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ALASKA DEPARTMENT OF FISH AND GAME
SUSITNA HYDRO AOUATIC STUDIES
REPORT NO.3 PART II.Chapter 6,Appendices
AQUATIC HABITAT AND INSTREAM FLO .....
INVESTIG:.TIONS (MAY-OCTOBER 1983)
ALASKA DEPARTMENT OF FISH AND GAME
SUSITNA HYDRO AQUATIC STUDIES REPORT SERIES
\
RECEIVED
MAY 291984
ALASKA POWER AUTHORl~
DRAFT
ALASKA DEPARTMENT OF FISH AND GAME
SUSITNA HYDRO AQUA TIC STUDIES
REPORT NO.3 PART II.Chapter 6,Appendices
AQUATIC HABITAT AND INSTREAM FLOW
INVESTIGATIONS (MAY-OCTOBER 1983)
Edlled by:
Christopher C.Est ••
and
Douglas S.Vincent-Lang
Prepared for:
ALASKA POWER POWER AUTHORITY
334 W.FIFTH AVE.
ANCHORAGE.ALASKA 99501
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APPENDIX 6-A
Passage Reach Cross Section Data Tables
May ID,1984
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May 10,1984
Table 6-A-1.Passage reach cross section data table,Slough 9 -Passage Reach I,September 29,1983.
Mainstem discharge =9,080 cfs.
Distance Between Distance Between
Point Points (ttl Depth (ftl Point Points (ftl Depth (ftlr:o
1 (LWEl 0.0 18 0.3
1.0 1.0
2 0.23 19 0.4
1.0 1.0
3 0.1 20 0.5
1.0 1.0
4 0.2 21 0.6
1.0 1.0
5 0.44 22 0.4
1.0 1.0
6 0.5 23 0.8
<;'0.1.0 1.0
~7 0.5 24 0.9
I 1.0 1.0
8 0.4 25 0.7
1.0 1.0
9 0.4 26 0.6
1.0 1.0
10 0.3 27 0.7
1.0 1.0
11 0.4 28 0.7
1.0 1.0
12 0.5 29 0.6
1.0 1.0
13 0.3 30 0.5
1.0 1.0
14 0.3 31 0.5
1.0 1.0
15 0.2 32 0.3
1.0 1.0
16 0.3 33 (RWEl 0.0
1.0
17 0.4
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May 10,1984
Table 6-A-2.Passage reach cross section data table,Slough 9 -Passage Reach II,September 29,1983.
Mainstem discharge =9,080 cfs..
Distance Between Distance 8etween
Point Points (ft)Depth (tt)Point P()ints (ft)Depth (ft)r.u
1 (LWE)0.0 13 0.6
1.0 1.0
2 0.1 14 0.6
1.0 1.0
3 0.1 15 0.6
1.0 1.0
4 0.2 16 0.6
1.0 1.0
S'-5 0.1 17 0.5
I 1.0 1.0
~6 0.2 18 0.5,1.0 1.0~7 0.3 19 0.5
1.0 1.0
8 0.4 20 0.5
1.0 1.0
9 0.5 21 0.6
1.0 1.0
10 0.5 22 0.5
1.0 1.0
11 0.5 23 0.2
1.0 1.0
12 0.6 24 (RWE)0.0
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May 10,1984
Table 6-A-3.Passage reach cross section data table.Slough 9 -Passage Reach III (TR4)August 25,1982.
Mainstem discharge 13,400 cfs.
Distance Between Distance Between
Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)
2.0"
1 (LWE)0.0 18 0.2
1.0 2.0
2 0.1 19 0.2
2.0 2.0
3 0.1 20 0.2
2.0 2.0
4 0.1 21 0.2
2.0 2.0
5 0.2 22 0.25
2.0 2.0
6 0.3 23 0.2
2.0 2.0
7 0.1 24 0.1
2.0 2.0
8 0.2 25 0.1
1.5 2.0
9 (RWE)0.0 26 0.1
15.5 2.0
10 (LWE)0.0 27 0.1
1.0 2.0
11 0.1 28 0.1
2.0 2.0
12 0.1 29 0.1
2.0 2.0
13 0.2 30 0.1
2.0 2.0
14 0.1 31 0.1
2.0 2.0
15 0.1 32 0.1
2.0 2.0
16 0.1 33 (RWE)0.0
2.0
17 0.1
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May 10.1984
Table 6-A-4.Passage reach cross section data table.Slough 20 -Passage Reach I July 16.1983.
Mainstem discharge'16.400 cfs.
Oistance Between Distance Between
Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)r:o
1 (LWE)0.0 19 0.3
1.0 1.0
2 0.2 20 0.3
1.0 1.0
3 0.1 21 0.3
1.0 1.0
4 0.1 22 0.3
1.0 1.0
5 0.1 23 0.3
1.0 1.0
~6 0.1 24 0.3
1.0 1.0I70.1 25 0.3~1.0 1.0
8 0.2 26 0.3---e 1.0 1.0
g 0.3 27 0.3
1.0 1.0
10 0.1 28 0.3
1.0 1.0
11 0.1 29 0.3
1.0 1.0
12 0.2 30 0.3
1.0 1.0
13 0.1 31 0.2
1.0 1.0
14 0.2 32 0.2
1.0 1.0
15 0.2 33 0.2
1.0 1.0
16 0.1 34 0.1
1.0 0.4
17 0.3 35 (RWE)0.0
1.0
18 0.3
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May 10,1984
Table 6-A-5.Passage reach cross section data table,Slough 20 -Passage Reach II,July 16,1983.
Mainstem discharge -16,400 cfs.
Distance Between Distance Between
Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)-r:o
1 (LWE)0.0 18 0.3
1.0 1.0
2 0.1 19 0.2
1.0 1.0
3 0.2 20 0.4
1.0 1.0
4 0.2 21 0.2
1.0 1.0
5 0.3 22 0.3
1.0 1.0
~6 0.2 23 0.3
1.0 1.0
\7 0.3 24 0.3
~1.0 1.0,8 0.4 25 0.3
...\1.0 1.0
9 0.5 26 0.3
1.0 1.0
10 0.3 27 0.2
1.0 1.0
11 0.4 28 0.1
1.0 1.0
12 0.4 29 0.1
1.0 1.0
13 0.4 30 0.2
1.0 1.0
14 0.3 31 0.2
1.0 1.0
15 0.3 32 0.2
1.0 1.0
16 0.3 33 0.1
1.0 1.0
17 0.3 34 0.1
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Table 6-A-5 (continued).
May 10,1984
Distance 8etween Distance Between
Point pOinWlli Depth (ft)Point Points li!l ~1.0
35 0.0 40 0.1
1.0 1.0
36 0.0 41 0.1
1.0 1.0
37 0.2 42 0.1
1.0 1.0
3B 0.2 43 0.1
1.0 1.0
:i'-39 0.2 44 (RWE)0.0,
~
,I
S--
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May 10,1984
Table 6-A-6.Passage reach cross section data table,Slough 20 -Passage Reach III,July 16,1983.
Mainstem discharge =16,400 cfs.
Distance Between Distance Between
Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)
1.0"
1 (LWE)0.0 18 0.3
1.0 1.0
2 0.2 19 0.3
1.0 1.0
3 0.3 20 0.3
1.0 1.0
4 0.2 21 0.2
1.0 1.0
5 0.2 22 0.1
1.0 1.0
6 0.3 23 0.1
:---.1.0 1.0"I 7 0.2 24 0.1
~1.0 1.0,8 0.2 25 0.2
~1.0 1.0
9 0.3 26 0.2
1.0 1.0
10 0.3 27 0.1
1.0 1.0
11 0.2 28 0.1
1.0 1.0
12 0.2 29 0.2
1.0 1.0
13 0.2 30 0.2
1.0 1.0
14 0.2 31 0.1
1.0 1.0
15 0.2 32 O.1
1.0 1.0
16 0.2 33 0.1
1.0 1.0
17 0.3 34 0.1
6'
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Table 6-A-6 (continued).
Distance Between Distance Between
Point pOinl~o(ft)Depth (ftt Point Points (ft)Depth (ft)
1.0
35 0.1 39 0.1
1.0 1.0
36 0.1 40 0.1
1.0 1.0
37 0.2 41 0.1
1.0 1.0
38 0.1 42 (RWE)0.0
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May 10,1984
Table 6-A-7.Passage reach cross section data table,Slough 20 -Passage Reach IV,July 16,1983.
Mainstem discharge:16,400 cfs.
Distance Between Distance Between
Point Points (ftl Depth (ftl Point Points (ftl Depth (ftl-r:ll"
1 1.0 0.0 19 0.3
1.0
2 1.0 0.1 20 0.4
1.0
3 1.0 0.1 21 0.4
1.0
4 1.0 0.1 22 0.3
1.0
5 1.0 0.1 23 0.3
1.0
6 1.0 0.1 24 0.1
~1.0
7 1.0 0.1 25 0.1
1.0
\8 1.0 0.2 26 0.3-.0 1.0
9 1.0 0.2 27 0.1
1.0
10 1.0 0.3 28 0.1
1.0
11 1.0 0.3 29 0.1
1.0
12 1.0 0.3 30 0.2
1.0
13 1.0 0.4 31 0.1
1.0
14 1.0 0.3 32 0.1
1.0
15 1.0 0.2 33 0.1
1.0
16 1.0 0.3 34 0.1
1.0
I 17 1.0 0.2 35 (RWEI 0.0
18 0.2
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May 10,1984
Table 6-A-8.Passage reach cross section data table,Slough 20 -Passage Reach V,July 16,1983.
Mainstem discharge =16,400 cfs..
Distance Between Distance Between
Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)
1.0"
1 (LWE)1.0 0.0 18 0.1
1.0
2 1.0 0.2 19 0.2
1.0
3 1.0 0.1 20 0.2
1.0
4 1.0 0.2 21 0.2
1.0
5 1.0 0.1 22 0.1
1.0
6 1.0 0.3 23 0.1
1.0
S'7 1.0 0.3 24 0.1
I 1.0
~8 1.0 0.3 25 0.1
I '
1.0,-9 1.0 0.2 26 0.1<)1.0
10 1.0 0.1 27 0.1
1.0
11 1.0 0.2 28 0.2
1.0
12 1.0 0.3 29 0.1
1.0
13 1.0 0.2 30 0.1
1.0
14 1.0 0.1 31 0.1
1.0
15 1.0 0.1 32 0.1
1.0
16 1.0 0.1 33 0.1
1.0
17 0.2 34 0.1
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Table 6-A-8 (continued).
May 10,1984
Distance Between Distance Between
Point pOinl~o(ft)Depth (ftt Point Points (ft)Depth (ft)
1.0
35 0.1 45 0.1
1.0 1.0
36 0.1 46 0.1
1.0 1.0
37 0.1 47 0.1
1.0 1.0
38 0.1 48 0.1
If'1.0 1.0
1 39 0.1 49 0.1
::h 1.0 1.0
40 0.1 50 0.011.0 1.0
41 0.1 51 0.1
1.0 1.0
42 0.2 52 0.1
1.0 1.0
43 0.2 53 0.1
1.0 0.5
I-44 0.2 54 (RWE)0.0
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May 10.1984
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Table 6-A-9.Passage reach cross section data table.Slough 21 -Passage Reach I.September 13.1983.
Mainstem discharge·16.400 cfs.
Distance 8etween Distance Between
Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)
1.0
1 (LWE)0.0 7 0.3
1.0 1.0
2 0.1 8 0.4
1.0 1.0
3 0.2 9 0.3
1.0 1.0
4 0.1 10 0.4
1.0 1.0
5 0.2 11 0.4
1.0 4.0
6 0.2 12 (RWE)0.0
The last four feet of the cross section are blocked by large boulders making fish passage impossible.
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APPENDIX 6-8
Analysis of the Influence of Local
Flow Conditions on Fish Passage
by
Larry Rundquist
and
Janet Hearns
Woodward Clyde Consultants
1984
May 10,1984
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OBJECTIVE
May 10.1984
The objective of this passage analysis is to estimate the flows that
correspond to successful and unsuccessful passage within specific
sloughs and side channels in the middle reach of the Sus-itna River.
Thi s phase of the investi gation concentrates on I oca I fl ow condi'ti.tl ns
only.It does not include an evaluation of the influence of mainstem
discharge on the backwater at the mouth of a site or overtopping at the
upstream end of the site which can also influence passage in these
areas.
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METHODS
Data Base
May 10,1984
The data base for the slough passage ana lys is vari ed between sloughs.
Available data at all sloughs included:
o slough thalweg and water surface profiles,
o at least one surveyed transect,and
o aerial photography coverage of the slough for Susitna nainstem
flows of 9,000,12,500,16,000,21,000 and 23,000 cfs.
Many of the sloughs had several surveyed transects located on riffles or
within pools of the sloughs which corresponded to staff gage or flow
measurement sites.Rating curves were available for most flow
measurement sites.Sloughs 9,9A,20,and 21 had transect data for one
to three passage reaches within the slough;these transects had a width
equa 1 to that of the water surface at the time of the survey,which
usually corresponded to a relatively low flow.
Analyses
The available data were not sufficient to conduct a direct analysis of
slough flows required for passage within the sloughs.An indirect
approach was developed based on the concept of "at-a-station"channel
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geometry relations introduced by Leopold and Maddock (1953).They used
discharge measurement data at a number of gaging stations in the United
States to obtain power relations for width and depth in terms of
discharge at a particular station.These relations are given by
They found that the geometry varied considerably between cross sections
and thus,the coefficients varied.Many streams,however,had similar
rates of change of geometry.Based on a sample of 20 river cross
sections in the Great Pla-jns and the Southwest,Leopold and Maddock
obtained average exponent values of 0.26 for width and 0.40 for depth.
They found that the expon~nts are a function of the shape of the channel
and the hydraulics of the flow.
Further study has been made on relations of the hydraulic geometry of
stream channels by Leopold,Wolman and Miller (1964).It was found that
channels in the humid eastern United States and in the wet mountain area
of the central and north Rocky Mount!ins have a slower rate of increase
of width (low b)than those of channels in the semiarid Southwest or the
High Plains.This is due,at least in part,to the typical shape of the
channel cross section in the various regions.Some values of the
exponents in the hydraulic geometry relations are given in Table 6-B-1.
Li (1974)presented a theoretical development of hydraul i c geometry
relations for channels in homogeneous,coarse alluvium and small
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drainage basins.The assumptions of the derivation conclude that all
particles on the boundary of the channel are at a condition of incipient
motion at bank-full.Li obtained equations of the form:
W=a 0°·24
D =c 0°·46
Tab 1e 6-B-1.Average values of exponents in the At-A-Station Hydraulic
Geometry Relations (after Leopold.et.al.1964).
I
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b f
Average values midwestern United States .26 .40
Brandywine Creek.Pennsylvania .04 .41
Ephemeral streams in semiarid
United States .29 .36
Average of 15B gaging stations in
United States .12 .45
Ten gaging stations on Rhine River .13 .41
Symbol s:Q discharge
W channel top width W=a Qb
0 hydraulic depth o =c Qf
'.
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May 10.1984
The exponents vary only slightly with the angle of repose of the bed and
bank material and with the lift to drag ratio.
Slough Geometry Relations.It has been noted that the width and depth
of a stream channel increase at some uniform rate with increasing flow.
This is not always true.however.A logarithmic plot of the width or
depth with flow may be a curved line or it may be a series of straight
line segments with one or more breaks in slope.These types of plots
may be due to variability of bed and bank material type.a break in the
slope of the banks.channelization at low flows.or some other
nonuniformity in the bed and banks.
Riffle transects with developed rating curves were available for Sloughs
9,11,and 21 and Upper Side Channel 11.The transect data were input
to a computer program that uses the Manning equation to calculate the
hydraul ic geometry and flow for a range of selected water surface
elevations.The reach gradient was used for the energy slope and
Manni ng n was vari ed unti 1 the output from the computer matched the
rating curve reasonably well.All four transects were fairly well
calibrated using a Manning n value of 0.110.
Power form relations for hydraulic (mean).depth as a function of flow
were developed from the computer model output.Exponents in the
equations were 0.38 for Sloughs 9 and 11.0.39 for Slough 21.and 0.45
for Upper Side Channel 11.These compare well with the values reported
by Leopold,Wolman and Miller (1964).The r.ange of coefficients from
0.13 at Upper Side Channel 11 to 0.26 at Slough 11 was enough to cause
~-'n·b _
TADjdonrep May 10,1984
DRAFT
the range of flows for a single depth to be large.The coefficients
were not correlated to the reach gradient,which was the only variable
that was available for passage reaches which lacked transect data.
Thus,the wide range of calculated flows for a given depth could not be
reduced based on the available data base.
The hydraulic geometry relations were modified by plotting the mean
depth against the unit flow (total flow divided by top width).The
resulting lines were straight and parallel (on log-log paper)and the
variation in coefficients could be reasonably explained in terms of
reach gradient variation (Figure 6-8-1).Additional transects without
rating curves were input to the Manning equation computer model using
the reach gradient and the average Manning n value of 0.110 to compute
their hydraulic geometry;these data were also plotted on Figure 6-8-1.
The resulting set of curves can be used to evaluate the unit f~ows for
selected mean depths in a passage reach having a known reach gradient.
Specific application of Figure 6-8-1 for the passage reach analysis is
discussed in more detail in a subsequent section.
Channe 1 top wi dth was a1so plotted agai nst flow (Figure 6-8-2).These
curves for the four transects having rating curves were generally
non-parallel and non-linear,indicating a bad fit to the power form
equation presented above.This is likely due to the existence of
shelf-like areas on some transects which cause a large increase in width
for a small flow.
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Passaoe Depth Definition.Passage depth is the depth of water at a
transect which a fish must navigate through in order to proceed
upstream.Using the mean depth as the indicator depth for fish passage
i.-?>-'K
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Table 6-B-1.Average values of exponents in the At-A-Station Hydraulic
Geometry Relations (after Leopold.et.al.1964).
b f
Average values midwestern United States .26 .40
Brandywine Creek.Pennsylvania .04 .41
Ephemeral streams in semiarid
United States .29 .36
Average of 158 gaging stations in
United States .12 .45
Ten gaging stations on Rhine River .13 .41
Symbols:Q di scharge
W channel top width W=a Qb
D hydraulic depth D •c Qf
--------
<I!".~
.1
.01 .02 .03 .04 .05 .06 .08 .10 .2 .3 .4 .5 .6 .7 .8 .9 1.0
6-8-1
q (cll/ltl
Relation between mean depth and unit 41o<J
300
200
.2 .3 .4.S.6.7 .8 .9 1.0 2 3 4 S 6 7 8910 20 30 40 60 80 100
6-8-2
Q (ets)
Relation between top width and total discharge.
1.0 •••.9
••.8 ••
.7 •.'.•
••••.6 •••••
••••.5-••Q;l r I •,J.96 I •..~•-•
.4 •~•
Q.•..•a •..•'"•0 3 •:;l •0 •0.•-••
0 d 0.11-0 d••1.27
•
.2 ••I•o:ii 1.10
a'l~l •d •d.
•1.27 l 1.27 I
•
.IL ----,!-.....L.__---IL-_-!-_-+_+----:!_-!-..!
.1 .2.3.4 .5 .6 .7 .8 .9 1.0
d (Mean Depth,feet)
6-8-3 Relation between mean depth and passage depth.
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May 10,1984
is somewhat conservative,since the maximum depth can be as large as 50
percent greater than the mean depth.Use of the maximum or thalweg
depth is not a very good indicator of passage since it often represents
the depth at one location on the transect,and this location may not be
connected to the maximum depth on an adjacent transect.A passage depth
term has been developed which is simply an average of the mean depth and
maximum depth of a transect.Thus,the passage depth for a
I
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triangular-shaped transect would be the average of the mean depth,which
is two-thirds of the maximum depth,and the maximum depth,which gives
five-sixths of the maximum depth for the passage depth.The passage
depth for a rectangu 1ar-shaped transect wou 1d be equa 1 to the max i mum
depth,since the mean depth and maximum depth are equal.Most transects
would fall between these two extreme cases.A relation was developed
between passage depth and mean depth based on data from surveyed
transects (Figure 6-8-3).
Passage Depth Criteria.Criteria were developed for the depth required
for passage as a function of passage reach length based on the
experience of biologists familiar with passage conditions in the
sloughs.Details of the development of the criteria are found elsewhere
in the ADF&G report.The resulting criteria consisted of two sets of
curves,each set containing two lines.One set of curves was developed
for slough conditions with small substrate (less than 3 inches
diameter),uniform transects,straight channel,and velocities less than
2 fps.These conditions are failoly typical in many of the sloughs.The
other set of curves was developed for sloughs with large substrates,
non-uni form transects,bra i ded channel with numerous dead ends,and
velocities typically greater than 2 fps.Each set of curves had three
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May 10,1984
categories of passage separated by the two curves (Figure 6-8-4).The
three categories are defined below:
Successful Passage (unrestricted):fish access into and/or passage
within the spawning area to spawning sites is uninhibited,and
would not affect production in this area.
Successful Passage With Difficulty &Exposure:fish access into
and/or passage within the spawning area is accomplished,but with
stress and predation;although a sufficient number of fish pass to
allow continued production in the area,this condition,over a long
period of time,could result in a reduction in production.
Unsuccessful Passage:fish access into or within an area to a
spawning area may be accompl i shed by a 1imited number of fish;
howE'ver,if exposure to excessive stress and increased predation
(which are associated with these conditions persist)the population
would eventually be eliminated.
The curves sepa~ating these categories are thus threshold conditions and
are of most interest in this analysis.
Passage Reach Length.The passage reach lengths were determined by
ADF&G based on the thalweg and water surface surveys.This typically
corresponded with the distance between pools.It was assumed that thE'
reach length remained constant with flow,since pool stage did n0t vary
substantially with change in flow,especially over the small range of
flow considered in this analysis.
/_~-Ii ~~•
'.0
00 11"'"'-.--'........"......h <.11 .._
..,1 <Ill'...
o
e..,.I..."••...»0...'M
•,<0"
_....S-.-
e.......'...,
i'.iiO..-...Itt-.-"".In
0.'
...
~....•w
a ••
o...
0.'
~.SS.G[!t[ACM I.E N«;TM lIn.I
-'-...,..-...-
-'-••---
-'-M..........
-'-••..--
•
~e ..
__~S~.~":..:.~':.~'..
~-~-::.:..~'~W~.~;.:.~D~;"~;~.:.:":.~-:~[~.:..::.-:.-----------0
......h"ItUCM CilUTUI&eUlty[S
_·1 _ •
....._••>11 .
.,.........<a ,"...
'.0
·
%..••w ••a
••
••.,
""$S.GE lII(aCH I.[NGTH I''''t
Figure 6-8-4 Passage depth criteria as a function of passage
reach length,
( -1<.
TAD/donrep May 10,1984
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Application to Sloughs.The general application of the relations,
criteria,and data described above is summarized in this section in the
form of a series of steps.Specific applications to each slough
depended on the database for the slough and is described in the
following section.
o Step 1 -Identify the number and location of all passage
reaches in the slough.
o Step 2 -Evaluate the length of the passage reach from the
thalweg survey.
o Step 3 -Identify the passage depths for threshold values
corresponding to successful and unsuccessful passage
based on the reach length and the passage depth
criteria (Figure 4).
o Step 4 -Determine the mean depths that corresponds to the
identified threshold passage depths (Figure 3).
o Step 5 -Evaluate the reach gradient corresponding to each
passage reach from the thalweg survey.
o Step 6 -Evaluate the unit flows corresponding to both
threshold depths for each passage reach by using the
curve with the applicable reach gradient (Figure 1).
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DRAFT
o Step 7 -Plot a width versus flow curve for all
surveyed transects on the slough.
May 10.1984
o Step 8 -Measure the width of flow at the surveyed transect
and at each passage reach on each of the fi ve sets
of aerial photographs.
o Step 9 -Use the measured top width at the surveyed
transect for each set of photographs to evaluate the
slough flow for each of the photographs.
o Step 10 -Modify the slough flow.if necessary.to
account for upwell i ng or tri butary i nf1 ow between
the surveyed transect and each passage reach.
o Step 11 -Use the slough flow and the corresponding top
width measured from the aerial photographs to define
several points on a curve of width versus discharge
for each passage reach.
o Step 12 -Plot lines of constant unit flow at the
values obtained for both threshold depths.The
intersect i on of these 1i nes wi th the wi dth versus
fl ow curve deve loped for each passage reach gives
the total flow that corresponds to both threshold
depths.
TAD/don rep May 10,1984
DRAFT
o Step 13 -Tabulate the required depths and flow for
both successful and unsuccessful passage for each
passage reach.
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DRAFT
Whi skers Creek
May 10,1984
The data base for the Whiskers Slough Site that proved useful for
passage analysis includes transects at the slough mouth and at the
slough discharge site (AOF&G gage 10l.253)located in the slough above
Whiskers Creek,and a thalweg profile for Whiskers Slough.Additional
data include flow measurements in Whiskers Creek (AOF&G gage 101.2T2B).
These flow measurements were not useful because neither the discharge
site nor the creek thalweg have been surveyed.Thus,no reliable rating
curve with which to generate a width-discharge curve could be developed
for the creek site.Because both passage reaches are located below
Whiskers Creek,the flow contributions of the creek had to be accounted
for.This was done using the following approach.
A rating curve was developed for the slough discharge site.The general
method could not be used because the transect is located at a pool,and
the general approach only applies to riffles.Once an appropriate
Manning n and energy slope were selected for the flow site,the same
values were used to generate a rating curve at the slough mouth.The
width-flow curve at the slough mouth was plotted and used to generate
width-flow curves for both passage reaches.It was assumed that the
flow remained the ;ame between Passage Reach and the mouth.Once the
width vs.flow curves were plotted for the ?assage reaches,total flow
was found by locating the required unit flow on each of the curves.
L,-_.~~-.,~?S _
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DRAFT
Mainstem II Side Channel
May 10.1984
The data base for Mainstem II consists of a thalweg profile and five
surveyed transects located at two discharge $ites.one in each of the
two forks.and three staff gage sites below the confluence of the forks.
Photographic enlargements,available for mainstem flows of 9,000;
12.500;and 16.000 cfs.do not provide adequate resolution with which to
generate width versus flow curves for the passage reaches based on the
rating curve for the flow site.Therefore.passage flows are based on
field observations by E.Woody Trihey and Associates.
Slough 9
Since all three passage reaches had been surveyed.the passage analysis
at Slough 9 was a straight-forward appl ication of the general approach
to developing rating curves.No extrapolation of the rating curves
beyond the limits of the survey data was necessary.
Slough 9A
The data base at Slough 9f1 includes a thalweg profile and four flow
measurements taken on October 25,1982.Because the measurements were
taken on the same day and span almost the entire length of the slough.
they provide an indication of the volume of upwelling within the slough.
Three of the discharge sites coincide with passage reaches I.II I.and
V.Ra ti ng curves for these sites were developed us i ng the genera 1
TAO/donrep
DRAFT
Hay 10,1984
method described previously;the measured flows were used as a
calibration check.The calculated and measured flows compared to within
7 to 9 percent.
Passage flows at reaches II,IV,and VI were determined·using the top
width vs.flow curves for passage reaches I,III,and V and applying
adjustments for groundwater upwelling and relative differences in top
width.This information was provided by AOF&G personnel.
Slough 11
The data base at Slough 11 includes a thalweg profile and surveyed
transects at the mouth and at a flow site about 1,000 ft upstream of the
mouth.The qual ity of aerial photography at this slough ·is very poor;
the only set of photos on which any resolution is possible is that which
was taken at a mainstem flow of 21,000 cfs.This does not provide
adequate information with which to generate width ver~us flow curves for
the passage reaches based on the rating curve at the flow site.
Therefore,passage flows are based on f·e1d observations provided by E.
Woody Trihey and Associates.
Upper Side Channel 11
Access analysis for Upper Side Channel 11 was based on the rating curve
developed for the flow site at AOF&G gage 136.251.This site is
coincident with Passage Reach 1.1.The overall gradient through both
reaches is the same,and aerial photographs indicate that the width of
flow at both sites is similar.Thus,the top width versus flow
TAD{donrep
DRAFT
May 10.1984
curve that was developed directly for Passage Reach II was also applied
to Passage Reach I.Because the slopes were the same for both reaches,
a direct plot of passage depth vs.flow yields the same results.
Slough 20
Rating curves for the three passage reaches in Slough 20 were calculated
using the general methodology described previously and depth
measurements from each site.There were no flows with which to
calibrate these curves.The general method was not used to calibrate
the rating curve at the flow site (ADF&G gage 140.155)because the site
is located in a pool,and the method is only applicable at riffle sites.
Because passage reaches were quite shallow at the time they were
surveyed.their rating curves do not extend to the depths required for
passage analysis.The curves were extended by scaling the width of each
site,including the flow site,off the set of large scale aerial
photographs (l "s50';ma i nstem flow equa 1 21,000 cfs).Assumi ng that
flow within the slough remained constant.the width of each passage
reach was plotted against the flow at the gaging site.This provided an
extension that was sufficient to determine the total flow corresponding
to the required unit flow at each passage reach.
A1though the extens ions do not account for any upwell i ng if'the slough.
the shape of the extended portions of the curves is such that the impact
of disregarding this effect is not substantial.
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DRAFT
Side Channel 21
May 10.1984
Three of the five passage reaches in Side Channel 21 coincided with
surveyed transects and/or flow sites at either staff gages or IFG study
sites.Passage Reach III is located at the flow site situated at
Transect 4 of the lower IFG study site (ADF&G gage 140.654).The rating
curve was developed using the general methodology described previously
using the flow measurements as a calibration check.No modifications to
the rating curve or wi dth versus fl ow curve were needed in order to
obtain the passage flows.
Passage Reach IV is coincident with the transect surveyed at ADF&G gage
140.652.A rati ng curve was generated us i ng the genera I method and
applied without modification.
Passage Reach V is situated at the downstream end of the Upper IFG study
site and is coincident with Transects 1-3.A rating curve at Transect 3
was developed using the general approach described previously.No
changes were made to the rating curve in order to determine the passage
flows.
No data were availa~le at Passage Reaches I and II other than the aerial
photo enlargements.Passage is not a problem.however,at the mainstem
flows represented in the photographs,so they did not prove particularly
useful for this analysis.Thus.for simplicity and lack of a better
approach.the passage flows for Passage Reaches ·1 and II were taken from
the width versus flow curve for Passage Reach III.
TAO/donrep
DRAFT
May 10,1984
In addition to a surveyed thalweg.Slough 22 has surveyed transects at
the mouth (AOF&G gage 144.3W3).mid-slough (AOF&G gage 144.354)and at
the flow site just below the tributary (AOF&G gage 144.356).Aerial
photo enlargements are available for a mainstem discharge of 21.000 cfs
only.
Rating curves were developed for the gage sites at the mouth and
mid-slough.Both these sites are riffles,so the general method
described previously was applicable.Passage Reach I coincides with the
gage site at the mouth.so passage flows could be determined directly
from the rating curve.
Passage Reach II is situated about 300 ft upstream of the mid-slough
gage site and has a reach gradient of 20.7 ft/mi as compared to
6.3 ft/mi at the mid-slough gage.The enlarged aerial photos taken at a
mainstem discharge of 21,000 cfs indicate that Passage Reach II is
roughly twice as wide as the mid-slough gage site.A width vs.
flow curve for the passage reach was generated from the wi dth vs.
flow curve for the mid -slough gage site by assuming that flow remained
constant between the two sites.but at all .flow the top width at the
passage reach was double that at the ga~e.The validity of the numbers
obtained in this manner depends primarily upon how well the width
relationship holds at flows other than the one shown in the aerial
photos.
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DRAFT
RESULTS AND DISCUSSION
May 10,1984
Table 2 sUlI'IIIarizes the results of the passage analysis for the nine
sloughs in which passage problems were identified.Based on the
existing data,the numbers presented are a reasonable estimate of the
slough flows needed to meet the passage criteria for successful and
unsuccessful passage.However,because the data were not easily applied
to this type of analysis,it is strongly suggested that field
verification of the calculated values be included in the 1984 field
program.
In addition,further field investigation may reveal additional passage
problems that were not apparent on the thalweg and water surface
surveys,and/or eliminate some reaches that were previously identified
as problems.
_r _TAD/donrep
DRAFT .
4
Table 6-8-2.Summary of slough flows needed to meet passage criteria for successful and unsuccessful
passage.
SUCCEsSFUL PASSAGE -llIFFICULT PASSAGE
Passage Mean Passage Mean
Length Depth Depth Unit Flow Depth Depth Unit Flow
Site PR (ft)(ft) (ft)Flow (ds)(ft) (ft)Flow (cfs)
Whiskers Creek I 226 0.50 0.36 0.145 10.5 0.38 0.26 0.089 4.2
II 50 0.42 0.30 0.107 10.1 0.28 0.19 0.050 5.0
Hainstem II 1 Point 0.50 0.:16 ---5 0.35 0.24 ---3
II 200 0.67 0.49 ---5 0.50 0.36 ---3
III Point 0.50 0.36 ---5 0.35 0.24 ---3
IV 40 0.60 0.44 ---5 0.42 0.30 ---3
V 200 0.67 0.49 ---5 0.50 0.36 ---3
~VI 260 0.67 0.49 ---5 0.50 0.36 ---3
':P 9 I 167 0.48 0.34 0.073 2.3 0.35 0.24 0.041 1.2
II 292 0.67 0.49 0.137 3.2 0.50 0.36 0.080 1.7
).::III 83 0.60 0.44 0.115 10.15 0.42 0.30 0.060 5.8oJ,
9A I 20 0.60 0.44 0.150 2.4 0.42 0.30 0.079 1.0
11 10 0.50 0.36 0.220 3.4 0.35 0.24 0.110 1.5
III 175 0.65 0.48 0.360 5.5 0.48 0.34 0.200 2.4
IV 10 0.50 0.36 0.078 0.5 0.35 0.24 0.040 0.2
V 130 0.62 0.45
0.270 2.8 0.45 0.32 0.150 \.4
VI 240 0.67 0.49 0.122 2.0 0.50 0.36 0.108 1.8
II J 35 0.42 0.30 ---4.0 0.28 0.19 ---2.5
II 35 0.42 0.30 ---4.0 0.28 0.19 ---2.5
III 61 0.42 0.30 ---4.0 0.29 0.20 ---2.5
IV 26 0.42 0.30 ---8.0 0.28 0.19 ---5
(right channel)V 30 0.42 0.30 ---4.0 0.28 0.19 ---2.5
(left channel)V 41 0.42 0.30 ---4.0 0.28 0.19 ---2.5
_"1"-TAO/donrep
DRAFT
Table 6-8-2 (continued)
Upper Side
Channel 11 1 40 0.60 0.44 0.22 16.0 0.42 0.30 0.115 7.0
11 670 0.67 0.49 0.26 20.0 0.50 0.36 0.155 10.1
20 I 90 0.42 0.30 0.091 3.4 0.30 0.20 0.046 1.6
11 100 0.43 0.30 0.091 4.1 0.30 0.20 0.046 1.9
1II 95 0.60 0.44 0.172 8.5 0.43 0.30 0.091 4.1
I
Side Channel I 10 0.50 0.36 0.105 8.0 0.35 0.24 0.053 3.1
21 II 15 0.55 0.40 0.125 10.0 0.39 0.27 0.065 4.1
111 175 0.65 0.48 0.290 27.5 0.48 0.34 0.163 14.0
IV 200 0.67 0.49 0.240 30.0 0.50 0.36 0.145 16.5
V 200 0.67 0.49 0.079 4.2 0.50 0.36 0.065 3.2
22 I 40 0.60 0.44 0.118 14.0 0.42 0.30 0.063 3.6
II 220 0.67 0.49 0.257 9.0 0.50 0.36 0.154 20.0
TAD/donrep
DRAFT
LITERATURE CITED
APPENDIX B
May 10,1984
Leopold,L.B.,and Maddock,T.,Jr.,1953,The Hydraulic Geometry of·
Stream Cr.~nnels and Some Physiographic Implications:U.S.
Geological Survey Prof.Paper 252.
Leopold,L.B.,Wolman,M.G.,and Miller,J.P.,1964,Fluvial Processes
in Geomorphology:W.H.Freeman and Company,San Francisco.
Li,R.M.,1974,Mathematical Modeling of Response from Small Watershed:
Ph.D.Dissertation,Department of Civil Engineering,Colorado State
University,Fort Collins,Colorado.