HomeMy WebLinkAboutAPA2919SUSITNA
.HYDROELECTRIC PROJECT
FEDERAL ENERGY·RE.GULATORY COMMISSION
PROJECT No,711-4
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C ARACTERIZATION OF
AQUATIC HA IT A TS IN THE
TALKEETNA-TO-D VIL CANYON SEGMENT
OF TH SUSITNA RIVER,ALASKA
PREPARED BY
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lJt.I>ER CONTR C TO
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SUSITNA JOINT V NTURE
FINAL REPORT
OCTOBER 188&
DOCUMENT No.2919
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SUSITNA HYDROELECTRIC PROJECT
CHARACTERIZATION OF AQUATIC HABITATS
IN THE TALKEETNA-TO--DEVIL CANYON SEGMENT
OF THE SUSITNJ~RIVER,ALASKA
Prepared by
E.Woody Trihey and Associates
and
Arctic Environmental Information and Data Center
University of Alaska-Fairbanks
Under Contract to
Harza-Ebasco Susitna Joint Venture
P~epared for
Alaska Power Authority
Document No.2919
Susitna File No.4.3.1.3
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ARLIS
Alaska Resources
Library &Infonnatl0n Servtces
Anchorage.Alaska Final Report
October 1985
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Nm~ICE
ANY QUESTIONS OR COMMENTS CONCERNING
THIS REPORT SHOULD BE DIRECTED TO
THE ALASKA POWER AUTHORITY
SUSITNA PROJECT OFFICE
ACKNOWLEDGEMENTS
This report was funded by the Alaska Power Authority as part of the licensing
studies for the proposed Susitna Hydroelectric Project.The authors
acknowledge the following Susitna Hydro Aquatic Study Team members for thei r
assistance in the preparation of this report:Shelley Williams,E.Woody
Trihey and Associates,for suggestions which improved the organization of the
rE!port;Denise Cote,Arctic Environmental Information and Data Center,and
Linda Sewright for technical editing;Bill Wilson,Arctic Environmental
Information and Data Center,for review comments;Jean Baldridge,Entrix,and-
Greg Reub,E.Woody Trihey and Associates,for field data collection;Dr.
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Alexander Milner and Diane Hilliard,E.Woody Trihey and Associates,for
technical assistance with the statistical analyses;Paul Suchanek,Alaska
Department of Fi sh and Game (ADF&G),for explanati on of ADF&G substrate and
cover codes;Wanda Seamster,Arctic Enviironmental Information and Data Center,
for graphics expertise;and Sally Healey and Cheryl Martinez,Arctic Environ-
--mental Information and Data Center,and Peggy Skeers,for diligently typing
the manuscript.
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PREFACE
The goal of the Alaska Power Authority in identifying environmentally
acceptable flow regimes for the proposE!d Susitna Hydroelectric Project is the
maintenance of existing fish resources ,and levels of production.This goal is
consistent with mitigation goals of the U.S.Fish and Wildlife Service and the
Alaska Department of Fish and Game.Maintenance of naturally occurring fish
populations and habitats is the preferrl~d goal in agency mitigation policies.
In 1982 t following two years of baseline studies,a multi-disciplinary
approach to quantify effects of the proposed Susitna Hydroelectric Project on
existing fish habitats and to identify mitigation opportunities was initiated.
The Instream Flow Relationships Studies (IFRS)focuses on the response of fish
habitats in the middle Susitna River to incremental changes in mainstem
discharge,temperature and water quality.As part of this multi-disciplinary
effort t a technical report series was planned that would (1)describe the
existing fish resources of the Susitna River and identify the seasonal habitat
requirements of selected species t and (2)evaluate the effects of alternative
pr'oj ect des i gns and operati ng scena ri os on physi ca 1 processes whi ch most
influence the seasonal availability of fish habitat.
The summary report for the IFRS t the Instream Flow Relationships Report
(IFRR),(1)identifies the biologic significance of the physical processes
evaluated in the technical report series,(2)integrates the findings of the
technical report series,and (3)provides quantitative relationships and
discussions regarding the influences of incremental changes in streamflow,
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stream temperature,and water quality on fish habitats in the middle Susitna
River on a seasonal basis.
The IFRR consists of two volumes.Volume I uses project reports,data and
p'rofessional judgement available before March 1985 to identify evaluation
slPecies,important life stages,and habitats.The report ranks a variety of
physical habitat components with regard to their degree"of influence on fish
habitat at different times of the year.This ranking considers the biologic
n~quirements of the evaluation species and life stage,as well as the physical
characteri sti cs of different habitat types,under both natural and anti ci pated
with-project conditions.Volume II of the IFRR will address the third
objective of the IFRR and prOVide quantitative relationships regarding the
influences of incremental changes in streamflow,stream temperature and water
quality on fish habitats in the middle Susitna River on a seasonal basis.
The influence of incremental changes;n streamflow on the availability and
quality of fish habitat is the central theme of the IFRR Volume II analysis.
PI"oject-induced changes in stream temperature and water qual ity are used to
condition or qualify the forecasted Y'esponses of fish habitat to instream
hydraulics.The influence of streamflow on fish habitat will be evaluated at
the microhabitat level and presented at the macrohabitat level in terms of a
composite weighted usable area curve.This composite curve will describe the
combined response of fish habitat at all sites within the same representative
group to incremental changes in mainstern discharge.
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Four technical reports are being prepared by E.Woody Trihey and Associates in
support of the IFRR Volume II analysis.The function of each report is
depicted in a flow diagram and described below .
Quantify Wetted
Surface Area
Response
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Assess the Representa-
tiveness of Modeled
and Non-modeled Sites
1
Determine Site-
Specific Hydraulic
Conditions
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Quantify Streamflow Dependent Habitat Response
Functions for Juvenile Chinook and
Spawning Chum Salmon
RESPONSE OF AQUATIC HABITAT SURFACE AREJ\S TO MAINSTEM DISCHARGE IN THE
HILKEETNA-TO-DEVIL CANYON SEGMENT OF THE SUSITNA RIVER,ALASKA
This report identifies five aquatic habitat types within the middle
Susitna River directly influenced by changes in mainstem discharge
and presents the necessary photography and surface area measurements
to quantify the change in wettE!d surface area associated with
incremental decreases in mainstem discharge between 23000 and 5100
cfs.The report also describes the influence of mainstem discharge
on habi tat transformati ons and tabul ates the wetted surface area
responses for 172 specific areas using the ten representative groups
presented in the Habitat Characterization Report.Surface area
measurements presented in thi s report provi de a basi s for
extrapolating results from intensively studied modeling sites to the
remainder of the middle Susitna River.
CHARACTERIZATION OF AQUATIC HABITATS IN THE TALKEETNA-TO-DEVIL CANYON SEGMENT
OF THE SUSITNA RIVER,ALASKA
This report describes the characterization and classification of 172
specific areas into ten representative groups that are hydro-
109i ca 11y,hydraul i ca 11y and morpho 109i ca 11y simi 1ar.Emphas is is
placed on the transformation of spE~cific areas from one habitat type
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to another in response to incremental decreases in mainstem dis-
charge from 23000 cfs to 5100 cfs.Both modeled and nonmodeled
sites are classified and a structural habitat index is presented for
each specific area based upon subjective evaluation of data obtained
through field reconnaissance surveys.Representative groups and
structural habitat indices presented in this report provide a basis
for extrapolating habitat response functions developed at modeled
sites to nonmodeled areas within the remainder of the river .
HYDRAULIC RELATIONSHIPS AND MODEL CALIBRATION PROCEDURES AT 1984 STUDY SITES
IN THE TALKEETNA-TO-DEVIL CANYON SEGMENT OF THE SUSITNA RIVER,ALASKA
This report describes the influence of site-specific hydraulic
conditi ons on the avail abil ity of habitat for juvenil e chi nook and
spawning chum salmon.Two aquat'ic habitat models are app1ied to
quantify s ite-specifi c habitat responses to incremental changes in
depth and velocity for both steady and spatially varied streamflow
conditions.Summaries of site-specific stage-discharge and flow-
discharge relationships are presented as well as a description of
data reduction methods and model calibration procedures.Weighted
usable area forecasts are provided for juvenile chinook at 8 side
channel sites and for spawning chum salmon at 14 side channel and
mainstem sites.These habitat response functions provide the basis
for the instream flow assessment of the middle Susitna River.
RESPONSE OF JUVENILE CHINOOK AND SPAWNING CHUM SALMON HABITAT TO MAINSTEM
DISCHARGE IN THE TALKEETNA-TO-DEVIL CANYON SEGMENT OF THE SUSITNA RIVER,ALASKA
This report integrates results from the surface area mapping,
habitat characterization,and hydraulic modeling reports to provide
streamflow dependent habitat response functions for juvenile chinook
and spawning chum salmon.Wetted surface area and weighted usable
area are the principal determinants of habitat indices provided ;n
Part A of the report for juveni1e chinook at each specific area and
the ten representative groups identified in the habitat character-
izati on report.Part B of thi s report provi des habitat response
functions for existing chum salmon spawning sites.The habitat
response functions contained in this report will be used for an
incremental assessment of the rearing and spawning potential of the
entire middle Susitna River under a wide range of natural and with-
project streamflows.
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TABLE OF CONTENTS
ACKNOWLEDGEMENTS II ;...
PJ~EFACE '-..
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LIST OF TABLES..............................................................................................................vi-;i
LIST OF FIGURES.............................................................................................................x
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2.,
INTRODUCTION -..
I NVESTI GA TI VE FRAMEWORK ..••......••......•...•....•...•.••.....•.
1
12
2.1 HYDROLOGIC COMPONENT........................................17
-2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
Habitat Transformation Tracking .......•..•••....•.••.
Breaching Flow •..•....~•••.•••..•.••...•.......•....•
Cross-Sectional Geometlry of Side Channel
H-ead Be rms IJ ..
Cross-Sectional Geometry of Mainstem ...•••.•.......•.
Evaluation of Upwellin!].....•....••.•.•........•..••.
17
22
25
27
28
2.2 HYDRAULIC COMPONENT.........................................29
2.2.1
2.2.2
2.2.3
Mean Re,ach Vel Dci ty ~l ,..
Substrate Size ~I ••••••••••••••••••••••••••••••
Channel Morphology ..•.,t ••••••••••••••••••••••••••••••
30
31
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2.3 STRUCTURAL COMPONENT •.•.......,..............................36
2.3.1 Structural Habitat Indiices............•.•.•.•.•.•.•.•38
3.RESULTS AND DISCUSSION ..................................•........49
3.1 HYDROLOGIC COMPONENT........................................49
3.1.1
3.1.2
3.1.3
3.1.4
3.1.5
Habitat Transformation Tracking ......••..•.•...•.•.•.
Breaching Flow ....•.....•.•.•.•......•..•..........•.
Cross-Sectional Geometry of Side Channel
Head Berms ........•.•.............................•..
Cross-Sectional Geometry of Mainstem .........•.•..•.•
Evaluation of Upwelling •.•.•...•.•.•••..••......•...•
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56
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3.2 HYDRAULI C COMPONENT.........................................60
--3.2.1
3.2.2
3.2.3
Mean Reach Velocity ..
Su,bstrate Si ze .
Channe 1 Morpho logy ..•.•.•.....•.........•............
\/i
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63
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TABLE OF CONTENTS
(Continued)
Page
3.3 STRUCTURAL COMPONENT........................................67
3.3.1 Structural Habitat Indices...........................67
3.4 DEVELOPMENT OF REPRESENTATIVE GROUPS........................68
4.FUNCTION OF RESULTS IN EXTRAPOLATION.............................83
LITERATURE CITED ..89
AIJPENDICES '... .. .. .. .. .. .. .. .. .. .. .. ...... ...... .... ..........92
Appendix 1 Specific Areas Delineated on 23000 cfs
Aerial Photography...................................92-Appendix 2 Habitat Inventory Techniques .102
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Appendix 3 Aquatic Habitat Transformations of Specific
Areas of the middle Susitna River at Several
Mainstem Discharges Referenced to 23000 cfs..........117
Appendix 4 Approximate Breaching Flows of Specific Areas
of the mi ddl e Sus i tna Ri ve r.. .•. ..•.. . . ... . . .. .... .. .122
Appendix 5 Fish Observations....................................125
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LIST OF TABLES
Table No.
1.
2.
3.
4.
Summary of the differences between the IFIM extrapo-
lation procedure for a single-thread river and that
developed for a multiple-thrE!ad river •........•••.••..•.•..
Use of black and white aeri,al photography in charac-
terization of aquatic habitat ••..••.•.•.......•.•.••••...•.
Description of Habitat Transformation Categories .••.•.•.•..
The relationship between the height (h)that water
climbs a staff when held perpendicular to the flow and
mean reach velocity ...•.•...4~~••••••••••••••••••
9
14
20
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5.Cover suitability criteria recommended for use in
modeling juvenile chinook habitat under clear water
conditions 41...............................40
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7.
8.
9.
10 •
11.
Dominant cover/percent cover rating factors •.••••.•.•••....
Channel morphology rating factors for the various
combi nations of cross-secti ana 1 geometry types that
could be represented at a specific area•....••.•..•......••
Substrate size/substrate embE!ddedness rating factors •......
Streamside vegetation rating factors ..•.••.•...........••.•
Structural habitat vari abl eSi and thei r corresponding
wei ght;ng factors 41 ..
Number of specific areas in each habitat transforma-
tion category by evaluation mainstem flow,referenced
to 23000 cfs I ..
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44
45
46
50
12.Curve slope classes of plots of wetted top width
versus discharge from measurements made at channel
head berms at 46 specific areas in the Talkeetna-to-
Devil Canyon segment of the Sus itna Ri ver ..•.•..•.•..•..•.•
13.Stage increase at selected cross sections in the
Talkeetna-to-Devil Canyon segment of the Susitna River
as mainstem discharge increases from 9700 to 23400
56
CfS I~..............................57
14.Summary of the specific areas that possess upwelling
in the Talkeetna-to-Devil Canyon segment of the
Susitna River fi..............................58
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Table No
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
LIST OF TABLES
(Continued)
Definition of subsegments within the Talkeetna-to-
Devil Canyon segment of the Susitna River .............•.••.
Major side channel complexes of the Talkeetna-to-Devil
Canyon segment of the Susitna River ......•.•...............
Representative Group I III ..
Representative Group II .•..................................
Representative Group III .
Representative Group IV ...............................•.....
Representative Group V...•.•.•.....•......................•
Representative 'Group VI •.•.•.•.•.......•...................
Representative Group VII .
Representative Group VIII .•...............•................
Representative Group IX .•...••.............................
Representative Group X..........................•.....e ••••
ix
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66
73
74
75
76
77
78
79
80
81
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F'j gure No.
1.
2.
3.
4.
5.
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6.
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LIST OF FIGURES
Page
Flow chart for the extrapolation methodology...............4
Examples of continuous and discontinuous subsegments.......7
Schematic of aquatic habitat components and descri p-
tive variables.............................................13
An indistinct side channel that becomes a distinct
side channel with decreasing mainstem discharge............18
Flow chart for classifyin'9 the transformation of
aquati c habitat types betwE!en two flows (categori es
0-10).21
Channel relationship betwE~en breach"ing flow and
habitat type in the Tal keetna-to-Devi 1 Canyon segment
of the Susitna River -.................23
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7.
8.
9.
10.
11.
12.
13.
14.
Cross-sectional geometry at the head berm of two
channels having the same breaching flow ..•.•...•.•.........
The relationship between height (h)and mean reach
velocity as depicted by the rise of the wc:.ter colL;lw
ag~i nst a staff he 1c perper:o'j cul ar tu the fl 0\'1.••••••••••••
Structural habitat index form for specific area
136.0L .
Number of specific areas in each habitat transforma-
tion category at various mainstem flows .
Representative wetted top width versus discharge plots
for each category of curve s"1 ope .•.•.•...•••...............
Derivation of a HAl versus discharge curve for a
nonmodeled specific area (SA)from the representative
curve of a modeled specific area (MS)showing:(a)
breaching flow adjustment;(b)structural habitat
quality adjustment;(c)the derived curve ................•.
,Flow chart for the stratification pathway of the
extrapolation methodol 09y ...".....•...•.•.•.•.•.•..........
Habi tat inventory form "................•.............
x
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86
88
104
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1.INTRODUCTION
The Alaska Power Authori ty has proposed the constructi on of two dams on the
Susitna River.Construction of the proposed hydroelectric project will alter
the flow regime downstream of the dam,resulting in corresponding changes to
the quality and quantity of fi sh habitat.The most pronounced i nfl uences of
the project are expected to occur in the Talkeetna-to-Devil Canyon segment of
the Susitna River (the middle Susitnal River).Two major tributaries,the
Talkeetna and Chulitna rivers,will buffer the impacts of the project
downstream of Talkeetna.
To evaluate the effects on fish habitat of this project,it is necessary to
document natural conditions.To this end,fish habitat model ing techniques
WE!re applied at a spectrum of aquatic habitats and a methodology was developed
to ext:r>apoZate results to other areas of the river.The extrapolation
methodology has three components:1)quantification;2)stratification,or
groouping of individual aquatic habitats on the basis of hydrologic,hydraulic,
and morphologic similarities;and 3)s'imulation.This report focuses on the
stratification pathway of analysis.For a detailed discussion of the
quantification and simulation pathways,see Klinger-Kingsley (1985)and
Steward etal.(1985).The basis of the extrapolation methodology is
explained below.
To apply or extrapolate the results from modeled sites to nonmodeled areas of
the middle Susitna River in order to determine the systemwide response of fish
hclbitat quantity and quality to mainstem discharge,it is necessary to assess
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the representativeness of modeled sites to nonmodeled areas.In the
application of the Instream Flow Incremental Methodology (IFIM),which is used
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in this study and described by Bovee (1982),extrapolation is typically done
by identifying segments and subsegme!nts of the subject river that are
h.l,drol ogi ca lly,hydraul i ca lly,and morplhol ogi ca lly homogeneous.By model i ng a
representative reach of a homogeneous subsegment and extrapolating to the rest
of the subsegment on a proportional le!ngth basis,it is possible to develop.-
systemwide habitat response to discharge relationships.This approach is
F""commonly applied to single-thread rivers.
Although multi pl e-thread rivers can be divi ded into homogeneous segments and
subsegments in a manner similar to single-thread rivers (Mosley 1982,Glova
and Duncan 1985),extrapolation of modeling results from representative
reaches of braided river subsegments on a proportional length basis cannot be
done routinely with reliable results (Mosley 1983).The braided river
environment is too dynamic and variable for the development of quantitative
re~lationships between discharge and physical habitat variables such as depth,
v€!locity,and channel structure on a river corridorwide basis for use in
extrapolation (Mosley 1983).
Instead,an approach for evaluating habitat is needed that focuses on portions
of the river corridor.By applying modeling techniques at individual channel
br'anches of the braided river system,the variability of the physical
environment is reduced to a level that permits the development of quantitative
relationships between discharge and physical habitat variables.This allows
the extrapolation of model results from the study reach (i.e.,representative
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r1each)to the rest of the channel bra.nch with reliable results.Even with
tlhis approach,however,the problem remains of how to extrapolate results from
modeled channel branches to the rest of the river to develop systemwide
habitat response relationships.It would be impractical to apply modeling
t,echniques at every channel branch.
lin the fisheries habitat studies of the Talkeetna-to-Devil Canyon segment of
the Susitna River,which is a large"frequently braided or split-channel
r'iver,an approach to extrapolating results from modeled sites to nonmodeled
areas of the river was developed that relies on two data bases which are
complementary but different in scope"One data base is used to develop
dletailed physical habitat models to sinmZate habitat response to discharge at
a number of channel branches representi ng a spectrum of habitat types in the
m'iddle Susitna River.The second data base is much broader in scope and
includes aerial photo coverage of the entire middle Susitna River at several
selected discharges.It also includes reconnaissance level field surveys of
sel ected phys ica 1 habitat parameters at nearly a 11 nonma instem channel
blranches and severa 1 rna i nstem channel:s.Thi s second data base is used to
(1)quantify the relationship of sUI"face area response to discharge of
individual channel branches using aerial photography,and (2)stratify or
glroup individual channel branches of the middle Susitna River based on common
hydrologic,hydraulic,and morphologic characteristics.The three components
of the extrapolation methodology (i.e.,quantification,stratification,and
s"imulation)and their integration are summarized in Figure 1.As mentioned
earlier,this report focuses on the stratification component of the
ml:thodo logy.
3
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Quantification
Quantity surface areas
of individual channel
branches in the middle
Susitna River for each
flow for which aerial
photography is avail-
able to determine the
surface area response
to mainstem discharge.
Stratification
Use available infor-
mation to stratify indi-
vidual aquatic habitats
into groups that are
hydrologically,hydrau-
1i ca lly,and morpho-
logically similar.
Int,egration
For each evaluation
species/life stage:
Integrate the quantifi-
cation,stratification,
and simul,:ition compo-
nents to determine the
aquatic habitat response
to discharge for the
entire middle Susitna
River.
Simulation
Simulate the response
of aquatic habitat
qua 1i ty to di scha rge
with habitat modeling
techniques at selected
a reas of the mi ddl e
Susitna River.
Fi gure 1.Flow chart for the extrapolation methodology.
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There are three pri nci pa 1 differences between the conventi ona 1 I FIM approach
to extrapolating model results for a single-thread river system and the
m1ethodology presented in this report for relatively complex multiple-thread
river systems.First,for multiple-thread river systems,extrapolation from
representative reaches to the rest of the homogeneous subsegment is done on a
proportional area basis rather than a proportional length basis because of the
greater variability in channel widths within homogeneous subsegments of
braided river systems.This method of extrapolation is also necessary because
of the greater variability in hydrologic and morphologic character within
homogeneous subsegments of braided r-i vers compared to thei r si ngl e-thread
counterparts.
Slecond,in the IFIM procedures for silllgle-thread systems described by Bovee
(1982),a segment or subsegment boundary is defined where there is a
s'ignificant change in channel slope,flow regime,or morphology.In the
context of the IFIM,the middle Susitna River would be considered a segment of
the Susitna River because below Talkl:etna the flow regime changes as the
Cl1ul itna and Tal keetna rivers contribute flow and above Devil Canyon the
channel morphology changes significantly.At the subsegment level the
boundaries are not so well-defined.It is at this level that there is a
dl:parture in the segmentation criteria for a braided river system as compared
to a single-thread river system.
Inspection of aerial photography provid1es ample evidence of the variability of
channel morphology in the middle Susitna River.Nevertheless,after closer
i nspecti on,even the casual observer can also identify cons i derabl e evi dence
of repetitive channel form.Examples include relatively long sinuous channels
5
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that are peripheral to the main river corridor and shorter,wider channel
branches that trace a similar path in plan form.The significance of these
morphologically similar channel branches is that they are spatially
interspersed throughout the middle Susitna River.Although morphological
similarities between parts of the rivl~r are evident,it is not possible to
identify aontinuous homogeneous river subsegments containing them,as would be
done for morphologically similar portions of a single-thread river system.
The solution to this problem,then,is to identify discontinuous homogeneous
sllJbsegments based on common hydrologic,hydraulic,and morphologic
characteri"stics (see Figure 2).This necessarily involves dividing the river
into smaller homogeneous habitat units.
In this study,nearly all the individual nonmainstem channels plus several
mainstem channels were delineated and labeled on aerial photo reproductions of
tine middle Susitna River (se.e Appendix 1).These delineated areas,termed
speaifia areas,were then analyzed using aerial photo interpretation
tl~chniques and data from reconnaissance level field surveys.By evaluating
the hydrologic,hydraulic,and.morphologic character of each specific area,
including modeled and nonmodeled sitl~S,it was possible to assess which
nonmodeled site should be associated with which modeled site.These groupings
of simi 1ar specifi c areas were termed representative groups.In the context
of the IFIM,each representative group is equivalent to a homogeneous
subsegment.The only difference between representative groups and homogeneous
subsegments is that representative groups are spatially discontinuous,whereas
homogeneous subsegments in the IFIM are spatially continuous.
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SU4t'tn.a.-Riv&r 0t!51TlMtt--,-----------------,
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Figure 2.Examples of continuous and discontinuous subsegments.
7
The third difference between extrapolation methodologies for multiple-thread
rivers vs.single-thread rivers is in recognition of the greater variability
of nonhydraul ic habitat attributes (i .e.,structural cover,substrate
composition)within representative groups of multiple-thread rivers than is·
typically associated with homogeneous subsegments of single-thread river
systems.Although hydrolo~ic,hydraulic,and morphologic similarities may be
strong enough to associate·several spec'ific areas with the same representative
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group,structural inequalities between specific areas often preclude the
conclusion that the specific areas have the same habitat value.A methodology
for adjusting the habitat value of specific areas based on structural
attributes is discussed in detail in a later section.Table 1 summarizes the
differences between the IFIM extrapolat'ion procedure for a single-thread river
and that described in this report for multiple-thread river systems.
The specific area approach to extrapolating results from modeled sites to
nonmodeled areas for multiple-thread riiver systems offers several advantages
over conventional river corridorwide extrapolation schemes.Several of these
advantages can be summarized as follows:(1)it provides quantitative
physical habitat response to disch,arge relationships focused at the
representative group level rather than river corridorwide;(2)it simpl ifies
field data collection by reducing the effort of data collection in mainstem
channels;(3)it simplifies individual model calibration by restricting
calibration to one channel at a time;and (4)it increases the reliability of
forecasts at model ed sites.Of these advantages,the fi rst and fourth ones
are of particular importance.
8
Table 1.Summary of the differences between the IFIM extrapolation procedure
for a single-thread river and that developed for a multiple-thread
river.
-
.....
-
IFIM Extrapolation
for
Single-Thread River System
Proportional length basis
Continuous subsegments
Intensively studied representative
reaches
Extrapolation from representative
reaches to associated subsegments
without adjustment
9
Extrapolation
for
Multiple-Thread River System
Proportional area basis
Discontinuous subsegments termed
representative groups
Intensively studied representative
reaches plus general reconnaissance
level survey of entire river system
Extrapo 1ati on from representati ve
reaches to associated representative
groups with adjustment to account
for inequalities in structural
habitat between specific areas
---,--,-------------------,-,------,--------------
..-
,..,.
,....
.,...
The provision of relationships between quantitative physical habitat response
to discharge at the representative group level is of key importance to the
middle Susitna River studies since representative groups are often of
d"iffering habitat value to particular'fish species.For example,in the
m"iddle Susitna River,juvenile chinook salmon (Oncorhynchus tshawytscha)have
bl~en identified as a fish evaluation species (E.Woody Trihey &Associates and
Woodward-Clyde Consul tants,1985).The most important reari ng habi tat for
juvenile chinook salmon is found in side channels,side sloughs,and
tributaries (Schmidt et a1.1984).P~n extrapolation methodology with the
capability of forecasting habitat response to a changed flow regime for
particular habitat types "is necessary in this instance to corroborate with
juvenile chinook salmon utilization data bases.River corridorwide
extrapolation methodologies do not provide this level of resolution,in
addition to the problems associated with low reliability in their forecast
capability.The extrapolation methodology developed for this study was
designed to mitigate these problems.
The disadvantages of the specific area approach to extrapolating results from
modeled sites to nonmodeled areas are primarily twofold:(l)it requires a
substantial reconnaissance level data base and aerial photo coverage;and
(2)it requires considerable analyses to develop representative groups.Since
this approach to extrapolation will be applied for the first time on the
Susitna River,many of the procedures,ana lyses,and criteri a for
discriminating representative groups had to be develop~d.
The objectives of this report are to:(1)introduce the concepts behind a new
approach to extrapolation;(2)present the analyses and procedures used for
10
characterizing individual aquatic habitats (specific areas);(3)discuss the
aquati c habitat characteri sti cs and associ ated cri teri a considered in the
deve 1opment of representati ve groups ji and (4)present the representa ti ve
glroups developed for use in the extrapolation of habitat availability "indices
flrom modeled sites to nonmodeled areas of the middle Susitna River.
-
11
~---_._._-------------------""""--------------------
....
.....
.....
2.INVESTIGATIVE FRAMEWORK
The characterization of aquatic habitat can be approached from several per-
spec:tives and performed at several levels of detail.To fulfill the objec-
tives of the analysis,the investigative framework pursued in this report is
founded on the resolution of aquatic habitat into three components:(1)
hydr'ologic;(2)hydraulic;and (3)channel structure (see Figure 3).Aquatic
habitat was resolved in this manner to:(1)provide focus to the development
of analytical procedures;(2)organize the data base into a manageable format;
and (3)be consistent with the framework established in previous studies.
Two data sources were used primarily in the aquatic habitat characterization
process:a s ite-specifi c habitat reconna i ssance data base and aeri a 1 photo-
graphy.Additional information was incorporated into the analyses 'fro~the
Alaska Department of Fish and Gamel s (AClF&G)habitat model ing program,ADF&G
fish utilization studies,and personal communications withADF&G field person-
nel.
Five field trips provided the habitat reconnaissance data:a one-day trip on
August 21,1984;a five-day trip SeptembE!r 3-7,1984;a five-day trip Septem-
ber 10-14,1984;a four-day tri p SeptE!mber 29 -October 2,1984;and a
thre1:-day trip July 23-25,1985.The corresponding U.S.Geological Survey
(USGS)Gold Creek gage discharges were approximately 18000,11000, 10000,
8000,and 25000 cfs,respectively.The one-day field trip was a trial for the
refinement of field procedures and the planning of future field work.
Obsel"vers completed a habitat inventory form for each of 172 specific areas
over the course of the two five-day field trips.During the four-day field
1 '~~-
Aquatic Habitat
.-
.-
Hydrologic
Variables
~
•Water Source
•Water Supply
Compc)nents
/
Hydraulic
Variables
l
•Energy Slope
•Water Velocity
•Water Depth
•Substrate Size
•Channel Morphology
Channel
Structure
Variables,
•Substrate Size
•Cover Type
•Percent Cover
•Substrate Embeddedness
•Channel Cross-Sectional
Geometry
•Streamside Vegetation
Figure 3.Schematic of aquatic habitat components and descriptive variables
investigated to characteri;~e aquatic habitats in the Tal keetna-
to-Devil Canyon segment of the Susitna River.
13
_._-----
-
--trip additional information was collected to verify upwelling and side channel
breaching flows as well as mean reach velocities and habitat transformation
categories.The final field trip was used to confirm representative groupings
.....of specific areas.A detailed explanation of field habitat inventory tech-
niques appears in Appendix 2.
S'lack and white aerial photography was available at discrete middle Susitna
R'iver discharges of 5100,7400,9000,10600,12500,16000, 18000,23000,and
.....26900 cubic feet per second (cfs),as measured at the USGS Gold Creek gaging
station (Table 2).An additional set of aerial photography was available
which showed winter ice conditions.
Table 2.Black and white aerial photography used in the characterization of
aquatic habitat.
Mainstem
Discharge
(cfs)Date Taken Scale Comments
("~--
150O-200O March 1983 1 in.=1,000 ft ice cover
5100 10-14-84 1 in.=250 ft open water
7400 10-04-84 1 in.=250 ft open water
9000 10-08-83 1 in.=1,000 ft some ice present
10600 09-09-84 1 in.=250 ft open water
12500 09-11-83 1 in.=1,000 ft open water
16000 09-06-83 1 in.=1,000 ft open water
18000 08-20-80 1 in.=1,000 ft open water
23000 06-01-82 1 in.=1,000 ft open water
26900 08-27-84 1 in.=1,000 ft open water
Nearly all nonmainstem channel branches plus several mainstem channels were
delinE!ated and labeled on aerial photo reproductions of the middle Susitna
River (see Appendix 1).These specific areas,usually comprised of individual
14
--
--
s·ide channels,side sloughs,and upland sloughs,were used as a framework for
the systematic evaluation of aquatic habitat.Occasionally a large side
channel or slough was subdivided into two or more specific areas due to
d'ifferences in habitat character.EaiCh specific area was referenced to a
r'iver mile (RM)and the side of the main river channel looking upstream:left
(L),right (R),or middle (M)if betwe,en two mainstem forks.A total of 172
specific areas were delineated,representing four of the six habitat types
i <tentHi ed in the mi ddl e Sus itna Ri ver by Kl i nger and Tri hey (1984).These
habitat types are described as follows:
Mainstem hab ita ts a re those channels of the ri ver tha t convey rno re than
approximately 10 percent of the total flow at a given site.During the open
water season these channels are characterized as conveying water with high
turbidity levels derived from glacial ml~ltwater.
S1.:de ohannel habitats are those channel s of the ri ver that convey 1ess than
approximately 10 percent of the total flow.During the open water season
these channels generally convey highly turbid mainstem water.
Side slough habitats contain clear water.Local surface water runoff and
upwelling groundwater are the primary sources of water in these habitats.
Side sloughs have nonvegetated berms at the upstream ends that are overtopped
dLlrin~1 periods of moderate to high mainstem discharge.Once overtopped,side
~sloughs are tonsidered side channels.
I
15
--
Upland sloughs are clearwater habitats that depend upon upwelling groundwater
al1d/OI~local runoff for their water sources.The upstream ends of upland
s']ougl1s are vegetated and are seldom overtopped by mainstem discharge.
Tributary mouths are cl earwater habi talts at the confl uences of tributaries.
In the summer these habitats are readily apparent as clearwater plumes that
extend into the turbid glacial flow of the mainstem or a side channel.The
s"ize of the plume is a function of both tributary discharge and mainstem
d"ischarge.Tributary mouth habitats can also occur in the tributary channel
as a result of mainstem stage causing a,backwater at the tributary mouth.If
a backwater occurs,tributary mouth habitat extends into the tributary channel
to the upstream extent of the backwater.
TJ,:,ibutary habitats are reaches of tributary streams upstream of the tributary
mouth habitats.
Tl~ibutary habitats were not evaluated blecause they would not be affected by an
altere!d mainstem flow regime.Neither If/ere tributary mouth habitats evaluated
because they constitute a small portion of the middle Susitna River habitat
and would not be affected significantly.
Subhabitat types were required in this analysis to be consistent with the
resolution provided by aerial photography and are as follows:
Indistinct mainstem habitats occur at the margins of some mainstem channels.
In thE!23000 cfs photography they appear to be an integral part of a mainstem
habitalt.In photographs taken at lower flows,however,they are di sti nct
16
channels separated from the mainstem by gravel bars or are shallow expanses
(shoa"ls)at the margins of a mainstem channel (Figure 4).
Indistinct side channel habitats occur'at the margins of some mainstem and
side channels.In the 23000 cfs photog raphy they appea I'to be an i nteg ra1
part of a mainstem or side channel halbitat.In photographs taken at lower
f'lows!1 however,they are distinct channels separated from the mainstem or main
s'ide channel by gravel bars or are shoals at the margins of the mainstem or
s'ide channel.The primary distinction between indistinct mainstem and
indistinct side channel habitats is flow volume as per the previous defini-
t'ions of mainstem and side channel habitats.
2.1 HYDROLOGIC COMPONENT
.....
The suitability of a given specific ar'ea as aquatic habitat is dependent on
the quantity and quality of water supplied to the site.This hydrologic
component of aquatic habitat was evaluated for each specific area using up to
f'ive indices:(l)change of habitat type,or habitat transformation;(2)
bl'eact\ing flow;(3)cross-sectional geometry of side channel head berms;(4)
cl'oss-·secti ona 1 geometry of the rna i nstE~m;and (5)the presence or absence of
upwell ing groundwater.
2 ..1.1 HABITAT TRANSFORMATION TRACKING
The development of a methodology to examine changes in habitat in reference to-diischarge is a prerequisite to the assessment of the response of aquatic
17
....
....
"""
Indistinct specific area 138.8R across from
mouth habitat at Indian River at a main stem
of 23000 cfs.
Distinct specific area 138.8R across from tributa~y
mouth habitat at Indian River at a mainstem discharge
of 9000 cfs
....
Figure 4.An indistinct mainstem channel that becomes
a distinct side channel with decreasing
mainstem discharge .
18
significant because they
.....
habitat quality
I
transformations,
to
are
mainstem flow.Changes in habitat,
demonstrate
or
the
habitat
direct
re!lationship between habitat type and quality and mainstem discharge.The
:"""most common habitat transformation occUirs when a side channel becomes a side
slough as mainstem stage recedes to a level that prevents the flow of turbid
mainstem water through the side channel entrance.Another common
-
-
-
transformati on occurs when rna i nstem habi tat becomes si de channel habitat as
mainstem discharge decreases.
Eleven habitat transformation categories were defined to describe the types of
habitat transformation that a specific area may undergo as mainstem discharge
decreases from a higher reference flow to a lower evaluation flow (Table 3).
These categories were used to systematically evaluate habitat transformations
at spE~cific areas at successive mainstem discharges for which aerial photo-
graphy was available.
Methods
Aerial Rhotography of the middle Susitna River for mainstem discharges of
5100,7400,9000,10600, 12500, 16000, 18000,and 23000 cfs was used in the
analysis.Habitat transformations at each specific area were identified
between 23000 cfs and lower evaluation flows through photo comparison,with
the 23000 cfs aerial photography used as the reference flow for all lower flow
photography.A flow chart for classifying the transformation of aquatic
habitat types between two flows appears as Figure 5.
19
Table 3.Description of habitat transformation categories.*
Category 0
..-
,
Category 1
Category 2
Category 3
(hcr'sT~1)~~;!~Jr'ioeslou,9'!1'6gbhabitattype~t;the eV~luationfl~w.
the evallJation flow
throughout winter.
the same
....
Category 4
Category 5
Category 6
Category 7
Category 8
Category 9
Category 10
hie persists throughout winter.
Any_.~_~~~'orconsists of
isolated~pool"s"w'1tho'ut habitat value at the evaluation flow.
-~~.'JlfJ1.*I;lial'~~~at theevaluationflow.
*Habitats were based on a reference flow of 23000 cfs.
20
1 -I I I 1 1 J i ))J I i
I'V
t-"
WETTED AREA OF SITE
@ 23,000 CFS
I
I I
CLEAR WATER TURBID WATER
@ 23,000 CFS @ 23,000 CFS
I I I
Side Sloughs Distinct Channel Indistinct Channel (Shoals)
Tributary Mouths Upland Sloughs @ 23,000 CFS @ 23,000 CFS
0 1
Dewatered
@ 9,000 CFS
9
Clear Water Turbid Water Turbid Water Clear Water
@ 9,000 CFS @ 9,000 CFS @ 9,000 CFS @ 9,000 CFS
I I I I I J I
With Apparent Without Apparent Side Channel Mainstem Become Distinct Remain Indistinct With Appa'rent Without Apparent
Upwelling Upwelling (Less Ihan 10%Side Channels @ 9,000 Upwelling Upwelling
of Flow)@ 9.000
2 3 4 10 5 6 7 8
Figure 5.Flow chart for classifying the trans~ormation of aquatic habitat types
between two flows (Categories 0-10).It is important to note that
habitat transformations can be monitored between any two flows of
interest.
.....
",...
.....
.-
--
For example,consider specific area 139.5R (p.75).This specific area can be
described as a broad,relatively shallow expanse of turbid water that is not a
distinct channel (indistinct)at 23000 cfs.Comparison of the 23000 and 18000
cfs aerial photography reveals that specific area 139.5R persists as an
indistinct turbid water channel at 18000 cfs.From Table 3 it would thus be·
classified into habitat transformation category 6 at the 18000 cfs evaluation
flow.This procedure can be repeated for each successively lower evaluation
flow,always with reference to the 23000 cfs aerial photography.If this is
done for specific area 139.5R for evaluation flows of 18000,16000,12500,
10600,9000,7400,and 5100 cfs,a habitat transformation category sequence of
I6-6-6 J 5-5-7-7 will result.With reference to Table 3,this sequence indicates
that specific area 139.5R is an indistinct channel at mainstem discharges of
12500 cfs and above,a well-defi ned channel at flows between 10600 and 9000
cfs,and side.slough habitat at flows between 7400 and 5100 cfs.For the
purposes of thi s study,the habitat transformati on category sequence of a
specific area can be abbreviated to display only the changes in habitat type
that occur.For specific area 139.5R this would be 6-5-7.The habitat
transformation category sequence is thus a concise reference of habitat types
occurring at a specific area as well as a useful index of the site-specific
hydrologic process.
2.1.2 BREACHING FLOW
In addition to habitat transformation sequence,breaching flow is useful in
describing and classifying specific arleas.It is the""'"';.~',.'-"',~,'i••,'..~:iil,>~
and also identifies the relative position of
specific area habitats in the hydrologic spectrum between mainstem and upland
slough (Figure 6).
22
BREACHING FLOW
(CFS)
HABITAT TYPE 1
"""
UPLAND SLOUGH
35000
25000
SIDE SLOUGH
15000
,.,..SIDE CHANNEL
5000
~
r1AI NSTEM
1.refers to the habitat type that occurs most
frequently at a specific area during the open
water season.Actual habitat type at a specific
area depends on mainstem discharge •
.....
Figure 6.General relationship between breaching flow and
habitat type in the Talkeetna-to-Devil Canyon
segment of the Susitna River.
23
.....
I
Breaching flow is defined as the mainstem discharge at which the water surface
elevation (stage)in the main channel is sufficiently high to overtop the head
berm of a peripheral channel and allow mainstem water to flow through the
area.Not all specific areas have readily identifiable breaching flows,and
some areas are breached gradually over ,a range of mainstem flow.For example,
the overtopping of mainstem and side channel shoals is frequently a subtle
process as water laterally inundates these areas with increasing stage.Water
seldom overtops heads of upland sloughs because of their elevation relative to
the mainstem,while mainstem channels are always breached.
Methods
The series of black and white aerial photography from 5100 to 26900 cfs was
used as a visual reference frame for estimating breaching flows for specific
areas.Breaching flows were interpolated between photographed flows using
interpretive judgement and information provided by field observations where
applicable.For example,if a specifiic area was breached in the 18000 cfs
photography and nonbreached in the 16000 cfs photography,the breaching flow
.-was estimated between these flows.Interpretive judgement as to IIhow
,-breached ll the area appeared in the 18000 cfs photography refined the breaching
flow estimate.It was not possible to refine breaching flow estimates for
specific areas that breached significantly below 5100 cfs because of the lack
of available information.Some specif'ic areas appeared IIbarely breached ll in
the 5100 cfs photography,and breaching flows slightly below 5100 cfs were
estimated for those sites.Breaching flow estimates above 26900 cfs relied
exclusively on available ADF&G field information.
24
r 2.1.3 CROSS-SECTIONAL GEOMETRY OF SIDE CHANNEL HEAD BERMS
I
Just as breaching flow is an index of flow frequency in a specific area,the
cross-sectional geometry of the channel at the head berm determines the
magnitude of flow at the site.Breaching flow and channel geometry might thus
be considered an index of what would normally be termed climatic and basin
characteristics in conventional basin hydrology.The significance of the
cross-secti onal geometry at the head bl:!rm of channels in cl ass ifyi ng aquati c
habitat can be summarized best by examining the hypothetical flow apportion-
ment to two parallel channels with comparable breaching flows but different
cross-sectional geometry (Figure 7).Note that for the same increase in stage
at the head berm,a channel that is broad with gentle-sloping sides will
receive more now than a channel with a relatively narrow cross-sectional
geometry.The wetted surface area of the broad channel will likewise be
-
.-
greater than that for the narrow channel,and will increase at a faster rate
per incremental increase in stage.In short,the broad channel will provide
more,but less stable,aquatic habitat per unit of mainstem stage than will
the narrow channel.In a hydrologic sense,the broad channel would be termed
responsive or perhaps,Ilflashy."
Understanding the hydrology of individual channel branches is a prerequisite
to the development of representative ~lroups.Towards this end,a study to
identify the characteristic site-specific flow to mainstem discharge response
associated with the cross-sectional gl20metry of middle Susitna River side
channels was undertaken.Because of limitations in the aerial photo coverage
of the middle Susitna River,it was not possible to study the cross-sectional
geometry of every specific area.Instead,the objective was to develop a
25
J I J J .1 1 1 I )]1 I 1
1
d --=-FLAT~~~I
!Co-.-.«>w
d··
I-
U
W
VI
~
VIo
~
LJ I -:;:I I , I I I I I I I , I I I I , I I I I , I I I I J
TOP WIDTH (FT.)
LEGEND
Hater surface
VI
Z
o-.-.
0:(
~
-l
W
-I«z:o-.-.uw
VI
I
VI
VIo5[
J J I 1 I t I I I , I I I • , ) I I I , , I 1 1
TOP WIDTH (FT.)
Figure 7.Cross-sectional geometry at the head berm of two channels having the same breaching flow.Note
how differences in cross-sectional geometry affects the rate of wetted surface area development
for a comparable increase in mainstem stage,
,...,
qualitative appreciation of the types and range of site flow response that
could be expected at middle Susitna River specific areas.This information
aids the subjective consideration of cross-sectional geometry in the develop-
ment of representative groups.
Methods
The wetted top widths at the head berm of 46 distinct side channels were used
in the analysis of channel cross-sectional geometry.The project team iden-
tified the head berm for each channel using the 5100 cfs aerial photography,
and wetted top width at the head berm cross section was measured at all
photographed flows with a 40-division-per-inch scale.Top width versus
mainstem discharge was then plotted for each channel and subjectively
classified as steep,moderate,flat,or irregular,based on the characteristic
slope.
2.1.4 CROSS-SECTIONAL GEOMETRY OF MAINSTEM
An analysis of available cross-sectional geometry in the mainstem was per-
formed in conjunction with the site-specific analysis of channel geometry.
The rate of dJange in mainstem water'surface elevation to an incremental
increase in discharge varies between mainstem reaches.A reach of the
mainstem that is constricted will have a steeper stage/discharge relationship
than one that is less confined.The effect on side channels adjacent to
constricted areas is an increase in responsiveness of site flows to incre-
mental changes in mainstem discharge.The opposite is true for side channels
associated with reaches where the mainstem stage/discharge curve is flatter.
27
This analysis was undertaken to supplement the understanding of site flow
response gained from the study of cross-sectional geometry of side channel
head benl1s.The results will further aid the evaluation of the effects of
cross-sectional geometry on specific aY'ea hydrology and will be considered in
the development of representative groups.
Methods
Mainstem cross-sectional data from R&M Consultants (1982).was analyzed over a
stage increase from 9700 to 23400 cfs at selected cross sections distributed
throughout the middle Susitna River.The difference between the 9700 and
.23400 cfs water surface elevations at each section was scaled and the resul-
tant stage increase was recorded in feet.
2.1.5 EVALUATION OF UPWELLING
The presence of an upwelling groundwater source that persists through winter
is the most important habitat variable influencing the selection of spawning
areas by chum salmon (Q.keta)(Estes clnd Vincent-Lang 1984).Upwelling also
has a positive influence on the success of overwintering juvenile chinook
""'"salmon as well as on egg-to-fry survival for chum salmon (Vining et al.1985).
Methods
The project team examined each specific area in the winter photography for the
presence or absence of open leads in the ice cover.While open leads can be
28
caused by high velocities,it was assumed that leads were caused by the heat
of upwelling groundwater.The presence of clear water in the 5100 cfs photo-
graphy also suggested upwelling in many areas.
Field observers made on-site evaluations at each specific area.In clearwater
areas,upwellintg was indicated visually by the presence of small volcano-like
structures in the substrate caused by upwelling flow.The presence of upwell-
ing was difficult to determine in most breached areas because the turbidity
restricted visibility.Upwelling in these specific areas was determined
primarily by the evaluation of aerial photography.Site visits provided the-opportunity to evaluate whether open lleads visible in the winter photography
were caused by velocity or groundwater upwellings.
2.2 HYDRAULIC COMPONENT
-While the hydrologic component of an aquatic habitat may indicate favorable
conditions for fish,the site's suitability for fish may be limited by
hydraulic,or ,energy-related,conditions,such as high velocities.Three
indices of hydr'aulic energy were used in characterizing specific areas for
this report:(1)estimated and measured mean reach velocity;(2)dominant bed
material size;and (3)channel morphology.While slope is the conventional
index of the rate of energy required to move water and sediments downstream in
an open channel,due to the large number of side channels,it was impractical
to determine the slope of each channel by differential leveling.Therefore,
these particular indices were chosen.
29
_______________,-.--=_=...._=_,_.-I>t --_
.....
2.2.1 r~EAN REACH VELOCITY
In the hydraul i c component.mean reach velocity offers the best estimate of
channel slope with the additional advantage of being a significant index of
habitat quality.The weakness of mean reach velocity as an index of slope.
however.is its dependence on flow.A comparison of mean reach velocities of
several individual channels,therefore,is meaningful only if the relationship
between mean reach velocity.site-specHic discharge.and mainstem discharge
is understood.Generally,it is necessary to collect mean reach velocity data
at several mai nstem and si te-specifi c di scharges to adequately describe thi s
relationship.However,site-specific breaching flow defines the highest
mainstem flow in which site-specific discharge and mean reach velocity have a
magni tude of approximately zero.Breachi ng flows can thus be used to norma 1-
ize mean reach velocity values with respect to mainstem discharge and provide
a basis for comparing velocities of specific areas that have different
breachi ng flows ..
Other variables,such as differences in channel bed roughness (n,dimension-
less)and hydraul ic radius (R.in fleet)affect the relationship between
velocity (V.in feet per second (fps).and channel bed slope (5,in feet per
feet).Channel bed roughness is an emp"irical energy loss coefficient.and the
hydraulic radius is a function of stage and channel cross-sectional geometry,
although for wiide channels it is efflectively dependent on depth of flow.
Manning ' s Equatiion relates the variables as follows:
30
.....
.....
Mean reach velocities used in conjunction with corroborating evidence,such as
substrate size and channel morphology,reveal much about channel hydraulics.
Methods
Three methods were used to determi ne mean reach vel oci ty.The fi rst method
involved estimating the surface velocity by recording the time it took a
floating object to travel a known distance.The mean reach velocity was
estimated as 85 percent of this surface velocity (Linsley and Franzini 1979).
The second method involved measuring the height (h)that water II c limbed ll a
survey rod held perpendicular to the flow (i.e.,potential head).The
relationship bE~tween h and mean reaclh velocity is depicted in Figure 8.
Tabulated values of velocity corresponding with particular heights appear in
Table 4.On rare occasions,a Marsh McBirney Type 201 portable current meter
with wading rod was used to measure velocity.Velocity was measured at a
point 0.6 times the depth from the water surface elevation for depths less
than or equal to 2.5 ft.Velocity was determined as the average of
measurements made at 0.2 and 0.8 times the depth from the water surface
elevation for depths greater than 2.5 ft.The t~arsh McBirney was used
primarily to check the accuracy of the two approximate methods of estimating
mean reach velocities.
2.2.2 SUBSTRATIE SIZE
Substrate,or bed material size,is also related to channel slope,as can be
deduced from tnl.ctive force theory (Chm'J 1959):
31
---_._-------_._-------------~n=pm--------
.....
I
v =J 2gh
g =32.2 ft/sec 2
h =height in feet (ft)
water level
------~~-_.-----
flow direction
Figure 8.The relationship between height (h)and mean reach velocity as
depicted by the rise of the water column against a staff held
perpendicular to the flow.
Table 4.The relationship between the height (h)that water climbs a staff
~~hen held perpendicular to the flow and mean reach velocity.
Height (ft)Velocity (fps)Height (ft)Velocity (fps)
-0.01 0.8 0.14 3.0
0.02 1.1 0.15 3.1
0.03 1.4 0.15 3.2.....0.04 1.6 0.17 3.3!
I 0.05 1.8 0.18 3.4
0.06 2.0 0.19 3.5
~0.07 2.1 0.20 3.6
0.08 2.3 0.21 3.7
0.09 2.4 0.22 3.8
0.10 2.5 0.24 3.9
0.11 2.6 0.26 4.1
0.12 2.8 0.28 4.2
0.13 2.9 0.30 4.4
r
32
....
tc ='6 YS
where tc =tractive force,pounds per square foot (psf)
I =unit weight of water,pounds per cubic foot (pcf)
Y =depth (ft)
S =energy slope (ft/ft)
Tractive force is the force that water exerts on the channel bed.The
threshold size of bed material that can be moved is directly proportional to
tc.
~~here tc =d s (~s -~)Fs (Shields 1936)
ds =particle s'ize (ft)
Os =specific wl~ight of sediment (pcf)
Fs =dimensionless shear stress
Bed material sizes larger than the threshold size associated with a typical
-high flow event would theoretically makl~up the substrate •
.....
The elevation,configuration,and ori entati on of head berms strongly affect
the composition and size range of sediments delivered by mainstem flow into
side channel areas.Local geology and alluvial deposits also influence the
substrate compos iti on of si de channel beds.Smaller suspended sediments,
skimmed from th~~upper portion of the mainstem water column,tend to dominate
the sediment load entering side channels.
Despite these considerations,characteristic bed material size can be useful
in the assessment of available energy in individual channels.Large substrate
would suggest a steep channel gradient,whereas accumulation of fine substrate
33
,---~------~~--------------------
in side channe~ls and side sloughs is indicative of a mild (or low energy)
channel slope.
-Methods
Field observers coded the characteristic size of the bed materials of a
specific area IIJsing methods and codes described in Estes·and Vincent-Lang
(1984).Frequently,more than one code was selected because of the evenly
balanced mixture of fine and coarse substrate size classes at many specific
areas.The substrate type and corresponding code numbers are presented in
~
Appendix 2.
2.2.3 CHANNEL MORPHOLOGY
Channel morphology is the least direct index of instream hydraulics considered
in the analysis.The rationale for its use is that since the form of a river
is a function of river processes,river reaches undergoing similar processes
would be expected to display similar form.There is little precedent in the
1 iterature concerning the relationships between conventional morphological
indices of rivE~r form,such as sinuosity or radius of curvature,and site-
specific characteristics of individual side channels in a split channel or
braided river such as the Susitna.Nonetheless,careful inspection of aerial
photography reveals considerable evidence of repetitive form throughout the
middle Susitna River.
Specific areas may be grouped subjectively and through statistical analyses
that focus on correlating the morphologic variables that comprise the plan
-34
form of an area (such as channel length,channel width,and channel
sinuosity).St,atistics may also be applied to identify the variable that most
strongly defines each group.In this study,statistics were used to corrobo-
~rate subjective groupings of specific areas based on channel morphology.
Methods
-
Plan form analysis of each distinct side channel entailed measurement of
selected physical parameters,such as angular orientation to the mainstem,
total length,straight line length from channel head to mouth,and representa-
tive bankfull top width.Length and width were measured using a Numonics
Corporation Electronic Graphics Calculator and Model 2400 Digi Tablet from
aerial photographs that had been enlarged to a scale of 1 inch =250 feet.
Orientation angle was determined by drawing two lines,one parallel to the
mainstem flow,and one parallel to the flow of the side channel near the head.
The inside angle formed by these lines Iwas measured using a protractor.
Sinuosity was calculated for each specific area as the ratio of total channel
length to straight-line length between channel head and mouth.A straight-
line channel has a 1:1 ratio.This ratio increases with increased sinuousity.
Channel length-to-width ratios were also calculated for each specific area.
~OllOWing 'groups of variables were subject to cluster analysis using
Ward's method:length,width,length-to-width ratio,sinuosity,and number of
bends.These iinalyses were followed by a discriminant analysis using the
direct entry mE!thod.The number of cases (specific areas)utilized in the
analysis was limited to 70 distinct side channels.
-35
----------_-.-."M------.----....,~-----------.--------
.....
-
.....
.....
-
Cluster analysis is undertaken to sort cases into groups such that the degree
of association is high between member's of the same group and low between
members of different groups (Wi shart 1978).'Seven cl usteri ng methods are
available from the SPSS-X package (Statistical Procedures for the Social
Sciences -Vers·ion X):Between groups ,average,within groups average,single,
complete,centroid,median,and Ward.Of these seven methods,Wishart (1978)
considers Wardls method the best method for finding minimal variance spherical
clusters.Wardi's method was used in this study to identify groups of specific
areas that are morphologically similar.Once well-defined clusters are formed
from a cluster analysis,it is possible to determine which variables con-
tribute most to their separation.A suitable approach is to set up discrimi-
nate functions using a multiple-discriminant analysis.The weighting
coefficients (standardized discriminant functipn coefficients)for each of the
variables identHythose which contribute most to the separation of the groups
along each respective function (Klecka 1975).Numerical values give the
percentage varicinces that are accounted for by each function.Signs for the
coefficients indicate whether the variables are positively or negatively
correlated.Multiple discriminant function analysis was used in this study to
identify the most important variables for the discrimination of
morphologically similar groups.
2.3 STRUCTURAL COMPONENT
While site-specHic hydrologic and hydY'aulic indices are a ratiofial approach
to defining representativeness in terms of instream hydraulics,the structural
component is ne€!ded to consider the variation in aquatic habitat quality that
36
.....
....
results from dlifferences in nonhydrau1ic attributes between specific areas.
This component is defined as the physical formation of the channel bed,which
includes vegetation,debris,deadfall,sediments,etc.The evaluation of
structural COVE!r is an important habitat component influencing the dis-
tribution of juvenile salmon (Reiser and Bjornn 1979>,and therefore is a
prerequisite to the development of habitat assessments.
In the IFIM,the structural component lis typically described and incorporated
into the analysis using a number of substrate and cover codes depending on the
species/life stage and river system undler study.In the middle Susitna River,
cover codes developed by ADF&G (Suchanek et a1.1984)were used to describe
structural cover at study areas.CoveY'suitability data for juvenile chinook
salmon were then used to develop weighting factors for the evaluation of the
relative contrilbution to overall habitat quality of the various cover types.
By combining structural habitat weighting factors with hydrologic and hydrau-
lic input,a comprehensive physical habitat simulation model was developed for
each study area ..
Structural variables such as debris,deadfall,boulder,and vegetative cover
are frequently the result of localized conditions within a river corridor,
such as those of topography,soils,geology,or channel morphology.Bed
material size may also vary from one r'each to another,even within areas of
relatively uniform channel gradient (de Leeuw 1981).In a multiple-thread
river system such as the Susitna,structural diversity is increased because of
differences between channel branches.Braided river channel branches are of
37
----------..,..,.._._._.-----------------
.....
variable size and habitat character depending on local conditions and their
relative position in the river's geomorphic regime.Where a single-thread
river will often show characteristics of increased'geographic maturity as one
moves from the headwaters to its mouth (Lane 1955),a braided river w.ill
display longitudinal and lateral variation in age characteristics as channel
migration leaves a history of remnant,peripheral,and mainstem channels along
the same cross section •
2.3.1 STRUCTURAL HABITAT INDEX
To extrapolate habitat modeling results from study areas,the association of
channel branches of a common geomorphic regime into representative groups
significantly reduces the hydrologic,hydraulic,and morphologic disparity
between portions of the river.However,field observations substantiate the
expectation that,due to spatial variation,similar channel branches display a
certain amount of structural di versi ty withi n the same representati ve group
according to local conditions (e.g.,topographic,geologic,morphologic,
etc.).Consequently,a means was devised by use of a structural habitat index
(SHI)to comparatively evaluate and weight the structural habitat quality of
each specific area within each representative group.With this index,
extrapolation of modeling results can be done within representative groups
from modeled specific areas to nonmodE!led specific areas with an adjustment
for differences in structural habitat quality.
38
_________.....r~'~r_----=------~---------_
The basic premise behind the concept of the structural habitat index is
simple.If two channels have comparable hydraulics and hydrology and
different habitat values,the difference in habitat value must be attributed
to differences in channel structure.Outwardly,this is a simplistic con-
clusion which does not address the possible effects of differences in water
quality,nutrient loading,site location,and other environmental variables.
However,when ct judicious evaluation 'is made between sites within the same
stream subsegment,many of these variables can be considered constant,or of
secondary,or even minor,importance.
Methods
Structura 1 habitat i ndi ces (SHI)reprE~sent the synthesi s of si x structural
-habitat variables into a single value:dominant cover;percent cover;sub-
strate si ze;substrate embeddedness;channel cross-secti ona 1 geometry;and....
streamside vegetation.The procedure to deri ve structural habitat i ndi ces
involves three steps:(1)rating the affect of each variable on juvenile
chinook salmon habitat quality for each specific area;(2)ranking the rela-
tive importance of each variable to juvenile chinook salmon habitat quality;
and (3)combining rating and weighting factors into a structural habitat index
for each specific area.An explanation of each step follows.
Informati on obtai ned from habitat inventory and aeri a1 photo procedures was
the basis for rating each structural habitat variable.The precision of this
information permitted the rating of each variable into the following
categories:excellent,good,fair,poor,and nonexistent.These rating
39
-
categories were assigned numerical values of 1.0,0.75,0.50,0.25,and 0.0,
respectively.
Dominant cover and percent cover were rated as a variable combination to allow
for the use of ADF&G clearwater cover suitabil ity criteria for juvenile
chinook salmon in the rating process (Table 5).Clearwater criteria were
selected rather than turbid water criteria because of their independence from
the influence of turbidity as a cover variable.The clearwater criteria were
thus assumed to be more directly related to structural cover as described by
domi nant cover and percent cover codes (see Appendi x 2).Juvenil e chi nook
salmon criteria were used because they are a primary evaluation species in
middle Susitna River instream flow studies (E.Woody Trihey &Associates and
Woodward-Clyde Consultants,1985).
Table 5.Cover suitability criteria recommended!for use in modeling juvenile chinook habitat
~under clei3rwater conditions in the Susitna River (Schmidt et al.1984)•
COVER TYPE
Cobble or
Percent No Emergent Aquatic Large Rubble Boulders Debris &Overhanging Undercut
Cover Cover Veg.Veg.Gravel 3"'-5"5"Deadfall Riparian Banks
Clear Water (ADF&G)
P"'"'0-5'0.01 0.01 0.07 0.07 0.09 0.09 0.11 0.06 0.10
6-25%0.01 0.04 0.22 0.21 0.27 0.29 0.33 0.20 0.32
26-50%0.01 0.07 0.38 0.35 0.45 0.49 0.56 0.34 0.54
51-75%0.01 0.09 0.53 0.49 0.63 0.69 0.78 0.47 0.75
76-100%0.01 0.12 0.68 0.63 0.81 0.89 1.00 0.61 0.97
40
"The suitability criteria for'cover ",/ere rated by dividing the range of
suitability index values into discrete intervals,each corresponding to a
rating factor,as follows:0.0 (nonexistent),0.01-0.10 (poor),0.11-0.30
(fair),0.31-0.50 (good),and 0.51-1.0 (excellent).The professional judge-
ment of EWT&A and AEIDC staff biologists was used to establish these
intervals.The rating factors for dominant cover and percent cover codes for
each specific area were obtained by clalssifying the corresponding suitability
index into one of the above intervals.A matrix of dominant cover and percent
cover rating factors appears as Table 6.
Channe 1 cross-sectional geometry was evaluated as a structural habitat va ri-
able on the bas~is of the approximate proportions in which three general types
I"""of channel cross-secti ana 1 geometry were represented at each speci fi c area.
The three cross-·sectional types are as follows:(l)broad cross sections with
gentle-sloping banks;(2)cross sections with one gentle-sloping bank and one
steep bank;and (3)cross sections that are incised with two steep banks.The
fi rst cross-secti ona 1 geometry type has a pas iti ve carrel ati on with habitat
.....41--v_~..,...._~,
ijj!Wlll,
availability fOI'"juvenile chinook salmon by providing proportionately larger
areas along channel margins where edge effects retard velocities to suitable
levels.Velocity suitability criteria for juvenile chinook indicate that
suitability decreases as velocities become greater than 0.35 fps for turbid
conditions and 0.65 fps for clearwater conditions (Suchanek et al.1984).
Cross-sectional geometry with one gentle-sloping bank was rated half as
valuable as cross-sectional geometry with two gentle-sloping banks.Incised
cross-secti ana 1 geometry wi th steep banks received a zero rating factor.
-Streambank slope!codes (see"Appendix 2)and aerial photo interpretation were
used to evaluate the cross-sectional geometry of each specific area.Pro-
portions for the three types of channel cross-sectional geometry were allo-
cated into the following categories with the sum for a given specific area to
equal 1.0:0,0.25,0.50,0.75,and 1.00.Table 7 lists rating factors for
.-the various combinations of cross-sectional geometry types that could be
represented at a specific area .
.....
Table 7.Channel cross-sectional geometry rating factors for the various combinations of
cross·sectional geometry types that could be represented at a specific area.
Channel Cross·
secti onal
Ceometry Type Proportion of Cross-sectional Ceometry Type
2 gentle-
sloping
sides
1 gentle-
sloping
side
2 steep
sides
1.00 0.75 0.75 0.50 0.50 0.25 0.00 0.50 0.25 0.25 0.00 0.25 0.00 0.00
0.00 0.25 0.00 0.50 0.25 0.75 1.00 0.00 0.50 0.25 0.75 0.00 0.25 0.00
0.00 0.00 0.25 0.00 0.25 0.00 0.00 0.50 0.25 0.50 0.25 0.75 0.75 1.00
=---========:======---======-----==========--===========
Rating
Factor 1.00 1.00 0.75 0.75 0.75 0.75 0.50 0.50 0.50 0.50 0.50 0.25 0.25 0.00
42
:tW7M;;;t=taw_
....
....
,~
-
The channel cross-sectional geometry rating factors assume that velocities
I
prohibitive to juvenile chinook salmon occur in the primary flow corridor of
each specific area.While this is trUE!for the preponderance of side channel
habitats during breached conditions in the middle Susitna Rive.r,it is not
true for upland sloughs and side channel habitats that are nonbreached.For
this reason,upland slough habitats,which seldom have velocities that are
prohibitive to juvenile chinook,WerE!all rated as excellent for channel
cross-sectional geometry.This e1im"inated cross-sectional geometry as a
di scriminating factor of structural halbitat qual ity between up1 and sloughs.
Side channel hi~bitats were evaluated for breached conditions only,when it
could be assumed that cross-sectioncl1 geometry was correlated with the
availability of channel margin habitats possessing suitable velocity for
juvenile chinook salmon.The nonbreached phase of side channel habitats (side
slough habitat)is less heavily utilized by juvenile chinook salmon (Schmidt
et a 1.1984)•
Substrate size and substrate embeddedness are important descriptors of the
predominant constituent of a channel's bed material.Suitability criteria
indicate that increased substrate siz.e increases cover va 1ue for juvenile
chinook (Stewar'd 1985)by providing larger velocity breaks and more inter-
stiti a1 space for refuge.Substrate embeddedness,whi ch imp1 i es a 1a rge
streambed elemE!nt partially buried in a finer substrate material,has an
inverse relationship to structural habitat quality.In the middle Susitna
River,sand and silt are widely distributed and frequently fill a portion of
the interstitial space between coarse substrate size classes.This reduces
theinterstitia.l space available for occupancy by juvenile chinook and,in
heavily embedded areas,smooths the streambed,eliminating velocity breaks and
increasing flow velocity.
43
~__•m~",••m.....,z,~-----_
Substrate size and embeddedness were coded in the field (see Appendix 2)and
rated as a variable combination.Ratin9 values similar to suitability factors
for the cover variable combination of substrate size/percent cover reported by
Steway'd (1985)were incorporated into a.rating table (see Table 8).Differ-
ences between the rating table for substrate size/embeddedness and substrate
size/percent cover i ncl ude the incorporati on of more substrate si ze cl asses
into the former.Bed material in side channels of the middle Susitna River
varies in size from silt to boulders and it was essential to describe
substrate character as accurately as possible.Suitability factors for
substr'ate size/percent cover include only three size classes:large gravel
(1-3"),rubble (3-5 11
),and cobble/bouldE:r (>5 11
).Rating factors for substrate
size classes finer than large gravel were derived based on field experience,
professional judgement,and interpretation of the trends of coarser substrate
size suitability factors.
Table 8.Substrate si ze/substrate embeddedness ri~ti ng factors.
Substrate Substrate Size Code
Embeddedness
COd4~2 3 4 5 6 7 8 9 10 11 12 13
1 0.00 0.00 0.00 0.00 0.00 0.25 0.25 0.25 0.50 0.50 0.50 0.50 0.50
2 0.00 0.00 0.00 0.00 0.25 0.25 0.25 0.50 0.50 0.75 0.75 1.00 1.00
3 0.00 0.00 0.00 0.25 0.25 0.50 0.75 0.75 1.00 1.00 1.00 1.00 1.00
Stream~ide vegetation codes (see Appendix 2)and aerial photography were used
to evaluate the extensiveness of streamside vegetation for each specific area.
Channel width was also considered in the evaluation of rating factors because
the relative effect of streamside vegetation on overall channel habitat
44
-
quality is a function of width.Streamside vegetation as a structural habitat
variable affects shading,terrestrial insect import,and bank stability.
Vegetcltion as a cover parameter is included in the dominant cover coding
discussed earlier.The rationale behind the assignment of rating factors is
reflected in Table 9.Actual ratings of streamside vegetation were assessed
for each specific area based on professional judgement.
Table 9.Streamside vegetation rating factor.
Rati ng
Factor
Narrow Channel/Extensive Vegetation
Moderate Channel Width/Extensive Vegetation
Moderate Channel Width/Moderate Vegetation
Wide Channel/Extensive Vegetation
Wide Channel/Moderate Vegetation
1.00
0.75
0.50
0.25
0.00
.....
After each structural habitat variable/variable combination was rated,it was
necessary to weight the relative importance of each variable/variable com-
bination to overall structural habitat quality.As there is a negligible
amount of information in the literature pertaining to weighting schemes of
habitat variables,development of the clriteria to accomplish this task was not
straightforward.Hynes (1970)notes that it is generally recognized that
temperature,water quality,water depth and velocity,cover or shelter,and
streambed material are the most important physical variables affecting the
amount or quality of riverine fish habitat.Gorman and Karr (1978)suggest
that three physical habitat variables are important in the microhabitat
specialization of stream fishes;thesle are substrate,depth,and current.
Binns and Eiserman (1979)included cover,stream width,bank stability,and
45
....
substrate among nine habitat attributes used in a regression model developed
"to predict trout standing crop in Wyoming streams.In the final analysis,the
criterion used to weight the relativE!importance of the habitat variable/
variable combinations on overall structural habitat quality for juvenile
chinook salmon was that of corroboration between resulting structural habitat
i ndi CE!S and subjective habitat quality eva 1uati ons recorded on habitat i nven-
tory field forms.This corroboration was satisfied by the following weighting
cover/percent cover (0.45);(2)channe'J cross-sectional geometry (0.30);(3)
dominatnt substrate size/substrate embeddedness (0.20);and (4)streamside
vegetation (0.05).A summary of the weighting factors for each variable/
-scheme for the respective variable/variable combinations:(1)dominant
....
variable combination appears as Table 10.
Table 10.Structural habitat variables and their corresponding weighting
factors and order of importance .
Habitat Variable
Dominant Cover/Percent Cover
Channel Cross-Sectional Geometry
Substrate Size/Substrate Embeddedness
Streamside Vegetation
Weighting
Factor
0.45
0.30
0.20
0.05
....
Rati ng and wei ghti ng factors were combi ned ina matrix that provi ded a con-
venient form for evaluating structural habitat indices.For example,consider
specific area 136.0L.This specific area is a small side channel with a
domi nant cover code of 7,percent COVE!r code of 2,cross-secti ana 1 geometry
described as 75 percent 2 steep sides,l~5 percent 1 steep side,substrate size
46
"""
code of 8,and a substrate embeddedness code of 2.Streamside vegetation was
judged to be fair.From Table 6,dominant cover/percent cover receives a
ratinl~of good.Channel cross-sectioni~l geometry is rated as poor (Table 7)
and substrate size/substrate embeddednl~ss is rated fair (Table 8).Figure 9
demonstrates the use of the structural habitat index form to combine rating
and wl~ighting factors into a SHI value for specific area 136.0L.This process
was repeated for all 172 specific arleas inventoried in the middle Susitna
River ..
47
Habitat Variable/Variable Combination
(Weighting Factor)
Affect on
Habitat
Quality
(Rating Factor)
Dominant
Cover/Percent
Cover
(0.45)
Channel
Geometry
(0.30)
Substrate Size/
Substrate Streamside
Embeddedness Vegetation
(0.20) (0.05)
EXCE!ll ent
Good
Fair
Poor'
None~x is tent
(1.00)
(0.75)
(0.50)
(0.25)
(0.0)
J1,.30 .20 .05
.23 .15 .04
.23 15 ~(Q])
.11 ~.05 .01
.0 .0 .0 .0
-==============================================================================
Product of
rating and
wei9 hting
factors .
SHI =.55
.34 .08 .10 .03
_Figure 9.Structural habitat index form for specific area 136.0L.
48
-
....
.".,.
......
.....
3.RESULTS AND DISCUSSION
Results and discussion pertaining to the characterization of each aquatic
habitat component is presented {n this section in the order of their develop-
ment:hydrologic,hydraulic,and structural.The application of these
habitat characterizations to the development of structural habitat indices and
representative groups will follow.
3.1 HYDROLOGIC COMPONENT
Of thle five indices used to describe the hydrology of specific areas (Section
2.1),habitat transformation,breaching flow,and upwelling were the most
useful for characterizing aquatic habitat •
3.1.1 HABITAT TRANSFORMATION TRACKING
The results from the habitat transformation monitoring methodology appear in
Appendi x 3 where habitat transformati on categori es for each speci fi c area
betwelen the reference flow of 23000 cfs and all lower f1 ow aeri a 1 photography
are listed.From the results,the number of specific areas in each habitat
transformation category was tabulated for each evaluation flow (Table 11).
Table 11 and Figure 10 illustrate how the quantity of riverine habitats in the
middlle Susitna River change significantly as mainstem discharge decreases.
For a discussion of the qualitative a.spects of the change in habitats,see
Section 3.2.1,Mean Reach Velocity.The number of clearwater habitats with
breaching flows greater than 35000 cfs (Category 1)is relatively stable
throu'9hout the flow range.There is a substantial increase in the number of
49
side channels that transform to sloughs as mainstem discharge decreases
-(Categiory 2)and a correspondi ng decr'ease in the number of side channels
(Categ:ory 4).As can be expected,the number of indistinct areas (Category 6)
and mainstem areas (Category 10)also decrease.The number of areas that
dewate~r (Category 9)showed the most dramatic change,with a fivefold increase
betwee~n the highest and lowest flows.The number of areas described by the
remaining categories (Categories 3,5,7,and 8)fluctuate over the flow range
considered,but collectively account for only 10 to 20 percent of the 172
specific areas evaluated.
"'~
Table II.Number of specifi c areas i n e~ach habitat transformation category by
evaluation mainstem flow,referenced to 23000 cfs.
Evaluation Mainstem Q (cfs)
Ii-
18000 16000 12500 10600 9000 7400 5100
Category Number of Specific Areas
1 35 34 33 33 33 32 32
2 12 14 19 24 _27 30 30
3 7 6 8 8 11 10 13
~.4 48 46 40 35 26 24 24
5 5 6 8 11 13 11 11
6 33 32 28 22 18 18 15
7 3 3 3 3 3 4 5
8 3 3 5 7·8 5 4
9 6 8 13 14 20 27 30
10 20 20 15 15 13 11 8-
It is interesting to note that the number of dewatered specific areas remains
relatively stable between mainstem disc:harges of 12500 and 10600 cfs (13 and
14,rE!spectively),but then almost doulbles with a reduction in discharge to
7400 c:fs (27).An accelerated change in overall riverine habitat character
appea y's to occu r between 10600 and 7400 cfs.
50
CATEGORY 1 SPECIFIC AREAS CATEGORY 2 SPECIFIC AREAS
••
.....
.....
.....
Ul'UllD AIIlI stllZ 5LOIlClI5
•
•
•
•
•
CATEGORY 3 SPECTFIC AREAS
....'l'Itrrte ...•r---';"'~-------------------....,
SIIlE ClWlMtLS TO 511l£5LOUCRS IIlTIIDUT IIllltD III'V!LI.IllC
•
•
:II
•
w
.....-
CATEGORY 5 SPECIFIC AREAS
SIIlE CIW<lIlLS TO StilE 5tDUCH5 II'lTB IIlIfTD.IJ!'\o/tt.LlMC
•
•
"
•
•
w'"""'_
CATEGORY 4 SPECIFIC AREAS
•r-=.·::....:."":.:":.::I(:...:.....=....,
stilE ClWlHtLS
•
•
:II
w
CATEGORY 6 SPECIFTC AREAS
w r......-·~....;.;~"-"~......:..:.._------------------..,•
-
llllllSllMCT SIIl£CIWIN!LS to 01Sltllcr SlllZ C1WfIlELS
"
•
L'<tl15TlMet !l.\IH5Ttl1 ....'«1 511)£Cll......INa.AUAS
•
•
--
11
•
..
"
•
..
....
Figure 10.Number of specific areas in each habitat transformation category at
various mainstem flows .
51
_________________!fl ~~_
~(---
CATEGORY 7 SPECIFIC AREAS
•;_=.:~.::::9'lt::,::,:Tl'R:~:=.uos=---,..
CATEGORY a SPECIFIC AREAS
IIIIIlSTL'lCT SlOt CIIAIIIIELS to SlOt SLOllCIIS \11TH IlllltU UPIItLI.nG
•
•
,.
II
II
11
INDIS'I!!IC'I SlOt CIIAIIIIELS to SlOt Sl.OUCHS \/ITllOtn'\Il!l'l:tIl
UP\IELLIlIC
---....,..
--
..
CATEGORY 9 SPECIFIC AREAS
•
CATEGORY 10 SPECIFIC AREAS
"
•
S:PItCIFtC AUAS 'tIlA'I Dtl/ATEK
"
•
lIAIIIS'l'EIl CIIAIIIIELS
II
1II
I.
,...'OID -..II1II11_....,..
11
1II
I.
Figure 10 (Continued).
!32
-
KlingE!r and Trihey (1984)observed similar trends in the overall habitat
character as flows decrease.They uSl~d wetted surface area as an index of
habitat quanti ty and determined that as mai nstem di scharge decreases from
23000 to 9000 cfs,there was an associated decrease in mainstem habitat (from
3737 to 2399 acres)and side channel habitat (from 1241 to 762 acres)and an
increase in side slough habitat (from 53 to 156 acres).The wetted surface
area of upland slough habitat was relatively stable within this flow range.
3.1.2 BREACHING FLOW
Breaching flows were determined with a precision of approximately ±1500 cfs
within the flow range from 5100 to 18000 cfs,and ±2500 cfs above 18000 cfs
and below 5100 cfs.Breaching flows for each specific area are listed in
Appendix 4.
3.1.3 CROSS-SECTIONAL GEOMETRY OF SIDE CHANNEL HEAD BERMS
Plots of wetted top width at the head berm versus mainstem discharge were
r developed for 46 specific area channl~ls that had low breaching flows and
readi"ly identifiable head berms.These were classified by curve slope into.....
four categories:(1)steep;(2)moderate;(3)flat;and (4)irregular
(Figul"e 11).The interpretation of each category of curve slope ;s as
fall O\'IS:
.....(1)steep slopes are indicative of broad channel sections with rela-
tively gentle-sloped sides at the head berm;
53
.-.
130.2 R 129.3 L
~11"',".llIr----------------------------......
IlIIIl1II1II-
II
III
I.
..'(D1M iFt.,J
1I
..
1I
0
~C'-l
II
X
.....It
IDJl llllD •Il1S.l
STEEP MODERATE
127.0 N 128.5 R
TrP'Ilonr CrT.)lIr~~------------------.....,trrflD:IMif'U
1I
..
II-0.....N III
X
I.
1Il
10 _/
!t !,I I I t• I
lIIIl lllDl IlIIIl
!1 ,
Il1D1
IDJl llllD •Il1S.l
FLAT IRREGULAR
....
Figure 11.Representative wetted top width versus discharge plots for each
category of curve slope.
54
-
-
(2)moderate slopes are indicative of channels with cross-sectional
geometry at the head berm tlhat is gentle-sloped on one side and
steep on the other;
(3)flat slopes are indicative of channels where cross-sectional geo-
metry at the head berm has stE~ep-sloping sides;and
(4)irregular or stepped curves are indicative of channels with
irregular cross-sectional geometry at the head berm.
Of thE!46 side channels studied in th'is section,21 (46%)had curve slopes
that were flat,11 (24%)moderate,8 (l7%)irregular,and 6 (13%)steep
(Table 12).Generally,mainstem and large side channels had flat curve slopes
characteristic of steep-sided channels.There was also a tendency for the
large channels with breaching flows be-tween 8000 and 16000 cfs to be broad
.-
with gentle-sloping sides.
-
From Table 12,it is apparent that each curve slope class is distributed
throughout the middle Susitna River.No longitudinal trends were observed for
consideration in grouping specific areas.Although no consistent trends were
identified from the data,the study provided insights useful in the subjective
consideration of cross-sectional geometry as a criterion for the development
of representative groups •
....
55
Table 12.Curve slope classes of plots of wetted top width versus discharge
from measurements made at channel head berms at 46 specific areas in
the Talkeetna-to-Devil Canyon segment of the Susitna River.
-
-
Specific
Area
100.6L
100.?R
101.:~R
101.!jL
102.6L
105.~7R
106.:3R
108.n
108.9L
109.4M
110.8M
111.OR
l11.!jR
112.6L
114.0R
115.OR
116.BR
117.n
117.BL
119.:~R
119.6L
121.1L
121.?R
Curve
Slope
Class
3
2
2
2
4
4
4
3
2
3
3
3
3
1
3
1
4
3
2
2
3
2
3
Specific
Area
123.0L
124.1L
125.2R
125.6L
127.0M
127.1M
127.4L
128.5R
129.3L
130.2R
130.2L
131.7L
132.6L
134.9R
135.0L
136.0L
137.2R
138.0L
138.8R
139.4L
139.6L
144.2L
145.3R
Curve
Slope
Class
3
3
3
2
3
4
2
4
2
1
3
4
3
3
3
3
1
1
1
4
3
3
2
-Curve slope classes:1 =steep,2 =moderate,3 =flat,4 =irregular
3.1.4 CROSS-SECTIONAL GEOMETRY OF MAINSTEM
The increase in mainstem stage due to an increase in mainstem discharge varies
betwel~n mainstem reaches of the middle Susitna River (Table 13).The respon-
siveness of mainstem stage to discharge in a reach has a direct influence on
the hydrologic regimen of adjacent side channels.In reaches where mainstem
stage is .relatively responsive to changing discharge,the volume of flow
entering adjacent side channels will be relatively unstable.The opposite is
56
true in reaches where mainstem stage responds less dynamically to changing
discharge.From the information in Table 13,it would be expected that side
channel habitats within the continuous reach from river miles 131 to 137 would
have less stable flow regimes than other channels in the middle Susitna River.
Characteristic mainstem stage fluctuations may prove IJseful in subsequent
-analyses,especially in the interpret,ation of WUA curves.For example,a
steep and laterally compressed WUA curve could be explained by the relatively
large response of mainstem stage to dis.charge at a mainstem reach.
Table 13.Stage increase at selected cross sections in the Talkeetna-to-Devil
Canyon segment of the Susitna River as mainstem discharge increases
from 9700 to 23400 cfs.
....
Cross Section
No.
7
11
2~5
2~9
44
49
S4
~f5
Source:R&M Consultants 1982
3.1.5 EVALUATION OF UPWELLING
River IVlile
101.5
106.7
121.6
126.1
131.2
136.4
138.2
140.8
141.5
Stage Increase
(Ft.)
1.9
2.6
2.2
2.0
3.5
3.3
2.8
2.7
2.4
Table 14 lists the specific areas that were determined to possess upwelling.
Of 59 specific areas that had open leads in the March 1983 photography,40
57
58
-
(68%)were observed to have chum salmon spawning activity during the 1984
habitat reconnaissance surveys.There was also a strong corre 1ati on between
the presence of chum salmon spawners and those specific areas where upwelling
was observed in the field but did not necessarily have open leads in the
wi nter photography.Of these 85 sites,48 (56%)were observed to have chum
"""
salmon spawning activity.
More "indicative of the importance of upwelling to spawning chum salmon is the
percentage of specific areas where spawning activity was observed that also
had upwelling.Of the 53 specific areas where spawning activity was observed,
48 (91%)were observed to have upwelling.ADF&G maps of chum salmon spawning
areas were thus used to corroborate upwelling.A summary of fish observations
appears in Appendix 5.
Although field observations of upwelling are highly reliable,upwelling may
have !~one unobserved in some areas due to specific conditions.For instance t
turbid water conditions make it difficult to detect upwelling directly.Also,
the absence of open 1eads in the wi nter ice cover does not ru 1e out the
presence of upwelling.It is possible that the thermal quality of upwelling
that occurs in relatively deep or swift and turbulent currents will become
sufficiently diffused by mixing to preclude the formation of a thermal lead in
the winter ice cover.
The presence of upwelling is incorporated directly into the habitat transfor-
mation categories defined in Table 3.Upwelling is thus included implicitly
in the development of representative groups via the sequence of habitat
transformation categories that occur at a specific area.
~,
59
.....
3.2 HYDRAULIC COMPONENT
Analysis of the hydraulic component of specific area habitats was focused on:
1)estimated or measured mean reach velocity during breached conditions,
2)substrate size,and 3)channel morphology.Of these three variables,mean
reach velocity was the best and most direct index of channel hydraul ics for
use in the characterization of habitat.
3.2.1 MEAN REACH VELOCITY
The side channels of the middle Susitna River constitute a complex flow
delivl~ry system with individual side channels beginning to flow at various
mainstem discharges according to their breaching flows.A comparison of mean
reach velocities between side channels for any given mainstem stage would
yi e 1d a range of va 1ues dependi ng on whether the channels were nonbreached,
barely breached,or flowing full.Mean reach velocity is thus a
stage·-dependent variable whose use as a comparative index of side channel
hydraulics is complicated by a dependence on breaching flow.
Mean reach velocities were measured or estimated in this study at mainstem
discharges ranging from approximately 8000 to 11000 cfs.In a few cases,
estim.ates were made at 18000 cfs.Because of the relatively low flows that
were coincident with the field trips,channels where velocities were measured
for breached conditions had relatively low breaching flows.This reduced the
need to consider the variability of breaching flows between channels in the
interpretation of mean reach velocity data.Although it is possible to
normalize mean reach velocity measurements at different side channels on the
60
-
--
--
basis of breaching flow,it was not considered necessary in this study.Mean
reach velocities are presented in Tables 17-26.
The incomplete data set that was obtained due to consistent low flows during
reconnaissance restricted the use of mean reach velocities for the comparative
eva1ua,tion of hydraulics to specific areas with low breaching flows.Mean
reach velocities were obtained during breached conditions for 63 of the 172
specific areas delineated in the middle Susitna River.
The velocity data collected was also useful in describing the hydraulic
characteri sti cs of each habi tat tralnsformati on category.The foll owing
general1izations are provided for eaclh category to develop a qualitative
appreciation of the trends depicted in Figure 10.
Categclry a -Tri butary mouth habi tat.These habitats exi st as c1 ear water
plumes at the confluence of tributaries to the middle Susitna River.
Thi s category has not been di rectly addressed withi n the extrapol ati on
methodology because of the compal"ative1y small amount of surface area
associated with this habitat type.
Category 1 -Upland slough and side slough habitats that do not transform
...,ithin the flow range of interest.These areas offer low velocities,
frequently near-zero,with the greatest hydraulic disparity being depth.
Categclry 2 -Side slough habitats that have transformed from side channel
habitats and which possess winter upwelling.These areas are typified as
Cl series of clearwater pools connected by short,shallow riffles.Riffle
61
velocities are frequently less than 1 fps and 0.5 feet or less in depth.
Pool velocities are near zero and depths are generally less than 3 feet.
Category 3 -Side slough habitats that have transformed from side channel
habitats.These are distinguished from Category 2 areas only by the lack
of an upwelling groundwater source~that persists throughout winter.The
t~draulic characterization is the same as that of C~tegory 2.
Category 4 -Side channel habitat that has transformed from mainstem habitat
or has remained as side channel habitat at the evaluation flow.These
clreas display greater hydraulic diversity than the previous categories .
.-Velocities range from approximately 2-5 fps (10000 cfs mainstem)between
specific areas.-
Category 5 -Side channel habitat that has transformed from indistinct
channels (Category 6).These arE~distinguished from Category 4 areas
primarily by the presence of one Slravel bar bank which becomes inundated
at high mainstem discharges t causing the channel to appear less visible
(·indistinct)in the aerial photo9raphy.These channels typically have
higher velocities,often greater than 5 fps (10000 cfs mainstem)t than
Category 4 channel s.
Category 6 -Indistinct areas that remain indistinct through the flow range of
;:nterest.This category includes those riverine areas termed shoals.By
definition,they are shallow wa,ter areas,typically marginal to a
mainstem channel.Depths are genE~rally under 4 feet and velocities are
62
reduced compared to mean mainstem velocities as a result of channel edge
effects.
Category 7 -Side slough habitats that have transformed from turbid indistinct
channels and which possess winter upwelling.These areas are distin-
guished from Category 2 areas primarily by their origin from indistinct
rather than di sti nct channel s.The hydraul ic characterization is the
same as that for Category 2.
Category 8 -Side slough habitats that have transformed from turbid indistinct
areas.These areas are di sti ngui shed from Category 3 areas primarily by
-their origin from indistinct rather than distinct channels.The hydrau-
lic characterization remains the Silme as that for Category 3.
Category 9 -Specific areas that become dewatered.This is a terminal
category that requires no hydraul ic characterization.These areas may
-contain isolated pools that,by definition,have no habitat value.
Category 10 -Mainstem habitats that do not transform within the flow range of
interest.These channels are typically deeper and swifter than any other
habitat category.Mean vel ociti es are frequently 5 fps (lOOOO cfs
mainstem)or greater.
3.2.2 SUBSTRATE SIZE
.....
In the evaluation of substrate size,dominant substrate codes were used (see
Appendix 2).Frequently more than one code was selected because of the evenly
63
balanced mixture of fine and coarse substrate size classes present at many
specific areas.Sands were distributed throughout the middle Susitna River
segment and were considered to be less 'indicative of specific area hydraulics.
For this reason,when more than one dominant substrate size code was selected,
the coarser size class was uied as the index of channel hydraulics.
3.2.3 CHANNEL MORPHOLOGY.....
ChannE~l morphology was the most indirect index of specific area hydraul ics
used to characterize habitat.During the course of the habitat reconnaissance
field work,considerable evidence of repetitive form was observed throughout
the m"iddle Susitna River.Sometimes a distinct plan form was recognized from
the air in transit to a specific area.Other times a distinctive riffle/pool
-patte]!'n was recogni zed whil e on the !~round.Silllil ari t;es between spec;fi c
64
....
areas were recorded on the habitat inventory data form for consideration in
the development of representative groups.Careful inspection of aerial
phot09raphy also revealed similarities in plan form between individual side
channE!ls.
The m'iddle Susitna River has been divided into six discrete reaches by R&M
Consull tants (1982)based on characterii sti c mai nstem channel patterns (Table
15).Dividing the mainstem in this manner provides the basis for evaluating
long term trends in main channel morphology.More applicable to the study of
juven'i1e chinook salmon habitat,which is concentrated in the peripheral areas
of the river,is the identification of side channel complexes.Complexes are
systerns of adjacent,often interconnected,side channels which convey mainstem
water..Major side channel complexes of the middle Susitna River identified in
this study are listed in Table 16 and are easily discernible in the aerial
photo!~ra phy in Appendix 1.
Although channels within a complex are sometimes hydraulically,hydro-
10gici:l.l1y,and morphologically similar since they are influenced by the same
rna instem conditions,such as slope,stage response to di scharge,and sediment
load,more than one habitat type is generally represented in a complex.
Habitat type is thus sporadically represented in different side channel
complexes throughout the middle Susitna River •
A stcltistical approach was taken to study the similarities be-tween side
channel areas in the middle Susitna River based on plan form.Through a
cluster analysis of several side channel variables,including length,width,
1ength-to-width ratio,channel sinuosity,and the number of bends,six
65
Table 15.Definition of reaches within the Talkeetna-to-Devil Canyon segment
of the Susitna River.
-River Mile
RM 149 to 144
RM 144 to 139
RM 139 to 129.5
RM 129.5 to 119
RM 119 to 104
RM 104 to 95
Average
Slope
0.00195
0.00260
0.00210
0.00173
0.00153
0.00147
Description
Single channel confined by valley
walls.Frequent bedrock control
points.
Split channel confined by valley walls
and terraces.
Split channel confined occasionally by
terraces and valley walls.Main
channels~side channels,and sloughs
occupy valley bottom.
Split channel with occasional tendency
to braid.Main channel frequently
flows against west va 11 ey wa 11 .
Subchannels and sloughs occupy east
flood plain.
Single channel frequently incised,and
occasional islands..
Transition from split channel to
braided~occasionally bounded by
terraces.Braided through the
confluence with Chulitna and Talkeetna
Rivers.
Source:R&M Consultants 1982.
Table 16.Major side channel complexes of the Talkeetna-to-Devil Canyon
segment of the Susitna River.
RefE~rence Name Location (RM)
Whiskers Creek 100-102
Bushrod Slough 117 -118
Oxbow II 119-120
Slough 88 121-123
Sku']l Creek 125-126
Fourth of July 131-132
Slough 21 141-142.....
-
66
"""
distinct cluster groupings were identified.The findings corroborated subjec-
tive evaluations of morphologic s"inrilarities between side channels.
A discriminant function multivariate analysis was performed using the six
cluster groupings to determine the relative importance of variables in
defining morphologic groups.The length-to-width ratio was the most important
variable with channel width second,followed by channel length.A limitation
of thE!multivariate analysis was that it could be appl ied only for distinct
side channels where it was possible to evaluate each of the previously
mentioned variables.This limited the analysis to 70 specific areas.
Subjective evaluation of channel morphology was the primary criterion in the
development of three representative groups (Tables 21,22,and 26).
3.3 STRUCTURAL COMPONENT
3.3.1 STRUCTURAL HABITAT INDICES
The structural habitat index is used in the extrapolation methodology to
adjust the amplitude of the habitat availability curve of a modeled specific
area to more accurately represent an associated nonmodeled specific area
within the same representative group.The importance of the index is as a
species-specific,Susitna-specific,relative index to be applied within
representative groups and not as an absolute index of structural habitat
quality.It was not intended that the SHI be used as a comparative index of
habitat qual ity between representative groups.The criteri a for devel opi ng
the SHI for Representative Group I were slightly different than for the other
67
------_._----,------
""'"
....
-
.-
representative groups.Structural habitat quality should not be <:onfused with
overall habitat quality.Note that although a representative group may appear
to offer higher quality habitat than another representative group by virtue of
higher mean SHI values,when other (e.g.,hydraulic)criteria are considered
this may not be true.Comparative statistical treatments of SHI values for
representative groups are considered inappropriate and are not presented.
The structural habitat index for each specific area appears in Tables 17-26 .
In vi,ewing the range of SHI values within representative groups,two trends
are alpparent:(1)many specific are!as have comparable SHI values;and
(2)some specific areas are rated more than twice as valuable as others.The
first trend can be expected and explained as resulting from the occurrence of
similar river processes within each rl:!presentative group.The second trend
emphasizes the vari abi 1i ty of structulf'a 1 habitat attributes that may occur
within representative groups as accorded by local conditions.The range of
SHI values in these areas is reasonable and reflects the importance of struc-
tural cover to juvenile chinook habitat quality.In a previous study of
instrE~am enhancement structures by Ward and Slaney (1979),the standing crop
of steelhead parr and coho fingerlings increased threefold in a boulder-
enhanced reach of stream over preplacement values.
3.4 DEVELOPMENT OF REPRESENTATIVE GROUPS
Representative groups are composed of specific areas that are hydrologically,
hydraulically,and morphologically similar.Variables that were used in the
development of representative groups are:breachi ng flow,habitat trans-
format;on category sequence,mean reach velocity,flow pattern,and channel
68
....
....
....
....
morphology.Field notes provided core groupings of specific areas that were
observed to be similar.Field experience,.coupled with professional judge-
ment,provided the balance of the matrix needed to discern representative
groups.
Although variables describing each of the components of aquatic habitat
character were cons idered in the development of representative groups,fre-
quently one or two components dominated the distinction of a group.The
character of Representative Group I (Table 17),for example,is dominated by
its rE!lative isolation from a mainstern water source (hydrologic component).
This qroup includes upland sloughs and side sloughs with breaching flows
greater than 35000 cfs.Principal water sources are groundwater and surface
runoff,with several of these specif"ic areas receiving inflow from small
tributaries.In the geomorphic regimE~of the middle Susitna River,these
specific areas are remnant channels fo111owing events from ice processes and/or
channel migration.
The character of Representative Group II (Table 18)is dominated by relatively
high breaching flows (20000 to 33000 cfs)and the presence of upwelling
groundwater sources.These specifi c areas are commonly called side sloughs.
Morphologically,these channels tend to be more sinuous than those of other
representative groups.Geomorphica11y,several of these specific areas have
succeeded from side channels since 1949 as their head berms have emerged
relative to the mainstem (LaBelle et a1,.1985).Several others that were side
sloughs in 1949 have emerged to become upland sloughs (Representative Group I)
today.
69
!"'"
-
The ch,aracter of Representative Group III (Table 19)is dominated by breaching
flows (8200 to 16000 cfs)intermediate to those of most side channels and side
sloughs.Although the channel morphology is more characteristic of side
channels than side sloughs,portions of these channels commonly contain clear
groundwater from upwelling sources in their nonbreached phase.Transformation
from side channel to side slough habitat is thus characteristic of this group
as evidenced by the habitat transformatjion category sequence.
The character of Representative Group IV (Table 20)is dominated by low
breaching flows «5100 cfs)and mean reach velocities between 2 fps and 5 fps
(10000 cfs mainstem).This group includes specific areas commonly called side
channel s.The di sti nction between s'j de channel and mai nstem habitat is
primarily one of size.Generally,side channels convey less than approxi-
mately 10%of the total flow in the river.In addition,side channels tend to
have lower flow velocities and less coarse bed material than mainstem channels
on thE!average.
The character of Representative Group V (Table 21)is dominated by channel
morphology.This group includes shoatl areas,many of which transform to
slough habitats as mainstem discharge decreases.Shoal areas are described as
shallow water areas bordering deeper mainstem channels.Velocities in these
areas are generally less than mean mainstem velocity and flow characteristics
can be described as riffle or run.Shoals frequently form as a point bar on
the inside bend of a meander,as an alternate bar,or at the downstream end of
an island where the ~ainstem has aggraded.
70
The character of Representative Group VI (Table 22)is dominated by channel
morphology.This group includes overflow channels that parallel the adjacent
mainstem,usually separated by a sparsely vegetated gravel bar.These
po
speci fi c areas mayor may not possess eln upwell i ng groundwater source.It is
likely that many of these channels have formed as a result of ice jams rout"ing
mainstem water around the primary flow corridor.
The character of Representative Group VII (Table 23)is dominated by a charac-
teristic riffle/pool sequence.ThesE~specific areas would otherwise be
included in Representative Group IV or Group III except for a characteristic
large backwater that forms near the channel mouth and a riffle upstream of it.
Mean Y'each velocities are between 2.0 fiPs and 4.0 fps (10000 cfs mainstem).
.-
The character of Representative Group VIII (Table 24)is dominated by a
tendency of these channels to dewater at relatively high mainstem flows.
DewatE!ring frequently occurs soon after the channel becomes nonbreached and is
reflected by a 9 in the habitat transformation category sequence.Channels in
thi s 9rouP are frequently oriented wi tlh a 30+ang1 e to the rna i nstem fl owl-j ne
at their heads and contain finer substrate than IllOSt groups.Large sand
deposlits are common in the channels of this group •
Representative Group IX (Table 25)consists of mainstem habitats.The charac-
ter of this group is dominated by 10\~,breaching flows «5100 cfs)and mean
reach velocities frequently greater than 5 fps.These specific areas
generally convey more than approximate"ly 10%of the total di scharge and have
coarSE~r bed material on the average compared to other groups.Geomorphically,
71
these specific areas are currently the primary flow conveying channels in the
~middle Susitna River.
The character of Representati ve Group X (Table 26)is domi nated by channel
morphology and local hydrology.This gl"OUp includes large mainstem shoals and
mainstem margin areas that had open leads in the March 1983 aerial photo-
r-graphy.Mainstem shoals are large e;<panses of shallow water adjoining a
primary mainstem channel and they typically occur on the inside of a bend,as
an alternate bar,or at the downstream side of an island as the result of
aggradation in the mainstem.This groUip is distinguished from Representative
Group V primarily by size and typically coarser bed material.This group also
:-includes mainstem margin areas that \lfere suspected of having an upwelling
groundwater source as evidenced by open (possibly thermal)leads in the aerial
photography.Other than the possible presence of upwelling,nothing remark-
able distinguishes these specific areas from other mainstem channel margins in
the middle Susitna River.
Al though of 1ess importance in the developrnent of representative groups,
dominant substrate size codes and channel length-to-width ratios were included
in Tables 17-26 where data was availalble.These were included to aid the
readelr'in gaining an appreciation of the habitat characteristics of the
various specific areas.
--
72
Table 17.Representative Group I
--Description:Habitat character is domimited by high breaching flow.This group
includes all upland sloughs and Slough 11 (RM 135.6R).Specific area hydraulics are
characteri zed by pool ed cl ear water with vel ocit;es frequently near-zero and depths
greater than 1 ft.Pooled areas are commonly connected by short riffles where
velocities are less than 1 fps and depths are less than 0.5 ft.
Habitat Meatn 1 Channel,
Breaching Transformation Reach Dominant Length-Struct'ural
Specific Flow Category Veloc:i ty Substrate to-Width Ha'bitat
Area (cfs)Sequence (fps)Code Ratio IndeX:Model
-102.2L >35000 1 0+1 0.83
105.2R >35000 1 LO 1 0.69
107.6L >35000 1 0+2 0.44 RJHAB
108.3L >35000 1 LO 1 0.70
112.5L >35000 1 0 1 0.68 RJHAB
119.4L >35000 1-9 0 1 0.45
120.0R >35000 1 0+1 0.50
121.9R >35000 1 <LO 9 0.72
123.1R >35000 1 ()+1 0.45
123.3R >35000 1 0 2 0.67
127.2M >35000 1 ()+2 0.58
129.4R >35000 1 0+1 0.44
133.9L >35000 1 <0,.5 9 0.67
134.0L >35000 1 0+1 0.89
135.5R >35000 9 0+1 0.32
135.6R >35000 1 ()+6 0.54'
136.9R >35000 1 ()+2 0.69
139.0L >35000 1 0 2 0.45
139.9R >35000 1 0+1 0.74
""'"
I Mean reach velocities for nonbreached conditions
RJHAB :::tlDF&G Habitat Model
---=Data Not Available
"""
....
73
Table 18.Representative Group II
Description:Habitat character is dominated by relatively high breaching flows and
the pres€,nce of upwelling groundwater sources that persist throughout winter.This
group inc:ludes the specific areas that are commonly called sloughs.These specific
areas typically have relatively large channel length-to-width ratios.
F""Habitat Mecin Channel
Breaching Transformation Reiich Dominant Length-Structural
Specific Flow Category Veloc:i ty Substrate to-Width Habitat
Area (cfs)Sequence (fps)Code Ratio Index Model
100.6R 33000 1 9 0.60
101.4L 22000 2 10 38.4 0.54 RJHAB
101.8L 22000 2 10 77 .8 0.65
113.1R 26000 1 6 0.31
113.7R 24000 1 6 100.0 0.51 RJHAB
115.6R 23000 4-2 9 21.2 0.54
117.9L 22000 2 9 29.3 0.62 --
~118.0L 22000 3 9 12.8 0.39 '
121.8R 22000 3 2 20.9 0.27 ___
122.4.R 26000 1 1 23.1 0.29
122.5R 20000 2 8 104.5 0.51
123.6R 25500 1 2 0.43
125.1R 20000 2 3 25.5 0.48
125.9R 26000 1 12 74.7 0.56
126.0R 33000 1 9 71.8 0.51 IFG
126.3R 27000 4-2 9 39.6 0.59
131.8L 26900 1 ..-8 0.45
I"""133.9R 30000 1 7 0.50
135.3L 23000 3 12 19.1 0.30
137.5R 22000 2 12 0.44 DIHAB
137.5L 29000 1 1 0.61
137.8L 20000 2 11 15.0 0.54
137.9L 21000 2 11 76.0 0.50
140.2R 26500 1 ..-11 73.3 0.50
142.1R 23000 1 11 0.60
142.2R 26000 1 9 0.52
143.4L 23000 1 13 60.0 0.55-,144.4L 21000 2 13 91.5 0.60 RJHAB
....
IFG =Instream Flow Group Habitat Model
DIHAB =Direct Input Habitat Model developed by EWT&A
RJHAB =ADF&G Habitat Model
--=Data Not Available
74
-
.....
-
Table 19.Representative Group III
Description:Habitat character is dominated by intermediate breaching flows and
relatively broad channel sections.This group includes side channels which become
nonbreached at intermediate mainstem discharge levels and transform into slough
habitat at lower discharges.Breaching flows are typically lower than for Group II,
upwellingl is present,and the length-to-~~idth ratios of the channels are generally
1ess than rati os for Group I I.
IFG =Instream Flow Group Habitat Model
DIHAB =Direct Input Habitat Model developed by EWT&A
RJHAB =ADF&G Habitat Model
--=No Data Available
75
Table 20.Representative Group IV
Description:Habitat character is dominated by low breaching flows and intermediate
mean reach velocities.This group includes the specific areas that are commonly
called side channels.These specific areas possess mean reach velocities ranging from
2-5 fps at a mainstem discharge of approximately 10000 cfs.
-Habitat MecLn Channel
Breaching Transformation Reach Dominant Length-Structural
Specific Flow Category Vel oei ty Substrate to-Width Habitat
Area (cfs)Sequence (fps)Code Ratio Index ~Iode 1
100.7R <5100 10-4 3 ..8 8 14.5 0.49
108.7L <5100 10-4 3 ..0 11 6.9 0.53
110.8M <5100 4 3 ..5 6 5.9 0.48
111.5R 5100 10-4 2 ..5 9 13.8 0.48
r-112.6L <5100 4 3 ..0 10 10.0 0.60 IFG
114.0R <5100 4 3.0 9 0.43
116.8R <5100 10-4 4.5 9 10.6 0.48
.....119.5L 5000 4 2.5 8 20.9 0.54
119.6L <5100 4 3.0 10 54.6 0.53
121.7R <5100 10-4 4.0 8 24.7 0.48
124.1L <5100 10-4 3.5 11 17.0 0.46
125.2R <5100 4 4.5 10 .37.8 0.56 DIHAB
127.0M <5100 4 2.5 7 10.1 0.65
127.4L <5100 10-4 4.0 9 36.4 0.46-129.5R <5100 6-5 3.0 8 13.5 0.56
131.7L 5000 4 2.6 10 48.6 0.47 IFG
134.9R <5100 4 4.0 8 22.3 0.56 IFG
136.0L <5100 4 2.0 5 24.0 0.55 IFG
139.4L <5100 4 2.0 8 3.6 0.61
139.6L <5100 10-4 3.2 13 14.9 0.51
140.4R <5100 6 3.0 10 7.7 0.48
145.3R <5100 10-4 4.5 12 11.8 0.5-3
IFG =Instream Flow Group Habitat Model
DIHAB =Direct Input Habitat Model developed by EWT&A
--=No Data Available
-
76
....
MSS =Mainstem Shoal
IFG =Instream Flow Group Habitat Model
DIHAB =Direct Input Habitat Model developed by EWT&A
--=No Data Available
77
Table 22.Representative Group VI
~Description:Habitat character is dominated by channel morphology.This group
includes overflow channels that parallel the adjacent mainstem,usually separated by a
sparsely vegetated gravel bar.These specific areas mayor may not possess an
upwelling groundwater source.
-Habitat Mean Channel
Breaching Transformation Reilch Dominant Length-Structural
Specific Flow Category Velocity Substrate to-Width Habitat..,.,Area (cfs)Sequence (fps)Code Ratio Index Model
-102.6L 6500 4-3 2 ..0 12 14.2 0.69
106.3R 4800 4 2 ..5 11 17.4 0.53
107.1L 9600 4-3-9 12 0.69
117.9R 7300 4-3 2,,0 12 24.7 0.49
119.7L 23000 2 9 0.51
133.8L 17500 4-2 9 24.0 0.49 IFG
135.7R 27500 1 3 26.0 0.32
~136.3R 13000 4-2 11 14.4 0.54 IFG
138.0L 8000 4-2 11 0.53
138.8R 6000 6-5-9 3.0 9 15.0 0.31
r--139.5R 8900 6-5-7 2.5 12 0.31
140.6R 12000 6-5-8-9 10 0.61
142.0R 10500 5-8 12 0.53
....
"...IFG =Instream Flow Group Habitat Model--=No Data Available
-
78
.....
-
-
-
Table 23.Representative Group VII
Description:Habitat character is dominated by a characteristic riffle/pool sequence.
The Little Rock IFG modeling site (RM 119.2R)is typical)with a riffle just
downstream of the side channel head that flows into a large backwater pool near the
mouth •
Habitat Mean Channel
Breaching Transformation Reclch Dominant Length-Structural
Specific Flow Category Velocity Substrate to-Width Habitat
Area (cfs)Sequence (fps)Code Ratio Index Model
114.1R <5100 5 2,,5 8 22.8 0.31 DIHAB
119.2R 10000 4-3 3,,6 10 15.1 0.41 IFG
121.1L 7400 4-3 3,,0 6 41.2 0.43
123.0L <5100 4 2,,0 7 17.4 0.39
125.6L <5100 6-5 3,,5 12 9.5 0.52
127.5M <5100 6-5 3,,5 6 24.2 0.31
131.3L 9000 4-2 4,,0 7 18.2 0.31 DIHAB
IFG =Instream Flow Group Habitat Model
DIHAB =Direct Input Habitat Model developE~d by EWT&A
--=No Data Available
79
Table 24.Representative Group VIII
Description:Habitat character is dominclted by the tendency of these channels to
dewater at a relatively high mainstem discharge.Channels in this group are
frequently oriented with a 30°+angle to the mainstem flowline at their heads.
Habitat Melan Channel
Breaching Transformation Reach Dominant Length-Structural
Specific Flow Category Velodty Substrate to-Width Habitat
Area (cfs)Sequence .(tIPs)Code Ratio Index Model
.-.
101.3M 9200 4-9 11 9.3 0.57
102.0L 10000 4-9 5 2.4 0.43
104.3M 21000 4-3-9 9 4.3 0.48
109.5M 16000 4-9 9 8.7 0.49
112.4L 22000 9 11 18.4 0.27
117.1M 15500 4-3 3 16.0 0.32
117.2M 20000 3-9 3 9.8 0.32
118.6M 14000 5-8 3 0.36....119.8L 15500 4-9 9 7.8 0.51
120.0L 12500 4-3-9 10 20.3 0.32
121.5R 19500 3-9 6 0.32
121.6R 15500 4-3-9 9 0.60
123.2R 23000 8-9 3 0.2f
124.8R 19500 8-9 2 3.9 0.46
125.6R 26000 9 8 12.7 0.44
128.4R ·9000 6-5-9 8 0.56
132.5L 14500 4-9 11 10.0 0.57
135.0R 21500 9 6 11.2 0.44
135.1R 20000 3 6 18.9 0.44
144.0M 22000 9 12 9.0 0.31
145.6R 22000 9 8 56.3 0.6e
146.6L 26500 1-9 12 0~48
No Data Available
,....
80
Table 25.Representative Group IX
Description:Habitat character is dominated by low breaching flows and relatively
swift velocities.This group includes specific areas that were categorized as
mainstem at 5100 cfs,as well as side channels (Category 5)and indistinct side
channels (Category 6)with mean reach vE~locities greater than 5 fps at 10000 cfs
mainstem.
Habitat Mean Channel
Breaching Transformation Reach Dominant Length-Structural
Specific Flow Category Velocity Substrate to-Width Habi tat
Area (cfs)Sequence (fps)Code Ratio Index Model
r-101.5L <5100 10 3 ..0 12 12.7 0.45 IFGi
104.0R <5100 6 5..5 8 9.4 0.48
105.7R <5100 10 3,.0 11 8.6 0.53
108.9L <5100 10 5,,0 11 9.0 0.58
109.4R <5100 10 >4.0 12 18.2 0.45
111.OR <5100 10 3.5 6 12.3 0.35-113.8R <5100 6 6.0 12 7.2 0.53
117.7L <5100 6-5 5.5 8 8.5 0.41
127.1M <5100 6-5 5.0 10 13.9 0.53
128.3R <5100 6 >5.0 12 0.63
129.3L <5100 10-5 >6.0-12 12.2 0.62
129.8R <5100 10 >4.0 12 9.7 0.5E)
131.2R <5100 5 >5.0 8 13.6 0.48
135.0l <5100 10 4.5 12 6.1 0.48
139.2R <5100 6 >5.0 10 10.7 0.61
141.2R <5100 6-5 >5.0 13 0.69
F'141.3R <5100 5 >5.0 12 0.69
142.8R <5100 6 >5.0 12 0.56
144.0R <5100 10 >5.0 11 15.1 0.5"3
144.2L <5100 10 3.5 12 21.0 0.53
147.1L <5100 10 5.0 12 10.8 0.57 IFG
-
i
IFG =Instream Flow Group Habitat Model
--=No Data Available
81
Table 26.Representative Group X
Description:Habitat character is dominated by channel morphology.This group
includes large mainstem shoals and mainstl:m margin areas that had open leads in the
March 1983 photography.
Habitat Mean Channel
Breaching Transformation Reach Dominant length-Structural
Specific Flow Category Velocity Substrate to-Width Habi tat
Area (cfs)Sequence (fps)Code Ratio Index Model
105.8ll MSS 6 12 0.5]DIHAB
109.3M MSS 6-9 8 0.48
111.6R 11500 6-8-9 10 0.49
113.6R 10500 6-8 8 0.55
113.9R 7000 6 8 0.48
F"'119.11L MSS 6 2 ..0 8 0.41 DIHABI121.1R MSS 6-5 3..5 10 0.47!133.81R MSS 6 2 ..0 12 0.48 DIHAB
138.71L MSS 6 3,,0 12 0.5-7 DIHAB
139.3L MSS 6 10 0.56
139.41l MSS 6 3,,5 11 0.41 DIHAB
142.8L MSS 6 1..5 9 0.36
148.2R MSS 6-9 12 0.48
i"
MSS =Mainstem Shoal
DIHAB =Direct Input Habitat Model developed by EWT&A
--=No Data Ava i1 clb 1e
82
4.FUNCTION OF RESULTS IN EXTRAPOLATION
This section introduces the methodology used to extrapolate results from
modeled sites to nonmodeled areas of the middle Susitna River.As stated in
the introduction,this methodology consists of three parallel pathways of
analysis:1)quantification,2)stratification,and 3)simulation.The
-function of each of these pathways is dl~scribed below.
The quantification pathway,used to develop relationships between wetted
surface area (WSA)and discharge for each specific area,provides the basis
for detennining habitat quantities.The response to discharge relationships
F'are developed by digitizing areas delineated on aerial photo reproductions at
several mainstern flows.For a detailed discussion of the relationships of the
response of wetted surface area to discharge in the middle Susitna River see
Klinger~Kingsley (1985).
The stratification pathway,used to group individual channels based on common
characteri sti cs,assesses the representati veness of mode led sites to non-
modeled areas of the river and provides an index of site-specific structural
habitat qual ity for use in the derivation of habitat response to mainstem
..,"..q;:.,~
discharge relationships at nonmod~ed areas.Representativeness between
r"'"modeled and nonmodeled specific areas is ~valuated using hydrologic,hydrau-
lic,and morphologic indices derived from aerial photo and habitat inventory-data bases.Structural habitat indices are developed using habitat inventory
data and ADF&G suitability criteria for'juvenile chinook salmon.
,ct'';:~
.....
83
.....
The simul ati on pathway,usi ng habitat model s to develop rel ati onshi ps between
habitat availability and discharge at a spectrum of habitat types,identifies
the characteristic habitat response for a given type of habitat.The modeling
techniques used in this study are:1)the lnstream Flow Group1 (lFG)habitat
model (Milhous et ale 1984);2)a hablitat model (RJHAB)developed by ADF&G
(Schmidt et ale 1984);and 3)a direct input variation of the IFG habitat
.....model (DIHAB)developed by EWT&A (Hilliard et ale 1985).Tributary habitats
were not evaluated because they would not be affected by an altered mainstem
flow regime.Nleither were tributary mouth habitats evaluated,because they
constitute a small portion of the middlle Susitna River habitat and would not
be affected significantly.
~'
-
.....
The basic,unit generated by the habitat models is weighted usable area (WUA).
Weighted usable area is a quantitative index of juvenile chinook salmon
habitat availability at a given streamf"llow.It is a product of wetted surface
area (WSA)and suitabil ity factors for perti nent habitat variables (i.e.,flow
velocity,depth,and cover)(Suchanek et ale 1984).Pertinent to extrapo-
lation in the simulation analysis is the concept of the habitat availability
index (HAI).Dl~fined as WUA/WSA,the HAl provides a unitless measure of the
overall habitat suitability of a study site at a given streamflow.When the
HAl versus discharge is plotted,the resulting curve represents a characteris-
tic habitat response for a given type of habitat.This relationship is used
to derive habitat response to discharge relationships at nonmodeled areas.
1 Now known as the lnstream Flow and Aquatic Systems Group.
84
To derive HAl versus discharge relationships for nonmodeled areas,products
from the stratification and simulation pathways of analysis must be inte-
grated.These products are:(1)HAl versus discharge curves for each modeled
specific area;(2)representative groups;(3)breaching flows for modeled and
nonmodeled specific areas;and (4)structural habitat indices (SHI)for
modeled and nonmodeled specific areas.Three assumptions for these relation-
F""ships are also required:(1)the HAl versus discharge curve of modeled
specific areas is characteristic of nonmodeled specific areas within the same
representative fjroup;(2)breaching flows for modeled andnonmodeled specific
areas occur at the same relative position in the respective HAl versus dis-
charge curves;and (3)the amplitude of HAl versus discharge curves derived
for nonmodeled specific areas can be adjusted linearly using the ratio of
SHI's for nonmodeled and modeled specific areas.The procedures to derive HAl
versus discharge curves for nonmodele~d specific areas are illustrated in
Figure 12 and described as follows:(1)the characteristic curve of the
representative modeled specific area (MS)is assumed and shifted along the
,.....X-axis to correspond with the breachin~~flow of the nonmodeled specific area
(SA);and (2)the amplitude of the curve is adjusted using the formula
HAI(SA)=HAI(MS)X (SHI(SA)/SHI(MS)).This procedure is repeated for each
nonmodeled specific area in the middle Susitna River.
To calculate WLJA at nonmodeled specific areas,HAl versus discharge curves
from the foregoing analysis are combined with results from the quantification
pathway.As defined earlier,HAIls are unitless suitability factors calcu-
lated as WUA/WSA.From this definition it follows that WUA can be calculated
as HAl times WSA.By combining WSA rellationships developed for each specific
area via the quantification pathway with HAl versus discharge relationships,
85
BREACHING FLOW ADJUSTMENT
...
,
SA",
Qs,o.
-
MAINSTEM DISCHARGE
MS
(a)
-
STRUCTURAL HABlT~T QUALITY ADJUSTMENT
-
HAl =HAl .SHISA
SA MS.SHIMsv--.------.......
'-SA
'-/
......
MS
(b)
MAINSTEM DISCHARGE
.-
(c)
MODELED SPECIFIC
AREA (MS)CURVE
\DERIVED NON MODELED
/SPECIFIC AREA (SA)CURVE
MAINSTEM DISCHARGE
Figure.12.Derivation of
specific area
specifi c area
(b)structural
curve.
a HAl versus discharge curve for a nonmodeled
(SA)from the representative curve of a modeled
(MS)showing:(a)breaching flow adjustment;
habitat quality adjustment;and (c)the derived
86
."~
.--........------------f"""""""'....-,...---------------
-
.....
WUA versus discharge curves are derived for each specific area.By summing
the WUA versus discharge curves for each specific area within a representative
group,habitat response to discharge relationships are developed at the
habitat type level.Systemwide habita,t response to discharge relationships
can be developed subsequently by summinq the relationships determined for each
representative group.For a detailed discussion of the development and
presentation of habitat response relationships at middle Susitna River study
sites see Stew,ard et al.(l985).F'igure 13 shows a flow chart for the
stratification Clnd integration pathways of the extrapolation methodology •
87
r
.....
Stratification Palthway of 'the
Extrapolation Methodology
Stratification Pathway
•Delineate specific areas of homogeneous aquatic habitat type on aerial
photo plates.
•Conduct reconnaissance-level survey ()f aquatic habitat at each specific
area.
•Analyze aerial photography and habitat reconnaissance data base to
describe hydrologic,hydraulic,and structural components of each specific
area.
•Stratify -specific~Heas into Representaltive Groups using available hydro-
logic and hydraulic information.
•Develop Structural Habitat Indices for each specific area including
modeled sites using the habitat reconnaissance data base.
Quantification t Simulation
pathWay",Integra1l1on /pathway
The following steps are completed for each evaluation speciesllife stage.
•Use the habitat availability index (HAl)versus discharge curve of a modeled
specific iarea to synthesize the HAl versus discharge curve for a non-
modeled specific area within the same Representative Group.Shift the
curve laterally to compensate for differences in breaching flow between a
modeled and nonmodeled specific an~a.Adjust the HAl curve vertically
using the ratio of structural habitat indices to account for differences in
structural habitat quality between modeled and non modeled specific
areas.
•Calculate the weighted usable area (WUA)present within each specific
area using surface area and habitat availability indices for each mainstem
evaluation flow.
•Sum the WUA calculated for all specific areas within each Representative
Group fOIr each mainstem evaluation flow.
•Sum theWUA calculated.for all Representative Groups for each mainstem
evaluation flow to forecast Middle Sus/tna River habitat response to flow
variations.
Figure 13.Flow chart for the stratification and pathway of the extrapolation
methodology.
88
-
LITERATURE CITED
.....
lITERATURE CITED
Binns,N.A.and F.M.Eiserman.1979.Quantification of fluvial trout habitat
in Wyoming"Trans.American Fisheries Society 108:215-228.
Bovee,K.D.1982. A guide to stream habitat analysis using the instream flow
incrementa"1 methodology.U.S.Fish and Wildlife Service.Instream Flow
Information Paper 12.1 vol.
Chamberlin,T.W.1981.Systematic aquatic biophysical inventory in British
Columbia,Canada in Acquisition and utilization of aquatic habitat
inventory 'information.Armantrout,N.B.ed.,Proceedings of a symposium
held 28-30 October,1981 Hilton Hotel,Portland,Oregon.
Chow,V.T.1959.Open-channel hydraulics.McGraw-Hill.680 pp.
deleeuw,A.D.1981. A British Columbia stream habitat and fish population
inventory system in Acquisition and utilization of aquatic habitat
inventory 'information.Armantrout,N.B.ed.,Proceedings of a symposium
held 28-30 October,1981 Hilton Hotel,Portland,Oregon.
E.Woody Trihey and Associates and Woodward-Clyde Consultants.1985.
--Instream flow relationships report.Volume No.1.Draft report for
Alaska POWE~r Authority,Susitna Hydroelectric Project,Anchorage,AK.
-
-
....
Estes,C.C.,and D.S.Vincent-lang,eds.1984.Report No.3.Aquatic
habitat and instream flow investigations (May-October 1983).Chapter 7:
An evaluat"ion of chum and sockeye salmon spawning habitat in sloughs and
side channels of the middle Susitna River.Susitna Hydro'Aquatic
Studies,Alaska Dept.of Fish and Game.Report for Alaska Power
Authority,Anchorage,AK.Document 1936.1 vol.
Glova,G.J.and M.J.Duncan.1985.Potential effects of reduced flows on
fish habitats in a large braided r'iver,New Zealand.Transactions of the
Ameri can Fli sheri es Soci ety 114:165·-181.
Gorman,O.T.and J.R.Karr.1978.Habitat structure and stream fish commu-
nities.Ecology,59(3):507-515.
Hilliard,N.D.,et al.1985.Hydraul'ic relationships and model calibration
procedures at 1984 study sites in the Talkeetna-to-Devil Canyon segment
of the Susitna River,Alaska.E.Woody Trihey and Associates.Report
for Alaska Power Authority,Anchoriige,AK.1 vol.
Hynes,H.B.N.1970.The ecology of running waters.University of Toronto
Press.55~j pp.
Klecka,W.R.1975.Discriminant analysis.Pp.434-467 in Nie,N.H.et al.
S.P.S.S.:statistical package for the social sciences.McGraw-Hill .
89
.-
Klinger,S.and E.W.Trihey.1984.Response of aquatic habitat surface areas
to mainstem discharge in the Ta'lkeetna-to-Devil Canyon reach of the
~Susitna River,Alaska.E.Woody Trihey and Associates.Report for
Alaska Power Authority,Susitna Hydroelectric Project,Anchorage,AK.
Document 1693.1 vol.
Kl i nger-Ki ngs 1ey,S.1985 ..
mainstem discharge in
Susitna River,Alaska.
Alaska POWE!r Authori ty.
Response of aquatic habitat surface areas to
the Talkeetna-to-Devil Canyon segment of the
Draft report.E.Woody Trihey and Associates.
Susitna Hydroelectric Project.1 vol.
Labelle,J.C.,M.S.Arend,L.D.Leslie,W.J.Wilson.1985.Geomorphic change
in the middle Susitna River since 1949.University of Alaska,Fairbanks,
Arctic Environmental Information and Data Center.Report for Alaska
Power Authority.Susitna Hydroelectric Project.1 Vol.
Lane,E.W.1985.The importance of fluvial morphology in hydraulic engineer-
ing.Amer'ican Society of Civil Engineers,vol.81,Paper No.745.
Hydraulics Division.
Water-resources engineering.1979.Linsley,R.K.,and J.B.Franzini.
McGraw-Hill.716 pp.
Milhous,R.T.,D.L.Wegner,and T.Waddle.1984.Users guide to the Physical
Habitat Simulation System (PHABSIM).U.S.Fish and Wildlife Service.
Instream Flow Information Paper 11.1 vol.
Mosley,M.P.1982.Analysis of the effect of changing discharge on channel
morphology and instream uses in a braided river,Ohau River,New Zealand.
Water Resources Research,Vol.18,No.4,pp.800-812.
R&M Consultants,Inc.1982.Sus itna Hydroel ectri c Project
Morphology"Prepared for Alaska Power Authority,Anchorage,AK.
River
105 pp.
Reiser,D.W.,.and I.C.Bjornn.1979.Influence of forest and rangeland
management on anadromous fi sh habi tat in Western North Ameri ca -l.
Habitat requirements of anadromolls salmonids.Gen.Tech.Rep.PNW-96
Pacifi c Northwest Forest and Range Experiment Stati on,Forest Servi ce,
U.S.D.A.Portland,Oregon.
Schmidt,D.C.et al.1984.Report No.2.Resident and juvenile anadromous
fish investigations (May -October 1983).Susitna Hydro Aquatic Studies,
Alaska Dept.of Fish and Game.Report for Alaska Power Authority,
Anchorage,AK.Document 1784.1 vol.
Shera,W.P.,and E.A.Harding.1981.Cost-efficient biophysical stream
surveys:a proven approach 1i!.Acqui siti on and util izati on of aquati c
habitat inventory information.Armantrout,N.B.ed.,Proceedings of a
symposium held 28-30 October,1981 Hilton Hotel,Portland,Oregon.
Shields,A.1936.ItAnwendung der Aehnlichkeitsmechanik und der Turbulenz-
forschung auf die Geschiebebewegung ll (Application of Similarity Princi-
pl es and Turbul ence Research to Bed-Load Movement),lV1itteil ungen der
Preuss.Versuchsanst fur Wasserbau und Schiffbau,Berlin,No.26.
90
--
Steward,III,C.R.1985.Suitability criteria recommended for use in IFR
habitat modeling studies of thl~middle Susitna River.Technical
memorandum.E.Woody Tri hey and Associates,Anchorage,AK.11 pp.
Steward,III,C.R.,R.C.Wilkinson,and A.Milner.1985.Response of juve-
nile chinook habitat to mainstem discharge in the Talkeetna-to-Devil
Canyon segment of the Susitna River,Alaska.E.Woody Trihey and Associ-
ates.Draft report for Alaska Powe~r Authority,Anchorage,AK.1 vol.
Suchanek,P.M.,R.P.Marshall,S.S.Hale and D.C.Schmidt.1984.Juveni1e
salmon rear'ing suitability criteri,a.49 pp.Part 3 in D.C.Schmidt et
al.,eds.Report No.2.Resident and juvenile anadromous fish inves-
tigations (May -October 1983).Susitna Hydro Aquatic Studies,Alaska
Dept.of Fish and Game.Report for Alaska Power Authority,Anchorage,
AK.Document 1784.1 vol.
Vining,L.J.,J ..S.Blakely,and G.M.F'reeman.1985.Report No.5.Winter
Aquatic Investigations (September 1983-May 1984).Vol.1:An .evaluation
of the incubation life-phase of chum salmon in the middle Susitna River,
Alaska.SLlsitna Hydro Aquatic Studies,Alaska Dept.of Fish and Game.
Report for Alaska Power Authority,Anchorage,AK.Document 2658.1 vol.
Ward,B.R.and P.A.Slaney.1979.Evaluation of instream enhancement struc-
tures for the production of juvenile steel head trout and coho sa lmoni n
the Keogh River:progress 1977 and 1978.B.C.Ministry of Environment,
Fisheries Technical Circular No.45.47 pp.
Wishart,D.19~78.Clustan User Manua'J 3rd Edition.Program Library Unit,
Edinburgh University.
91
APPENDIX 1
SPECIFIC AREAS DELINEATED ON THE 23000 CFS AERIAL PHOTOGRAPHY
1 )I 1 'I .~1 I 1 1 )
'0
W
~~~2;OL_
:.........'...
~.....~./~.:.;.::~~~";::..:.:~~:/~:,,-~~:.~:~:.:.~!'~.j-~.~~~::~,~'~;iJt~¥~~f.~~i;~.tt~l#'~'-,;--,'~~.!\.}.u".~.·'\~.~r·.~(.'t--·:·~"ti<f!:!.S..•~;;'~~.Vk!~··~Il'"w.""-1..~.$.tt.if;iJt.:;:5.}:~;~~
Specific areas from river mile 100 to 104 at a
LEGEND:
L :::Left
R :=Right
H :::Middle
RNR
LNR
111S
Right Not Reconned
:::Left Not Reconned
Left Mainstem Spawning
reMS =Right Mainstem Spawning
NNS :::~1iddle Hainstem Spawning
T :::
+
~:::
Tributary
River Mile
Flow Direction
J J I 1 1 1 1 J I
\.D..,.
Specific areas from river mile 104 to 110 at a mainstem discharge of 23000 cfs.
LEGEND:
L =Left
R =-Right
H =~1iddle
RNR
LNR
LMS
Right Not Reconned
Left Not Reconned
=Left Hainstem Spawning
RMS
t1MS
Right Mainstem Spawning
Middle Hainstem Spawning
T =
+=
.-L.=
Tributary
River Bile
Flow Direction
1 1 i ]J J -1 J
~en
Specific areas from river mile 110 to 115 at a mainstem discharge of 23000 cfs.
LEGEND:
L =Left
R ""Right
M =Middle
RNR ;:
LNR
LMS
Right Not Reconned
Left Not Reconned
Left Mainstem Spawning
R}IS
MMS
I •
Right Mainstem Spawning
""Middle Mainstem Spawning
T ""Tributary
+=·River Mile
-...=Flow Direction
)-1 I I 1 I 1 J I I 1 1 i 1 1 I
1.0
O'l
Specific areas from river mile 115 to 121 at a mainstem discharge of 23000 cfs.
LEGEND:
L =Left RNR =Right Not Reconned RMS =Right Hainstem Spawning T =Tributary
R =Right LNR =Left Not Reconned MMS =Middle Mainstem Spawning +=River Mile
M =Middle LMS =Left Mainstem Spawning --=Flow Direction
-)1 1 1 ]1 i 1 ]J I
l.O.......'>~1i:~<~1~;~~
..."!..,:....::"""N~1~~f;~&1
'"
Specific areas from river mile 121 to 126 at a mainstem discharge of 23000 cfs.
LEGEND:
L =:Left RNR =:Right Not Reconned RMS =:Right Mainstem Spawning T =:Tributary
R =Right LNR =:Left Not Reconned MMS =Middle Mainstem Spawning +=River Mile
M =:Middle LMS =Left Mainstem Spawning -'=:Flow Direction
1 I J J 1 1 I
lD
0::>
;m:''''~':M'lI''"!::lf~'ml"l"'~,III<"t;~''I'.',,,,,:'Jtl<;~;.i!.'l"]l;:~,E .J .,;~'f.:\~.:;'''\!l{~,.~::..,..",,~!.,~~.::.J>.:(;>,~~j~~~;!'b~~~Z~~f~.·,~,,;~~~~.;~4,"'::;'\:::;I;~t':-~.~~~.:.~~~~~~.:.'~~~~':r~~~t4':t111:.~'~~i~~!~~"r~{·:~~)~~:,·,:;'-:'~"~'<;:~'''~,(''''';!'i~,•.,...~.,.;~••.~.,~~'If:\'.,..•.••'f'<,;-1 1:•.."•...~"'".-f:i",..~4;(_......
'.......r;t1 ••.f.:.""~~.j'"'\'...,,;--'\l'l···"':i;.,..';l'"~..~i~~;~~~
Specific areas from river mile 126 to 132 at a mainstem discharge of 23000 cfs.
LEGEND:
L =Left RNR =Right Not Reconned RMS ==Right Mainstem Spawning T ==Tributary
R ==Right LNR ==Left Not Reconned MMS =Middle Hainstem Spawning +=River Mile
M =Middle LMS =Left Mainstem Spawning -'==Flow Direction
J 1 1 l 1 i J I 1 1 1 1
f)~.~,-:~.:./.f!~:
.;.....:~135 1A~~"~:'".~~~,:.:;~
,I -,.~t''''.•.
Specific areas from river mile 132 to 138 at a mainstem discharge of 23000 cfs.
+
.-r-
LEGEND:
L =Left
R ::Right
H =Middle
RNR =Right Not Reconned
LNR ::Left Not Reconned
LMS=Left Mainstem Spawning
RMS
MMS
=Right Mainstem Spawning
Middle Mainstem Spawning
T ::Tributary
==River Mile
Flow Direction
I I 1 -1 -,i 1 1 1 J 1 I 1 j
~
D
D
Specific areas from river mile 138 to 144 at a mainstem discharge of 23000 cfs.
LEGEND:
L =Left
R =Right
M =Middle
RNR
LNR
LMS
Right Not Reconned
=Left Not Reconned
Left Mainstem Spawning
RMS
MMS
=Right Mainstem Spawning
Middle Mainstem Spawning
T
+
....tt£..
Tributary
River Mile
Flow Direction
1 ]1 1 J I .~-j j 1 »-1 .,
.......o.......
Specific areas from river mile 144 to 148 ata mainstem discharge of 23000 cfs.
LEGEND:
L ""Left RNR ""Right Not Reconned RMS ""Right Mainstem Spawning T =Tributary
R =Right LNR =Left Not Reconned MMS ""Middle Mainstem Spawning +""River Mile
M ""Middle LMS =Left Mainstem Spawning ~=Flow Direction
-
APPENDIX 2
HABITAT INVENTORY TECHNIQUES
"
-
HABITAT INVENTORY TECHNIQUES
The habitat reconnaissance work was based on the premise that the habitat
characteristics of each specific area could be averaged in order to develop a
reliable composite description of the entire area.The intent was to describe
the habitat in general terms (for example,mean reach velocity)and not to map
localized habitat features.
The habitat inventory forms (Figure 14)provided a framework for the field
reconnaissance work.These forms were designed to facilitate a cost-effective
means of gathering reliable field observations based on visual assessment and
minimal field measurements.
Several factors were considered whill~developing the habitat inventory form.
These included:(1)the total time allocated for the habitat inventory task
(approximately one month);(2)the large number of specific areas to be
surveyed;(3)a limitation of approximately one hour per specific area;
(4)the use of minimal field gear (for ease in maneuvering at each specific
area and dur"ing helicopter transport);(5)compatibility with ADF&G data;and
(6)ease in computer data management.The methods and field techniques for
completing the habitat inventory form are described below.
103
Sheet 1 of __
Habitat Inventory
Date:
Time:
R.M.:
Category:_
Breached?Yes/No
Location:_,_
Mainstem Discharge:_
Crew:
.....
Mean Reach Velocity:Estimated/Measured
Site Specific Discharge:Estimated/Measured
Does Upwelling Occur?Ye:s(No/Cannot Be Detected Visually
Do Tributaries Enter the Slough or Side Channel?Yes/No
If Yes,Description of Tributary (size~location):_
-.Head Gage:_
Mid-Reach Gage:_
Mouth Gage:
WSEl:
WSEl:
WSEL:
Remarks:
Substrate:1 2 3 4 5 6 7 8 9 10 11 12 13
Substrate Embeddedness:1 2 3
Dom.inant Cover Code:1 2 3 ,4 5 6 7 8 9
Percent Cover:1 2 3 4 5 6
Streambank Slope:LB 1 2 3 Stuble/Unstable RB 1 2 3 Stable/Unstable
Streambank.Vegetation:LB 1 234 RB 1 2 3 4
Represent~ltive Top Width:Bankfull Top Width:
Representative Depth:Bankfull Depth:,_
Water Clarity:Clear/Turbid ft.
length of Backwater.Estimated/Measured
Were Fish Observed?Yes/No
Adult:Chinook Coho Sockeye_Chum __Pink _
Juvenile:Chinook Coho __Sockeye __Chum __Pink __
Remarks:
FiourFl 14.....:1!:..l:O:.;;:;4 -"'"""'"'.='"'...
,~
I
I
,....
Habitat Inventory
Crew:
Site Sketch &Habitat Mapping
Sheet 2 of _
Date:_
Time:
R.M.:
Flow Description &Remarks
Habitat Type Proportions:
Habitat QuaUty Proportions:
Figure 14 (cont)
Pool
105
___Run
EWTAA
Sheet 3 of __
Habitat Inventory
-
-
-
Crew:
PHOTOGRAPHS
No.Description
Figure 14 (cont)106
Date:_
Time:_
R.M.:
Film 1.0.No.:_
EWT&A
_c ,~_
,....
I
Habitat Inventory
Crew:
DETAIL:Sketch and Description
Figure 14 (cant)
I
107
Sheet _of __
Date:_
Time:_
R.M.:
EWT&A
-
-
......
Two field crews were in the helicopter for "initial morning flights.Upon
reaching a spe!cific area,an overflight of the area provided an overview for
determining features such as flm"patterns,breached or nonbreached
conditions,backwater influence,etc.Low altitude aerial photos were taken
at this time.The helicopter would then land and drop off the first crew to
complete the ground survey and fill in the habitat inventory form.A separate
form for each specific area was completed.The remaining crew would then
proceed to the next specific area downstream of the first crew and complete
that area.This "leap-frogging"down the river was a fast and efficient way
of covering many specific areas each day.On the average,27 specific areas
were visited per day.For a more detailed discussion of habitat
reconnai ssance~methodo 1ogi es see Chamberl in 1981,and Shera and Hardi ng 1981.
DESCRIPTION AND USE OF THE HABITAT INVENTORY FORM
PAGE ONE
Crew:A minimum of two people were sent to evaluate each specific area.Two
people were important because of the subjectivity of the work.The ability to
discuss the habitat and work out perceived differences helped remove
individual bias from the data.
R.M.:Each specific area was referenced to a river mile and with respect to
the mainstem looking upriver:left (L),right (R),or middle (M)if between
two mainstem forks .
108
Category:The perceived habitat transformation category of the specific area.
Location:Designations commonly uSled to reference the specific area,if
applicable.
Mainstem Discharge:This data was obtained from USGS records for the Gold
Creek gage.
Breached:Whether the channel was breached or nonbreached.
Mean Reach Velocity:Three methods were used to determine mean reach
velocity.The first method involved estimating the surface velocity by
recording the time it took a floating object to travel a known distance.The,-
mean reach velocity was estimated as 85 percent of this surface velocity
(linsley and Franzini 1979).The second method involved measuring the height
(h)that water "climbed"a survey rod held perpendicular to the flow (i.e.,
.~conversion of kinetic energy to potential energy).The relationship between h
and mean reach velocity is depicted in Figure 13.Tabulated values of
velocity corresponding with particular heights appear ~n Table 19.On rare
occasions,a Marsh McBirney Type 201 portable current meter with wading rod
was used to measure velocity.Velocity was measured at a point 0.6 times the
depth from the water surface elevation for depths less than or equal to 2.5
ft.Velocity was determined as the average of measurements made at 0.2 and
0.8 times the depth from the water surface elevation for depths greater than
2.5 ft.The Marsh McBi rney was used primarily to check the accuracy of the
two approximate methods of estimatingl mean reach velocities.
109
-
Site Specific Discharge:The discharge was estimated using the equation
Q=V(W)(d),where V is estimated mean reach velocity (fps),W is the
representative top width (ft),and d is the mean depth of the portion of the
top width conveying most of the flow (ft).
Does Upwell·jng Occur?:Visual detection was recorded as positive if actual
upwelling was observed as a volcano-like structure in fine sediments.If an
area was breached,turbidity made it difficult to visually determine if
upwelling occurred.A response of IIcannot be detected visuallyll was then
appropriate.A negative response was recorded only if a channel was dewatered
or consisted of isolated pools.
Do Tributaries Enter the Slough or Side Channel?:If one or more tributaries
entered the specific area,a brief description of each was recorded.
Information included where it entered the specific area,its estimated
discharge,and the effect this additional inflow had on fish habitat.
Head Gage,Mid-Reach Gage,Mouth Gage:One or more staff gages were
occasionally in place within the specific area.If so,the water surface
elevation and gage number was recolr"ded,as well as any remarks about the
condition of the gage (e.g.,bent).
Substrate:The coding scheme and methods chosen for this habitat inventory
parameter corresponded directly with ADF&G field methods (Estes and
Vincent-Lang 1984).The substrate type and corresponding code numbers are:
110
r
Code
1
2
3
4
5
6
7
8
9
10
11
12
13
~
Si 1t
Silt and Sand
Sand
Sand and Small Gravel
Small Gravel
Small and Large Gravel
Large Gravel
Large Gravel and Rubble
Rubble
Rubble and Cobble
Cobble
Cobble and Boulder
Boulder
Size (inches)
1/8 - 1
1 - 3
3 - 5
5 -10
10+
"""'
This was one of the more difficult parameters to average for an entire
specific area.For this reason,tw'o codes indicating substrate size were
often chosen Clnd a map indicating substrate zones within the specific area was
drawn on page two of the habitat inventory form.
Substrate Embeddedness:Substrate embeddedness descri pt ions and thei r code
numbers are:
-Code
1
2
3
DE~scription
Embedded,consolidated,and cemented
Embedded but not cemented
Not embedded
.....
Embeddedness implies a larger substrate material partially or fully buried in
smaller material.If a substrate constituent was not embedded in smaller
material it l,alaS coded 3.Substrate that was partially embedded but not
consolidated was coded 2.The deglree of consolidation was determined by
trying to penetrate the upper substrate 1ayer with a boot.If the upper
111
layer was difficult to break through,then the substrate was considered
cemented for a substrate embeddedness code of 1.
Dominant Cover Code:The codes used were developed by ADF&G (Schmidt etal.
1984):
Code
1
2
3
4
5
6
7
8
9
No Cover
Emergent Vegetation
Aquatic Vegetation
Lclrge Gravel
Rubble
C()bb 1e/Bou 1der
Debris/Deadfall
Overhanging Riparian
Undercut Banks
More than one cover code was recorded if the avail ab 1e cover ina specifi c
area was not dominated by one type.
Percent Cover:This code indicates the percent surface area available as
cover to juvenile fish.These codes were developed by ADF&G (Schmidt et al.
1984):
Code
1
2
3
4
5
6
Percent Cover
0··5
6··25
26-50
51-75
76-95
96-100
112
Streambank Sl(~:Streambank slope and stability for both the left and right
banks was recorded.The slope was determined to be steep if the horizontal to
vertical ratio was greater than or equal to 1:1 (code number 1);moderate if
the ratio was between 1:1 and 20:1 (c:ode number 2);and flat if the ratio was
greater than 20:1 (code number 3).The streambank stability was determined by
observing the composition of each bank.Sandy banks and broad,flat gravel
bars were considered the least stable,while rocky or heavily vegetated banks
were considered stable.
Streambank Vegetation:The vegetatiion for each bank was described by the
following codes:
Code
1
2
3
4
Description
Less than 50 percent of streambank vegetated
Dominant vegetation is grass
Dominant vegetation is shrub
Dominant vegetation is of tree form
......
-
Two or more codes were used if one code did not adequately describe the
vegetation.The areas of differing vegetation were then noted on page two of
the habitat inventory form.
Representative Top Width,Bankfull Top Width,Representative Depth,and'
Bankfull Depth:Depth was measured using a yardstick or surveyor rod and
distances were determined using either a Ranging 600 range finder or
fiberglass tape.Bankfull top widths and bankfull depths were sometimes
impossible to measure.A shoal for example has only one bank and top widths
and depths are therefore not appl iCCtble.Some difficulty in deternrining the
113
water 1i ne for bankfull depths wa.s encountered.Thi s was overcome by
observing indicators such as debris lines,water stained or dirty rocks,
damage to strE~ambank vegetation,or channel morphology.
Water Clarity:Water within each specific area was identified as clear or
turbid.If turbid,the depth,in feet,of how far one could see into
the water was determined by reading the lowest visible mark on a survey rod or
ya rdstick.
Length of Backwater:The intrusion of backwater was either measured or
estimated,in feet,from the point of the confluence with the mainstem.
I''''''
Were Fish Observed?:Determination of fish presence was through visual
observation.Information recorded included the presence or absence of fish,
whether the fish was an adult or juvenile,the species,the abundance,and the
activity (spawning adults for example).To ensure positive identification of
--juvenile fish,attempts were made to capture a sample using either a beach
seine or a hl~l1d-held dip net.The beach seine,used primarily in turbid
.....
water,proved to be too time-consuming.The use of this form of capture was
discontinued after the first field trip .
.-PAGE TWO
-
-i
i
Site Sketch and Habitat Mapping:A sketch of each specific area was made.
Additionally,any notes on plan form;habitat types;discharge;velocities;
size of pools,riffles,runs,and their relative proportions;fish usage;
1.14
general slope or gradient of the streambed;substrate;vegetation;fish
activities;or other information which would help characterize the habitat was
recorded.
Habitat Type Proportions:After the first field trip this parameter was
added.An estimate of the percentage of pool and/or riffle and/or run was
recorded.
Habitat Quality Proportions:Habitat quality proporti ons were recorded for
juvenile chinook salmon according to the following codes:
Code
1
2
3
4
5
Description
No habitat value
Habitat quality was poor
Habitat quality was fair
Habitat quality was good
Habitat quality was excellent
For example,a specific area could have been recorded as 20%,code 2,poor
habitat;30%,code 3,fair habitat;and 50%,code 4,good habitat.Habitat
quality proportions were subjective evaluations based on knowledge of fishery
habitats.
PAGE THREE
Photographs were described and recorded on this page.Photographs were taken
to help describe the specific area in general,or a particular feature of the
area (such as substrate).
115
PAGE FOUR
This page was used for additional notes or detailed drawings to further
describe a specific area.
~
i 116
--.,..-------------~-------___..,_..,.i---~--"'F,.---------·-------------
APPENDIX 3
AQUATIC HABITAT TRANSFORMATIONS OF SPECIFIC AREAS
OF THE MIDDLE SUSITNA RIVER
AT SEVERAL MAINSTEM DISCHARGES REFERENCED TO 23000 CFS
APPENDIX 3
Aquatic Habitat Transformations of Specific Areas
of the Middle Susitna River
at Several Mainstem Discharges
Referenced to 23000 cfs
Mainstem Q(cfs)
River
Mile 2~3000 18000 16000 12500 10600 9000 7400 5100
100.40 R SC 4 4 2 2 2 2 2
100.60 R SS 1 1 1 1 1 1 1
100.60 L SC 4 4 4 4 3 3 3
100.70 R MS 10 10 4 4 4 4 4
101.20 R SC 4 4 4 4 2 2 2
101.30 M SC 4 4 4 4 9 9 9-101.40 L SC 2 2 2 2 2 2 2
101.50 L MS 10 10 10 10 4 4 4
101.60 L SC 4 4 2 2 2 2 2
101.70 L SC 4 4 4 4 3 3 3
r-o 101.71 L MSS 8 8 8 8 9 9 9
101.80 L SC 2 2 2 2 2 2 2
102.00 L SC 4 4 4 4 9 9 9
102.20 L US 1 1 1 1 1 1 1
102.60 L SC 4 4 4 4 4 4 3
104.00 R IMS 6 6
6·6 6 6 6
104.30 M SC 3 3 9 9 9 9 9
105.20 R US 1 1 1 1 1 1 1
105.70 R MS 10 10 10 10 10 10 10
105.81 L MSS 6 6 6 6 6 6 6
106.30 R SC 4 4 4 4 4 4 4
107.10 L SC 4 4 4 4 3 9 9
107.60 L US 1 1 1 1 1 1 1....108.30 L US 1 1 1 1 1 1 1
108.70 L MS 10 10 4 4 4 4 4
108.90 L MS 10 10 10 10 10 10 10
~109.30 M MSS 6 6 6 6 9 9 9
109.40 R MS 10 10 10 10 10 10 10
109.50 M SC 4 4 9 9 9 9 9
110.40 L SC 4 4 4 2 2 2 2
~110.80 M SC 4 4 4 4 4 4 4
111.00 R MS 10 10 10 10 10 10 10
111.50 R MS 10 10 4 4 4 4 4
111.60 R MSS 6 6 6 8 8 9 9
112.40 L SC 9 9 9 9 9 9 9
112.50 L US 1 1 1 1 1 1 1
112.60 L MS 4 4 4 4 4 4 4
Habitat Type at Reference Flow SC =Side Channel
IMS =Indistinct Mainstem SS =Side Slough
MSS =Mainstem Shoal US =Upland Slough
ISC =Indistinct Side Channel MS =Mainstem
118
-
River
Mile 23000 18000 16000 12500 10600 9000 7400 5100
113.10 R SS 1 1 1 1 1 1 1
113.60 R IMS 6 6 6 6 8 8 8
113.70 R SS 1 1 1 1 1 1 1
113.80 R IMS 6 6 6 6 6 6 6
113.90 R IMS 6 6 6 6 6 6 8
114.00 R MS 4 4 4 4 4 4 4
114.10 R ISC 5 5 5 5 5 5 5
115.00 R SC 4 4 4 2 2 2 2
115.60 R SC 2 2 2 2 2 2 2
116.80 R MS 10 10 4 4 4 4 4
117.00 M ISC 6 6 8 8 8 9 9
F'"117.10 M SC 4 4 3 3 3 3 3
117.20 M SC 3 9 9 9 9 9 9
117.70 L IMS 6 6 5 5 5 5 5
117.80 L SC 4 4 4 4 4 2 2
117.90 R SC 4 4 4 4 4 4 3
117.90 L SC 2 2 2 2 2 2 2
118.00 L SC 3 3 3 3 3 3 3
118.60 M ISC 5 5 8 8 8 8 8
118.91 L MSS 6 6 6 6 6 6 6
119.11 L MSS 6 6 6 6 6 6 6
~119.20 R SC 4 4 4 4 3 3 3
119.30 L SC 4 4 2 2 2 2 2
119.40 L US 1 1 9 9 9 9 9
119.50 L SC 4 4 4 4 4 4 4
~...119.60 L SC 4 4 4 4 4 4 4
119.70 L SC 2 2 2 2 2 2 2
119.80 L SC 4 4 9 9 9 9 9
120.00 R US 1 1 1 1 1 1 1
120.00 L SC 4 4 3 3 3 9 9
121.10 R IMS 6 6 6 6 6 6 5
.-121.10 L S,C 4 4 4 4 4 4 3
121.50 R SC 3 3 3 3 9 9 9
121.60 R SC 4 4 3 3 9 9 9
121.70 R MS 10 10 4 4 4 4 4
121.80 R SC 3 3 3 3 3 3 3
121.90 R US 1 1 1 1 1 1 1
122.40 R SS 1 1 1 1 1 1 1
122.50 R SC 2 2 2 2 2 2 2
123.00 L SC 4 4 4 4 4 4 4
123.10 R US 1 1 1 1 1 1 1
123.20 R ISC 8 8 8 8 8 8 9
123.30 R US 1 1 1 1 1 1 1
123.60 R SS 1 1 1 1 1 1 1
Habitat Type at Reference Flow SC =Side Channel
IMS =Indistinct ~ainstem SS =Side Slough
MSS =Mainstem Shoal US =Upland Slough
ISC =Indistinct Side Channel MS =Mainstem
-,
,119
--~"""'""""'-
River
Mile 23000 18000 16000 12500 10600 9000 7400 5100
124.00 M ISC 7 7 7 7 7 7 7
124.10 L MS 10 10 10 10 10 10 4
124.80 R ISC 8 8 8 8 8 8 9
125.10 R SC 2 2 2 2 2 2 2
125.20 R MS 4 4 4 4 4 4 4
125.60 L MSS 6 6 6 6 5 5 5
125.60 R SS 9 .9 9 9 9 9 9
125.90 R SS 1 1 1 1 1 1 1
126.00 R SS 1 1 1 1 1 1 1
126.30 R SS 1 1 1 1 1 1 1
127.00 M SC 4 4 4 4 4 4 4
~'IiIIi 127.10 M IMS 6 6 6 5 5 5 5
127.20 M US 1 1 1 1 1 1 1
127.40 L MS 10 10 10 10 10 4 4
~127.50 M ISC 6 6 6 6 5 5 5
128.30 R IMS 6 6 6 6 6 6 6
128.40 R MSS 6 6 6 5 5 9 9
128.50 R SC 4 4 4 4 2 2 2-128.70 R SC 4 4 2 2 2 2 2
128.80 R SC 4 2 2 2 2 2 2
129.30 L IMS 10 10 10 10 5 5 5
129.40 R US 1 1 1 1 1 1 1
129.50 R ISC 6 6 5 5 5 5 5
129.80 R MS 10 10 10 10 10 10 10
130.20 R SC 4 4 4 2 2 2 2
130.20 L SC 4 4 4 4 4 3 3
131.20 R IMS 5 5 5 5 5 5 5
131.30 L SC 4 4 4 4 4 2 2
~131.70 L SC 4 4 4 4 4 4 4
131.80 L SS 1 1 1 1 1 1 1
132.50 L SC 4 4 9 9 9 9
.g
132.60 L SC 4 4 4 4 3 3 3
132.80 R IMS 7 7 7 7 7 7 7
133.70 R .SC 4 4 4 2 2 2 2
133.80 L SC 4 2 2 2 2 2 2
133.81 R MSS 6 6 6 6 6 6 6
133.90 R SS 1 1 1 1 1 1 1
133.90 L US 1 1 1 1 1 1 1
134.00 L US 1 1 1 1 1 1 1
134.90 R SC 4 4 4 4 4 4 4
135.00 R SC 9 9 9 9 9 9 9,....135.00 L MS 10 10 10 10 10 10 10
135.10 R SC 3 3 3 3 3 3 3
135.30 L SC 3 3 3 3 3 3 3
135.50 R US 9 9 9 9 9 9 9
Habitat Type ,at Reference Flow SC =Side Channel
IMS =Indistinct Mainstem SS =Side Slough
MSS =Mainstem Shoal US =Upland Slough
ISC =Indistinct Side Channel MS =Mainstem-
120
~-
_Nl!1'___
-";:p1"lIE"!I77j1<l1i4
River-Mile 23000 18000 16000 12500 10600 9000 7400 5100
135.60 R SS 1 1 1 1 1 1 1
135.70 R SS 1 1 1 1 1 1 1
136.00 L SC 4 4 4 4 4 4 4
136.30 R SC 4 4 2 2 2 2 2
136.90 R US 1 1 1 1 1 1 1
~137.20 R SC 4 4 4 4 2 2 2
137.50 R SC 2 2 2 2 2 2 2
137.50 L S5 1 1 1 1 1 1 1
137.80 L SC 2 2 2 2 2 2 2
137.90 L SC 2 2 2 2 2 2 2
138.00 L SC 4 4 4 4 4 2 2
.-138.71 L MSS 6 6 6 6 6 6 6
138.80 R IMS 6 5 5 5 5 5 9
139.00 L US 1 1 1 1 1 1 1
139.01 L MSS 6 6 6 6 6 6 6
139.20 R IMS 6 6 6 6 6 6 6
139.30 L MSS 6 6 6 6 6 6 6
139.40 L SC 4 4 4 4 4 4 4
,~139.41 L MSS 6 6 6 6 6 6 6
139.50 R IMS 6 6 6 5 5 7 7
139.60 L MS 10 10 10 10 10 10 4
~139.70 R SC 2 2 2 2 2 2 2
139.90 R US 1 1 1 1 1 1 1
140.20 R SS 1 1 1 1 1 1 1
140.40 R IMS 6 6 6 6 6 6 6
140.60 R ISC 6 6 5 8 8 9 9
141.20 R IMS 6 6 6 5 5 5 5
141.30 R IMS 5 5 5 5 5 5 5
141.40 R SC 4 4 4 2 2 2 2
141.60 R ISC 7 7 7 7 7 7 7
142.00 R ISC 5 5 5 5 8 8 8
142.10 R SS 1 1 1 1 1 1 1
142.20 R SS 1 1 1 1 1 1 1
142.80 R IMS 6 6 6 6 6 6 6
142.80 L MSS 6 6 6 6 6 6 6
143.00 /.;MSS 6 6 6 6 6 6 7
143.40 L SS 1 1 1 1 1 9 9
144.00 R MS 10 10 10 10 10 10 10
144.00 M SC 9 9 9 9 9 9 9
144.20 L MS 10 10 10 10 10 10 10
144.40 L SC 2 2 2 2 2 2 2
~145.30 R MS 10 10 10 10 10 10 4
145.60 R SC 9 9 9 9 9 9 9
146.60 L SS 1 9 9 9 9 9 9
147.10 L MS 10 10 10 10 10 10 10
148.20 R MSS 6 6 6 9 9 9 9
~Habitat Type at Reference Flow 5C =Side Channel
IMS =Indistinct Mainstem SS =Side Slough
MSS =Mainstem Shoal US =Upland Slough....ISC =Indistinct Side Channel MS =Mainstem
121
-
APPENDIX 4
APPROXIMATE BREACHING FLOWS
OF SPECIFIC AREAS OF THE MIDDLE SUSITNA RIVER
APPENDIX 4
Approximate Breaching Flows of Specific Areas
of the Middle Susitna River
River Breaching Model River Breaching Model
Mile Flow Type Mile Flow Type
100.40 R 12500 113.80 R <5100
100.60 R 33000 113.90 R 7000
100.60 L 9200 114.00 R <5100
100.70 R <5100 114.10 R <5100 DIHAB
101.20 R 9200 I FG 115.00 R 12000 DIHAB
101.30 M 9200 115.60 R 23000~101.40 L 22000 RJHAB 116.80 R <5100
101.50 L <5100 IFG 117.00 M 15500
101.60 L 14000 117.10M 15500
101.70 L 9600 117.20 M 20000
101.71 L MSS DIHAB 117.70 L <5100
101.80 L 22000 117.80 L 8000
102.00 L 10000 117.90 R 7300
102.20 L >35000 117.90 L 22000
102.60 L 6500 118.00 L 22000
104.00 R <5100 118.60 M 14000
104.30 M 21000 118.91 L MSS DIHAB
105.20 R >35000 119.11 L MSS DIHAB
105.70 R <5100 119.20 R 10000 IFG-105.81 L MSS DIHAB 119.30 L 16000
106.30 R 4800 119.40 L >35000
107.10 L 9600 119.50 L 5000
,lFQi 107.60 L >35000 RJHAB 119.60 L <5100
108.30 L >35000 119.70 L 23000
108.70 L <5100 119.80 L 15500-108.90 L <5100 120.00 R >35000
109.30 M MSS 120.00 L 12500
109.40 R <5100 121.10 R <5100
109.50 M 16000 121.10 L 7400
110.40 L 12000 121.50 R 19500
110.80 M <5100 121.60 R 15500
111.00 R <5100 121.70 R <5100
111.50 R <5100 121.80 R 22000
111.60 R 11500 121.90 R >35000
112.40 L 22000 122.40 R 26000
112.50 L >35000 RJHAB 122.50 R 20000
112.60 L <5100 IFG 123.00 L <5100
113.10 R 26000 123.10 R >35000
113.60 R 10500 123.20 R 23000
113.70 R 24000 RJHAB 123.30 R ::>35000
..-MSS =Mainstem Shoal
RJHAB =ADF&G Habitat Model DIHAB =EWT&A Direct Input
Habitat Model
IFG =Instream Flow Group
123
-~~~....-r-'
.....
I
River Breaching Model River Breaching Model
Mile Flow Type Mile Flow Type
123.60 R 25500 135.60 R >35000
124.00 M 23000 135.70 R 27500
124.10 L <5100 136.00 L <5100 IFG
124.80 R 19500 136.30 R 13000 IFG
125.10 R 20000 136.90 R >35000
125.20 R <5100 DIHAB 137.20 R 10400
125.60 L <5100 137.50 R 22000 DIHAB
125.60 R 26000 137.50 L 29000
,""125.90 R 26000 137.80 L 20000
126.00 R 33000 IFG 137.90 L 21000
126.30 R 27000 138.00 L 8000
~127.00 M <5100 138.71 L MSS DIHAB
127.10 M <5100 138.80 R 6000
127.20 M >35000 139.00 L ;.35000-127.40 L <5100 139.01 L MSS DIHAB
127.50 M <5100 139.20 R <5100
128.30 R <5100 139.30 L MSS
128.40 R 9000 139.40 L <5100
~128.50 R 10400 139.41 L MSS DIHAB
128.70 R 15000 139.50 R 8900
128.80 R 16000 IFG 139.60 L <5100
129.30 L <5100 139.70 R 22000
129.40 R >35000 139.90 R >35000
129.50 R <5100 140.20 R 26500
129.80 R <5100 140.40 R <5100
130.20 R 12000 DIHAB 140.60 R 12000
130.20 L 8200 141.20 R <5100
131.20 R <5100 141.30 R <5100
.[i!III3l\131.30 L 9000 DIHAB 141.40 R 11500 IFG
131.70 L 5000 IFG 141.60 R 21000 IFG
131.80 L 26900 142.00 R 10500
r-132.50 L 14500 142.10 R 23000
132.60 L 10500 IFG,RJHAB 142.20 R 26000
132.80 R 19500 142.80 R <5100
133.70 R 11500 142.80 L MSS
133.80 L 17500 IFG 143.00 L 7000
133.81 R MSS DIHAB 143.40 L 23000
133.90 R 30000 144.00 R <5100.-133.90 L >35000 144.00 M 22000
134.00 L >35000 144.20 L <5100
134.90 R <5100 IFG 144.40 L 21000 RJHAB.....135.00 R 21500 145.30 R <5100
135.00 L <5100 145.60 R 22000
135.10 R 20000 146.60 L 26500
135.30 L 23000 147.10 L <5100 IFG
135.50 R "35000 148.20 R MSS
!""'"RJHAB =ADF&G Habitat Model MSS =Mainstem Shoal
DIHAB =EWT&A Direct Input
Habitat Model
IFG =Instream Flow Group
124
-
-
-
-
APPENDIX 5
FISH OBSERVATIONS
.....
APPENDIX 5
FISH OBSERVATIONS
All fish observations made during the field reconnaissance are presented
below.Most observations were made late in the spawning season.
-
Consequently,some of the specific areas may have had spawning activity before
the field investigations took place.There were no fish observed in 58 (34%)
of the 172 specific areas visited during the field work.Fish observations
included an estimate of numbers,species,and life stage (i.e.,adult or
juvenile),as well as any spawning activity and the number of redds observed.
126
ADULT AND JUVENILE SALMON OBSERVATIONS
HABITAT INVENTORY 8-21-84 THROUGH 10-2-84
RM =River Mi"I e
L =Left Bank Looking Upstream
R =Right Bank Looking Upstream
M =Middle of River (usually island)
*=Spawning Activity Observed As Indicated by the Presence of Redds or
Spawning Behavior.
r-
I
I
-
SPECIFIC
AREA (RM)
100.4R
100.4R
100.5R
100.6R*
100.6R*
100.6L
101.2R*
101.3L
101.4L*
101.4L*
101.6L
101.6L *
101.7L
101.8L*
101.8L*
102.0L
102.2L*
102.2L*
105.2R
107.1L
107.6L
109.3M
109.5M
110.4L
111.5R
111.5R
111.6R
DATE
09-11-84
10-02-84
09-11-84
08-22-84
10-02-84
09-11-84
09-11-84
09-11-84
09-10-84
08-22-84
08-22-84
09-10-84
09-10-84
09-10-84
10-02-84
09-10-84
09-10-84
10-02-84
09-10-84
09-10-84
09-10-84
09-10-84
09-10-84
08-22-84
09-06-84
10-01-84
09-06-84
OBSERVATIONS
Lots of coho juveniles
One unidentified juvenile in pool (dry channel)
Chum salmon adults
Chum salmon adults,unidentified juveniles,redds
Unidentified juveniles,several redds,scattered
salmon eggs
Pink and chum adults,few unidentified juveniles
Twenty+chlJm .adults and several redds
Two dead chum,1 dead pink
Coho juvenile (dead),juvenile chinooks
Chum,pink adults,several unidentified juveniles
About 10 chum adults
Spawning chum,adult sockeye,numerous unidentified
juvenil es
One adult chum,1 chum carcass
Hundreds of juvenile (coho),3 adult sockeye,3 adult
chum
Lots of unidentified juvenile salmonids
One unidentified juvenile salmonid,2 unidentified
carcasses
Thousands of salmonid juveniles (identified 2 coho and
1 sockeye
Hundreds of unidentified salmonid juveniles,15 redds,
1 sockeye adult,2 chum adults,1 dead pink
Few juveniles (chino,coho)
Chum and pink carcasses
One pink carcass,several juveniles (2 identified as
coho)
One chum carcass
One chum carcass
One chum adult,1 chum carcass
Several chum carcasses,couple of unidentified
juveniles
Several chum carcasses,lots of unidentified juveniles
Three chum carcasses
127
.....
SPECIFIC
AREA (RM)
112.5L
112.5L
112.5L
112.6L
112.6L
113.6R
113.7R*
113.7R*
113.7R*
114.OR
114.1R
115.0R*
115.0R*
115.0R*
115.6R*
116.3R
117.OM
117.1M
117.1M
117.2M
117.85L
117.9R
117.9L*
118.91L*
119.11L*
119.2R
119.3L*
119.4L
119.4L*
119.5L
119.7L
120.0L
120.0R*
121.1L*
121.5R
121.6R
121.7R
121.8R*
121.8R*
121.9R*
DATE
09-06-84
09-06-84
08-22-84
09-06-84
09-11-84
09-06-84
09-06-84
08-22-84
09-11-84
09-06-84
09-06-84
09-06-84
08-22-84
09-06-84
09-06-84
09-06-84
09-06":84
09-06-84
08-22-84
09-06-84
10-01-84
09-06-84
09-06-84
09-07-84
09-07-84
09-07-84
09-07-84
09-07-84
08-22-84
09-07-84
09-07-84
09-07-84
09-07-84
09-07-84
09-07-84
09-07-84
09-07-84
08-22-84
09-07-84
09-07-84
OBSERVATIONS
Several unidentified juveniles
Thousands of juveniles unidentified
Unidentified juveniles
Several juvenile chinook
Juvenile salmonids -unidentified
Chum and pink carcasses - 1 juvenile unidentified
About 40 adult chum,lots of juveniles (chinook and
coho)
About 50 adult chum
Greater than 20 adult chum,redds,juvenile chinook,
coho,sockeye
Chum carcasses,1 adult chum,chinook juvenile (1)
One chum carcass
Fourteen+adu"lt chums,1 sockeye adult,1 unidentified
juvenil e
Several adult chums
Several chinook juveniles,1 rainbow juvenile
Sixty+adult chum,several chinook juveniles,1 rain-
bow juvenile
One chum carcass,several unidentified juveniles
Several chum carcasses
Chinook juveniles
Several unidentified juveniles
Scattered eggs
Chinook and coho juveniles
Adult coho (in tributary),chum carcass,unidentified
juveniles
Two coho juveniles
About 16 chum adults
About 6 chum adults,3 redds
Several unidentified juveniles
Two chum adults,chinook and sockeye juveniles,
1 grayl i ng
A few unidentified juveniles
Redds
Several chinook juveniles and unidentified
Coho juveniles
Unidentified juveniles
One redd observed
One chum adult,2 unidentified juveniles
Chinook juveniles
Chinook juveniles
Chum adults,chinook juveniles
Chum adults,unidentified juveniles
Greater than 40 chum adults
One chum carcass,chinook juvenile,obvious spawning
acti vity
128
,~
.....
r
.....
....
SPECIFIC
AREA (RM)
122.4R*
122.5R*
122.5R*
123.1R
123.1R
123.2R
123.3R
123.6R*
123.6R*
124.0M
125.1R
125.1R
125.2R
125.9R*
125.9R*
126.0R*
126.0R*
126.3R*
127.0L
127.4M
127.5M
128.3R
128.5R
128.7R*
128.8R*
128.8R*
129.4R*
129.5R
129.5R
130.2R*
130.2L*
131.3L *
131.7L*
131.8L*
132.6L
132.8R*
133.7R*
133.7R*
133.8R
133.8L
133.8L
133.9R*
133.9L*
DATE
09-07-84
09-07-84
08-21-84
09-07-84
09-30-84
09-07-84
09-30-84
08-21-84
09-07-84
09-07-84
09-05-84
09-05-84
09-05-84
08-21-84
09-05-84
09-05-84
08-21-84
08-05-84
09-05-84
09-05-84
09-05-84
09-05-84
09-05-84
09-05-84
08-21-84
09-05-84
09-05-84
09-05-84
09-30-84
09-05-84
09-05-84
09-05-84
09-04-84
09-04-84
09-05-84
09-05-84
08-21-84
09-04-84
09-04-84
08-21-84
09-05-84
09-04-84
09-04-84
OBSERVATIONS
Several chum adults,several redds,coho juvenile
About 150 chum adults,unidentified juveniles,chinook
juvenile
Chum adults
Several unidentified juveniles
~1any unidentified juveniles
Several chinook and coho juveniles,1 grayl"ing juvenile
One unidentified juvenile
Sockeye and chum adults
Chum adults,chinook and coho juveniles
Several chinook juveniles
Two chum carcasses
Several unidentified juveniles
One chum adult,few unidentified juveniles
Few sockeye adults,75+chum adults,school of
unidentified juveniles
Sockeye and chum adults
Sockeye and chum adults,several unidentified juveniles
Some sockeye adults,few pink adults,hundreds of chum
adults
Sockeye and chum adults
One chum carcass,several unidentified juveniles
Several unidentified juveniles
One chum carcass
One chum,chinook juveniles
Chinook juveniles
Chum adults
Several adult chums
Several unidentified juveniles
Several chum adults,unidentified juveniles
Chum adults
One coho carcass
Chum adults,chinook juveniles
One chum carcass,unidentified juveniles (1 chinook
identified)
Chum adults,redds
Lots of chum adults,few unidentified juveniles
About 20 chum adults,lots of redds,1 unidentified
juvenile
Unidentified juveniles
Chum adults,1 dead chinook juvenile
Some chum adults
Chum adults,few chinook juveniles
Chum adults,1 unidentified juvenile
Chum adult
Chinook juveniles
Chinook juveniles
Chum adults,chinook juveniles
129
-
.-
f
.....
I
....
n
I I
SPECIFIC
AREA (RM)
134.0L
134.9R*
134.9R*
135.0l*
135.1R
135.6R*
135.6R*
135.7R
136.0L
136.3R*
137.2R*
137.5R
137.SL
137.9L
138.7L
139.01L*
139.0L*
139.4l
139.5R
139.6L
139.9R*
140.2R*
140.2R*
140.6R*
141.4R*
141.6R*
142.0R
142.0R
142.1R*
142.8L*
143.0L*
143.4L*
144.2L
144.4L*
145-:6R
DATE
09-04-84
08-21-84
09-04-84
09-04-84
09-04-84
09-04-84
08-21-84
08-21-84
09-04-84
09-04-84
09-04-84
09-04-84
09-04-84
08-21-84
09-04-84
09-04-84
08-21-84
09-03-84
09-03-84
09-03-84
09-03-84
08-21-84
09-03-84
09-03-84
09-03-84
08-21-84
09-03-84
09-29-84
09-03-84
09-03-84
09-03-84
09-03-84
09-03-84
08-21-84
08-21-84
OBSERVATIONS
One chum carcalss~few unidentified juveniles
One chum adult,1 chum carcass
Several chum aldults,several unidentified juveniles
Chinook and unidentified juveniles
Several unidentified juveniles
Hundreds of sockeye adults,thousands of chum adults,
chinook juveniles
Sockeye,chum,pink adults greater than 400 fish
Some chum adults,2 pink carcasses,several
unidentified juveniles (1 chinook)
Two chum carCC:lsses,uni dentifi ed adults
Chum adults,chinook juveniles
Chum adults,2 unidentified juveniles
Chum adults,2 chum carcasses,chinook juveniles
Chum carcasses,chinook juveniles
Few unidentified juveniles
One chum carcass~1 unidentified adult
About 30 chum adults
Some sockeye adults,SO+chum adults,1 pink carcass
Several chum carcasses,several unidentified juveniles
(1 chinook identified)
Sockeye and chum adults
Several chum carcasses,several unidentified juveniles
(1 chinook identified)
Sockeye and chum adults,chinook juveniles
Lots of chum adults,lots of unidentified juveniles
About 12 chum adults,lots of coho and chinook
juveniles
Several chum carcasses,redds,few unidentified adults
(1 chinook identified)
Hundreds to thousands of sockeye and chum adults,
chinook juveniles
Some sockeye cidults ~hundreds of chum adults,
1 unidentified juvenile
Chum adults,unidentified juveniles
Fifteen+unidentified juvenile fish
Sockeye and chum adults,greater than 500 chinook
juveniles,several unidentified juveniles
Fifty+chum adults
Twelve+chum adults,unidentified juveniles
Thi rty-two+chum adults,uni dentifi ed j uvenil es
(1 chinook identified)
Chum carcass,chinook juveniles
Fifty+chum adults
One chinook juvenile
130