miles (60 km), two
parallel sets of towers will be built during Stage 1 construction;the
towers will require a 285 foot (87 m)wide right-of-way through tundra and
occasionally dense vegetation.The transmission lines will consist of a
series of steel towers approximately 1300 ft (393 m)apart.The towers will
be x-f'ramed guy towers,capable of supporting three conductors.The
transmission towers will be spaced so that structures are not located within
Cur ,...tty active stream channels and are removed from floodplains to the best
extent practicable.
In the right-of-way,trees and shrubs within 20 ft (6 m)of the conductors
and trees within 55 ft (16.5 m)of the tower centerline will be cleared as
well as any other trees or shrubs that may hamper construction or pose a
threat to the completed line.The selective clearing will retain low shrubs
and grasses in order to minimize erosion.Revegetation in the corridor will
be allowed to proceed so long as the integrity of the lines is not endangered
and vehicles are able to foHow the cleared area associated with the lines.
Where vegetation is dense between the Susitna River crossing and Gold Creek,
cleared vegetation will be hauled to a designated area and salvaged or
burned.Deciduous vegetation may be piled at the corridor margins;
coniferous slash may be chopped with a hydro-axe and broadcast in the
corridor.Piled coniferous vegetation will be burned within the first year
after cutting.Clearing activities are scheduled to OCcur from 1992 to 1993.
The transmission line construction will necessitate stream crossings by heavy
equinment such as hydro-axes and drill rigs.·Streams and lakes potentially
impacted are previously identified in Sections 2.1.2 and 2.1.4 since the
transmission corridor will closely parallel the Devil Canyon dam access road
and the railroad spur connecting Devil Canyon to Gold Creek (Figure 23).
Temporary bridges may be installed depending on the stream size and passage
requirements.For small streams with low gradients and gradual banks,low
water crossings may be used .All crossings will be designed to provide
adequate fish passage (Harza-Ebasco 1985a).
70
The towers will be supported by a variety of foundations designed for soil
conditions at each site.Driven steel pilings and steel grillage foundations
will be prefercntially utilized although cast-in-place concrete piles will
occasionally be necessary.Buffers of at least 100 ft (30 m)between active
stream channels and the sites of driven piles will be retained to avoid
increased sedimentation from soil vibration in the channel during pile
driving.Waste concrete will be disposed at designated sites away from
streams and lakes.Concrete batch water will be neutralized prior to
discharge.
Ground access will be provided in transmission line corridors for periodic
maintenance and repair of lines,towers and conductors.Within the
transmission line corridor,a 25 ft (7.5 m)wide trail will be cleared;the
trail will be suitable for flat tread,balloon tire vehicles.The
maintenance trail will remain clear of vegetation and will be accessed using
secondary trails from the Devil Canyon access road and railroad.Stream
crossings in the corridor will be minimized by clearing secondary trails to
the sections of the corridor trail separated by major streams.Vegetation or
man-made buffers between the corridor trail and the stream will discourage
stream crossings.Along the Watana to Gold Creek corridor,a secondary trail
will connect each tower to the road or railroad access corridor.The
secondary trails will not be maintained by the APA.
(b)Potential Impacts
Potential aquatic impacts from Stage I construction of the transmission line
from Watana to Gold Creek are similar to those of the Devil Canyon access
road (Section 2.1.2)and the railroad spur (Section 2.1.4).Impacts
discussed in these sections are generally applicable to transmission line
construction.Variations or alterations in impacts are discussed further .
o Clearing
Residual impacts from transmission line clearing from the Watana dam
71
site to Gold Creek will include minor water quality degradations and
small amounts of aquatic habitat loss from cover removal.Clearing
activities will conform to the BMPM on Erosion and Sedimentation Control
(APA 1985a)to avoid or minimize the potential clearing impacts which
are expected to be similar though of less significance than clearing
impacts for the Devil Canyon road and railroad access (Section 2.1.1).
As described in Section 2.1.2.adherence to the BMPM construction
techniques (APA 1985a)will minimize potential impacts associated with
clearing.At transmission line stream crossings,clearing may remove
overhanging vegetation that provides cover for fish.Fish may not
utilize the available habitat if cover is not available.This habitat
loss is expected to be temporary and minor relative to the total amount
of available habitat.BMPM techniques (APA 1985a)will be followed at
cleared vegetation stockpiling,salvaging or burning sites to prevent
surface runoff from contributing ash or organic materials to streams and
lakes as described in Section 2.1.1.
o Stream Crossings and Encroachments
During transmission line construction,instream activities will be
conducted according to the BMPM guidelines (APA 1985a)to avoid or
minimize impacts to the aquatic resources.Residual impacts from stream
crossings consist of temporary habitat losses.which are not believed to
be of significant magnitude to require mitigation.Mitigation for a
major petroleum spill is presented in Section 2.2.1.
Instream activities will be limited to the installation of necessary
stream crossing structures designed to provide adequate fish passage
(Harza-Ebasco 1985).Stream crossings at major fish supporting
streams will be avoided by utilizing the alternative access secondary
trails from the access road and railroad to Devil Canyon.Instream use
of equipment will be required to be short in duration and avoid
environmentally sensitive periods for the designated streams (Figures
II and 15).
72
o Operation and Majntenance Activities
All maintenance activities will be conducted in accordance with the BMPM
(APA 1985a)and significant impacts are not expected to occur.Some
localized habitat disruptions could occur when maintenance vehicles need
to cross wetlands and streams to repair damaged lines or towers.
Streams may be forded to make repairs if the temporary bridges or
culverts are removed after construction is complete.AQuatic habitat in
the immediate vicinity of the crossing could be affected.In addition,
there may be increases in suspended sediments and sedimentation in
downstream reaches.However,maintenance activities in remote areas are
expected to utilize helicopter transportation.
In the longer term,the transmission line corridor and maintenance road
may increase fishing pressure on lakes and streams in the vicinity.
Because the vegetation will be kept relatively low,hikers and all
terrain vehicles will be able to use the transmission corridor as a
trail.In winter,snow machines will also be able to traverse these
cleared areas.Between Watana and Devil Canyon,access may be increased
marginally beyond that provided by the nearby Devil Canyon access road.
The corridor and maintenance track between Devil Canyon and Gold Creek
paralleling the railroad spur would marginally improve access to
tributaries and sloughs of the Susitna River and may slightly increase
the fishing pressure on these habitats.
4.1.2 Devil Canyon to Gold Creek
(a)Description
The Stage 2 construction on the Devil Canyon dam will add two transmission
lines to the transmission corridor from Devil Canyon to Gold Creek.This
will result in an arrangement of four parallel sets of towers extending for 8
miles (13 km).110ng this segment of the lines.The corridor will be widened
to 515 f't (157 m).Additional clearing along the corridor will be necessary
as described in Section 4.1.1.
73
(b)PQtential Impacts
The potential impacts associated with installing two additional transmission
lines in the Devil Canyon to Gold Creek corr idor will be identical to those
impacts identified in Section 4.1.1.Disposal sites from stage one clearing
will be utilized.Significant new impacts are not expected with this
incremental addirion.
4.1.3 WillQW to Healy
(a)DescriptiQn
The transmission lines will join the Anchcrage-Fairbanks Intertie at Gold
Creek.The Anchorage-Fairbanks Intertie,which connects Willow to Healy,is
being built as a separate project and is expected to be completed in 1985
(Figures 24,2S and 26).During Stage I construction,the Susitna
Hydroelectric Project will add another line of towers from Gold Creek to
WillQW within the same right-of-way;the Stage 2 Devil Canyon coustruction
will include building an additional transmission line in the Inter tie
corridor from Gold Creek to Healy.A third transmission line will be
constructed from Gold Creek to Willow to transport power following Stage 3
development at Watana (Figure 22).The Intertie corridor for the Stage 3
development will be cleared to a width of 285 ft (87 m)from Gold Creek to
Healy and 400 ft (120 m)from Gold Creek to Willow.The impacts will be
similar to those experienced during Intertie construction.The Environmental
Assessment Report f'or the Intertie (Commonwealth et al. 1982)discusses the
expected environmental effects of transmission line construction in this
segment.Fish streams that will be crossed include the Nenana River,
Talkeetna River,Chunila Creek,Susitna River.and the Kashwitna River.A
total of 77 streams will be crossed (Table 10).
The majority of streams crossed by the transmission lines along the Intertie
route are utilized throughout the year by anadromous and resident species
(Table 10).Anadromous fish include chinook,sockeye,coho,pink,and chum
74
salmon;resident species include Arctic grayling,Dolly Varden and rainbow
trout.
Construction will proceed in a similar manner to the construction of the
Intertie transmission lines.Experience gained from the previous
construction will be applied and is likely to result in a shortened
construction period.Access established during construction of the Intertie
will likely be utilized.During construction,heavy equipment will cross
small streams.Temporary bridges or culverts may be installed to minimize
impacts to aquatic organisms.The majority of stream crossings will utilize
log stringer and temporary bridges.Small headwater streams without fish
populations will be forded.These streams are identified in Table 10 and are
located at the approximate mile post (AMP) 79, 90.5, 91.5, 92.5, 94, 117.5
and 137.5 as measured from the Willow substation.Large streams in the
transmission corridor will not be crossed by equipment;sections of the
transmission line separated by major streams and rivers will be accessed from
existing roads such as the Parks Highway.Construction where secondary roads
to the site would be long and cross many streams is expected to utilize
helicopter transportation in a similar manner to construction along the
Anchorage-Fairbanks Intertie.
(b)Potential Impacts
The potential impacts of constructing additional transmission lines in the
Anchorage-Fairbanks Intertie corridor are expected to be similar,but less
significant than the impacts associated with the original construction
activities.Impacts identified for transmission line construction in Section
4.1.1 are applicable .Additional site specific impacts are discussed
further.
o Clearing
The additional clearing required for the installation of the second and
third transmission line will be conducted using BMPM techniques (APA
1985a).Sites previously selected during construction of the Intertie
7S
for vegetation broadcasting.stockpiling and/or burning will be
utilized.Residual impacts are not expected if the BMPM (APA 1985a)
techniques are followed.
a Stream Crossings and Encroachments
Access provided during Intertie construction will be used.Any instrearn
activities will follow BMPM guidelines (APA 1985a) to avoid significant
increases in suspended sediments.sedimentation.or petroleum
contamination.Aquatic organisms in nearby habitat will be temporarily
disturbed.
a Operation and Maintenance Activities
The operation and maintenance of additional transmission lines in the
Intertie corridor are not likely to increase aquatic impacts beyond the
existing level of impact.
4.1.4 Healy to Ester
(a)Description
The transmission line corridor will be extended from Healy to Ester (Figures
28 and 29)during construction of the Stage I Watana dam.A second
transmission line will be added to transport power during the Stage 2
development of the Devil Canyon dam.When the two transmission lines are
installed,the corridor will have a 285 ft (87 m)width.The Nenana River is
crossed 2.75 and 58.75 miles (4.4km and 94.5 km)from the Healy substation.
The line will turn north after crossing Dry Creek at AMP 4.75 and roughly
parallel the Parks Highway for the greatest part of its length.The line
will end at the Ester Substation (AMP 94.25).Clearing and construction will
proceed as described for the Watana to Gold Creek section (Section 4.1.1).
The streams crossed by the northern leg are listed in Table 11 .Streams of
the Nenana Basin that are accessible and have appropriate spawning habitat
support spawning runs of resident species such as Dolly Varden,round
76
whitefish and Arctic grayling.A number of interconnected lakes lie in the
Nenana Basin.Fish found in the lakes include Arctic grayling,whitefish,
lake trout,and burbot.
(b)Potential Impacts
Impacts in the Healy to Ester segment will be similar to impacts identified
for the transmission line construction of other segments (Section 4.1.1).
Additional impacts specific to this segment of the transmission line are
discussed below.
o Clearing
Impacts to aquatic organisms from clearing activities are likely to be
minor as the BMPM on Erosion and Sediment Control (APA 1985a)will be
followed.Large amounts of clearing are not anticipated as much of the
vegetation is tundra.Cleared vegetation will be broadcast or removed
to selected sites and stockpiled or burned.Ash and other organic
material will be prevented from entering streams or lakes.
o Operation and Maintenance Activities
The corridor from Healy to Ester will follow the route of the Parks
Highway;access will therefore be available previously and the aquatic
resources are not expected to be incrementally impacted by the operation
and maintenance of the transmission lines.
4.1.5 Willow to Anchorage
(a)Description
The transmission corridor from Willow to Anchorage (Figure 27)will be
established during the Stage I development of the Susitna Hydroelectric
Project.The Willow substation is located approximately 0.5 miles (0.8 km)
north of Willow Creek.Proceeding first west then south,the lines will be
77
routed between the Susitna River and the Nancy Lake area,passing within 0.75
miles (1.3 km)of the Susitna River.The lines will cross several Susitna
River tributaries,including Fish Creek at AMP 18 as measured from the Willow
substation .The Little Susitna will be crossed at AMP 26.Few streams are
crossed between the Little Susitna River and the Knik Arm at AMP 44.The
Knik Arm,which is approximately 2.5 miles (4.1 km)wide at the transmission
line crossing,will be crossed by a submarine cable system.The Knik Arm
switching station will be located between Sixmile Creek and Eagle River.
From there the transmission lines will bypass Otter Lake and cross the Alaska
Railroad and Fossil Creek.The the corridor will parallel the Glenn Highway
for about 2 miles (3 km).Ship Creek will be crossed at AMP 75 and the lines
will traverse the Chugach Foothills before terminating at the University
substation near the corner of Tudor and Muldoon roads.Table 12 presents a
list of the streams to be crossed by the transmission lines.
Construction of the two transmission lines from Willow to Anchorage during
Stage I development will be similar to previous construction (Section
2.1.1). A third transmission line will be installed from Willow to the
Knik Arm crossing during Stage 3 development.Details of the installation of
the cable under Knik Arm are to be developed during final design.The Knik
Arm is primarily a migration route for anadromous species that utilize the
Knik and Matanuska River drainages.The anadromous species include five
species of Pacific salmon,Dolly Varden,eulachon,and Bering cisco.Benthic
organisms and other resident species are sparse because of the excessive
amounts of fine glacial sediments on the sea floor.Alteration of this area
from the cable installation and operation is unlikely and effects upon
resident or anadromous species are expected to be minor.The presence of an
operating cable under the Knik Arm should not affect fish populations.
(b)Potential Impacts
Potential impacts associated with the transmission lines from Willow to
Anchorage are similar to impacts previously discussed (Section 4.1.1).
Additional site specific information is provided.Impacts during
construction are expected to be more severe than impacts connected with
78
maintenance activities.
o Operation and Maintenance Activities
Increased fishing pressure will likely result from construction of the
transmission lines from Willow to Anchorage.The transmission corridor
is likely to experience heavy usage by ATV's and snowmachines due to the
close proximity of dense population areas such as Willow and Wasilla .
Access by road is available to the Nancy Lake region.The corridor will
also roughly parallel an existing tractor trail from the Little Susitna
to the Susitna River.However,an increase in fishing pressure on both
resident and anadromous species may be expected at sloughs of the
Susitna River West of the Nancy Lakes region.Fish Creek,other Susitna
River tributaries and the Little Susitna River may also be more heavily
utilized.Fishing pressure increases may have a moderate impact on the
fish resources of the region.
4.2 -Transmission CorridQr Mitigation
Mitigation of potential impacts during transmission line construction and
maintenance will be achieved primarily by adherence to the BMPM construction
techniques (APA 1985a.1985b. 1985c ,1985d,1985e).Proper clearing and soil
stabilization procedures will be followed as outlined in the BMP manual on Erosion
and Sedimentation Control (APA 1985a).Shrubs and small trees will be allowed to
revegetate the transmission corridor;the access trail will be kept clear for
maintenance needs.Streams will be crossed utilizing BMPM procedures (APA 1985a)
in order to minimize impacts.Instream activities required for transmission line
construction will be scheduled for mid-summer months to the greatest extent
feasible to avoid the biologically sensitive spawning and overwintering
migrations .
Potential impacts of the transmission line construction and maintenance were
described in Section 4.1.Impact mechanisms identified and the corresponding
m itigation measures to be applied during and after construction are discussed in
Sect ion 4.2.1 and are similar to those discussed in Section 2.2.1.Mechanisms
79
believed to have the largest potential impacts to the aquatic environment
requiring mitigation are considered first.Impact avoidance,minimization,
rectification and reduction are discussed.Adherence to the BMPM techniques (APA
1935a)is the primary mitigation measure.
Monitoring of the transmission line through the construction and maintenance
phases will assist in avoiding or minimizing impacts to the aquatic resources.As
described in Section 2.2.2,monitoring will be used to identify rehabilitation or
maintenance requirements for mitigation measures.Inadequate mitigation measures
may be identified and remedied by monitoring efforts and additional measures.
Costs associated with all phases of construction monitoring are outlined in Table
8.
4.2.1 Impact Mechanisms and Mitigation Measures
(a)Stream Crossings
(i)Impact Mechanism
During construction and maintenance activities,suspended solids
and petroleum contamination may be increased.Siltation of
downstream reaches may occur.Fish are likely to a void areas
disturbed by equipment operated in or near streams.
(ii)Mitigation
Instream activities will be minimized during the periods of peak
fish movement as described in Section 2.2.1.Previously installed
temporary bridges or culverts will be utilized if available.
During the remainder of the open water season the duration of
instream activities will be minimized as suggested by the BMP
manual on Erosion and Sedimentation Control (APA 1985a).The use
of helicopters will avoid much of the potential instrearn
disturbances in remote areas.
80
Spawning and overwintering migration disturbances are not expected
if instream activities are minimized during sensitive spring and
fall months (Figure 5).
(b)Water Quality
(i)Imp3ct Mechanism
Temporary degradations in water Quality.including increased suspended
solids,sedimentation and petroleum contamination,could alter species
productivity (Bell 1973,Alyeska Pipeline Service Company 1974).
(ii)Mitigation
The primary mitigation measures that will be used to minimize water
quality degradation from transmission line construction are (1)adhering
to the BMPM (APA 1985a)guidelines;(2)employing erosion control
measures such as runoff control,stream bank stabilization and
revegetation;and (3)minimizing the time necessary to complete instream
activity so that water quality degradations are short-term and
non-reoccurring events.
Additional mitigative measures are not expected to be needed.
(e)Increased Fishing Pressure
(i)Impact Mechanism
Sport fishing pressure on local streams and lakes will likely increase.
The transmission line corridor will allow fishermen to reach areas
previously unexploited.
(ii)Mitigation
Section 2.2.1 presents the recommended mitigation for increased fishing
81
pressure impacts.Modifications to current seasons and catch limits may
be necessary to maintain current stocks,particularly along the Willow
to Anchorage transmission corridor.
(c)Oil and Hazardous Material Spills
(i)Impact Mechanism
Spills of oil and other hazardous substances into streams are toxic to
fish and their food organisms.
(ii)Mitigation
Mitigation for oil and hazardous material spills is described in Section
2.2.1 and includes the preparation of a Spill Prevention,Containment
and Countermeasure Plan (SPCC)as required by EPA (40 CFR 112.7)prior
to construction commencement.
(d)Water Removal
(i)Impact Mechanism
Fish fry and juveniles can be impinged on intake screens or entrained
into hoses and pumps when water is withdrawn from water bodies for
miscellaneous uses during construction .
(ii)Mitigation
The construction and maintenance activities will require small amounts
of water which will be withdrawn as described in Section 2.2.1 to avoid
significant impacts.Barren lakes will be used pref'ere-it ia lly as a
water source during transmission line construction.
82
4.2.2 Monitoring
Monitoring will verify that proper construction practices,as detailed in the BMP
manuals (APA 1985a,1985b,1985c,1985d,1985e),are being Followed during
transmission line construction and maintenance.During transmission line
construction,monitoring will be conducted to verify compliance with regulations
and permits obtained from the ADEC,ADF&G,ADNR and Corps of Engineers (CaE).The
Environmental Field Office (EFO)will provide guidance on permit compliance
relative to daily activities as described in Section 2.2.2.
After the construction phase,the transmission lines will be periodically
monitored as part of the maintenance schedule.Chronic erosion sites will be
identified and corrected;stream crossings will be inspected to prevent fish
passage blockages.Costs associated with the monitoring program are estimated in
Table 8.
83
S -ACKNOWLEDGEMENTS
Funding for this report was provided by the State of Alaska,Alaska Power
Authority.
The document was initiated while the authors were employees of Woodward-Clyde
Consultants.The draft was completed by the ll.uthors while employees of Entr ix,
Inc.
The authors gratefully acknowledge the comments and assistance received from
reviewers.Howard Teas,Susan Ban and Fred Eiserman of Woodward-Clyde Consultants
assisted in the identification of biological impacts.Don Beyer of Harza-Ebasco
reviewed and commented on a preliminary version of the document.Jean Baldrige of
Entr ix,Inc.contributed comments following a review of the plan.
Typing efforts by Rhonda Steward and Susan Bryan of Entr ix,Inc.were very much
appreciated.The authors would also like to thank Fineline Graphics for the
prompt preparation of the figures.
84
6 •REFERENCES
Alaska Department of Fish and Game.1981.Susitna Hydro Aquatic Studies -Phase
Final Draft Report:Resident Fish Investigation on the Upper Susitna River.
Prepared for Acres America Incorporated,Buffalo,N.Y.
ADF&G.1982.Statement of Policy on Mitigation of Fish and Game Habitat
Disruptions.Juneau,AK.
ADF&G.1983.Susitna Hydro Aquatic Studies·Phase II Basic Data Report,Volume
5:Upper Susitna River Impoundment Studies.1982.
Alaska Power Authority.1982.Susitna Hydroelectric Project:Fish and Wildlife
Mitigation Policy.Anchorage,AK.
Alaska Power Authority.1983a.Application for license for major project,Susitna
Hydroelectric Project,before the Federal Energy Regulatory Commission.Vol.
1.Exhibit A.Anchorage,AK.
Alaska Power Authority.1983b.Application for license for major project,Susitna
Hydroelectric Project,before the Federal Energy Regulatory Commission.Vol.
6A.Exhibit E.Chap.3.Anchorage,AK.
Alaska Power Authority.1983c.Application for license for major project.
Susitna Hydroelectric Project,before the Federal Energy Regulatory
Commission.Vol. SA.Exhibit E,Chap.2.Anchorage,AK .
Alaska Power Authority.1984.Application for License for major project,Susitna
Hydroelectric Project,before the Energy Regulatory Commission.Responses to
Agency Comments on License Application.Anchorage,AK.
Alaska Power Authority.1985a. Best Management Practices Manual on Erosion and
Sedimentation Control.Anchorage.AK.
85
Alaska Power Authority.1985b.Best Management Practices Manual on Water Supply.
Anchorage,AK.
Alaska Power Authority.1985c. Best Management Practices Manual on Liquid and
Solid Waste.Anchorage.AK.
Alaska Power Authority.1985d.Best Management Practices Manual on Fuel and
Hazardous Materials.Anchorage,AK.
Alaska Power Authority.1985c. Best Management Practices Manual on Oil Spill
Contingency Planning.Anchorage.AK.
Alyeska Pipeline Service Company.1974.Environmental and Technical Stipulation
Compllance Assessment Document for the Trans-Alaska Pipeline System.Volume
I.Anchorage.AK.
Balding.G.O .1976.Water Availability.Quality,and Use in Alaska.United States
Department of the Interior Geological Survey.
Barrett,B.M,F.M Thompson.and S.N. Wick. 1984.
fish investigations:May-October 1983.Alaska
Susitna Hydro Aquatic Studies Report No.I.
Authority.Anchorage,AK.
Report No.1.Adult anadromous
Department of Fish and Game.
Prepared for Alaska Power
Barrett,B.M,F.M Thompson.and S.N .Wick .1985.Report No .I.Adult
anadromous fish investigations:May-October 1984.Alaska Department of Fish
and Game.Susitna Hydro Aquatic Studies Report.Prepared for Alaska Power
Authority.Anchorage,AK.
Bates,D.W.and J.G.Vanderwalker.1964.Exploratory Experiments on the
Deflection of Juvenile Salmon by means of Water and Air Jets.Fish Passage
Research Program for U.S .Bureau of Commercial Fisheries.Seattle,
Washington.
86
Bell.MC.1973.Fisheries Handbook of Engineering Requirements and Biological
Criteria (Revised 1980).Prepared for Fisheries-Engineering Research
Program.Corps of Engineers.North Pacific Division.Portland.Oregon.
Bohme,V.E.and E.R.Brushett.1979.Oil Spill Control in Alberta.1977 Oil Spill
Conference (Prevention,Behavior.Control.Cleanup).American Petroleum
Institute,Environmental Protection Agency,U.S.Coast Guard.New Orleans,
LA.
Bormann,F .H.,T.G.Siccaman,G.E.Likens,and R.H.Whittake.1970.The Hubbard
Ecosystem Study:Composition and Dynamics of the Tree Stratum.Ecol,Mongr.
40.
Commonwealth Associates,Dowl Engineers and Kevin Waring Associates.1982.
Anchorage-Fairbanks Intertie:Environmental Assessment Report,Prepared for
Alaska Power Authority.Anchorage,AK.
Cordone,A.J.and D.E.Kelly.1961.The influence of inorganic sediment on the
aquatic life of streams.Cal.Fish and Game 47:189-228
Dehoney,B.and E.Mancini.1982.Aquatic Biological Impacts of Instream Right of
Way Construction and Characteristics of Invertebrate Community Recovery.
Right of Way Symposium.San Diego,CA .
Edfelt ,L.1981.
regulations.
Memorandum to Richard Logen regarding status of habitat
Alaska Department of Fish and Game.Anchorage,AK.
Harza-Ebasco Susitna Joint Venture.1985a.Drainage Structures and Waterway
Design.Prepared for Alaska Power Authority.Anchorage,AK.
Harza-Ebasco Susitna
Personnel Survey.
Joint Venture.1985b.Terror Lake Hydroelectric
Prepared for Alaska Power Authority.
Project
Harza-Ebasco Susitna Joint Venture.1985c.Aquatic Monitoring Plan.Prepared for
Alaska Power Authority.Anchorage,AK.
87
Hynes.H .B.N.1966.The Biology of Polluted Waters.Liverpool University Press.
Liverpool.U.K.
Iwamoto.R.N.• E.O.Salo,MA.Mades and R.L.McComas.1978.Sediment and water
quality:a review of the literature including a suggested approach for water
quality criteria.U.S.EPA.EPA 910/9-78-048.
Jennings,T .R.and L.L.Moulton.1985.Impoundment Fish Mitigation Plan.
Prepared for Alaska Power Authority.Anchorage.AK.
Joyce,MR.,L.A.Rundquist,and L.L.Moulton.1980a.Gravel Removal Studies in
Arctic and Subarctic Floodplains in Alaska -Technical Report.U.S.Fish and
Wildlife Service.Anchorage,AK.
Joyce.MR .• L.A.Rundquist,and L.L.Moulton.1980b.Gravel Removal Guidelines
Manual for Arctic and Subarctic Floodplains.Biological Services Program
FWS/OBS-80/09.U.S .Fish and Wildlife Service.
Latvaitis,B.,H.F.Bernard,and D.B.MacDonald.1977.Impingement Studies at
Quad Cities Station.Mississippi River.Third National Workshop on
Entrainment and Impingement.L .D.Jensen (ed.).Melville,N.Y.
Lauman,T.E. 1976.Salmonid Passage at Stream-Road Crossings.Oregon Department
of Fish and Wildlife.Oregon.
Likens,G.E.• F.H.Bormann,N.M Johnson,D.W.Fisher.and R.S.Pierce.1970.
Effects of Forest Cutting and Herbicide Treatment on Nutrient Budgets in the
Hubbard Brook Watershed -Ecosystems.Ecol.Monogr.40.
Lindstedt-Siva,S.J. 1979.Oil Spill Response Planning for Biologically Sensitive
Areas.1977 Oil Spill Conference (Prevention.Behavior,Control,Cleanup).
American Petroleum Institute,Environmental Protection Agency,U.S.Coast
Guard.New Orleans,LA.
88
Shaw,P.O.and 1.A.Maga .
Salmon Spawning Beds .
Morrow,J .E .1980.Freshwater Fishes of Alaska.Alaska Northwest Publishing
Company .Anchorage,AK.
Pierce,R .S.,J.W.Hornbeck,G.E .Likens,and F.H.Bormann.1970.Effects of
Elimination of Vegetation on Stream Water Quantity and Quality.Results on
Research on Representative and Experimental Basins,Proc.of International
Assoc.Sci.Hydrology.UNESCO.Wellington,New Zealand.
Saunier,1.S.and ME.Stratton .1984 .Access and Transmission Corridor Studies.
In.:Access and Transmission Corridor Aquatic Investigations,May-October
1983 .No.4 .,Part I.D.C.Schmidt,c.c.Estes,D.L.Crawford and D.S .
Vincent-Lang (eds.).Prepared for Alaska Power Authority .Anchorage,AK .
Schmidt,D .C.and ME.Stratton.1984 .Population Dynamics of Arctic Grayling in
the Upper Susitna Basin.l!!.:Access and Transmission Corridor Aquatic
Investigations,May-October 1983.No .4.,Part 2. D.C.Schmidt,C.C .Estes,
D .L.Crawford and D.S.Vincent-Lang (eds.).Prepared for Alaska Power
Authority .Anchorage,AK.
Scott,W.B .and E.l.Crossman .1973 .Freshwater Fishes of Canada.Bulletin 184.
Fisheries Research Board of Canada .Ottawa,Canada.
1943 .The Effects of Mining Silt on Yield of Fry from
California Fish and Game.2a(I).
Stene and Webster .1976.Niagara Mohawk Power Corporation,Rochester Gas and
Electric Corporation Final Report:Studies to Alleviate Fish Entrapment at
Power Plant Cool i ng Water Intakes .Stone and Webster Engineering
Corporation .Boston,Massachusetts.
Taft,E.P.,P.Hofmann,P .J.Eisele,and T.Horst.1977.An Experimental Approach
to the Design of Systems for Alleviating Fish Impingement at Existing and
Proposed Power Plant Intake Structures.Third National Workshop on
Entrainment and Impingement.Section 316(b)Research and Compliance.L.D.
Jensen (ed.).Melville,N .Y.
89
Teleki,G .C.and A.J.Chamberlain.1978.Acute Effects of Underwater
Construction Blasting on Fishes in Long Point Bay,Lake Erie.Journal of the
Fisheries Research Board of Canada.Vol. 35.
U.S.Environmental Protection Agency.
in Wetlands of the United States.
1976.Impacts of Construct ion Activities
NTIS.Springfield,VA.
U.S.Fish and Wildlife Service.1981.Endangered and Threatened Wildlife and
Plants.Federal Register 50 CFR 17.11 and 17.12.January I, 1982.
Vanderwalker,J.G.
Bio-acoustics.
1967 .Response of Salmon ids to Low Frequency Sound.
Vol. 2. W.N.Lavolga (cd.).
Marine
Warren,C.E .1971.Biology and Water Pollution Control.W.B.Saunders Company.
90
FIGURES
.--------
•
~.
)
•
OENAU
HATlONA!.
PARK
P'AIWAJto;' PA.VED U H Q(V IOEO l-tf'G)ofWAV
s.ECO"'Q.ISrY PlW'EO U NOIVlOEO to4 <;HWAV
SECONOARV GRAVEL >-4 IGWWAY
..,.._ - - -
-,-
LEGEND
THE SUSITNA RIVER BASIN AND THE PROPOSED SITES OF
THE WATANA AND DEVIL CANYON DAM
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Reference:APA.,1983.Figure 1
Woodward-Clycle Consulbints
AND
ENTAl)(,INC.
HARZA-EBASCO
SUS ITNA JOINT VENTURE
IDENTIFICATION OF
IMPACTS AND GOALS OF PLAN
OPTION ANALYSIS
NEGOTIATION OF ACCEPTABLE PLAN
-
IMPLEMENTATION OF PLAN
'-----------,r----------l
.
MONITORING OF PLAN
PLAN MODIFICATION
COMPLETION OF MITIGATION
TERMINATION OF MONITORING
MITIGATION PLAN DEVELOPMENT AND IMPLEMENTATION
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 2
Woodward.Clyde Consultants
AND
ENTRIX,INC.
HARZA -EBASCO
SUSITNA JOINT VENTURE
~--~TOTAL RECTIFICATION
~--~TOTAL COMPENSATION
------~)TOTAL AVOIDANCE
J------i'SOME MINIMIZATION
~--~SOME REDUCTION
PARTIAL AVOIDA."CE -1 AVOIDANCE ]
I
NO AVOIDANCE
1
MINIMIZATION
I
NO MINIMIZATION
1
PARTIAL RECTIFICATION~RECTIFICATION
I
NO RECTIFICATION
1
REDUCTION
I
NO REDUCTION
J
PARTIAL COMPENSATION ~COMPENSATION
[
NO COMPENSATION
UNMITIGATED /LOSS
RESIDUAL IMPACT
OPTION ANALYSIS
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 3
Woodw.rd.Clyde Consulbants
AND
ENTRIX,INC.
HARZA·EBASCO
SUSITNA JOINT VENTURE
/
t
~!,.........
·..f '
MILE
~EQE"O
....PROPOSE D 'RANSUISSIO ~COARIOOI:\
PRoPOseo DEV il CAN\'ON .-.CCESS CO AAIOOR
PROPOSED WAI4N"- ACCESS CORRIDOR
""'CHQRA.GE ~'AIRBANKS 1"41f ATIE
...........- OOtO CRE E...R.4IL CORRIDOR 'ATAN-A '<og
~A~"~ffFogC,.••,
\..."
\
.:»:
,-/
THE VICINITY OF THE DAM SITES. ACCESS CORRIDORS
AND TRANSMISSION LINE CORRIDORS
A LASKA POWER AUTHORI TY
S U S I T N A HYDROELECTRIC PROJECT
Reference :Sautne r andStrauon.1984.Figure 4
Woodwarct·Clrda Consultants
AND
ENTRIX,INC.
HAR lA ·EBASCO
SUSITNA JOINT VENTURE
J F M A M J J A S o N D
SPAWNING
INCUBATION 1--._._._.-I·_._.1-.-
~-.......,--
-1--"""--
_.-+0--._.....,...- .
.-.+-.-.~_._......
MIGRATIONS
ARCTIC GRAYLING
DOLLY VARDEN
~=.:4·=_.~...........---...--+--.--1-----
MIGRATION AND SPAWNING PERIODS FOR
ARCTIC GRAYLING AND DOLLY VARDEN IN TRIBUTARIES
ALASKA POWER AUTHORITY
SUStTNA HYDROELECTRIC PROJECT
Reference :Morrow 1980
Scan and Crossman .1973.Figure 5
Woodward·Clyde Conaultanta
AND
ENTRIX, INC.
HAAZA·EBASCO
SUSITNA JOINT VENTURE
INFORMATION NOT CURRENTLY AVAILABLE
SCHEDULE FOR THE CONSTRUCTION OF THE WATANA DAM
AND RELATED FACILITIES
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 6
Woodw.Ifd·Clyd.Con...lt.nt.
AND
ENTAIX.INC.
HARZA ·EeASCO
SUSITNA JOINT VENTURE
®
1-fi'
:1
BORROW SITE J
~.::=:-;~
SUS.!NA RivER
\/
FOG LAKES
RELICT CHANNEL
WATANA O"M l "!E9'?
DUARA\'L.)
SITE A
"
6
1(
"
....:.l\,
',', :',v"
'"..,:
_~..c~--1(1 1',.\I --1 i ,• 1 \'1 t il .' ""
"'",.......,.I
il l S" '."".I
LOCUIO.M."
,.,-..122.I•KAU
LEGEND
c:::a IIORIIOW'QUA,RA 't Ilff l l...IfS
, •T·u_I
PLAN VIEW OF POTENTIAL WATANA BORROW SITES
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Reference :APA, 1983.Figure 7
Woodward.Clyde Con.ullent.
AND
ENTRI)(.INC.
HARZA ·EBASCO
SUSI TNA JOINT VENTURE
....b=··zd-··
~::l]IIOfU'OWIQUAIIU'V IITt:&.'M.T5
®
,-P'
:1
\/
fOQ LAKES
RELICT CHANNEL
WATANADAM S "E ~
OUARRiW
SITE A
~
~·.':'I :'t.A
1I1",l u-..n~l i •
I
• I lf v II C"""~I I ".
~I ~f 1.'.1 1'11
lOCt.T1011 IIIAP
L f ......SCALI
LEO£ND
PLAN VIEW OF POTENTIAL WATANA BORROW SITES
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Reference :APA,1983.Figure 7
Woodward-Clrd.Con.ultanu
AND
ENTAIX.INC.
HAAZA ·EBASCO
SUSITNA JOINT VENTURE
@
~l',"....r!J"
oc.w..-
j
r-1
'\'l
l.llm!Q
MAIN ACCESS ROAD
CONSTRUCTION ROAD
PERMANENT SITE R04D
H4UL ROAD
WASTEWATEROUTF4LL
STAGE 3 NOAM"L M"X IMUM
RESERIIOIR LEVEL
STAGE I NORMAL MINIMUM
AESERIIOIA LEVEL
.:~I-MI XV TItANlIIIIUlON ;V ~-../1
UNO TO OOLO CREEK r=..:----'d:--CRlE/!~-/~~+-,=-=:
1/
.J;'
_ /1 ~~,V ---~
/
--SUSITHA ~"._-_.....
-'-----.,--RiVER »<>:'
ItORROW <:--DOWHSTREA"~AR~COFFERDAM
F1l.TEA I AOOREQATE ~aoUACE
r ~' ''''
PLAN VIEW OF THE WATANA DAM, COFFER
DAMS, RELATED FACILITIES AND DISPOSAL AREAS
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Reference :APA ,'983 Figure 8
Woodw.rct·CI,de Con.ul"nt.
AND
ENTRIX.INC.
HAAZA -EaASCO
SUSITNA JOINT VENTURE
....
L.l >D!Q
'..~&G S .,,""'"""YllE"Z1 e>lsr'OOG ........ss
_._-PROfI"OS,E O 'IfArAJi ~I£CESS CO ARI()(JA
SlN.Sl l lVE AQu.DIC "'oI.8lT&'"'JE..Afa r HE
&.::..CES S CQA A I(}CJl
"'ATCH l iNE FIGURE 10
SENSITIVE AQUATIC HABITAT ALONG THE NORTHERN
SECTION OF THE WATANA ACCESS CORRIDOR
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Ref,ffllnCe :SaLl1nef'JI1<l Stranon ,1984 .Figure 9
Wooclward-Cfyde Coneuttanta
AND
ENTRIX ,INC.
HAAZA ·EBASCO
SUSITNA JOINT VENTURE
UGEHD
8 £Dl'&G STRU"~U"'lII:R
ell E"ST"'G LJo~ES
-PAOPOSEO OE'VIL e.u.tvo.."C CESS COFtRIOCA
-PROPOSED WAT~A ICCESS COARIOOA
SE"'SITlV£&.QUAne MA.SIUJ "'£~~, ...£ACCE SS
CO RAt OOA
SENSITIVE AQUATIC HABITAT ALONG THE CENTRAL
SECTION OF THE WATANA ACCESS CORRIDOR
ALASKA POWER AUT HORITY
SUSITNA HYDROELECTRIC PROJECT
Referef'.ee:Saulner and SlraltOn.1984 .
Figure 10
Wooctwarcf.Clyde Conault.nta
AND
ENTRIX.INC.
HARZA -EBASCO
SUSITNA JOINT VENTURE
STREAM eM J F M AM J J AS 0 N D
Unnamed Creek Nenana SYstem .3
Trlbutarv to Lllv Creek 2
LIlv Creek 3
Seattle Creek 5.8 V/h ~~@ ~
Trlbutarv to Seattle Creek 7.7
Trlbutarv to Seattl.Creek 8.7 ~~1m ~~
Brushkana Creek 10.7
Tributary to Brulhkana Creek 11.7 @ ~
Bruahkana Creek
12 .0 ~~
Trlbutarv to Brulhkana Creek 13.7 ~~
Trlbutarv to 'Sruahkana Creek
16.9 @ ~~~~
li'lbutarv to Bruahkana Creek
18.0
Deadman Creek
19.7 ~~
Trlbutarv to Deadman Creek
23.0
TrIbutary to De.dman Creek 23.7
Trlbutarv to Deadman Creek
24.8
1I'lbutarv to Deadman Cre.k 27.5 f'l'~~
lrlbutarv to D••dman Creek
28.5 ~~~~
Trlbutarv to Deadman Creek
29.5 ~~tij
'n'lbutarv to Deadman Creek
31.4
Trlbutarv to De.dman Creek 36.9 ~~~V~r0/.~
lrlbutarv to De.dman Creek 37.2 ~~~
Tlrbutary to Deadman Creek
37.8 'l"h:~
r02l =Instream
Activity
Prohibited
RESTRICTED PERIODS OF INSTREAM ACTIVITY FOR
STREAMS CROSSED BY THE ACCESS CORRIDOR FROM
THE DENALI HIGHWAY TO THE WATANA DAM SITE ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 11
Woodw.rd·Clwde Conaultanta
AND
ENTRll,INC.
HARZA ·EBASCO
SUSITNA JOINT VENTURE
INFORMATION NOT CURRENTLY AVAILABLE
SCHEDULE FOR THE CONSTRUCTION OF THE DEVil
CANYON DAM AND RELATED FACILITIES
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 12
Woodward-C1rd.Conault.nt.
AND
ENTRIX,INC .
HARZA ·EBASCO
SUSITNA JOINT VENTURE
o I
,I
"'~l
£
~z
~m..,
Gi
"-I ~i ~,
;
\
LDn-A -tflU".
L......../P/
~n.;'~;O~::,
(/JlPj
I
oC?O
~
LIOINO
AOf'O !nREW Nu..BER
EKI~"NG LA~fS
PAQPOSED 'RAHS"'SSION CORRIDOR
PROPOSED DEVIL CANYON ACCESS CORRIDOR
PROPOSED WATA"'.ACCESS CORRIDOR
SENSITI VE AOUA.TlC "'''8 1'A1 ~e"R 1HE ACCESS CO RF:lIlOOR
@
ClJ
:':'.'".:
SENSITIVE AQUATIC HABITAT ALONG THE WATANA AND
DEVIL CANYON ACCESS CORRIDORS
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Aeference:Saumer and Stranon ,1984 .
Figure 13
Woodw.rd-CIVde Conault.nta
AND
ENTRIX.INC.
HARZA·EBASCO
SUSITNA JOINT VENTURE
SENSITIVE AQUATIC HABITAT ALONG THE WESTERN
SECTION OF THE DEVIL CANYON ACCESS CORRIDOR
It..
o I
~__.I
"'I.!
LEGEND
-++GOlD CREEK RAILROAD CORRIDOR
It ADF&O STRU"Nu ..aER
~E "STINQ LAKES
PROPOSED TRANS" 'SSo()N CORRIDORS
PROPO SED DEVIL CANVON ACCESS CORRIDOR
oll,N CHORAQf F'AIRBANICS 1NT ERJlE
.:":'::SEfIlSIT!vE AOl,..IA1 'C J"I1A8 Ir",~f"f'f totE ACCESS COR RIDOR
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Relelence:Saulnerand Strauon.1984 .Figure 14
Woodward-Clyde Con.ullant.
AND
ENTRIX,INC.
HAAZA ·EBASCO
SUSITNA JOINT VENTURE
STREAM eM J F M AM J J AS 0 NO
Tausena Creek 2.2 ~/~~C/~V~~
'Tribulary 10 Swimming Bear Creek 8.0 ~~V~~
Trlbulary 10 Swimming Bear Creek 8.7
Tributary to SWimming Bear Creek 11.1 ..
Tributary 10 Swimming Bear Creek 11.4
Tributary to Swlmmlna Bear Creek 12.0
Tributary to Swimming Bear Creek 12.4
Tributary to Swlmmlna Bear Creek 13.9
Trlbulary to Swimming Bear Creek 15.7 ~/~'l'/,;j ~
Tributary to Devil Creek 18.9 l'l'~ 'l'/~~
Tributary to Devil Creek 22.2
Devil Creek 22.4
Tributary to Devil Creek 24.3 V/h Y/h ~
Tributary to Devil Creek 24.5 ~/hV/h ~
Tributary 10Devil Creek 26.3
Susltna River 35.1
Jack Lona Creek Encroachment 36.3-39.3 V/~)'l 'l'~'l'/~~
Tributary to Jack Long Creek 37.3
Tributary 10Jack Lona Creek 38.9
Tributary to Jack Long Creek 43.3
Unnamed Creek 43 .3 I"/h ij -j/h';V~~
Unnamed Creek ("Waterfall Creek")44.5
Gold Creek 47.9 W~~j/~V;!/~~.
~:Inslream~Actlvlly
Prohlblled
RESTRICTED PERIODS OF INSTREAM ACTIVITY FOR
STREAMS CROSSED BY THE ACCESS AND TRANSMISSIO~
LINE CORRIDORS TO THE DEVIL CANYON DAM SITE
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 15
Woodward-CI,de Conaultanta
AND
ENTRIX.INC.
HAAZA -EBASCO
SUSITNA JOINT VENTURE
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
PLAN VIEW OF THE DEVIL CANYON DAM, COFFER DAMS
AND DISPOSAL AREAS
--~:!!!!!Iil';';'.'iiIiiI
®
--..
""".
""'---....·000 ,
1
I
"'\.
"\-.
~,..•...-.,._..--
.......--................
""'.-:-"""-.
<,-
-,
"\
'.~-,
~'\
.~
Fifo.,"'ATAIi'A
.__/"\_--<,
}
\.
..",\.,
'-.
\
."-...
:~::.::i>::.·t~~~~")
'•.1
1)00 ---
-'\
.I \
\
WAI"
~..
<,
'100
2·3.~KV TAANSIIISSION{-..-. ---"
LINES TO GOLD CREEK _. '.-'--
LEGEND
----_.HAUL ROAD
_._--RUNOUT
•••••••••••• NORMAL MAXIMUM
RESERVOIR LEVEl
\
\
\,\~-:.:\'\J>-_
'"-..""--~000 ~~" .SUSITNA H~~
LEVE~DRI
Reference: APA. 1983.Figure 16
Woodw.rd-Clrda Conaultanta
AND
ENTRIX. INC.
HARZA·EBASCO
SUSITNA JOINT VENTURE
,.;~'
f~0~~~·:Ii/._ .'\,-'";1',/"---:1 _.iiiai :........---,..;.;••••,;::,',
...----,.,,~--.....',"<,
I -
.....
G
'.
I ,;".
)}
CJlIJO
S<J.t"~"'!J.1t J ~
---'\f;M
LOCATIO"IIA',.....,.
{
,......
""--I
~l·,iJ-~
!r L.01"
.."",'tCIiIO&M
---or-
~..","(,'r
0....,
....,"..
l
I \I
,
0010
~eilEEN
I \
I
)
(
J
\
\
......,
,
(
(
t.II'
~
-"A~'
o lGUO.eo ....E__a
I
)
L~91_~
---BOflRONOUARRV SITE LI...T8
"'~
l~
......
'.....
"
/
,~
---~~~/'-...-----,/'--.......\,-
\~-
)
-,''J '\\J
V"',--~...
<,
PLAN VIEW OF POTENTIAL DEVIL CANYON BORROW SITE
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 17
Relerenee: APA,1983 ,
Woo"wa~lrd.Conaultant.
AND
ENTAIX,INC.
HARZA ·EBASCO
SUSITNA JOINT VENTURE
SCALE
o 500 Ft.,I
RESERVOIR
EL.2000
"'-,
<,-.~,
"\"\./
--1st STAGE DAM
___3rd STAGE DAM
t
r
STAGES 1 AND 3 OF THE WATANA DAM ALASKA POWER AUTHOfllTY
SUSITNA HYDROELECTR IC PROJECT
Figure 18
Woodward·Clyde Conaultanta
AND
ENTRIX. INC.
HAAZA ·EBASCO
SUSITNA JOINT VENTURE
@ IC .....
eco eoo'li.
"'I-
/
./
./
LEGEND
BORROW SITE LIMIT
MAXIMUM NORMAL DEVIL
CANYON RESERVOIR
lEVEL (IU5 FT.,
BUFFERS TO aE
MAINTAINED
TOPOGRAPHIC CONTOURS
STREAM MARGINS
BORROW SITE E
I J I I I I
1 .1 .1 ,1 I
'../.'~.ci:I~
,..',,~.~..=.l
J6>'~.,'•• ,:,'1l1....".,p.''I".,1 1
.... •'14'.I ."
,~Il '/
:,,";,',",.'.'f.,'/......-.'//6 I .•.'
J ".,'I,'..../:'.__~\.... ".(,..!l ,
. ",.i '(•, .'_..",....."'''''''''~\.".»:..'..../J ,',',.'/.,-..'1\......'....1 I I~'....! '''..,".....''I ','··/..'.~j\._._.__._._._../'_"..v'(.',......,.;::}./:~}"~"...'"/.'t .,' : \..'".'I ',1. :.'
.r'I "•,~1 ••'\../,''J}:,,...:. .::.1::.:"/.!!!!.:~........
,..-.." .'~.,',II 1.''": ",.,',~.~.,.., \'r-"'""./.,'Ii !'.....,;....I ~..,J.....'I .,t'."'...,_I . .,'L I '."
"J';'·c....., /'''.'
",..r \I '-....~__....I ,':'~J!~~',..
'.:.'~.\l"I 61:
r
"~'.......~_~....." ,I.,.,..........-.,.II"oJ I I .'..I ••../"..~,~'J~/),I ".,/........•'.).....~J !y I.'I /'.-'\.~-""','..../.••.......I '..',...<:>:.~~-~."I.'/',oo..•. .. ..", .,./: ','..".r >../,.~__r'..,.,~",;J ~" ~l!:,),J..J !,~~"'S\Zi·Zur .;\:..J(,~~'t:~-:;t ,<~,
! /..../\,. _~~,.\\:..>'U'''N'....."OW
.• ,"J\,J ---;/.'",',V '/......-._.•~_•.--'.•_..._.....-........
..,.,."., I II .".."---'.......'/ .',',J,.,.r ...-...------.--..r.--.':I'....I ,./....../''"---.....;;;::;--.-.... ),:,v ,--.,---......'<,
•r -,A:.',I i "~,"
'.I •.,."', '/./..........-
.:,.,,,:I /,',y ,--
."...;.t-.I I /
" .'•,_..I j.
,.'.'/,I ',I I I •I "..;,,,...._'-'.....w.·~ltlll,1 I •I ~I '/',.,;"<'.~""""","--04~'.I ,I .I .'_V,Ii ......·~I 'I '1 ".•y ,.,-•
•f ••••',~'~I I·'·J,.-/.f I I .."I I I ".i l l..........-
/''."".~J l l ,..I 1 1,lj.'··-.....-..._........,_....__)~:., .;~).l..Y"
".-/~
BORROW SITE E ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Reference :APA. 1983.Figure 19
Woodw.rd·C1rd.Coneultanta
AND
ENTRIX,INC .
HAAZA ·ESASCO
SUSITNA JOINT VENTURE
www
.--~.
@
=--10..,,..1,.."'"
~
~.,
\r
(:
(<.1'ACCESS ROAO IPER"'ANENTI
)----ACCESS ROADlTEIIIPORARVI
)
CONStRuCTION ROAO
~---PERMANENt SITE ROAD
""------RAllROAO
)'g _...__STREA"""'ARGINS
G --.-TRANS"',SStON LINESr-...
)\
\..-.\
2·JUKYLlIt ~FROM WAr'ES ----.~.V·'~·
I
V
,
'\
-~
~
/
I
.--·l'
/
/
\~~~---·~fi-----;~~---\~....:----.._/~~~'--.~~-~
~'-~
)~~";WAnil ~)'
fNTAKE :':
OUTFALL ,
SEWAGE
toM'ltV TfIA ......'SI /!;~...,~(
.....:~...sou .....,,CON"'''''''''''''.4(":.'ON""ocrro t ~P:____UItOFlllI.ND VillAGE .'CAMP I
.....dHCINfRATION /~'r 'l"-~- " ._:ff WATER .GO(,.',:.':';=.zf;/_./--TREAT'" NT '\')
D ~"'""'"..l4c~LON~REEl(::=:--=3-'..-RAILH~AD""""..........------.......:.--....../- /d -'""'~'_-------~-_':_~---~.::--~--"-~~---r----------........--~-i\.:i("O~O ----.-.•~:~----....r
.r:-"2J--- --J .--
»:~--. ,----,--,s·---/---.(-.
,~oo
PLAN VIEW OF THE DEVIL CANYON DAM AND RELATED
FACILITIES ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Re'efence:APA. 1983.
Fi~lIr,.~I)
Woodwerd-Clyde Con.ultent.I H A A I ".E B "SeD
AND SUS,T N A J 0 I N T VEN TU A E
J ENTRIl(,INC,I
/
REHABILITATED BORROW SITE E
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
•
Figure 21
Woodw.~lycI.Conaultanta
AND
ENTAIl(,INC.
HARZA·EBASCO
SUSITNA JOINT VENTURE
___EXISTING INTERTIE
••"''''~WATANA INITIAL DAM
1 DEVIL CANYON
•••••••••••.WATANA HIGH DAM
HEALY
IIII/OF.~/""':;___AIRBANKS
~---!I::.~
:-:r_-.r.r~DEVIL CANYON
'1."I.I.'IIII "'.~i\.r"""",,,,,,,,,,,~WATANA
GOLD CREEK '
STAGED CONSTRUCTION OF TRANSMISSION LINES
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Figure 22
Woodw.rd·Clyde Conault.nta
AND
ENTRIX,INC.
HARZA ·EBASCO
SUSITNA JOINT V ENTURE
TRANSMISSION LINE CORRIDOR FROM THE WATANA DAM
SITE TO GOLD CREEK
@
LEGEND
,u..,....,
I
/
\~{~.~--f~J ;'~:l i ~:E
"""--'-_/~...c.hn
,WArA"A
.JCAW~SirE
WAYANA /..-J~~£.,~WArANA DAW
-=c~,_./
flll/EfI '-
RAILROAO
._ - _ ACCESS ROAD
IRAIIISIoIISSION LIlliE
SUSITNA
~
;f
",",~'",.."V0,-sr
:../'
~+-t'
q.I(;0
(.;/
••ri-,
,#,o '
)
",".'/..I;~\¥oO\~
!
/
: Al ASIl A
"RAILROAD'-.
'~
\
.#}§~\'"~rl ,
·~t.__,';~~:M;'.':..,.
/'•;/O';R U C I I O~'-~E~'l CA'N~~~"-J'\-C Gf -AN'fONVILL A :-,J,JOEVIL C P SITE~~~~~~~~-~CAM ~
"I ~
RAILHEAU If>
'"'~"\
j.:
I'
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Relerenee :APA.'983
Figure 23
Woodw.rd·C'wde Coneu'h1nta
AND
ENTAIl(,INC.
HAAZA ,EBASCO
SUSITNA JOINT VENTURE
HARZA ·EBASCO
SUSITNA JOI N T VENTURE
-t+t+'t'+"LASKA IU.ILPQAO
STAU....S
PARKS ""Gt<WAY
TA....NS...ISS,ON LINE COI'lI'lIDOI'l
THE SOUTHERN SECTION OF THE
ANCHORAGE ..FAIRBANKS INTERTIE
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
Woodw.rd.C.,de Conautbnts
AND
ENTRIX .INC.
/,-
lit....I :'
'I.
\
\
~
~
Figure 24
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
THE CENTRAL SECTION OF THE
ANCHORAGE-FAIRBANKS INTERTIE
o t J
C::::±::::J MILO
HARZA·EBASCO
SUSITNA JOINT VENTURE
"£aENO<--_
+H+++AlASlU RAllR~D
STREAMS
PARKS HIG~WAV
TRANSt.llSSION LINE CORRIOOR
Woodwercl·Clyde Con.u.tanb
AND
EHTAIX.IHC.
\,
I,
I
I
I
I
},
I,
I,
)
'\
\
'\
XTCH LINE FIGURE 2.
Figure 25
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
THE NORTHERN SECTION OF THE
ANCHORAGE-FAIRBANKS INTERTIE
.,
......lCH UHE FIGURE 25
HARZA·EBASCO
SUS I T N A J 0 I N T V E N T U REFigure 26
l,J.!O~NO,<--_
~ALASIU RAILROAD
STRUMS
PAAKS HIGHWAY
TRANSloIlSSION LINE CORRIDOR
Woodward-Clyde Consultants
AND
ENTRIX.INC.
o ,
..lUll t:::1
!,J'3EHO
~ALASKA RAILROAD
STREAMS
PARKS HIGHW"'V
___TAANS~ISSIOIII LIlliE CORRIDOR
/".
",.
......1..
Figure 27
IotAlt:H UHE FIGURE 24
HAAZA -EBASCO
SUSITNA JOINT VENTURE
,
/
/
/
/'
/
/
i
I
I
I
r
I
I,
i COlt/LAKE
I
\
\
\
\,
\
\
\
\
\
ALASKA POWER AUTHORITY
SUS I T r<l A H Y 0 ROE LEe T RIC P ~0 J EC T
THE TRANSMISSION LINE CORRIDOR
FROM ANCHORAGE TO WILLOW
Reference :APA 1983
WoodwIIrd-C1yde Conaultanta
AND
ENTRtX .INC.
Referenu:APA 1983
HAAZA·EBASCO
SUSITNA JOINT VENTURE
L£OENO'!!!L _
ALASKA RAILROAD
STREAMS
PARKS HIGHWAY
TRANSMISSION LINE CORRtDOR
o I
t::J
ALASKA POWER AUTHORITV
SUSITNA HVDROELECTRIC PROJECT
MATCH UNE FIGURE 2t
WoocIward-C1yde Con.uRanu
AND
ENTAtX,INC.
:
THE SOUTHERN SECTION OF THE TRANSMISSION LINE
FROM HEALY TO ESTER
FIgure 28
HEALY
.---.-
,
I,
/
I
/
.//
"
/
/
/
;!,
,~~~
.>6/..../'1
/
/
"
MATCH UNE FIGURE 2e .
I I
MIl£S C:::J
l£GEHD<--_
-t+++++AlASII.'RAI~AOAI"
ST'REAMS
PAAKS HIGHWAY
TRANSt,l'SSION ~INE CORR IDOR
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
THE NORTHERN SECTION OF THE TRANSMISSION LINE
FROM HEALY TO ESTER
Refel1!nce:APA 1983
.',.
r
:
T.iIlNANA R/V""
MATCH UNE FIGURE 28
_FIgure 29
WOoclw8rdoClrd_Consultants
AND
EHTRIX.INC.
HARZA·EBASCO
SUSITNA JOINT VENTURE
TABLES
Table 1 .Access,construction,and trans~isslon 1~8ct aechanis.s and associated mitigation.
Project Polley
.1 Scheduling of &Modification
Best Management PractIces Manu,ls Construction of current Water Strea.Margin Rehab! .
lapact Mechanls.s 19858 1985b 1985c 1985d 1985e Actlvlti.a .eason./1 i.1 t8 Yr.ataent Buffers II tat ion Monitoring
Increased Fishing
Pressures X II
Borrow Site Excavations II II X X II )(
Stream Crossings
and Encroachments X X II )()(
Water Quality X X X X X X X X
Degradat Ions
Oil and Hazardous
Material Spills X )(X X X X )(
"ater Removlll X II X II
Clearing X II X II X
Sualtna River
Diversions
APA,1985a.
APA,198'.ib.
APA,1985c.
APA,1985d.
APA,1985e.
Eros ion and Sed imentation Control
"'liter Supply
liquid and sol id Waste Management
fuel and Hazardous Materials
OiL Spill Contingency Planning
Table 2.Summary of comments from the resource management agencies pertaining to access,
construction and transmission lines.
(2)Design of tunnel intakes
(3)Scheduling of construction
activities
(2)Access road usage by
non-project personnel
(3)Transmission line routing
Agency
USFWS
ADF&G
ADNR
ADEC
Date
10/5/82
1/4/83
1/13/83
12/23/82
1/28/83
2 /8/83
1/21/83
Reason for correspondence
Review of Draft
Exhibit E,FERC
License Application
Review of Draft
Exhibit E,FERC
License Application
Review of Draft
Exhibit E,FERC
License Application
Review of Draft
Exhibit E,FERC
License Application
(1)
(1)
(1)
(1)
(2)
Comments
siting of access and
transmission line corridors
Design of tunnel intakes
Watana camp domestic water
supply source
Hazardous material handling
Wastewater treatment
(3)Concrete production
(4)Access road design
Table 3.streams crossed by the Denali Highway from Cantwell to
the watana access road junction.
Stream
Approximate miles from
the Richardson Hwy.Species Present
Tributary 132.5
to Jack River
Tributary to 132
Jack River
Unnamed Creek 128
(Jack R.System)
Edmonds Creek 121
Nenana River Oxbow 119.8
Nenana River Oxbow 119.5
Tributary to 118
Nenana River
Tributary to 117.8
Nenana River
Unnamed Creek 114.3
(Nenana R.System)
Arctic grayling,(Whitefish)l
Arctic grayling,(Whitefish)l
(Arctic grayling,whitefish)l
Arctic grayling,northern pike,
burbot,Whitefish,sculpin
Arctic grayling,northern pike,
burbot,whitefish,sculpin
Arctic grayling,northern pike,
burbot,Whitefish,sculpin
Arctic grayling,northern pike,
burbot,Whitefish,sculpin
Arctic grayling,northern pike,
burbot,Whitefish,sculpin
Arctic grayling,northern pike,
burbot,Whitefish,sculpin
1 (species)can be reasonably expected,but not verified
Reference:ADF&G 1978 Fisheries Atlas.Volume II.
Table 4.Streams to be crossed by the Watana access road
(Denali Highway to the Watana dam).
Habitat
stream Miles From Conditi<;ln ~t
(ADF&G Survey No.)Denali Highway Species Present Cross1ng
Unnamed Creek 0.3 (grayling)2 3
(Nenana System)2.0
Trib.to Lily Cr.(l)3.0 Dolly Varden,3
sculpin
Lily Creek (2)3.0 Dolly Varden,3
sculpin
Seattle Creek (3)5.8 Dolly Varden,2
grayling,sculpin
Trib.to Seattle Cr.(4)7.7 Dolly Varden 4
Trib.to Seattle Cr.(5)8.7 (Dolly va2'den,2
grayling)
Trib.to Brushkana 10.7 {grayling,sculpin)2 4
Cr.(6)
Trib.to Brushkana 11.7 {grayling,sculpin)2 5
Cr.(7)
Brushkana Cr.(8)12.0 grayling,sculpin 1
Trib.to Brushkana 13.7 grayling,sculpin 1
Cr.(9)
Trib.to Brushkana 16.9 Dolly Varden,
Cr.(10)grayling,sculpin 2
Trib.to Brushkana 18.0 (grayling,sculpin)2 5
Cr.(11)
Deadman Creek (12)19.7 grayling,whitefish 5
sucker,burbot,
sculpin
Trib.to Deadman Cr.(13)23.0 probably 4 5none
Trib.to Deadman Cr.(14)23.7 probably 4 5none
Trib.to Deadman Cr.(15)24.8 probably 4 5none
Table 4 (continued)
Habitat
stream Miles From conditic;ln ~t
(ADF&G Survey No.)Denali Highway Species Present Crossl.ng
Trib.to Deadman Cr.(16)27.5 (grayling,Lo i 2 1scupln)
Trib.to Deadman Cr.(17)28.5 probably none 4 5
Trib.to Deadman Cr.(18)29.5 Dolly Varden,5
sculpin
Trib.to Deadman Cr.(19)31.4 sculpin 5
Trib.to Deadman Cr.(20)36.9 Dolly Varden,3
grayling,sculpin
Trib.to Deadman Cr.(21)37.2 (grayling,scu1pin)2 3
Trib.to Deadman Cr.(22)37.8 (grayling,sculpin)2 3
1
3
4
1 =excellent,2 =good,3 =limited,4 =marginal,5 =poor
Ratings deduced from information presented in Sautner and
stratton (1984).
(species)can be reasonably expected,but not verified
---=not evaluated
steep contours on downstream side of road probably preclude
fish from this reach
Biological Data Source:Sautner and Stratton 1984
Table 5.Alaska Department of Fish and Game standards for passing
Arctic grayling to be US!d on Susitna Hydroelectric
Project stream crossings •
Length of CUlvert
(feet)
30
40
50
60
70
80
90
100
150
200
Average cross-section2l
Velocities at outlet
(ftjsec)
4.6
4.5
4.0
3.6
3.3
3.0
2.8
2.5
1.8
1.8
1 Each culvert must be installed so that at least 20 percent of the
diameter of each round culvert or at least 6 inches of the height of
each elliptical or arch type culvert are set below the streambed at
both the inlet and outlet of the culvert except when using
bottomless arch culverts or to avoid solid rock excavation.
2 Average cross-sectional velocities at the outlet of the culvert may
not exceed the velocities in the table except for a period not
exceeding 48 hours during the mean annual flood.
Source:Edfelt 1981 and Title 5 Fish and Game Part 6 Protection of
Fish and Game Habitat Chapter 95 -Alaska Department of Fish
and Game.
Table 6.Alaska Department of Fish and Game Temporary Stream Diversion
Standards
Temporary diversion channels in all streams
frequented by fish must be constructed and
controlled in the following manner:
(I)The width and depth of the temporary diversion channel must equat or exceed
75 percent of the width and the depth,respectively,of that portion of ~h e
streambed which is covered by ordinary high water at the diversion site,
unless a lesser width 01'depth is specified by the department on the permit
for activities undertaken during periods of lower flow;
(2)During excavation or construction,the temporary diversion channel must be
isolated from water of the stream to be diverted by natural plugs (unaltered
streambank)left in place at the upstream and downstream ends of the
diversion channel;
(3)The diversion channel must be constructed so that the bed and banks will not
significantly erode at expected flows;
(4)Diversion of water flow into the temporary diversion channel must be
conducted by first removing the downstream plug,then removing the upstream
plug,then closing the upstream end and the downstream end,respectively,of
the natural of the diverted stream;
(5)Rediverslon of flow into the natural stream must be conducted by removing the
downstream plug from the natural channel and then the upstream plug,then
closing the upstream and the downstream end,respectively,of the diversion
channel;
(6)After use,the diversion channel and the natural stream must be stabilized
and rehabilitated as may be specified by permit conditions.
Source:Edfelt 1981
Table 7.streams to be crossed by the Devil Canyon access road
and railroad spur from Gold Creek.
stream
(ADF&G Survey No.)
Miles From
Watana Road
Habitat
Condition it
Species Present Crossing
SCUlpin 3 (because
of fish barrier)
Tsusena Cr.(23)
Trib.to swimming
Bear Cr.(24 )
Trib.to Swimming
Bear Cr.(25)
Trib.to Swimming
Bear Cr.(26)
Trib.to Swimming
Bear Cr.(27)
Trib.to Swimming
Bear Cr.(28)
Trib.to Swimming
Bear Cr.(29)
Trib.to Swimming
Bear Cr.(30)
Trib.to Swimming
Bear Cr.(31)
'I'rib.to Devil
Cr.(32)
Trib.to Devil
Cr.(33)
Devil Creek (34)
2.2
8.0
8.7
11.1
11.4
12.0
12.4
13.9
15.7
18.9
22.2
22.4
grayling,white-
fish,sucker,
Dolly Varden and
sculpin
Dolly Varden,
SCUlpin
probably none
(Dolly v~rden,
sculpin)
(Dolly V~rden,
sculpin)
Dolly Varden,
sculpin
Dolly Varden,
sculpin
probably none
Dolly Varden,
SCUlpin
Dolly Varden,
sculpin
sculpin
1
3
5
5
5
3
3
5
2
1
3
Trib.to Devil
Cr.(35)
Trib.to Devil Cr.
Cr.(36)
24.3
24.5
Dolly Varden,3
sculpin
Dolly Varden 3
Stream
(ADF&G Survey No.)
Miles FrQm
Watana Road
Habitat
Condi ti<;>n it
Species Present Cross~ng
Trib.to Devil Cr.
Susitna River
26.3
35.1
(Dolly Varden)2
grayling,Dolly
Varden,sculpin,
whitefish,burbot,
sucker,chinook,
coho,pink and
chum salmon.
3
Trib.to Jack 37.3
Long Cr.(37)
Trib.to Jack 38.9
Long Cr.(38)
Trib.to Jack 39.9
Long Cr.(39)
Unnamed Creek (40)43.3
Unnamed Creek (41)44.5
(Waterfall Cr.)
Gold Creek (42)47.9
Jack Long Cr.
Encroachment
36.3-39.3 chinook,coho,
chum and pink
salmon,rainbow
trout,grayling,
sculpin
sculpin 4
(chinook,coho)2 4
(sculpin)2 4
chinook salmon,
sculpin 2
probably none 4 (because
of fish barrier)
chinook,coho,1
pink salmon
1
2
3
1 -excellent,2 z good,3 -limited,4 •marginal,5 =poor
Ratings deduced from information presented in Sautner and
Stratton (1984).
(speci~s)can be reasonably expected,but not verified
----not evaluated
Biological Data Source:Sautner and stratton 1984
Table 8.costs 1 associated with the access,construction and
transmission line mitigation and monitoring.
Description Capital Costs 2 ($)Annual costs 3
Borrow site E
0 4Rehabilitation65,000
Environmental
05MonitoringProgram 102,000
(a)Effluent Monitoring 4,000 20,000
Total:$69,000 $122,000
1 All costs in 1985 dollars.
2 Details of cost analysis in Appendix A.
3 Annual costs are estimated for 20 years of construction activity.
4 No annual cost expected prior to inundation by the Devil Canyon
Reservoir.
5 Average annual operatin~costs only are evaluated.
Table 9.Alaska Department of Fish and Game standards for blasting
near an anadromous fish stream.
DISTANCE TO ANADROMOUS FISH STREAM MEASURED IN FEET l
Explosive Charge Weight in Pounds
Substrate 1 2 5 10 25 100 500 1000
Rock 50 80 120 170 270 530 1180 1670
Frozen Material 50 70 110 160 250 500 1120 1580
stiff Clay,Gravel,Ice 40 60 100 140 220 440 990 1400
Clayey Silt,Dense Sand 40 50 80 120 180 370 820 1160
Medium to Dense Sand 30 50 70 100 160 320 720 1020
Medium Organic Clay 20 30 50 70 100 210 460 660
Soft organic Clay 20 30 40 60 100 190 440 620
1 Required distances for charge weights not set forth in this table
must be computed by linear intropolation between the charge weights
bracketing the desired charge if the charge weight is between one
and 1000 pounds:example:for 15 pounds of explosive in rock
substrate -required distance -
15 Ibs-10 Ibs170feet+25 lbs-10 Ibs (270 feet-170 feet)=203 feet:
for charge weights greater than 1000 pounds,the required distance
may be determined by linear extrapolation.
Source:Edfelt 1981
Table 10.streams crossed by the Anchorage-Fairbanks Intertie.
Stream
Approximate miles from
Willow Substation species Present
willow Creek
Rogers Creek
Iron Creek
Little Willow
Creek
Unnamed creeks
196 Mile Creek
197 1/2 Mile
Creek
Kashwitna River
Caswell Creek
Sheep Creek
Unnamed Creek
Goose Creek
.4
2.5
4
5
7,8.5
10
11.5
13
16
17
19.5
24
Chinook,coho,chum,pink and
sockeye salmon:Dolly Varden:
rainbow trout:Arctic grayling:
whitefish:(burbot)
(Arctic grayling,rainbow trout'l
Dolly Varden,whitefish,burbot)
(Arctic grayling,rainbow trout'l
Dolly Varden,whitefish,burbot)
(Chinook,sockeye,chum,coho and
pink salmon;whitefish;Arctic
grayling:rainb~W trout:Dolly
Varden:burbot)
(Arctic grayling,rainbow trout,
Dolly Varden,whitefish,burbot)l
(Arctic grayling,rainbow trout'l
Dolly Varden,whitefish,burbot)
(Arctic grayling,rainbow trout,
Dolly Varden,whitefish,burbot)l
Chinook,coho and chum salmon:
(Arctic grayling:rainbow trout;l
Dolly Varden:whitefish;burbot)
Chinook salmon:(Arctic grayling:
rainbow trout:Dolly Varden;
whitefish;burbot)
Chinook,pink and chum salmon;
(Arctic grayling:::-ainbow trout;1
Dolly Varder.~~h1tefish;burbot)
(Arctic grayling,rainbow trout,1
Dolly Varden,whitefish,burbot)
Chinook and pink salmon;(Arctic
grayling;rainbow trout;D~lly
Varden;~hitefish;burbot)
Table 10 (ccntinued)
stream
Approximate miles from
willow Substation Species Present
Unnamed Creek
Mont.ana Creek
Unnamed Creek
Answer Creek
Unnamed Creek
Talkeetna River
Unnamed creeks
Chunilna Creek
Tributary of
Chunilna Creek
Lane Creek
Unnamed creeks
Sherman Creek
Unnamed creeks
Gold Creek
Unnamed Creek
(Waterfall Creek)
27.5
30
34
36.5
41
45
48,50.5
54.5
63
63.5
67,70
70.5
71.5,73
76
79
(Arctic grayling,rainbow trout,
Dolly Varden,whitefish,burbot)l
Chinook,pink and chum salmon;
(Arctic grayling;rainbow trout;l
Dolly Varden;whitefish;burhot)
(Arctic grayling,rainbow trout,1
Dolly Varden,whitefish,burhot)
(Arctic grayling,rainbow trout'l
Dolly Varden,whitefish,burhot)
(Arctic qrayling,rainbow trout'l
Dolly Varden,whitefish,burhot)
Chinook,sockeye,coho,pink and
chum salmon;(Arctic grayling,
rainbow trout,Dolly Varden,
whitefish,burbot)
(Arctic grayling,rainbow trout,
Dolly Varden,whitefish,burbot}l
Chinook,coho,pink and chum
salmon;(Arctic grayling;rainbow
trout;£OllY Varden;whitefish;
burbot)
(Chinook and coho salmon;Arctic
grayling;rainbow trout;D£llY
Varden:Whitefish;burbot)
(Arctic grayling,rainboy trout,
Dolly Varden,Whitefish)
(Arctic grayling,rainb0Y trout,
Dolly Varden,Whitefish)
(Arctic grayling,rainb0Y trout,
Dolly Varden,Whitefish)
(Arctic grayling,rai.nb0Y trout,
Dolly Varden,whitef13h)
Chinook,coho and pink salmon,
Arctic grayling,rainbow trout,
Dolly Varden,Whitefish,SCUlpin
none2
Table 10 (CXI1tinued)
stream
Approximate miles trom
Willow Substation Species Present
Unnamed Creek 90
Pass Creek 90.5
Unnamed creeks 91.5,92.5,
94
Granite Creek 94.5
Hurricane Gulch 96
Little Honolulu 98.5
Creek
Unnamed Creek 100
Honolulu Creek 101.5
Antimony Creek 103.5
Unnamed Creek 105.5
Hardage Creek 106
East Fork 111.5
Chulitna River
Unnamed Creek
Susitna River
Tributary of
Indian River
Indian River
80.5
81
86
87.5
Chinook salmon,SCUlpin
Chinook,sockeye,coho,pink and
chum salmon:Arctic grayling:
Dolly Varden,whitefish,longnose
sucker,burbot,SCUlpin
(Arctic grayling,rainb0Y trout,
Dolly Varden,whitefish)
Chinook,coho,pink and chum
salmon:Arctic grayling:Dolly
Varden:1rainbow trout:(Whitefish,
burbot)
(Arctic grayling,rainbow trout'l
Dolly Varden,whitefish,burbot)
none2
none2
(Arctic grayling,rainb0Y trout,
Dolly Varden,whitefish)
(Arctic gr!y1ing,rainbow trout,
whitefish)
(Arctic griyling,rainbow trout,
whitefish)
(Arctic griyling,rainbow trout,
Whitefish)
(Arctic griyling,rainbow trout,
whitefish)
(Arctic griyling,rainbow trout,
Whitefish)
(Arctic griyling,rainbow trout,
Whitefish)
(Arctic griy1ing,rainbow trout,
Whitefish)
Sockeye,coho and chum salmon:
(Arctic griyling:rainbow trout:
Whitefish)
Table 10 (0CI'l'tinued)
stream
Approximate miles from
Willow Substation Species Present
Fourth of July
Creek
Unnamed Creek
Coal Creek
Middle Fork
Chulitna River
Unnamed creeks
Unnamed creeks
Jack River
Unnamed creeks
Nenana River
Unnamed Creek
Slime Creek
Carlo Creek
Yanert Creek
Unnamed Creeks
Montana Creeks
Unnamed Creeks
copeland Creek
Healy Creek
114.5
117.5
118
120
122.5,125
125.5,126.5,
128
131.5
133.5,134.5,
136.5
137
137.5
141
145.5
154
155,156.5
158
159,162.5,
163.5,164.5,
165
168.5
172
(Arctic griyling,rainbow trout,
Whitefish)
none2
(Arctic griyling,rainbow trout,
Whitefish)
Sockeye,coho and chum salmon;
(Arctic griyling,rainbow trout,
whitefish)
(Arctic griyling,rainbow trout,
whitefish)
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
Arctic grayling,whitefish,
burbot,northern pike,SCUlpin
none2
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)l
(Arctic grayling,whitefish)1
(Arctic grayling,whitefish)l
1 (species)can be reasonably expected,but not verified
2 Steep contours probably preclude fish
Reference:ADF&G 1978 Fisheries Atlas.Volumes I and II.
I
Table 11.Streams to be crossed by the transmission line from
Healy to Ester.
stream
ApproxImate mIles from
Healy Substation Species Present
Nenana River
Dry Creek
panguingue Creek
Little Panguingue
Creek
Slate Creek
Nenana River
Tributary to
Moose Creek
Moose Creek
Tributaries to
Nenana River
Unnamed Creek
Winc:;.y Creek
Tributaries to
Julius Creek
Fish Creek
1.5
3
6
7.5
11.5
14.5
15.5
16
18.5,19.5,
21
24
30,32
34.5,35.5,
36,36.5,38.5
41
Arctic grayling,round whitefish,
Dolly Varden,longnose sucker,
burbot,chum and coho salmon
(Arctic grayling,whitefish)l
Arctic grayling,round whitefish,
Dolly Varden,longnose sucker,
sculpin
Arctic grayling,round Whitefish,
Dolly Varden,longnose sucker,
sculpin
(Arctic grayling,whitefish)l
Arctic grayling,round Whitefish,
Dolly Varden,longnose sucker,
burbot,chum and coho salmon,
Inconnu,northern pike
(Arcticlgrayling,whttefish,Dolly
Varden)
(Arctic1grayling,Whitefish,Dolly
Varden)
(Arcticlgrayling,whitefish,Dolly
Varden)
(Arcticlgrayling,whitefish,Dolly
Varden)
(Arctic grayling,whitefish,D£llY
Varden,burbot,northern pike)
Arctic grayling,round Whitefish,
Dolly Varden,longnose sucker,
sculpin
Arctic grayling,round Whitefish,
Dolly Varden,longnose sucker,
sculpin
Unnamed creeks 43,43.5,
45,46,46.5,
49,49.3,49.7,
50,50.5,51,51.5
(Arctic grayling,whitefish,D£lIY
Varden,burbot,northern pike)
Table 11 (oart:inued)
Stream
Approximate miles from
Healy Substation Species Present
Tanana River 52.5
Unnamed creeks 55,56
Little Goldstream 60.5
Creek
Tributary to Little 59
Goldstream Creek
Chum,coho and chinook salmon,
Inconnu,northern pike,Arctic
grayling,whitefish,burbot
CArcticlgrayling,whitefish,Dolly
Varden)
Arctic ~raYling,whitefish,Dolly
Varden)
Arctic grayling,round whitefish,
Black fish,lonqnose sucker,
sculpin
CArctic1grayling,whitefish,Dolly
Varden)
63,64.5,65.5
66.5,68,68.2,
70
Tributaries to
Goldstream Cr.
Little Goldstream
Creek
Tributaries to
Bonanza Creek
Tributaries to
Ohio Creek
70.2
71,72,72.5
73
78,78.5,79
80.5,82,83.5,
84
Arctic grayling,round whitefish,
Black fish,longnose sucker,
sculpin
CArcticlgrayling,whitefish,Dolly
Varden)
(Arcticlgrayling,whitefish,Dolly
Varden)
Tributary to
Alder Creek
Alder Creek
Emma Creek
Tributary to
Emma Creek
Ester Creek
87
88
89.5
90
93
CArcticlgrayling,whitefish,Dolly
Varden)
CArctic1grayling,whitefish,Dolly
Varden)
(Arctic1grayling,whitefish,Dolly
Varden)
(Arcticlgrayling,whitefish,Dolly
Varden)
CArctic1grayling,whitefish,Dolly
Varden)
1 (species)can be reasonably expected,but not verified
References:Letter from Jerry Hallberg (ADF&G sport fish Div.)to
Nancy Heming (Falls Creek Environmental)October 29,1982.
ADF&G 1978 Fisheries Atlas.Volume II.
Table 12.streams crossed by the transmission lines from Willow
to Anchorage.
Stre.am
Approximate miles from
University Substation
in Anchorage Species Present
Ship Creek
Fossil Creek
otter Creek
Knik Arm
Unnamed Creek
Little Susitna
River
Tributary to
Fish Creek
Fish Creek
Tributaries
to Susitna River
Willow Creek
7.5
12.5
18
20-22
26
36.5
45
47
52,53,58
61
Chinook,coho,chum and pink
salmon;Dolly Varden;rainbow
trout;(Arctic grayling)
none
Sockeye salmon,rainbow trout,1
(Arctic grayling,Dolly Varden)
Chinook,sockeye,coho,chum and
pink salmon,eulachon,Bering
cisco,Dolly Varden
(Burbot,rain~ow trout,whitefish,
Dolly Varden)
Chinook,sockeye,coho,chum and
pink salmon:Dolly Varden:rainbow
trout;Arc!ic grayling;(burbot,
'Whitefish)
(Chinook and coho salmon;rainbow
trout,~urbot,whitefish,Dolly
Varden)
Chinook,sockeye,coho and pink
salmon;rainbow trout:(burbot;
rainbow1trout;whitefish;Dolly
Varden)
(Coho salmon,burbot,rainbow 1
trout,whitefish,Dolly Varden)
Chinook,~oho,chum,pink and
sockeye salmon;Dolly Varden;
rainbow trout:Arctic grayling,
whitefish;(burbot)
1 (species)can be reasonably expected,but not verified
Reference:ADF&G 1978,Fisheries Atlas Volumes I and II
Appen:ti.x A
Detailed Mitigation am Monitoring Costs
This apperrli.x presents the prelilllinary costs for the mitigation am naU.toring
program proposed in this volume.Mitigation will preQominantly be composed of
adherence to the envirornnentally acx:eptable construction practices detailed in the
EMR1's (APA 1985a,1985b,1985c,1985d,1985e);no direct costs have been assigned
to this mitigation.All costs are evaluated in terms of 1985 dollars.Equipment
am personnel are assunm to be available at the sites ani not require additional
transportation.Effluent narltorirq will be corxfucted throughc::ut the year;
laboratory analysis costs are estimated as average annual costs.For the
environmental field officer program,capital costs includirq transportation have
been incorporated into the average annual operatin;costs.
Borrow Site E Rehabilitation
labor
Equipment
EngineeringJManagement
Total
$42,000
17,000
6,000
$65,000
Total Initial Costs of Bo~:M site E Rehabilitation $65,000
No Annual Costs are anticipated
Environmental Field Officer Program
Iabor
EFO #1 (20 yrs)
EFO #2 (7 yrs)
Equipment
(a)Effluent Mrmitoring
laboratory Analysis
(a)Effluent Monitoring
-stream crossings
-Tsusena am Deadman creeks
-settling Fords
-Wastewater Treatment Plant
$70,000/yr
70,000/yr
7,800/yr
4,000
$13,500/yr
5,000/yr
l,500/yr
1-0-
Total Initia~costs
Average Annual costs
$4,000
$122,000
1 All costs are included in the design and constl:Uct:ion of the plant.
-.-------~~--