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Susitna-Watana Hydroelectric Project Document
ARLIS Uniform Cover Page
Title:
Study of fish passage barriers, Implementation plan SuWa 200
Author(s) – Personal:
Author(s) – Corporate:
HDR, Inc.
AEA-identified category, if specified:
Final study plan
AEA-identified series, if specified:
Series (ARLIS-assigned report number):
Susitna-Watana Hydroelectric Project document number 200
Existing numbers on document:
Published by:
[Anchorage : Alaska Energy Authority, 2013]
Date published:
June 2013
Published for:
Alaska Energy Authority
Date or date range of report:
Volume and/or Part numbers:
Study plan Section 9.12A
Final or Draft status, as indicated:
Document type:
Pagination:
62 p. in various pagings
Related work(s):
Pages added/changed by ARLIS:
Notes:
Comprises a cover letter and two attachments; title from title page of Attachment 1.
All reports in the Susitna-Watana Hydroelectric Project Document series include an ARLIS-
produced cover page and an ARLIS-assigned number for uniformity and citability. All reports
are posted online at http://www.arlis.org/resources/susitna-watana/
June 17, 2013
Ms. Kimberly D. Bose
Secretary
Federal Energy Regulatory Commission
888 First Street, NE
Washington, DC 20426
Re: Susitna-Watana Hydroelectric Project, FERC Project No. 14241-000;
Study of Fish Passage Barriers Implementation Plan
Dear Secretary Bose:
On February 1, 2013, the Federal Energy Regulatory Commission (Commission or
FERC) issued its Study Plan Determination (February 1 SPD) for 44 of the 58 proposed
individual studies in the Alaska Energy Authority’s (AEA) Revised Study Plan (RSP) for
the Susitna-Watana Hydroelectric Project, FERC Project No. 14241 (Project).
When approving the Study of Fish Passage Barriers in the Middle and Upper Susitna
River and Susitna Tributaries (RSP 9.12), the Commission recommended that AEA file a
detailed plan that provides additional information described below on implementation of
the study within the Middle River study area:
1) A specific schedule for completing the following Middle River study components
proposed for future development in consultation with the TWG as set forth in
section 9.12.4 of the RSP: (a) identifying fish species to be included in the
passage barrier study; (b) defining the passage criteria for the identified fish
species; (c) selecting the number and location of study sites for each element of
study implementation; and (d) filing the results of items (a), (b), and (c).
2) A description of how the effects of load-following during the winter ice-cover
period on salmonid juvenile and fry passage (e.g., depth, velocity, potential ice
blockages) from mainstem into off-channel habitats would be evaluated.
3) A description of the specific methods as set forth in section 9.12.4.5 (e.g., 2-
dimensional modeling, or other unspecified modeling approach) that would be
applied at the off-channel and tributary delta locations selected for the depth
barrier analysis. This would include an explanation of the proposed methods and
study sites for the open-water period for adult and juvenile fish, and the ice-cover
period for juvenile fish.
2
4) A description of a subsample of tributary deltas and off-channel habitat entrances
within Middle River focus areas where velocity measurements will be taken to
determine if velocity barriers to juvenile salmonids (particularly salmonid fry)
would be created at tributary deltas and off-channel habitat entrances by
modifications to river stage and discharge through proposed project operations.
5) Documentation that a draft plan and schedule were provided to FWS, NMFS, and
any other TWG participants at least 30 days prior to the due date of the plan and
schedule (allowing at least 15 days for comment); a description of how FWS’,
NMFS’, or other TWG participant’s comments are incorporated into the final
plan; and an explanation for why any of FWS’, NMFS’, or other TWG
participant’s comments are not incorporated into the final plan.
Consistent with the Commission’s recommendations within the February 1 SPD, AEA is
filing the attached Study of Fish Passage Barriers Implementation Plan (attached as
Attachment 1).
On May 15, 2013, AEA provided to U.S. Fish and Wildlife Service (USFWS), National
Marine Fisheries Service (NMFS), and other Technical Work Group participants for
comment a Draft Study of Fish Barriers Implementation Plan (Draft Implementation
Plan) that was developed to provide responses to the February 1 SPD
recommendations. The Draft Implementation Plan was also made available on the
Project website (http://www.susitna-watanahydro.org). Consistent with the February 1
SPD, AEA initially allowed 15 days for comment by requesting that all comments be
submitted, in writing, by Thursday, May 30, 2013. At the request of NMFS, AEA
extended the deadline for comments to June 5, 2013. NMFS and USFWS jointly
submitted comments on June 7, 2013. AEA received no other comments on the Draft
Implementation Plan. Attached as Attachment 2 is a comment response table that
includes a description of how the NMFS and USFWS joint comments are incorporated
into the final plan; and an explanation for why certain comments were not incorporated
into the final plan.
As always, AEA appreciates the participation and commitment to this licensing process
demonstrated by Commission Staff, federal and state resource agencies, and other
licensing participants. AEA looks forward to working with licensing participants and
Commission Staff in implementing the approved studies, which AEA believes will
comprehensively investigate and evaluate the full range of resource issues associated
with the proposed Project and support AEA’s license application, scheduled to be filed
with the Commission in 2015.
3
If you have questions concerning this submission please contact me at wdyok@aidea.org
or (907) 771-3955.
Sincerely,
Wayne Dyok
Project Manager
Alaska Energy Authority
Attachments
cc: Distribution List (w/o Attachments)
Attachment 1
Study of Fish Passage Barriers Implementation Plan (June 2013)
Susitna-Watana Hydroelectric Project
(FERC No. 14241)
Study of Fish Passage Barriers
Implementation Plan
Prepared for
Alaska Energy Authority
Prepared by
HDR, Inc.
June 2013
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page i June 2013
TABLE OF CONTENTS
1. Introduction ........................................................................................................................1
2. FERC Staff Recommendation ..........................................................................................1
3. Goals and Objectives .........................................................................................................2
4. Study Area ..........................................................................................................................3
5. Background and Existing Information ............................................................................3
6. Fish Passage Through Devils Canyon ..............................................................................3
7. Detailed fish barrier Methods ...........................................................................................4
7.1. Implementation Plan Components ...........................................................................4
7.1.1. (a) Identify Fish Species to be Included in Passage Barrier Study ............. 4
7.1.2. (b) Define Passage Criteria for Identified Fish Species .............................. 5
7.1.3. (c) Select Number and Location of Study Sites for each Element of Study
Implementation ........................................................................................... 6
7.1.4. (d) File Results of Items (a), (b), and (c) .................................................... 6
7.1.5. Schedule Overview ..................................................................................... 7
7.2. Effects of Load-following on Passage during Ice-cover Periods .............................7
7.3. Description of Study Sites and Modeling Methods .................................................9
7.3.1. Proposed Study Sites for Modeling .......................................................... 10
7.3.2. Modeling Methods for Ice-free Periods .................................................... 11
7.3.3. Modeling Methods for Ice-cover Periods ................................................. 12
7.4. Identification and Location of Existing Physical Barriers to Fish Passage ...........14
7.4.1. Middle and Upper River ........................................................................... 14
7.5. Study of Fish Passage Barriers in the Lower River ...............................................15
7.6. Documentation of Consultation .............................................................................16
8. References Cited...............................................................................................................16
9. Tables ................................................................................................................................18
10. Figures ...............................................................................................................................20
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page ii June 2013
LIST OF TABLES
Table 1. Tally of off-channel and tributary deltas by Middle River Focus Area. ........................ 18
Table 2. Named and unnamed tributaries in the Middle River selected for fish passage barrier
investigation. ......................................................................................................................... 19
LIST OF FIGURES
Figure 1a. Three potential impediment areas (Impediments 1, 2, and 3) to fish passage on the
Susitna River located between Portage and Devil creeks at the top end of the Middle River
Segment (AEA 2013c). ......................................................................................................... 20
Figure 1b. Example of a location within Impediment area 1 where a velocity barrier could be
created at a high river discharge. Photo at PRM 154.8, September 11, 2012, 11,600cfs
(provisional) at Gold Creek................................................................................................... 21
Figure 2. Proposed HSC curve development priority (AEA 2013a). .......................................... 22
Figure 3. Example of proposed winter fish habitat use sampling sites at the Skull Creek
Complex in the Middle Susitna River Segment (AEA 2013e). ............................................ 23
Figure 4. Predicted stage hydrographs in the Susitna River at Gold Creek (USGS 15292000)
under Pre-Project and Maximum Load Following OS-1 conditions during the week of
January 8 to 14, 1984. Actual results may differ from those depicted as a result of ice
formation in the river (AEA 2013d). .................................................................................... 24
Figure 5. Conceptual layout of 2-D coarse and fine mesh modeling within the proposed
Whiskers Slough Focus Area. .............................................................................................. 25
Figre 6 - 15 Instream Flow Focus Areas showing Off-channel and tributary habitat units
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page iii June 2013
LIST OF ACRONYMS AND SCIENTIFIC LABELS
Abbreviation Definition
Active floodplain The flat valley floor constructed by a river during lateral channel migration and
deposition of sediment under current climate conditions.
ADF&G Alaska Department of Fish and Game
AEA Alaska Energy Authority
Age-0 juvenile
The description of an organism that, in its natal year, has developed the anatomical
and physical traits characteristically similar to the mature life stage, but without the
capability to reproduce.
Algae Single-celled organisms (as individual or cells grouped together in colonies) that
contain chlorophyll-a and are capable of the photosynthesis.
Anadromous Fishes that migrate as juveniles from freshwater to saltwater and then return as
adults to spawn in freshwater.
APA Alaska Power Authority
APA Project APA Susitna Hydroelectric Project
Backwater
Off-channel habitat characterization feature found along channel margins and
generally within the influence of the active main channel with no independent
source of inflow. Water is not clear.
Bank
The sloping land bordering a stream channel that forms the usual boundaries of a
channel. The bank has a steeper slope than the bottom of the channel and is
usually steeper than the land surrounding the channel.
Bankfull stage (flow) The discharge at which water completely fills a channel; the flow rate at which the
water surface is level with the floodplain.
Bankfull width The width of a river or stream channel between the highest banks on either side of
a stream.
Baseline
Baseline (or Environmental Baseline): the environmental conditions that are the
starting point for analyzing the impacts of a proposed licensing action (such as
approval of a license application) and any alternative.
Benthos (benthic) Defining a habitat or organism found on the streambed or pertaining to the
streambed (or bottom) of a water body.
Braided streams
Stream consisting of multiple small, shallow channels that divide and recombine
numerous times. Associated with glaciers, the braiding is caused by excess
sediment load.
Break-up Disintegration of ice cover.
Cascade
The steepest of riffle habitats. Unlike rapids, which have an even gradient,
cascades consist of a series of small steps of alternating small waterfalls and
shallow pools.
Catch per unit effort The quantity of fish caught (in number or in weight) with one standard unit of fishing
effort.
Cfs cubic feet per second
Channel A natural or artificial watercourse that continuously or intermittently contains water,
with definite bed and banks that confine all but overbank stream flows.
Cross-section A plane across a river or stream channel perpendicular to the direction of water
flow.
Depth Water depth at the measuring point (station).
Devils Canyon
Located at approximately Susitna River Mile (RM) 150-161, Devils Canyon contains
four sets of turbulent rapids rated collectively as Class VI. This feature is a partial
fish barrier because of high water velocity.
Distribution (species) The manner in which a biological taxon is spatially arranged.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page iv June 2013
Abbreviation Definition
et al. “et alia”; and the rest
FERC Federal Energy Regulatory Commission
Fishwheel
A device for catching fish which operates much as a water-powered mill wheel. A
wheel complete with baskets and paddles is attached to a floating dock. The wheel
rotates due to the current of the stream it is placed into. The baskets on the wheel
capture fish traveling upstream. The fish caught in the baskets fall into a holding
tank.
Flood Any flow that exceeds the bankfull capacity of a stream or channel and flows out on
the floodplain.
Floodplain
1. The area along waterways that is subject to periodic inundation by out-of-bank
flows. 2. The area adjoining a water body that becomes inundated during periods of
over-bank flooding and that is given rigorous legal definition in regulatory programs.
3. Land beyond a stream channel that forms the perimeter for the maximum
probability flood. 4. A relatively flat strip of land bordering a stream that is formed by
sediment deposition. 5. A deposit of alluvium that covers a valley flat from lateral
erosion of meandering streams and rivers.
Focus Area Areas selected for intensive investigation by multiple disciplines as part of the AEA
study program.
Fork length A measurement used frequently for fish length when the tail has a fork shape.
Projected straight distance between the tip of the snout and the fork of the tail.
Fry A recently hatched fish. Sometimes defined as a young juvenile salmonid with
absorbed egg sac, less than 60 mm in length.
Fyke net Hoop nets are tubular shaped nets with a series of hoops or rings spaced along the
length of the net to keep it open.
Geomorphic reach Level two tier of the habitat classification system. Separates major hydraulic
segments into unique reaches based on the channel’s geomorphic characteristic.
Geomorphology The scientific study of landforms and the processes that shape them.
Gillnet With this type of gear, the fish are gilled, entangled or enmeshed in the netting.
These nets may be used to fish on the surface, in midwater or on the bottom.
GIS
Geographic Information System. An integrated collection of computer software and
data used to view and manage information about geographic places, analyze
spatial relationships, and model spatial processes.
Glacier geometry changes Changes in the size or shape of a glacier over time.
Glide An area with generally uniform depth and flow with no surface turbulence. Low
gradient; 0-1 % slope.
GPS global positioning system. A system of radio-emitting and -receiving satellites used
for determining positions on the earth.
Groundwater (GW) In the broadest sense, all subsurface water; more commonly that part of the
subsurface water in the saturated zone.
Habitat
The environment in which the fish live, including everything that surrounds and
affects its life, e.g. water quality, bottom, vegetation, associated species (including
food supplies). The locality, site and particular type of local environment occupied
by an organism.
Hook and line A type of fishing gear consisting of a hook tied to a line.
Hoop net Hoop nets are tubular shaped nets with a series of hoops or rings spaced along the
length of the net to keep it open.
Ice cover A significant expanse of ice of any form on the surface of a body of water.
ILP Integrated Licensing Process
Inclined plane trap This trap consists of a revolving screen suspended between two pontoons.
Downstream migrant fish reaching the back of the trap are dropped into a live box
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page v June 2013
Abbreviation Definition
where they can later be enumerated.
Instream flow The rate of flow in a river or stream channel at any time of year.
Juvenile A young fish or animal that has not reached sexual maturity.
licensing participants; Participants Agencies, ANSCA corporations, Alaska Native entities and other licensing
participants
Life stage
An arbitrary age classification of an organism into categories relate to body
morphology and reproductive potential, such as spawning, egg incubation, larva or
fry, juvenile, and adult.
Lower segment Susitna The Susitna River from Cook Inlet (RM 0) to the confluence of the Chulitna River at
RM 98.
M meter(s)
m2 square meter(s)
Macroinvertebrate An invertebrate animal without a backbone that can be seen without magnification.
Main channel For habitat classification system: a single dominant main channel. Also, the primary
downstream segment of a river, as contrasted to its tributaries.
Main channel habitat
Level four tier of the habitat classification system. Separates main channel habitat
types including: tributary mouth, main channel, split main channel, multiple split
main channel and side channel into mesohabitat types. Mesohabitat types include
pool, glide, run, riffle, and rapid.
Mainstem
Mainstem refers to the primary river corridor, as contrasted to its tributaries.
Mainstem habitats include the main channel, split main channels, side channels,
tributary mouths, and off-channel habitats.
Mainstem habitat
Level three tier of the habitat classification systems. Separates mainstem habitat
into main channel, off-channel, and tributary habitat types. Main channel habitat
types include: tributary mouth, main channel, split main channel, multiple split main
channel and side channel. Off-channel habitat types include: side slough, upland
slough, backwater, and beaver complex. Tributary habitat is not further categorized.
Major hydraulic segment
Level one tier of the habitat classification system. Separates the River into three
segments: Lower River (RM 0-98), Middle River (RM 98-184), and Upper River (RM
184-233).
Mesh size The size of holes in a fishing net.
Mesohabitat
A discrete area of stream exhibiting relatively similar characteristics of depth,
velocity, slope, substrate, and cover, and variances thereof (e.g., pools with
maximum depth <5 ft, high gradient rimes, side channel backwaters).
Middle segment Susitna The Susitna River from the confluence of the Chulitna River at RM 98 to the
proposed Watana Dam Site at RM 184.
Migrant (life history type) Some species exhibit a migratory life history type and undergo a migration to from
rivers/lakes/ocean.
Migration Systematic (as opposed to random) movement of individuals of a stock from one
place to another, often related to season.
Minnow trap Normally composed of small steel mesh with 2-piece torpedo shape design, this
trap is disconnected in the middle for easy baiting and fish removal.
N/A not applicable or not available
Non-native Not indigenous to or naturally occurring in a given area.
ºC degrees Celsius
ºF degrees Fahrenheit
Off-channel Those bodies of water adjacent to the main channel that have surface water
connections to the main river at some discharge levels.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page vi June 2013
Abbreviation Definition
Off-channel habitat Habitat within those bodies of water adjacent to the main channel that have surface
water connections to the main river at some discharge levels.
Out-migrant trap Several types of trapping equipment that can be used to estimate the abundance of
downstream migrating anadromous salmonid smelts.
Overwintering
Freshwater habitat used by salmonids during the winter for incubation of eggs and
eleven in the gravel and for rearing of juveniles overwintering in the stream system
before migrating to saltwater the following spring.
pH A measure of the acidity or basicity of a solution.
PIT Passive Integrated Transponder tags used to individually identify animals and
monitor their movements.
PM&E protection, mitigation and enhancement
Pool Slow water habitat with minimal turbulence and deeper due to a strong hydraulic
control.
POW Palustrian open water (ponds under 20 ac)
PRM
Project River Mile(s) based on the digitized wetted width centerline of the main
channel from 2012 Matanuska-Susitna Borough digital orthophotos. PRM 0.0 is
established as mean lower low water of the Susitna River confluence at Cook Inlet.
Project Susitna-Watana Hydroelectric Project
Radiotelemetry Involves the capture and placement of radio-tags in adult fish that allow for the
remote tracking of movements of individual fish.
Rapid
Swift, turbulent flow including small chutes and some hydraulic jumps swirling
around boulders. Exposed substrate composed of individual boulders, boulder
clusters, and partial bars. Lower gradient and less dense concentration of boulders
and white water than Cascade. Moderate gradient; usually 2.0-4.0% slope.
Rearing Rearing is the term used by fish biologists that considers the period of time in which
juvenile fish feed and grow.
Resident Resident fish as opposed to anadromous remain in the freshwater environment
year-round
Riffle
A fast water habitat with turbulent, shallow flow over submerged or partially
submerged gravel and cobble substrates. Generally broad, uniform cross-section.
Low gradient; usually 0.5-2.0% slope.
Riparian Pertaining to anything connected with or adjacent to the bank of a stream or other
body of water.
River A large stream that serves as the natural drainage channel for a relatively large
catchment or drainage basin.
River corridor
A perennial, intermittent, or ephemeral stream and adjacent vegetative fringe. The
corridor is the area occupied during high water and the land immediately adjacent,
including riparian vegetation that shades the stream, provides input of organic
debris, and protects banks from excessive erosion.
River mile The distance of a point on a river measured in miles from the river's mouth along
the low-water channel.
RM River Mile(s) referencing those of the APA Project.
RSP Revised Study Plan
Run (habitat)
A habitat area with minimal surface turbulence over or around protruding boulders
with generally uniform depth that is generally greater than the maximum substrate
size. Velocities are on border of fast and slow water. Gradients are approximately
0.5 % to less than 2%. Generally deeper than riffles with few major flow
obstructions and low habitat complexity.
Run (migration) Seasonal migration undertaken by fish, usually as part of their life history; for
example, spawning run of salmon, upstream migration of shad. Fishers may refer to
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page vii June 2013
Abbreviation Definition
increased catches as a “run” of fish, a usage often independent of their migratory
behavior.
Screw trap A floating trap that relies on an Archimedes screw built into a screen covered cone
that is suspended between two pontoons is used.
Seine (beach)
A fishing net that hangs vertically in the water with its bottom edge held down by
weights and its top edge buoyed by floats. Seine nets can be deployed from the
shore as a beach seine, or from a boat.
Side channel
Lateral channel with an axis of flow roughly parallel to the mainstem, which is fed by
water from the mainstem; a braid of a river with flow appreciably lower than the
main channel. Side channel habitat may exist either in well-defined secondary
(overflow) channels, or in poorly-defined watercourses flowing through partially
submerged gravel bars and islands along the margins of the mainstem.
Side slough Off-channel habitat characterization of an Overflow channel contained in the
floodplain, but disconnected from the main channel. Has clear water,
Slope The inclination or gradient from the horizontal of a line or surface.
Slough
A widely used term for wetland environment in a channel or series of shallow lakes
where water is stagnant or may flow slowly on a seasonal basis. Also known as a
stream distributary or anabranch.
Smolt An adolescent salmon which has metamorphosed and which is found on its way
downstream toward the sea.
Smoltification The physiological changes anadromous salmonids and trout undergo in freshwater
while migrating toward saltwater that allow them to live in the ocean.
Spawning The depositing and fertilizing of eggs by fish and other aquatic life.
Split main channel Main channel habitat characterization where three of fewer distributed dominant
channels.
Stratified sampling
A method of sampling from a population. In statistical surveys, when
subpopulations within an overall population vary, it is advantageous to sample each
subpopulation (stratum) independently. Stratification is the process of dividing
members of the population into homogeneous subgroups before sampling.
Three Rivers Confluence
The confluence of the Susitna, Chulitna, and Talkeetna rivers at Susitna River Mile
(RM) 98.5 represents the downstream end of the Middle River and the upstream
end of the Upper River.
Tributary A stream feeding, joining, or flowing into a larger stream (at any point along its
course or into a lake). Synonyms: feeder stream, side stream.
Turbidity The condition resulting from the presence of suspended particles in the water
column which attenuate or reduce light penetration.
TWG Technical Workgroup
Upland slough
Off-channel habitat characterization feature that is similar to a side slough, but
contains a vegetated bar at the head that is rarely overtopped by mainstem
flow. Has clear water.
Upper segment Susitna The Susitna River upstream of the proposed Watana Dam Site at RM 184.
Watana Dam
The dam proposed by the Susitna-Watana Hydroelectric project. The approximately
750-foot-high Watana Dam (as measured from sound bedrock) would be located at
river mile (RM) 184 on the Susitna River.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page viii June 2013
STUDY PLANS REFERRED TO IN THIS IMPLEMENTATION PLAN
RSP Section Study Section
Geomorphology (RSP Section 6) Fluvial Geomorphology Modeling below Watana Dam Study (Section 6.6)
Hydrology-Related Resources (RSP
Section 7)
Groundwater Study (Study Section 7.5)
Ice Processes in the Susitna River Study (Study Section 7.6)
Instream Flow (RSP Section 8) Fish and Aquatics Instream Flow Study (Study Section 8.5)
Fish and Aquatic Resources (RSP
Section 9)
Study of Fish Distribution and Abundance in the Upper Susitna River (Study
Section 9.5)
Study of Fish Distribution and Abundance in the Middle and Lower Susitna River
(Study Section 9.6)
Salmon Escapement Study (Study Section 9.7)
Study of Fish Passage Feasibility at Watana Dam (Study Section 9.11)
Study of Fish Passage Barriers in the Middle and Upper Susitna River and Susitna
Tributaries (Study Section 9.12)
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 1 June 2013
1. INTRODUCTION
On December 14, 2012, Alaska Energy Authority (AEA) filed with the Federal Energy
Regulatory Commission (FERC or Commission) its Revised Study Plan (RSP), which included
58 individual study plans (AEA 2012). Included within the RSP was the Study of Fish Passage
Barriers in the Middle and Upper Susitna River and Susitna Tributaries, Section 9.12. RSP
Section 9.12 focuses on the methods for locating, describing, and assessing potential fish passage
barriers in the Middle and Upper Susitna River that could be created or eliminated as a result of
Project construction and operation. RSP 9.12 provided goals, objectives, and proposed methods
for identification, classification, measurement, and analysis of potential fish passage barriers.
On February 1, 2013, FERC staff issued its study determination (February 1SPD) for 44 of the
58 studies, approving 31 studies as filed and 13 with modifications. RSP Section 9.12 was one
of the 13 approved with modifications.
In accordance with the February 1 SPD, recommended modifications are addressed in detail in
this implementation plan. Any area not discussed within this implementation plan will remain as
detailed in the RSP.
2. FERC STAFF RECOMMENDATION
In its February 1 SPD, FERC recommended the following:
We recommend that AEA assess discharge conditions at the streamflow gages established by
AEA closest to Devils Canyon and near the dam site during the time periods when salmon
are documented to successfully pass upstream of the Devils Canyon passage impediment in
2013 and 2014 (via radio-tagging as set forth in study 9.7, salmon escapement), and
document the results in the initial and updated study reports.
We do not recommend use of any of AEA’s criteria set forth in section 9.12.4.4 of the RSP for
excluding study sites from the Middle River passage barrier evaluation. Instead, we
recommend that AEA prepare and file a detailed plan by no later than June 15, 2013, that
provides the additional information described below on implementation of the study within
the Middle River study area.
1) A specific schedule for completing the following Middle River study components
proposed for future development in consultation with the TWG as set forth in section
9.12.4 of the RSP: (a) identifying fish species to be included in the passage barrier study;
(b) defining the passage criteria for the identified fish species; (c) selecting the number
and location of study sites for each element of study implementation; and (d) filing the
results of items (a), (b), and (c).
2) A description of how the effects of load-following during the winter ice-cover period on
salmonid juvenile and fry passage (e.g., depth, velocity, potential ice blockages) from
mainstem into off-channel habitats would be evaluated.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 2 June 2013
3) A description of the specific methods as set forth in section 9.12.4.5 (e.g., 2-dimensional
modeling, or other unspecified modeling approach) that would be applied at the off-
channel and tributary delta locations selected for the depth barrier analysis. This would
include an explanation of the proposed methods and study sites for the open-water period
for adult and juvenile fish, and the ice-cover period for juvenile fish.
4) A description of a subsample of tributary deltas and off-channel habitat entrances within
Middle River focus areas where velocity measurements will be taken to determine if
velocity barriers to juvenile salmonids (particularly salmonid fry) would be created at
tributary deltas and off-channel habitat entrances by modifications to river stage and
discharge through proposed project operations.
5) Documentation that a draft plan and schedule were provided to FWS, NMFS, and any
other TWG participants at least 30 days prior to the due date of the plan and schedule
(allowing at least 15 days for comment); a description of how FWS’, NMFS’, or other
TWG participant’s comments are incorporated into the final plan; and an explanation for
why any of FWS’, NMFS’, or other TWG participant’s comments are not incorporated
into the final plan.
3. GOALS AND OBJECTIVES
As described in RSP Section 9.12.1, the goal of this study is to evaluate the potential effects of
Project-induced changes in flow and water surface elevation on free access of fish into, within,
and out of suitable habitats in the Upper Susitna River (inundation zone above the Watana Dam
site) and the Middle Susitna River (Watana Dam site to the confluence of Chulitna and Talkeetna
rivers). This goal will be achieved by meeting the following objectives:
1. Locate and categorize all existing fish passage barriers (e.g., falls, cascade, beaver dam,
road or railroad crossings) located in selected tributaries in the Middle and Upper Susitna
River (Middle River tributaries to be determined during study refinement).
2. Identify and locate using global position satellite (GPS) the type (permanent, temporary,
seasonal, partial) and characterize the physical nature of any existing fish barriers located
within the Project’s zone of hydrologic influence (ZHI).
3. Evaluate the potential changes to existing fish barriers (both natural and man-made)
located within the Project’s ZHI.
4. Evaluate the potential creation of fish passage barriers within existing habitats
(tributaries, sloughs, side channels, off-channel habitats) related to future flow conditions,
water surface elevations, and sediment transport.
These objectives will be met through the use of existing information, consulting with the Fish
and Aquatic Technical Workgroup (TWG) and other licensing participants, and by using the
methods described in the RSP.
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4. STUDY AREA
The study area, as described in RSP Section 9.12.3 includes the mainstem and selected
tributaries in the Upper and Middle segments of the Susitna River that would be affected by the
construction and operation of the Project. For purposes of this study, the study area has been
preliminarily divided into two segments:
• Upper River—Susitna River and selected tributaries within this segment up to the 3,000
foot elevation and extending upstream from Watana Dam site (RM 184) to the upper extent of
river influenced by Watana Reservoir up to and including the Oshetna River (see Section 9.5,
Figure 9.5-1).
• Middle River—Susitna River and selected tributaries within this segment, extending from
Watana Dam site to the confluence of the Chulitna River (RM 98). Passage studies in the
mainstem Middle Segment will include sloughs, upland sloughs, side channels, and tributary
mouths and deltas.
Passage studies in tributaries to the Middle River will include select tributaries and will extend
from the mouth to the upper extent of Project hydrologic influence. The upper limit of
hydrologic influence will be determined from supporting studies including the Instream Flow
Study (RSP Section 8.0) and the Geomorphology Study (RSP Section 6.0), among others.
5. BACKGROUND AND EXISTING INFORMATION
The background and existing information for this implementation plan is the same as described
in RSP Section 9.12.2.
6. FISH PASSAGE THROUGH DEVILS CANYON
The first paragraph of the February 1 SPD recommends that AEA evaluate discharge conditions
in the proximity of Devils Canyon and successful passage upstream of the canyon. AEA
accomplished this objective by evaluating the relationship between river discharge and passage
of radio-tagged salmon into and through Devils Canyon as part of the 2012 Salmon Escapement
Study. Consistent with FERC’s February 1 SPD, AEA will again accomplish this by evaluating
the relationship between river discharge and passage of radio-tagged salmon into and through
Devils Canyon from 2012-2014.
Mean daily discharge records will be obtained from one or more of the AEA stream gages
located in the Devils Canyon Area (ESS55 or ESS60). The gage closest to the impediment will
be used or discharge will be prorated between the two gages to obtain the most accurate
discharge estimate at the impediment at the time of attempted passage. Data on timing of radio-
tagged fish movements will be obtained from the salmon escapment study. Discharges during
both successful and unsuccessful passage by radio -tagged fish will be evaluated to discern any
possible relationship. If a relationship is found, these data can be used to model post-Project
discharges and potential effects on passage of adult salmon through Devils Canyon.
All field data collection will be conducted as part of RSP Section 9.7 and RSP Section 8.5 -
Hydraulic Routing and Operations Modeling.
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7. DETAILED FISH BARRIER METHODS
The February 1 SPD states:
We do not recommend use of any of AEA’s criteria set forth in section 9.12.4.4 of the RSP for
excluding study sites from the Middle River passage barrier evaluation. Instead, we
recommend that AEA prepare and file a detailed plan by no later than June 15, 2013, that
provides the additional information described below on implementation of the study within
the Middle River study area.
AEA is fulfilling this recommendation by providing this implementation plan.
7.1. Implementation Plan Components
The February 1 SPD states:
A specific schedule for completing the following Middle River study components proposed
for future development in consultation with the TWG as set forth in section 9.12.4 of the RSP:
(a) identifying fish species to be included in the passage barrier study; (b) defining the
passage criteria for the identified fish species; (c) selecting the number and location of study
sites for each element of study implementation; and (d) filing the results of items (a), (b), and
(c).
The study components requested for future development are addressed below in the order
presented.
7.1.1. (a) Identify Fish Species to be Included in Passage Barrier Study
Given the interdependencies between the barriers assessment and Instream Flow Study physical
habitat data collection, AEA proposes that target species for the fish barrier studies be the same
as, or a sub-set of, those selected for Instream Flow Habitat Modeling (RSP Section 8.5). For
planning purposes, target species proposed in RSP Section 8.5 were assumed to include Chinook,
coho, chum, and sockeye salmon, rainbow trout, Arctic grayling, Dolly Varden, burbot, longnose
sucker, humpback whitefish, and round whitefish. These target species were selected because
they are generally considered the most sensitive to habitat loss through manipulation of flows in
the Susitna River. All of theses species also have been identified as target species for RSP
Section 9.11 - Study of Fish Passage Feasibility at Watana Dam. RSP Section 9.11 target
species selection was first based on presence of the species in the Upper River, secondly on the
following three criteria, and thirdly in consultation with the Fish Passage Technical Team at their
workshop on April 9 and 10, 2013. Aspects of these criteria used by the Fish Passage study team
are also useful for selecting target species for passage barrier studies.
• The species exhibits migratory behavior – Fish passage has a greater importance to
species that may exhibit migratory behavior as part of their natural life history compared
to fish that exhibit only localized movement, especially when the migration is necessary
to complete the life cycle of the species.
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• The species has high relative abundance – Species that are relatively abundant in the
Upper River and its tributaries would theoretically utilize fish passage facilities with
greater frequency than less abundant species, disregarding other criteria (e.g., migratory
behavior).
• The species is important to commercial, sport, or subsistence fisheries – Species that are
harvested in commercial, sport, or subsistence fisheries have added importance with
regard to the study of fish passage feasibility.
Since submittal of RSP Section 8.5, AEA and the TWG have engaged in meetings to initiate
discussions of target species for Habitat Suitability Criteria (HSC) development and inclusion in
instream flow habitat modeling. At the March 27, 2013 TWG meeting (AEA 2013a), AEA
presented a proposed species priority list for HSC development (Figure 2). During 2013, AEA
will seek the input of the Instream Flow Technical Work Group when finalizing target species
and life stage for which HSC will be developed. AEA proposes that selection of target species
for fish passage analysis occur toward the end of the HSC development process. Technical
Team members, licensing participants, and AEA will have gained substantial knowledge of
species and lifestage utilization of off-channel habitats, seasonal movement into and out of off-
channel habitats, and microhabitat (depth and velocity) selection. This information will be
informative to the refinement of target species selection and passage criteria.
7.1.2. (b) Define Passage Criteria for Identified Fish Species
Basic categories of fish passage criteria include water depth, water velocity, and fish leaping
ability. The majority of passage criteria are based on the demonstrated swimming ability of a
species/lifestage in a laboratory, or in some cases, under controlled natural conditions.
The onus for most research on adult swimming ability is related to upstream fish passage at
manmade structures such as fishways, low head dams, weirs, and culverts. Most information on
juvenile and fry swimming ability is related to entrainment (open diversions) and impingement
(fish screens), of downstream migrating salmonids. Swim speed is the primary criterion
developed from these studies. Although information exists, depth criterion for fry and juvenile
salmonids is less researched. Although criteria are available for some of the proposed non-
salmonids target species, swimming capabilities for non-salmonids is the least researched.
AEA is in the process of collating existing information on passage criteria for the Fish Passage
Feasibility Study. Draft appendices summarizing these data have been developed for most of the
target species listed above and data will be summarized for the remaining species in Q2 of 2013.
These materials are being developed in collaboration with the Fish Passage Technical Team.
AEA proposes to use this information to inform passage criteria for the barrier study. Any
additional information necessary for the barriers assessment will be collated and summarized in
Q3 and Q4 of 2013. AEA proposes that consultation with Licensing Participants regarding
refinement of fish passage criteria occurs during TWG HSC development meetings scheduled for
late 2013. This timing would benefit passage criteria discussions because of the knowledge
gained from the HSC development process regarding species/lifestage use of different off-
channel habitat types and from HSC field observations.
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7.1.3. (c) Select Number and Location of Study Sites for each Element of
Study Implementation
Study elements and respective schedules for study site selection are presented below. Detailed
descriptions of these study elements and study sites are provided in this implementation plan.
Study Implementation Element Schedule for Study Site Selection
Adult salmon passage in tributaries above
Devils Canyon
79 tributaries (study sites) were selected and
surveyed for barriers in 2012 (AEA 2013b).
Follow-up surveys at a sub-set of these
tributaries are schedule for July - August 2013.
Adult salmon passage through Devils
Canyon
Impediment locations and radio-tracking
stations were established in 2012 for studies of
salmon passage at Devils Canyon (AEA
2013c).
Intensive study of passage at off-channel and
tributary deltas for adult and juvenile/fry
lifestages in Middle River Focus Areas
during ice-free and ice-cover periods.
The number and location of all Focus Areas,
within which all intensive study of fish passage
will occur, will be determined as part of the
implementation of RSP Section 8.5 - Fish and
Aquatics Instream Flow Study. The selection of
2-D modeling sites is anticipated to occur in
Q2-Q4, 2013.
Identification and location of physical
barriers to fish passage in tributaries outside
of Middle River Focus Areas.
In 2013, AEA proposes to ground survey 16
tributaries outside of Focus Areas for physical
barriers within the zone of hydrologic influence
(ZHI 1) in the Middle River. These tributaries
are listed below in Table 2.
7.1.4. (d) File Results of Items (a), (b), and (c)
The results of these implementation ideas will be included within the RSP Section 9.12 study
reports filed with the Commission.
1 The ZHI is defined as the approximated section of tributary extending from the Susitna River’s modeled water’s edge at a 1.5
year flow return interval downstream to the tributary’s confluence with the Susitna River at a base flow.
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7.1.5. Schedule Overview
Study Components,
Implementation Element Process/Field Effort Proposed Schedule for Consultation or Field
Surveys
(a) Identify Fish Species
to be included
Defined as part of instream flow, HSC target
species selection Completed
(b) Define Passage
Criteria for Fish Species
Define following initial results report for
instream flow HSC sampling and Fish
Distributin and Abundance sampling.
Q1 2014
(c) Select Number and
Location of Study Sites
Locations of all study sites are proposed in
this detailed implementation plan. Q2-Q4 2013
(ci) Upper River Tributary
Passage studies in tributaries intended for
survey but not completed in 2012 and
confirmation of possible barriers identified in
2012
Q3 2013
(cii) Upper River
Tribtaries within Reservoir
Varial Zone
Selection of tributaries will be a subsample
of the tributaries selected in 2012 and
coordinated with the Geomorphology Study,
RSP Section 6.5.4.8.2.2.
Q3 2013
(ciii) Tributaries, sloughs
and side-channels in
Focus Areas
Fish passage physical barrier field studies of
tributaries and off-channel habitat types in
Focus Areas will be conducted during
habitat mapping surveys.
August and/or September
2013.
(civ) Tributaries outside of
Focus Areas
Fish passage barrier field studies in selected
tributaries outside of Focus Areas (Table 2)
August and/or September
2013.
7.2. Effects of Load-following on Passage during Ice-cover Periods
A description of how the effects of load-following during the winter ice-cover period on
salmonid juvenile and fry passage (e.g., depth, velocity, potential ice blockages) from
mainstem into off-channel habitats would be evaluated.
For the assessment of fish barriers within Focus Areas, AEA will rely on data collected by the
intensive, multidisciplinary studies in Focus Areas to evaluate the effects of load-following on
juvenile and fry passage at off-channel habitats during the ice cover period. These studies
include:
• RSP Section 7.6 - Ice Processes in the Susitna River Study
• RSP Section 7.5 - Groundwater Study
• RSP Section 8.5 - Fish and Aquatics Instream Flow Study
• Hydraulic Routing and Operations Modeling;
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• Winter Habitat Use Sampling;
• Periodicity;
• Habitat-Specific Model Development
• RSP Section 9.6 - Study of Fish Distribution and Abundance in the Middle and Lower
Susitna River
• Winter Fish Study;
• Early Life History Study
An example of co-location of winter studies in Focus Areas is illustrated in Figure 3.
To study the effects of load-following on fish passage in the Middle River, AEA will use the
River1D predictive ice, hydrodynamic, and thermal model to simulate time-variable flow
routing, heat-flux processes, seasonal water temperature variation, frazil ice development, ice
transport processes, and ice-cover growth and decay.
The River1D model will be used to simulate conditions in the Middle River due to various
project operating scenarios and predict changes in water temperature, frazil ice production, ice
cover formation, elevation and extent of ice cover, and flow hydrograph. The model will also be
used to predict ice cover stability, including potential for jamming, under load-following
fluctuations. For the spring melt period, the model will be used to predict ice-cover decay,
including the potential for break-up jams. Proposed operating scenarios will include, at a
minimum, the load-following scenario described in the Pre-Application Document (PAD) and a
base-load scenario.
For Focus Areas, AEA will model and characterize ice processes using either River1D or
River2D models. The appropriate model will be selected on the basis of which model better
simulates the characteristics at the particular study location. The objective of this modeling will
be to evaluate project effects on smaller scale habitat in the focus areas to provide physical data
on winter habitat for RSP Section 8.5 (fish and aquatics instream flow) and RSP Section 9.12
(fish passage barriers).
As discussed by FERC (2013a), accuracy of hydrodynamic modeling during the ice-cover
periods may or may not be sufficient to predict passage conditions at the small, local scale.
FERC states:
…it’s not clear if the winter model can accurately predict stage-discharge relationships and
streamflow velocities at a scale that is fine enough to evaluate the effects of daily flow
fluctuations during proposed winter load-following operations on fish passage conditions
from the mainstem into off-channel habitats…While AEA’s proposed fish passage barrier
study plan does not appear to specifically address this issue, we assume the intensive,
multidisciplinary study elements that would be implemented within the focus areas would
provide some information to evaluate fish passage conditions between the mainstem and off-
channel habitats under ice cover and load-following operations.
The following is a discussion of multidisciplinary methods proposed by AEA to address FERC’s
comment.
The hydraulic data to be derived from the Focus Area ice models will be determined on a case-
by-case basis by the needs of instream flow, geomorphology, fish passage, and other studies, but
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will include at a minimum: extent of inundation; flow stages; and, velocities for post-Project
winter conditions under load-following and base-load scenarios.
Initial modeling results of load-following effects on stage indicate that in an ice-free channel
Project load-following (maximum load following OS-1 scenario) in January would result in a
daily stage cycle (fall and rise) of 1.0 to 1.5 feet at the Susitna stream gage near Gold Creek
(AEA 2013d). These initial modeling results also indicate that during the winter months, the
average stage during ice-free periods, in the vicinity of Gold Creek, will be approximately 3.5
feet higher with the Project than under existing ice-free periods. Figure 4 illustrates these initial
results.
The rise in stage described above is applicable to the ice-free period. Effects of load-following
on river stage during ice-cover periods will likely be much different than under ice-free periods.
One key finding of the 1980s modeling effort (Watana Dam only scenario) was that winter water
surface elevations under ice would generally be 2-7 feet higher under project conditions (RSP
Section 7.6). The combination of a predicted rise in stage due to winter Project flow releases and
a predicted rise in stage due to ice-cover would be a 5-10 feet.
Obvious from these initial studies, but important to note is the dramatic difference in scale
between predicted increases in river stage (depth) of several feet under Project operations, and
the minimum depth criteria for juvenile and fry salmonid passage of 2-3 inches. At least for
depth predictions, initial results indicate that model error can be large and still have sufficient
accuracy to predict that depth would exceed 3 inches.
As highlighted by FERC above and discussed in more detail in Section 7.3.1 below, ice-process
modeling may not provide detailed and accurate information at the micro scale. The study does,
however, exhaust scientific methodologies and resources to provide data within the current
bounds of research. Further, in combination with other multidisciplinary studies in Focus Areas,
the models will be useful for predicting and evaluating effects of ice process on fish passage at
the macro scale.
As discussed by FERC (2013a), for the purposes of the passage studies, stage and velocity model
predictions for post-Project winter conditions under load-following and base-load scenarios will
be augmented with other winter-period multidisciplinary study elements.
AEA does not propose any field data collection in RSP Section 9.12 for this study element. All
field data collection will be conducted as proposed in other RSPs, as described above.
7.3. Description of Study Sites and Modeling Methods
A description of the specific methods as set forth in section 9.12.4.5 (e.g., 2-dimensional
modeling, or other unspecified modeling approach) that would be applied at the off-channel
and tributary delta locations selected for the depth barrier analysis. This would include an
explanation of the proposed methods and study sites for the open-water period for adult and
juvenile fish, and the ice-cover period for juvenile fish.
AEA’s fish barrier assessment in Focus Area will rely heavily of models develop as part ongoing
Geomorphology, Instream Flow, and Ice Processes studies. Several environmental variables
may affect adult and juvenile fish passage in sloughs, side channels, and tributary deltas and the
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importance of these variables maybe different during ice-cover and ice-free periods. In general,
at a given passage reach the water conditions (depth and velocity) interact with conditions of the
channel (length and uniformity and substrate size) to characterize the passage conditions that a
particular fish encounters when attempting to migrate into, within, and out of a slough, side
channel, or tributary delta. The likelihood of a particular fish successfully navigating through a
reach will depend on these environmental conditions as well as the individual capabilities and
condition of the fish. These fish passage variables will be studied in Focus Areas using 1-D and
2-D models.
7.3.1. Proposed Study Sites for Modeling
As recommended by FERC (2013a), AEA will locate fish passage barrier intensive sampling
sites for both the ice-free and ice-cover periods within the selected Focus Areas. Ice-free data
collection includes a larger number and diversity of sample locations at off-channel and tributary
deltas. Both ice-cover and ice-free passage data collection sites will be located to overlap with
fine mesh 2-D modeling domains at the outlets and inlets of side channels, side sloughs, and
upland sloughs. Figure 5 illustrates the conceptual distribution of fine mesh modeling domains
in one Focus Area. Fine mesh 2-D modeling domains will be similarly distributed at tributary
mouths and at inlets and outlets of off-channel habitat units in all Focus Areas. The exact
locations of fine mesh sampling domains will be determined pursuant the Geomorphology Study,
RSP Section 6.6. Ice-cover sample sites within Focus Areas will be fewer in number due to the
inherent difficulties of measuring and modeling ice process and associated hydrodynamic
conditions that control fish passage.
With input from the RSP Section 9.12 study lead, Focus Area study sites for modeling juvenile
passage during the ice-cover period will be selected as part of RSP Section 7.6 - Ice Processes in
the Susitna River Study and RSP Section 8.5 - Fish and Aquatics Instream Flow Study. One
objective of the Ice Processes study is to develop detailed models and characterizations of ice
processes at instream flow Focus Areas in order to provide physical data on winter habitat for the
instream flow study. This study objective directly supports study site and modeling needs for
juvenile fish passage during ice-cover periods.
The February 1, 2013 Study Plan determinate included specific recommendations regarding
study sites for velocity measurements as follows.
A description of a subsample of tributary deltas and off-channel habitat entrances within
Middle River focus areas where velocity measurements will be taken to determine if velocity
barriers to juvenile salmonids (particularly salmonid fry) would be created at tributary
deltas and off-channel habitat entrances by modifications to river stage and discharge
through proposed project operations.
Consistent with AEA’s approach to co-locate intensive fish passage study sites with the Instream
Flow Study sites in Focus Areas, velocity measurements and modeling will be completed at
these locations. As described in RSP Section 6.6, Section 6.6.1.2.4, the use of Focus Areas is to
conduct concentrated interdisciplinary studies at selected areas within the study area. Such areas
represent specific sections of the river that will be investigated across resource disciplines and
will provide for an overall understanding of interrelationships of river flow dynamics on the
physical, chemical, and biological factors that influence fish habitat. Focus Areas will involve
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portions of the Susitna River and its floodplain where detailed study efforts will be jointly
conducted by the Fish and Aquatics Instream Flow (RSP Section 8.5), Riparian Instream Flow
(RSP Section 8.6), Geomorphology (RSP Section 6.5), Ice Processes (RSP Section 7.6),
Groundwater (RSP Section 7.5), Characterization and Mapping of Aquatic Habitats (RSP
Section 9.9) studies, and Fish Passage Barriers (RSP Section 9.12). The Focus Areas will allow
for a highly integrated, multidisciplinary effort to be conducted for evaluating potential Project
effects on key resource areas across a range of representative sites.
As required by FERC, final selection of ten Focus Areas was completed by May 31, 2013
(2013b). The ten Focus Areas include a large number and diversity of side channels, side
sloughs, upland sloughs, and tributary deltas that in sum would be representative of passage
conditions at off-channel and tributary deltas in the Middle River. The ten Focus Areas being
considered include a total of 34 side channels, 8 side sloughs (one with a beaver pond), 13
upland sloughs (one with a beaver pond), 2 macrohabitat backwaters, and 10 tributary
mouths/deltas. The inlets to these off-channel habitats will be modeled using 2-D or 1-D
hydraulic models as described in Section 6.3, above. Table 1 is a tally of off-channel and
tributary deltas by Focus Area. The domain for 2-D modeling for each off-channel will extend
from the mouth up to and including the inlet or head of each off-channel as illustrated in Figure
5. This domain will cover the fish entrance to the off-channel and breaching zone of the off
channel, as well as the entire length of the channel. The 2-D modeling domain for tributary
deltas will include the entire delta within the zone of hydrologic influence.
Final hydrodynamic model selection in Focus Areas will occur as part of the RSP Sections 6.6
and 8.5 study plan determination and modification process.
FERC (2013b) states:
Both one-dimensional and two-dimensional modeling approaches are consistent with
accepted practices for implementing an instream flow study using PHABSIM (section
5.9(b)(6)). We note, however, that AEA does not identify in the RSP the specific locations
where one-dimensional versus two-dimensional modeling would be applied, except for noting
that two-dimensional modeling would be applied within some focus areas. NMFS is
concerned that there may be disagreements about the selection of the appropriate habitat-
specific models and the specific locations where one-dimensional and two-dimensional
modeling would be applied. In our analysis and recommendations for Study 6.6
(geomorphology modeling), we are recommending that AEA file by the end of the second
quarter of 2013, its proposed technical memorandum that summarizes the specific models
and locations where one-dimensional and two-dimensional modeling would be applied
pursuant to Study 8.5 and Study 6.6.
AEA does not propose any data collection or hydrodynamic modeling under RSP 9.12 for this
study element. All data collection and hydrodynamic modeling will be conducted as proposed in
other RSPs, as described above.
7.3.2. Modeling Methods for Ice-free Periods
Depth and velocity passage for adults and juveniles in sloughs, upland sloughs, side channels,
and at tributary delta mouths in Focus Areas will be assessed following concepts similar to
ADF&G (1984b) in which depth, velocity, substrate, and length of the passage reach were
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considered together to determine successful or unsuccessful passage into and within these
habitats. Data collection and modeling methods, including two-dimensional modeling, not
available in the 1980s, will be applied in the current studies.
As discussed by FERC (2013a), for fish passage during ice-free periods, AEA will rely on 2-D
modeling already being conducted in Focus Areas under Section 6.6 - Fluvial Geomorphology
Modeling below Watana Dam Study and 8.5 - Fish and Aquatics Instream Flow Study. The
specific 2-D models will be selected from a list of candidate models in coordination with other
studies and the licensing participants. As specified by FERC (2013b), AEA’s schedule for
selecting the 2-D model will be described in a technical memorandum prepared in the second
quarter of 2013. The 2-D model selected will be applied over the full extent of all Focus Areas.
As described in RSP Section 8.5, the 2-D model will utilize a variable mesh (also referred to as
flexible mesh). A variable mesh allows a finer mesh to be used in areas where either the
information desired or the condition being modeled requires higher spatial resolution (RSP
Section 6.6.4). For off-channels and tributary deltas, velocities, bathymetry, and substrate will
be modeled at a fine mesh grid size of 2m x 2m. Figure 5 is an example of fine mesh 2-D
modeling at off-channel passage sites and coarse mesh modeling in the open water areas.
As in the ADF&G 1980s studies, passage in off-channel reaches requires evaluation under three
types of hydraulic conditions: breaching, backwater, and local discharge. The two-dimensional
model, coupled with the flow routing model and the groundwater model will be used to evaluate
passage conditions over the full range of pre- and post-Project flow conditions. To the extent
possible, passage criteria will be input to the 2-D habitat model, yielding an integrated analysis
tool.
Additional data will be collected in support of modeling effort, include stream flow data and data
on beaver dams as fish barriers. Tributaries within Focus Areas (Table 2) will be either gaged
with continuous stage recording instruments or they will be periodically measured at multiple
flow levels to establish a rating curve with the intent of establishing drainage-area-based
accretion estimates.
AEA will survey beaver dams encountered within the zone of hydrologic influence in select
tributaries and Focus Areas as shown in Table 2 of the Implementation Plan and as part of the
aquatic furbearers study RSP Section 10.11. Beaver dam ground surveys will follow those
methods described in RSP Section 9.9, Section 9.12.4.4. Dimensions of the dam including
height, length, and breadth, and depth of the leaping pool will be measured and observations of
possible passage ways through or around the dam will be described. Photographs will be taken.
Beaver dams, not ground surveyed, will be identified from high resolution aerial imagery. AEA
will use this information to map the distribution of beaver dams in GIS and, as applicable, for
extrapolation to beaver dams beyond Focus Areas. Data on stream flow and beaver dams will be
used in conjunction with modeling to evaluate potential barriers for fish in Focus Areas.
7.3.3. Modeling Methods for Ice-cover Periods
As described above in Section 7.2, ice-cover passage barrier modeling will rely on the river ice-
process model developed as part of RSP Section 7.6 - Ice Processes in the Susitna River Study.
The river ice-process model will rely on the River 1-D hydrodynamic flow routing/thermal
model to determine large-scale changes to ice-cover timing and structure, and under-ice
discharges including stage fluctuations.
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Ice-process studies will include 2-D modeling at the Focus Area below Devils Canyon (where
there will likely be an ice-cover post-project to model), 1-D modeling at Focus Areas upstream
of Devils Canyon for existing conditions, and using the open-water results for proposed
conditions.
One objective of the ice processes study is to develop detailed models and characterizations of
ice processes at instream flow Focus Areas in order to provide more detailed physical data on
winter habitat for the instream flow study. RSP Section 7.6 Ice Processes study objective
directly supports study site and modeling needs for juvenile fish passage during ice-cover
periods. In its study plan determination, FERC (2013b) concluded that:
AEA’s proposed modeling approach should provide the information necessary to describe
project effects with respect to ice processes to a degree which is consistent with generally
accepted practices in the scientific community (section 5.9(b)(6)) and, if effectively
implemented, is expected to be able to satisfy the study objectives.
If the initial results of the 2013 or 2014 study seasons (as documented in the initial study
report) indicate that the model does not adequately evaluate project effects, and it becomes
clear on the basis of the results that other procedures should be followed in order to meet the
study objectives, then alternative methods and/or procedures could be added in 2014 or in
subsequent study years (sections 5.15(d) and 5.15(e)).
In addition to the ice-process modeling, AEA will rely on multidisciplinary data collection in
Focus Areas to assess potential effects of the Project on salmonid juvenile and fry passage during
the ice-cover period. Other multidisciplinary studies include: RSP Section 6.6 - Fluvial
Geomorphology Modeling below Watana Dam Study and RSP Section 7.5 - Groundwater Study.
Subsections from RSP Section 8.5 - Fish and Aquatics Instream Flow Study include: Hydraulic
Routing and Operations Modeling, Winter Habitat Use Sampling, Periodicity, and Habitat-
Specific Model Development.
The ice processes study in 2013/2014 is planning repeat aerial observations at each focus area,
about 10 transects will be measured for ice thickness, frazil thickness, and water depth, and time-
lapse photography will be taken of a small portion of the area, including open-leads. For all of
the Focus Areas, ice thickness and elevation will be measured and inlets to side channels and
sloughs will be observed to qualitatively document any throughflow. Throughflow discharges
will be taken but only at the major side channels. The feasibility and application of ground
penetrating radar (GPR) will be investigated to determine if it will provide sufficient resolution
to determine frazil ice accumulations. This would provide broader and more continuous measure
of bed-fast ice thickness and floating solid ice thickness, than relying on auger holes.
Factors that affect fish passage are much more difficult to physically measure and much more
difficult to model for ice-cover than for ice-free conditions. The controlling forces over depth,
velocity, and the presence of potential obstructions are much different in ice-cover versus ice-
free conditions. Ice formation, including surface ice, frazil ice, and anchor ice can all physically
obstruct access into and out of off-channel habitats. Ice formations can reroute water flow,
thereby dewatering an access passageway that would otherwise be present under ice-free
conditions. An example of this is the blockage of water flow to an inlet of a side slough or side
channel, such that slough outflow is then insufficient for fish to access the off-channel habitat.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 14 June 2013
Localized passage conditions, such as a shallow riffle at the entrance of a slough, are extremely
dynamic and are virtually unpredictable during ice-cover periods. The presence of frazil and
structure ice appears or disappears in a matter of hours or days; likely opening up or closing fish
passageways at the same frequency. Passage opportunities might be improved at some locations
during winter Project operation due to the projected increase in river stage while at other
locations increase in stage might contribute to the degradation of passage conditions (ice
thickening at the inlets and outlets of off-channels).
These difficulties and uncertainties are noted here to bring attention to the difference in scale
between evaluations of fish passage in ice-cover versus ice-free conditions. Passage conditions
during ice-free periods can be observed and measured directly and modeled to the micro scale
(tenths of feet and velocity). Whereas, passage conditions during ice-cover periods are generally
not visible, very difficult to measure (the areal extent of the sample site might be the diameter of
an ice auger bit), and are modelable at a lesser resolution.
While ice-process modeling and winter Focus Area studies may provide some information at the
micro scale, they will likely be more useful for predicting and evaluating potential structural,
spatial, and temporal changes to fish passage at the macro scale. Some macro scale evaluations
during the ice-cover period include:
• Potential change in the timing of ice formation and breakup in relation to migration
periodicities of juvenile salmonids;
• Potential change in the thickness and elevation of ice at the inlets and outlets of off-
channels and tributary deltas;
• Potential for blockages created by unstable or thickened ice from frequent flow
fluctuations;
• Potential changes in the formation and longevity of ice-free leads at slough entrances;
• Potential changes in the depth of ice cover into and within off-channel habitats; i.e.
changes in passageways beneath the ice; and
• Potential changes in ice-process in sloughs due to changes in the dominant source of
through flow.
This research approach is a viable application of current, reasonably feasible scientific
application to address the issue. AEA does not propose any hydrodynamic or ice modeling
under RSP Section 9.12 for this study element. All hydrodynamic or ice modeling will be
conducted as proposed in other RSPs, as described above.
7.4. Identification and Location of Existing Physical Barriers to Fish
Passage
7.4.1. Middle and Upper River
Tributaries above Devils Canyon (inclusive and upstream of Cheechako Creek) were surveyed
by helicopter in 2012, followed by ground surveys of some barriers that could not be positively
classified as a barrier from the air. Methods and results of these surveys are reported in AEA
(2013b) 2012 Upper Susitna River Fish Distribution and Habitat Study, Fish Passage Barriers
Assessment.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 15 June 2013
Seventy-nine drainages were surveyed throughout the study area between Devils Canyon and
Oshetna River. A total of 43 potential fish passage barriers were identified from the helicopter
within 29 of the 79 drainages surveyed (more than one barrier was identified on some
tributaries). Of these 43 barriers, a total of 35 definitive passage barriers were identified within
24 tributaries, the majority of which had falls with a vertical height greater than 10 feet and that
could be visually estimated from the helicopter. Three of the 35 barriers were surveyed from the
ground with a range finder to determine vertical and horizontal distances from the crest to the
plunge pool and were confirmed as barriers to fish passage. An additional eight features, within
seven tributaries, were identified as potential fish passage barriers having falls heights visually
estimated to be near 10 feet or other apparent elements of passage barriers such as multiple
chutes and/or cascades and warranted further investigation; however, their challenging locations
in canyons precluded safely landing the helicopter for ground surveys.
During the 2013 and 2014 study seasons, subject to obtaining access authorization and necessary
permits, AEA will attempt on-the-ground measurement of the eight features that could not be
positively identified from the air in 2012. On-the-ground measurement will depend on
reasonably safe access. Accessible features will be measured using the methods as described in
Alaska Department of Natural Resources (ADNR 2007) and Powers and Orsborn (1984). The
geometry of the obstacle will be surveyed including measurements of barrier height, leap
distance, and depth of leaping pool at an estimated high and low flow. The barrier will be
photographed and its location fixed with GPS. If the obstacle is clearly not a barrier, its location
and basic dimensions will be noted with no further measurements.
AEA proposes to conduct foot surveys for physical barriers and intensive hydrodynamic
modeling studies for velocity and depth barriers within the zone of hydrologic influence at 20
named and unnamed tributaries in the Middle River below Devils Canyon (Table 2). This will
include intensive study of 10 tributary deltas in Focus Areas as described above in Sections 7.2,
7.3, and 7.4. In 2013, AEA proposes to conduct foot surveys for physical barriers within the ZHI
of the remaining 10 primary Middle River tributaries below Devils Canyon (Table 2). Foot
survey field methods will be those described in RSP Section 9.12, Section 9.12.4.4.4. In ad dition
to methods described in RSP Section 9.12.4.4.4, data collection on deltas of these 10 tributaries
will include: tributary thalweg length; thalweg depth and velocity profile (longitudinal); stream
gradient; dominant and subdominant substrate; and photographs from several angles of the delta
and tributary. Several of these tributaries will be gaged (Table 2).
7.5. Study of Fish Passage Barriers in the Lower River
Investigation and evaluation of fish passage barriers in the Lower River will follow a phased
approach in which studies of barriers in the Middle River will be used to determine the need and
design for 2014 barrier studies in the Lower River (FERC 2013a). Other studies to be conducted
in 2013 that will contribute to determining the need for barrier studies in the Lower River are
RSP Section 9.6 – Fish Distribution and Abundance in the Middle and Lower Rivers, RSP
Section 8.5 – Fish and Aquatics Instream Flow Study, RSP Section 6.5 – Geomorphology Study,
and the Open-water Flow Routing Model (RSP 8.5). If 2013 results, as presented in the Initial
Study Report, indicate that the Project will cause significant adverse effects on fish passage into
tributaries and off-channel habitats in the Middle River then additional study sites will be added
in the Lower River in 2014 (FERC 2013a).
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 16 June 2013
7.6. Documentation of Consultation
On May 15, 2013, AEA provided to U.S. Fish and Wildlife Service (USFWS), National Marine
Fisheries Service (NMFS), and other Technical Work Group participants for comment a Draft
Study of Fish Barriers Implementation Plan (Draft Implementation Plan) that was developed to
provide responses to the February 1 SPD recommendations. The Draft Implementation Plan was
also made available on the Project website (http://www.susitna-watanahydro.org). Consistent
with the February 1 SPD, AEA initially allowed 15 days for comment by requesting that all
comments be submitted, in writing, by Thursday, May 30, 2013. At the request of NMFS, AEA
extended the deadline for comments to June 5, 2013. NMFS and USFWS jointly submitted
comments on June 7, 2013. AEA received no other comments on the Draft Implementation
Plan. Attached as Attachment 2 to the cover letter for this filing is a comment response table
that includes a description of how the NMFS and USFWS joint comments are incorporated into
the final plan; and an explanation for why certain comments were not incorporated into the final
plan.
8. REFERENCES CITED
ADF&G (1984b). Susitna Hydro Aquatic Studies, Report No.3: Aquatic habitat and instream
flow investigations, May - October 1983 (Review Draft). Chapter 6: An evaluation of
passage conditions for adult salmon in sloughs and side channels of the Middle Susitna
River. Prepared for Alaska Power Authority, Anchorage, AK.
AEA (Alaska Energy Authority). 2012. Susitna-Watana Hydroelectric Project No 14241-000.
Revised Study Plan (RSP) submitted to FERC December 2012.
—. 2013a. R2 Resource Consultants PowerPoint presentation – slide 23. Update on Habitat
Suitability Criteria Development. March 27, 2013 Technical Workgroup Meeting,
Anchorage, AK.
—. 2013b. Susitna-Watana Hydroelectric Project No 14241-000. First Year Study Report –
2012 Upper Susitna River Fish Distribution and Habitat Study - Fish Passage Barriers
Assessment.
—. 2013c. First Year Study Report – 2012 Adult Salmon Distribution and Habitat Utilization
Study.
—. 2013d. Susitna-Watana Hydroelectric Project No 14241-000. First Year Study Report –
2012 Open Water HEC-RAS Flow Routing Model.
— 2013e. Susitna-Watana Hydroelectric Project No 14241-000. Technical Memorandum.
Selection of Focus Areas and Sites in the Middle and Lower Susitna River for Instream
Flow and Joint Resources Studies – 2013 -2014. March 1, 2013.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 17 June 2013
FERC (Federal Energy Regulatory Commission). Office of Energy Projects. 2013a. February
01, 2013 Study Plan Determination for the Susitna-Watana Hydroelectric Project No
14241-000. Federal Energy Regulatory Commission.
— . 2013b. April 01, 2013 Study Plan Determination for the Susitna-Watana Hydroelectric
Project No 14241-000. Federal Energy Regulatory Commission.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 18 June 2013
9. TABLES
Table 1. Tally of off-channel habitats and tributary deltas in Middle River Focus Areas.
Focus Area Side Channel Side Slough Upland Slough Backwater Tributary Mouth Total
104 7 2 1
1 11
113 2 1 2 5
115 1
3 1 1 6
128 8 1 1
1 11
138 3 1 2
6
141 1
1 1 1 4
144 6 1 2
1 10
151
1 1
173 4 3 2
2 11
184 2
2
Total 34 8 13 2 10 67
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 19 June 2013
Table 2. Named and unnamed tributaries in the M iddle River selected for fish passage barrier investigation.
Project
Rivemile
(PRM)
Tributary Name Geomorphic
Reach
Focus
Area
Intensive
Study in
Focus
Area
Identify and
Locate Potential
Barriers in ZHI1
Documented
in Anadromous
Waters Catalog
Historical Data
Available
Proposed
for FDA Fish
Sampling in 2013
Approximate Length of ZHI1 (mi) Drainage Area (mi2)
184.6 Tsusena Creek MR-2 2012 X Yes 145.3
179.3 Fog Creek MR-2 2012 X X Yes 144.1
174.3 Unnamed MR-2 FA173 X 2012 No
173.8 Unnamed MR-2 FA173 X 2012 Possible
164.8 Devil Creek MR-4 2012 X Yes 74.8
160.5 Chinook Creek MR-4 2012 X X Yes 24.7
155.9 Cheechako Creek MR-4 2012 X X Yes
152.3 Portage Creek MR-5 FA151 X X X Yes 0.19 178.6
148.3 Jack Long Creek MR-6 X X X Yes 0.03
144.6 Unnamed MR-6 FA144 X Yes 0.01
142.1 Indian River MR-6 FA141 X X X Yes 0.14 86.2
140.1 Gold Creek MR-6 X X X Yes 0.15 23.7
134.3 Fourth of July
MR-6 X X X Yes 0.12
134.1 Sherman Creek MR-6 X X X Yes 0.02
128.1 Skull Creek MR-6 FA128 X X X Yes 0.04
127.3 Fifth of July Creek MR-6 X X X Yes 0.01
124.4 Deadhorse Creek MR-6 X X X Yes 0.18 6.5
121.4 Little Portage
MR-7 X X X Yes 0.12 2.4
120.2 McKenzie Creek MR-7 X X X Yes 0.02 2.3
119.7 Lower McKenzie
MR-7 X X Yes 0.16
117.2 Lane Creek MR-7 X X X Yes 0.11 10.4
115.4 Unnamed MR-7 FA115 X Yes 0.12
115.0 Gash Creek MR-7 FA 113 X X X Yes 0.01
114.9 Slash Creek MR-7 FA 113 X X X Yes 0.02
113.7 Unnamed MR7 FA 113 X
110.5 Chase Creek MR-7 X X X Yes 0.17
105.1 Whiskers Creek MR-8 FA104 X X X Yes 0.33 17.2
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 20 June 2013
10. FIGURES
Figure 1a. Three potential impediment areas (Impediments 1, 2, and 3) to fish passage on the Susitna River located between Portage and Devil creeks
at the top end of the Middle River Segment (AEA 2013c).
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 21 June 2013
Figure 1b. Example of a location within Impediment area 1 where a velocity barrier could be created at a high river discharge. Photo at PRM 154.8,
September 11, 2012, at 11,600cfs (provisional) at Gold Creek.
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 22 June 2013
Figure 2. Proposed HSC curve development priority (AEA 2013a).
Agency Review Draft – Fish Passage Barrier Assessment Implementation Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 23 June 2013
Figure 3. Example of proposed winter fish habitat use sampling sites at the Skull Creek Complex in the Middle Susitna River Segment (AEA 2013e).
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 24 June 2013
Figure 4. Predicted stage hydrographs in the Susitna River at Gold Creek (USGS 15292000) under Pre-
Project and Maximum Load Following OS-1 conditions during the week of January 8 to 14, 1984. Actual
results may differ from those depicted as a result of ice formation in the river (AEA 2013d).
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 25 June 2013
Figure 5. Conceptual layout of 2-D coarse and fine mesh modeling within the proposed Whiskers Slough Focus Area.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 26 June 2013
Figure 6. Instream Flow Focus Area 104.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 27 June 2013
Figure 7. Instream Flow Focus Area 113.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 28 June 2013
Figure 8. Instream Flow Focus Area 115.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 29 June 2013
Figure 9. Instream Flow Focus Area 128.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 30 June 2013
Figure 10. Instream Flow Focus Area 138.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 31 June 2013
Figure 11. Instream Flow Focus Area 141.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 32 June 2013
Figure 12. Instream Flow Focus Area 144.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 33 June 2013
Figure 13. Instream Flow Focus Area 151.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 34 June 2013
Figure 14. Instream Flow Focus Area 173.
Revised Study Plan
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 35 June 2013
Figure 15. Instream Flow Focus Area 184.
Attachment 2
Alaska Energy Authority Response to the June 7, 2013 Joint Comments of
National Marine Fisheries Service and U.S. Fish and Wildlife Service on
the Study of the Fish Passage Barriers Implementation Plan
1
ATTACHMENT 2
Alaska Energy Authority Response to the June 7, 2013 Joint Comments of National Marine Fisheries Service and
U.S. Fish and Wildlife Service on the Study of the Fish Passage Barriers Implementation Plan,
the Susitna-Watana Hydroelectric Project, FERC Project No. 14241
Comment AEA Response
Section 7.1.1 Identify Fish Species to be included in Fish Passage Study
1. The Implementation Plan should
clearly state which species are
proposed for inclusion in the fish
passage barrier study for each of the
four study areas: above the dam,
through Devils Canyon, in the
Middle River, and in the Lower
River. If only a subset of all species
is proposed, the Implementation Plan
should list and describe the criteria
used to select these species and
eliminate species from consideration
and present these to the TWG for
discussion and concurrence.
The candidate list of target species for passage studies in the Middle River is stated in Section
7.11 of the Fish Passage Barriers Implementation Plan. These species include Chinook, coho,
chum, and sockeye salmon, rainbow trout, Arctic grayling, Dolly Varden, burbot, longnose
sucker, humpback whitefish, and round whitefish. These target species were selected because
they are generally considered the most sensitive to habitat loss through manipulation of flows in
the Susitna River. Section 7.11 of the Fish Passage Barriers Implementation Plan also states the
basis or criteria for their selection as candidate species.
Consistent with the February 1, 2013 Study Plan Determination (February 1 SPD), the Fish
Passage Barriers Implementation Plan does not include identification of fish species in the
Upper River or Lower River, or for passage through Devils Canyon. This agency
recommendation pertaining to identification of fish species in these locations is beyond the
scope of the issues addressed in the Fish Passage Barriers Implementation Plan.
Revised Study Plan (RSP) Section 9.12.4.3 addresses how Upper River 2013–2014 passage
studies will proceed. AEA proposes that candidate target species for passage studies in the
Upper River be the same as those for the Middle River as listed above. The Alaska Energy
Authority (AEA) intends to seek the input of the Technical Workgroup (TWG) in finalizing the
selection of target species.
Identification of, and the selection of, salmon species for passage assessment through Devils
Canyon is included in RSP Section 9.7 – Salmon Escapement Study. Objective 1 of RSP
Section 9.7 states “Capture, radio-tag, and track adults of five species of Pacific salmon in the
Middle and Upper Susitna River in proportion to their abundance,” and Objective 2 states
“Determine the migration behavior and spawning locations of radio-tagged fish in the Lower,
2
Middle, and Upper Susitna River.”
Identification of resident species to be radio-tagged and monitored is included in Section 5.8 of
the Fish Distribution and Abundance Implementation Plan corresponding to RSPs 9.5 and 9.6.
Arctic grayling, burbot, Dolly Varden, humpback whitefish, lake trout, longnose sucker,
northern pike, rainbow trout, and round whitefish will be radio-tagged with the goal of 30 tags
to each species in the Middle and Lower River. Tracking of tagged resident fish below, within,
and above Devils Canyon is described in the Fish Distribution and Abundance Implementation
Plan.
Comment AEA Response
Section 7.1.2 Define Passage Criteria for Identified Fish Species
2. Recommendations
The conflicting schedules for the
proposed consultation process for
defining passage criteria for identified
fish species should be resolved.
The schedule outlined in the Fish Passage Barriers Implementation Plan has been revised to be
more in line with the Habitat Suitability Criteria (HSC) and Habitat Suitability Index
development schedule to be presented at the June 25, 2013 Fish and Aquatics TWG meeting.
AEA proposes to seek input of licensing participants regarding refinement of fish passage
criteria following the distribution of the Initial Study Report (ISR) in the first quarter of 2014
(Q1 2014). This timing will allow the TWG passage criteria discussions to be informed by the
HSC development process regarding species/lifestage use of different off-channel habitat types
and from HSC field observations.
3. The draft Implementation Plan
should propose passage assessment
criteria. The criteria should include:
• Combined water depth and
channel length criteria for
adult and juvenile salmon and
resident fish species that
results in physical and
behavior barriers.
• Leap height and pool depth
barrier criteria for all adult
AEA has revised the implementation plan to indicate that it will finalize the fish passage
criteria during Q1 2014. This schedule will allow AEA to consider the results of other studies
including habitat suitability sampling and fish distribution and abundance sampling. Prior to
finalizing the fish passage criteria, AEA will seek the input of the Federal agencies and other
licensing participants during Q1 2014. In developing the fish passage criteria, AEA will
consider the categories of criteria included in the agencies’ comments.
3
salmon species, resident fish
species and lengths, and all
species of juvenile salmon.
• Combined channel slope and
length criteria resulting in
presumed migration barriers
for all adult salmon species,
resident fish species and fork
lengths, and juvenile salmon
species.
• Burst and sustained
swimming speeds with time to
exhaustion for all adult
salmon species by fork or
total length, juvenile salmon
by fork length or total length,
and resident fish species.
• Definition of permanent,
temporary, seasonal, and
partial barriers.
• The Implementation Plan
should provide a description
of the proposed survey dates,
methods, and criteria that will
be used to accomplish the first
two objectives of the study
plan and proposed dates for
consultation with the Services.
• Consultation for development
of passage criteria should
occur prior to fish passage
barrier surveys (Objectives 1
and 2).
4
Comment AEA Response
Section 7.1.3 Select Number and Location for Study Sites for each Element of Study Implementation
4. Recommendations
The Implementation Plan should
provide a schedule of when field
surveys of tributary streams and off-
channel habitats would be conducted
to identify and classify potential
barriers and provide for TWG
review.
In response to agency comments, Section 7.1.5 of the Fish Passage Barriers Implementation
Plan has been modified to include a schedule of fish passage barrier field studies at tributary
streams and off-channel habitats. Fish passage physical barrier field studies of tributaries and
off-channel habitat types in Focus Areas will be conducted during habitat mapping surveys in
August and/or September 2013.
Surveys of physical barriers to fish passage in off-channel habitat types outside of Focus Areas
will also be conducted in August and/or September 2013.
Fish passage barrier field studies in tributaries outside of Focus Areas are currently scheduled
for August and/or September 2014.
5. Field methods and passage criteria
should be described and adequate
time for consultation with the
Services and TWG should be
scheduled as proposed in RSP 9.12.
Fish passage field study methods are described in detail in RSP Section 9.12.4.4.
Regarding Agencies’ comments on passage criteria consultation, please see AEA’s Response to
Comment 3.
6. Initial surveys should be
conducted at all tributary and side
slough locations; however, if sites
are excluded, the rationale for
excluding those locations should be
provided. The distribution of
barriers by barrier type could then be
evaluated to determine if they are
adequately represented in Focus
Areas where post project effects will
be evaluated for extrapolation to the
larger area of project influence on
river functions.
RSP Section 9.7 and the accompanying Fish Barriers Implementation Plan proposes ground
surveys in Focus Areas and in selected tributaries (27, or 34 percent of Middle River
tributaries). Table 2 of the Fish Passage Barriers Implementation Plan lists the 27 tributaries in
the Middle River AEA selected to be surveyed, and provides the criteria that were used in
selecting these tributaries for sampling. The distribution of these barriers will be mapped in
GIS. This data will then be available, as applicable, for extrapolation purposes.
Within the Middle River, there are over 75 tributaries, including both perennial and ephemeral
streams. Consistent with standard scientific practices, AEA is subsampling a larger population
of habitats. To ensure a representative sample, AEA has selected tributaries that reflect a full
range of stream sizes and species utilization in the Middle River.
5
7. All Middle River tributaries
should be surveyed to identify those
that currently have migration
barriers or may have migration
barriers under some flow
conditions.
The agency recommendation that all Middle River tributaries be surveyed is inconsistent with
RSP Section 9.12.3 – Study Area, which states: “Passage studies in tributaries to the Middle
River will include select tributaries and will extend from the mouth to the upper extent of
Project hydrologic influence. . . .”
Table 2 of the Fish Passage Barriers Implementation Plan lists the 27 tributaries in the Middle
River AEA selected to be surveyed for physical barriers to fish passage within the zone of
hydrologic influence. This list represents the largest tributaries and numerous smaller perennial
tributaries that are known to support target species in the Middle River. These 27 tributaries
represent approximately 34 percent of over 75 perennial and ephemeral tributaries identifiable
from high resolution imagery.
Please see AEA’s Response to Comment 6.
8. Surveys also should be conducted
to identify those locations where
project-induced changes in channel
morphology or tributary deltas could
form migration barriers.
Studies of the effects of the proposed Project on channel morphology at tributary deltas are
addressed in RSP Section 6.6 – Geomorphology at Section 6.6.4.1.2.6.
9. Many small streams are important
for juvenile salmon rearing and may
not be accessible during low
flows. These should be included in
the survey of potential migration
barriers and included in the list of
potential study sites. Otherwise,
important fish habitat that is likely to
be affected by changes in
accessibility due to project
operations will not be assessed for
effects or development of mitigation.
The 27 tributaries to be surveyed for fish passage barriers include the largest tributaries as well
as smaller perennial tributaries that are known to support target species in the Middle River (see
Table 2 of the Fish Passage Barriers Implementation Plan).
Please see AEA’s Response to Comments 6 and 7.
6
Comment AEA Response
Section 6. Fish Passage through Devils Canyon
10. Recommendations
Target fish species and life stages for
fish barrier assessment through
Devils Canyon should be selected in
consultation with the Services.
Consistent with the February 1 SPD, the Fish Passage Barriers Implementation Plan does not
include identification of fish species and life stages for passage through Devils Canyon. This
agency recommendation pertaining to identification of fish species in these locations is beyond
the scope of the issues addressed in the Fish Passage Barriers Implementation Plan.
FERC recommends that AEA assess discharge conditions closest to Devils
Canyon during the time that salmon are documented to successfully pass
upstream of Devils Canyon passage impediments. Identification of and the
selection of salmon species for passage assessment through Devils Canyon is
included in RSP Section 9.7 - Salmon Escapement Study. Objective 1 of RSP
Section 9.7 states “Capture, radio-tag, and track adults of five species of Pacific
salmon in the Middle and Upper Susitna River in proportion to their abundance”
and Objective 2 states “Determine the migration behavior and spawning
locations of radio-tagged fish in the Lower, Middle, and Upper Susitna River.”
Section 5.8 of the Fish Distribution and Abundance Implementation Plan states that Arctic
grayling, burbot, Dolly Varden, humpback whitefish, lake trout, longnose sucker, northern pike,
rainbow trout, and round whitefish will be radio-tagged with the goal of 30 tags to each species
in the Middle and Lower River. Tracking of tagged resident fish below, within, and above
Devils Canyon is described in the Fish Distribution and Abundance Implementation Plan.
11. The probability of a tagged
resident or anadromous fish being
detected should be calculated given
the number of tags and frequency
and duration of aerial surveys and
time when stationary receivers are
operating. The lengths of all tagged
fish moving through Devils Canyon
should be recorded and the lengths
of all captured above Devils Canyon
This recommendation pertains to RSP Section 9.7 and is therefore outside the scope of RSP
Section 9.12 – Fish Passage Implementation Plan. The study methods described in RSP
Section 9.7.4 provides a detailed description of metrics to be collected on tagged fish and fish
tracking methods.
7
should be recorded.
The burst and sustained swimming
speeds of fish passing through
Devils Canyon should be observed
and/or obtained from literature
where other high-velocity salmon
rivers have been assessed and
compared to the burst and sustained
swimming speeds of other fish
species to estimate passage potential
and to develop environmental flows
that may condition the license for
protection of migrating fish.
Comment AEA Response
Section 7.2 Effects of load following on passage during ice-cover periods.
12. Recommendations
Ice process models and winter flow-
routing studies need to be linked to
the elevations and cross-sectional
area of tributary and off-channel
habitats to predict the effect of ice
formation on water velocities at
different stage heights during pre-
project conditions to assess post-
project conditions.
Within all Focus Areas, cross-
sectional surveys should be
conducted at multiple transects to
measure ice thickness and open
As described in Section 7.2 of the Fish Passage Barriers Implementation Plan, the measuring
and modeling micro-hydraulics (such as to a scale relevant to a 3-5 inch fry/juvenile salmonid)
under ice, over a broad enough area to have any relevance, is physically infeasible and would
not produce data or information that could be used to assess potential effects of the proposed
Project.
As discussed by FERC (2013a), accuracy of hydrodynamic modeling during the ice-cover
periods may or may not be sufficient to predict passage conditions at the small, local scale.
FERC states:
. . . it’s not clear if the winter model can accurately predict stage-discharge
relationships and streamflow velocities at a scale that is fine enough to evaluate the
effects of daily flow fluctuations during proposed winter load-following operations on
fish passage conditions from the mainstem into off-channel habitats…While AEA’s
proposed fish passage barrier study plan does not appear to specifically address this
issue, we assume the intensive, multidisciplinary study elements that would be
8
channel area on multiple dates
through the winter at representative
side sloughs, upland sloughs and
tributary mouths. Ice thickness and
the cross-sectional area of open
channels could be used to test for
relationships between mid-channel
ice thickness and predicted ice
cover.
Flow routing during winter
combined with measures of cross-
sectional area at tributary and off-
channel habitat mouths could be
used to predict water velocity
barriers due to load-following
operations.
implemented within the focus areas would provide some information to evaluate fish
passage conditions between the mainstem and off-channel habitats under ice cover
and load-following operations.
AEA’s proposed winter studies in Focus Areas, as described in Section 7.2 of the Fish Passage
Barriers Implementation Plan, are consistent with FERC’s findings that assessment of passage
under ice-cover conditions will likely be at a larger rather than a finer scale.
The RSP Section 7.6 – Ice Processes study objective directly supports study site and modeling
needs for juvenile fish passage during ice-cover periods. In the February 1 SPD, FERC (2013b)
stated:
AEA’s proposed modeling approach should provide the information necessary to
describe project effects with respect to ice processes to a degree which is consistent
with generally accepted practices in the scientific community (section 5.9(b)(6)) and, if
effectively implemented, is expected to be able to satisfy the study objectives.
If the initial results of the 2013 or 2014 study seasons (as documented in the initial
study report) indicate that the model does not adequately evaluate project effects, and it
becomes clear on the basis of the results that other procedures should be followed in
order to meet the study objectives, then alternative methods and/or procedures could be
added in 2014 or in subsequent study years (sections 5.15(d) and 5.15(e)).
Comment AEA Response
Section 7.3.1 Proposed Study Site for Modeling
13. Recommendations
The draft Implementation Plan
should provide proposed study
locations and a schedule for
consultation with the Services prior
to final study site selection. A
sufficient number of ice-covered
Study sites for fish passage in Focus Areas will be located at the inlets and/or outlets of upland
sloughs, side sloughs, and some side channels. Two-dimensional fine mesh hydraulics and
substrate will be collected at most of these habitat types in all Focus Areas. The
Implementation Plan has been revised to include maps of all Focus Areas showing the
delineation of off-channel types that will be included for investigation of fish passage (Figures
6-15). The upland sloughs, side sloughs, or side channels that will not be investigated for fish
passage must be determined during field reconnaissance by the fish passage barrier, the Fish
9
sites should be included in the study. and Aquatic Instream Flow study, and Geomorphology study leads. AEA will report on the
identification of these study sites during the scheduled quarterly TWG meetings and in the ISR.
Comment AEA Response
Section 7.3.2 Modeling Methods for Ice-Free Periods
14. Recommendations
Beaver dams within Focus Areas
should be surveyed so that fish
passage into and out of these
important habitats can be assessed.
Beaver dams are transient and dynamic in the Susitna River, as they are in most large rivers.
They are removed by high river flows, by ice, or are abandoned and deteriorate over time. The
beaver dam may be partially removed by flow or ice and rebuilt within a matter of days, or
alternatively, the dam may be completely removed and rebuilt in the future or never rebuilt.
Beaver are opportunistic dam builders.
As described in Section 7.5 of the Fish Passage Barriers Implementation Plan, AEA will survey
all beaver dams encountered within the zone of hydrologic influence in select tributaries and
Focus Areas as shown in Tables 1 and 2 of the Fish Passage Barriers Implementation Plan.
Survey methods of beaver dams will follow those described in RSP Section 9.9, Section
9.12.4.4. Dimensions of the dam including height, length, and breadth, and depth of the leaping
pool will be measured and observations of possible passage ways through or around the dam
will be described. Photographs will be taken. The Fish Passage Barriers Implementation Plan
at Section 7.3.2 has been modified to specify these methods at all beaver dams in Focus Areas.
Because beaver dams are transient and dynamic, it is unlikely that this assessment will be
material in analyzing potential Project effects.
15. The mouths of all tributaries
within all Focus Areas should be
surveyed and discharge measured
and gauged to evaluate fish passage
conditions under multiple pre- and
post-project flows.
Velocities should not be reported as
averages, the range of flow
velocities should be collected and
As described in Section 7.5 of the Fish Passage Barriers Implementation Plan, barrier surveys
will be conducted in all 11 tributary mouths found within Focus Areas. The 11 tributaries are
listed in Table 2 of the Implementation Plan. Two-dimensional hydraulic models of all
tributary mouths within the zone of hydrologic influence will be modeled using 2-D or 1-D
models. Tributaries within Focus Areas (Table 2) will be either gaged with continuous stage
recording instruments or they will be periodically measured at multiple flow levels to establish
a rating curve with the intent of establishing drainage-area-based accretion estimates. Section
7.3.2 of the Implementation Plan has modified accordingly.
AEA will record all point velocity measurements on data sheets when using manual meters, or
10
reported in order to characterize
passage velocities applicable to
small fish – juvenile salmonid
resident fish species.
in the case of the acoustic Doppler current profiler (ADCP), point velocities in the water
column will be recorded into the ADCP data file.
Comment AEA Response
Section 7.3.3 Modeling Methods during Ice-cover Conditions
16. Recommendations
Ice thickness and water depth should
be measured along multiple cross-
section transects or grids at the
upstream and downstream controls
and within side channels and off-
channel habitats of Focus Areas.
Measurements should be taken at
each transect at least twice during
winter. Enough transects should be
established to adequately evaluate
flow and water depth related juvenile
fish passage. Sites should include all
of the major off-channel habitats
within Middle River Focus Areas.
As described in Section 7.2 of the Fish Passage Barriers Implementation Plan, the measuring
and modeling micro-hydraulics under ice, over a broad enough area to have any relevance, is
physically infeasible and would not produce data or information that could be used to assess
potential effects of the proposed Project. See AEA response to Comment 12.
11
Comment AEA Response
Section 7.4. Description of Ice-Free Off-Channel and Tributary Delta Study Sites
17. Recommendations
The draft Implementation Plan still
needs a description of the tributaries
that will be evaluated for fish
passage, passage criteria, and
methods that will be used to evaluate
project effects to juvenile and
resident fish movement into Middle
and Lower River tributaries.
Tributaries to be evaluated for fish passage in the Middle River are included in Table 2 of the
Fish Passage Barriers Implementation Plan. This table also includes characteristics of these
tributaries that were used in selecting them. Also please refer to Response to Comments 14 and
15.
Regarding passage criteria, please see AEA Response to Comments 2 and 3.
As recommended by FERC, AEA will locate fish passage [including juveniles and resident
fish] study sites in Focus Areas. Section 7.3 of the Implementation Plan describes the models
that will be used for evaluating potential project effects to fish depth and velocity barriers.
Regarding fish passage studies in the Lower River, please AEA Response to Comment 1.
Comment AEA Response
Section 7. Identification and Location of existing Physical Barriers to Fish Passage 5
18. It is still unclear from the
combined RSP 9.12 and Draft
Implementation Plan if surveys will be
conducted throughout the Middle
River to locate and categorize all
existing fish barriers within the project
zone of influence including falls,
cascades, beaver dams, road or
railroad crossings or if the study plan
is proposing to locate and categorize
potential barriers only within the 20
tributaries listed. If only for 20 listed
tributaries, there is no assessment of
the representativeness of this sample.
Sections 7.3 and 7.4 of the Fish Passage Barriers Implementation Plan describes the
application of 2-D modeling to assess barriers in off-channel habitats of Focus Area. The
actual sites to be modeled will be determined as part of the Fish and Aquatic Instream Flow
(RSP Section 8.5) and Ice Processes (RSP Section 7.6) studies. Section 7.5 of the Fish
Passage Barriers Implementation Plan identifies 27 tributaries in the Middle River which
will be surveyed for physical barriers to fish passage within the zone of hydrologic influence
(see Table 2). These tributaries represent 34 percent of all the tributaries in the Middle River
and include both the largest tributaries and numerous smaller perennial tributaries that are
known to support target species in the Middle River.
12
19. Based upon our review of the
video, beaver dams occur most often
in upland sloughs and side
sloughs. Fish access to rearing habitat
within a beaver dam could occur
during high flow conditions that allow
passage during breaching or backwater
conditions. The total number of
beaver dams within each geomorphic
reach must be known to determine if
those located within the Focus Areas
are representative and to extrapolate
project effects on fish migration to this
habitat type to the Middle and Lower
River. All road or railroad crossings
should be surveyed to determine if
they are within the zone of project
influence, and if passage is flow
dependent. Similarly, all tributary
mouths should be surveyed to
determine low mainstem flow passage
conditions.
Regarding Agencies’ comments on beaver dams, please see Response to Comment 14.
Furthermore, AEA will identify beaver dams with high resolution aerial imagery. The
location of beaver dams also will be identified as part of the implementation of RSP 10.11 –
Aquatic Furbearer Study. AEA will use this information to map the distribution of beaver
dams in GIS. These data will also be available, as applicable, for extrapolation purposes.
Section 7.5.1 of the Fish Passage Barriers Implementation Plan has been revised to include
GIS mapping of potential physical barriers (including beaver dams) using aerial imagery.
20. The passage criteria in RSP 9.12
including the references to Powers and
Osborn, ADNR 2007, and the decision
tree have all been developed to
evaluate barriers to adult salmon
migration. As state in the Services
RSP comments, passage criteria need
to be established for juvenile salmon
and resident fish species prior to
conducting barrier surveys.
Regarding development of passage criteria, please see AEA Response to Comments 2 and 3.
Passage criteria for barrier assessment are typically applied after passage barrier field data
are collected. The parameters of a barrier, such as depth, velocity, and barrier height, are
measured independent of the criteria. The timing of the establishment of the criteria does not
impact the type of field measurements to be taken. AEA is not adopting the Services’
recommendation because it would result in unacceptable and unnecessary delays in the
collection of field data.
13
Comment AEA Response
Section 7.6 Study of Fish Passage Barriers to the Lower River
21. Recommendations
A draft study plan should be
developed for the Lower Susitna
River, identifying target fish species,
passage criteria, study methods, and
study locations.
Consistent with the February 1 SPD, the Fish Passage Barriers Implementation Plan does not
include identification of a list of target fish species, passage criteria, study methods, and
locations for study in the Lower River. This agency recommendation pertaining to the Lower
River is beyond the scope of the issues addressed in the Fish Passage Barriers Implementation
Plan.
However, as stated by FERC and quoted in the Fish Passage Barriers Implementation Plan: “If
2013 results, as presented in the [ISR], indicate that the Project will cause significant adverse
effects on fish passage into tributaries and off-channel habitats in the Middle River then
additional study sites will be added in the Lower River in 2014, or in subsequent study years
(FERC 2013).”
Following the filing of the ISR, AEA will seek the input of the TWG when determining the
need for fish passage barrier studies in the Lower River.