BLM LIBRARY
88040584
Salmon Falls Creek
Fish Inventory
5
IDAHO BUREAU OF LAND MANAGEMENT TECHNICAL BULLETIN NO. 95-2
FEBRUARY 1995
Hi
SALMON FALLS CREEK FISH INVENTORY
Challenge Cost Share Project
Charles D. Warren
Regional Fishery Biologist
and
Fred E. Partridge
Regional Fishery Manager
Idaho Department of Fish and Game
1995
Prepared for the Boise District
Bureau of Land Management
ABSTRACT
Salmon Falls Creek fisheries and instream habitat was
investigated between Lily Grade and Salmon Falls Creek Dam in
1994. This reach of Salmon Falls Creek is within a remote,
narrow steep sided canyon with .limited access. The source of
most of the water within the stream is from springs and seepage
around the dam since none is released directly from the dam
itself. Water quality is good but the lack of annual flushing
flows has resulted in a narrow riparian zone with dense
vegetation encroaching on the stream channel and a deep build up
of fine sediments in most pools. Habitat features are nearly
identical at all sites investigated with numerous pools created
by the presence of large boulders which have fallen into the
stream from the surrounding steep canyon walls.
Fish survey results indicate a fish community dominated by
numerous nongame and game fish species including smallmouth bass
Micropterus dolomieui and wild rainbow trout Oncorhynchus mykiss
from Lily Grade upstream with a shift to one dominated
exclusively by rainbow and brook trout Salvelinus fontinalis
immediately below the dam. Salmonid spawning habitat appears to
be limited by the presence of large quantities of fine sediments
in most sections. Bull trout S. conf luentus and leatherside chub
Gila copei , both species of special concern, were speculated to
be present within this reach of Salmon Falls Creek but none were
found in any of the surveys.
INTRODUCTION
Salmon Falls Creek downstream of Salmon Falls Creek Dam in
south central Idaho was investigated in 1994 with a Challenge
Cost Share project between the Idaho Department of Fish and Game
and the Boise District of the Bureau of Land Management (BLM) .
The project plan was to inventory and measure distribution of
fish species within the reach; collect biological data from game
fish species sampled; gather habitat usage and biological data on
any fish species of special concern sampled; and to identify
natural and manmade barriers to movement of fish within the
reach.
Study Area Description
Most of Salmon Falls Creek water originates in Nevada before
flowing northward into Idaho where it is impounded by Salmon
Falls Creek Dam at river mile 46, 11 km west of the town of
Rogerson. Downstream of the dam, Salmon Falls Creek flows
through a narrow steep sided canyon until it approaches its
confluence with the Snake River between the towns of Buhl and
Hagerman, Idaho. The only major tributaries to the 48 km (30
river miles) reach of Salmon Falls Creek between the dam and
Balanced Rock is Cedar Creek and Devil Creek, both of which are
dry during the summer due to irrigation diversions. Within this
reach vehicle access is limited to crossings at Balanced Rock,
Lily Grade and Salmon Dam. Foot access is extremely difficult
due to the vertical walls of the canyon which varies from 80 to
90 meters deep. The reach between Salmon Falls Creek Dam and
Balanced Rock is relatively unimpacted by human influences and
has been considered for listing as a Wild And Scenic River with
the BLM upstream of Lily Grade.
Flows within lower Salmon Falls Creek are greatly modified
by the dam since its construction in 1910. Virtually all of the
water is diverted into a canal "bypassing the natural stream
channel, except that during an emergency water may be spilled
over the rim into the canyon from the canal. The only releases
made into the canyon since the dam was constructed were from May
11 to June 29, 1984 and April 22-30, 1985 (Harenberg et al.
1987) . Water does leak out from the reservoir into the lower
canyon through crevices in the rock strata around the dam. This
leakage probably amounts to less than 0.30 m 3 /second (10.6
ft 3 /second) . Instream flows probably increase slightly by the
time it reaches Lily Grade (river mile 31) with downstream ground
water influence. With the loss of the natural hydrologic cycle
downstream of Salmon Falls Creek dam there is no longer stream
bed scouring and flooding. Without water flowing directly from
upper Salmon Falls Creek there is also no longer an influx of
sands, fine sediments or gravels from upstream erosion. Many
sites throughout the reach have numerous large boulders from the
inner canyon walls piled into the stream bed. Since there is no
annual over bank flooding, the riparian zone is narrow with
vegetation encroaching on the stream channel. Riparian shrub
species include rose Rosa woodsii , coyote willow Salix exique ,
red-osier dogwood Cornus stolonifera , golden currant Ribes
aureum , poison ivy Toxicodendron radicans , and a few other
species. Dominant herbaceous species include cattail Tvpha spp . ,
reed Phragmites spp . , Nebraska sedge Carex nebraskensis , beaked
sedge Carex spp . , spikerush Eleocharis spp . , baltic rush Juncus
bealticus , bulrush Scirpus spp . , meadow foxtail Alopecurus
pratensis . horsetail Equisetum spp . , goldenrod Solidaqo spp . , and
mint Mentha spp . . Upland vegetation within the canyon is
dominated by several grass species with big sagebrush Artemesia
tridentata . and rabbitbrush Chrysothamnus spp . (J. Klott, BLM
pers. comm.). There has been no grazing by livestock within this
reach of the canyon since 1984.
The fishery in this reach of Salmon Falls Creek historically
included anadromous Chinook salmon Oncorhynchus tshawytscha .
steelhead trout 0. mykiss and other native species normally found
below Shoshone Falls. Anadromous fish are known to have spawned
and reared in the mainstem and tributaries of the Snake River up
to Shoshone Falls until the construction of Swan Falls, Brownlee
and Oxbow dams (Idaho Dept. Fish and Game 1992) . Recent
incidental fishing reports from Salmon Falls Creek indicate
populations of wild rainbow/redband trout 0. mykiss , introduced
brook trout Salvelinus fontinalis and smallmouth bass Micropterus
dolomieui . One angler reported last catching bull trout S.
conf luentus downstream of the Balanced Rock crossing as recently
as the early 1960's. Hatchery reared rainbow trout 0. mykiss are
currently stocked at the Balanced Rock Park.
Prior to the construction of Salmon Falls Creek Dam, the
hydrologic cycle of the lower Salmon Falls Creek system probably
simulated todays cycle at the U.S.G.S. gaging station near San
Jacinto, Nevada. In records published for the period between
1910 and 1993 (Harenberg, et al. 1993) the highest annual mean
discharge at this site was 439 ft 3 /second (cfs) in 1984 and the
lowest annual mean discharge was 45 cfs in 1934. The highest
daily mean discharge ever recorded was 3,620 cfs on May 16, 1984
and the lowest daily mean was 3.2 cfs on September 4, 1961.
METHODS
A total of four sites between Lily Grade and Salmon Falls
Creek dam were investigated for fish species composition and
instream habitat (Figure 1) . Fish were also sampled at the
Balanced Rock Park (approximately river mile 16) within a 234 m
long reach, but no habitat assessment was made there. Habitat
and flows in this reach have been altered by road and park
construction which backs water up in the channel for several
N
A
HWY 30
* SH Buhl
Lega
Descriptions
Site 1: SW1/4, SEC30, RUE, T11S
Site 2: SW1/4, SEC10, RUE, T12S
Site 3: SE1/4, SEC7, R15E, T13S
Site 4: SW1/4, SEC6, R15E, T14S
Hwy 93
Holltster
Legend
Highway or county road
Stream
5 km
I 1
Rogerson
Figure 1. Map of Salmon Falls Creek depicting survey sites.
hundred meters. Total length of each site between Lily Grade and
Salmon Falls Creek dam ranged from 98 to 190 m long. An effort
was made to select sites which appeared to represent habitat
types within the reach. Prior to the survey, a video tape was
made of the entire stream from Balanced Rock to Salmon Falls
Creek dam from fixed wing aircraft. The purpose of this was to
identify possible fish barriers as well as access sites into the
canyon.
Fish were sampled at each site by electrof ishing with the
sampling crew working their way upstream. At the Balanced Rock
Park site a drift boat with a Coffelt WP-15 Electrof isher
powered with a Honda 5000 generator was used. Utilizing the boat
hull as the cathode and two anodes suspended off the bow, two
crew members acted as netters and one crew member rowed and
controlled the electrical output. All fish stunned were netted
and put into a live well in the boat. At the other four sites
fish were sampled with a Smith-Root Model 15-A backpack shocker
with two to three crew members working as netters and one
additional crew member receiving netted fish into a bucket. Two
passes were made at the four sites that the backpack shocker was
used. All fish were identified, measured, and enumerated from
each pass. Scale samples and weights were taken from some of the
game fish species. A Seber LeCren (1967) two pass population
estimate was made for game fish species. Fish population
densities were estimated based on total surface area of site
sampled and total population estimates. Length-at-age was
estimated from scale samples at each site. Ten each of the brook
and rainbow trout sampled from Site 4 were preserved on ice in
the field then frozen and transported to the Fish and Game Fish
Health Laboratory to be tested for Bacteria Kidney Disease (BKD)
Renibacterium salmoninarum and whirling disease Myxosoma
cerebralis . For BKD testing the 10 fish were pooled into 2
groups of 5 fish each. Tests were run utilizing the Enzyme
Linked Immuno-Sorbant Assay (ELISA) and Flourescent Antibody Test
(FAT) procedures.
Habitat assessments were made where possible utilizing Idaho
Department of Fish and Game standardized stream survey procedures
which are based on methods described by Platts et al. (1983) and
Rosgen (1985) . Four to ten transects were systematically
selected for habitat measurements throughout each sample site.
Features measured across transects include total stream width,
total depth, water column habitat type and substrate class at
one-fourth, one-half, and three-fourths the distance across the
transect. Total stream discharge volume was measured at the Lily
Grade site on August 4, 1994 using a Marsh-McBirney flow meter
and methods described by Platts et al. (1983).
Water temperature profiles" were measured at two sites on
Salmon Falls Creek using continuously recording Ryan TempMentor
thermographs. A thermograph was set approximately 20 m upstream
of the Lily Grade crossing within site one between the dates of
May 14 and September 22, 1994 and a thermograph was set
approximately 10 m upstream of the Lateral 10 power plant outflow
between June 11 and October 17, 1994. Both thermographs were
completely submerged within the main channel of the stream and
set to record ambient water temperature every 3 minutes.
RESULTS
Due to the nature of the steep narrow canyon and the side
view from the fixed wing aircraft, portions of the stream
channel between Lily Grade and Salmon Falls Dam were not covered
on the video tape. However, the majority of the stream was
observed. Large rock slides with boulders exceeding 3 meters
across are common throughout the canyon and in many areas cover
the entire stream channel. Although these slides have filled the
canyon bottom, in most cases they are not barriers to fish
movement. Inspection of some of these slides at sample sites
found water flowing under and through the boulders which allowed
fish to pass these slides. Not all slides were inspected and it
is possible that a large slide area near site 3 may be an
upstream barrier at current water flows. Additional barriers to
fish movement in Salmon Falls Creek are seasonal dams located at
several irrigation pump sites between Balanced Rock and the Snake
River. Besides the dams, pumping during low water years can
dewater short reaches of the stream during the summer.
Fish sampled in Salmon Falls Creek in 1994 included hatchery
and wild rainbow trout, brook trout, smallmouth bass, largescale
sucker Catostomus macrocheilus , bridgelip sucker C. columbianus ,
redside shiner Richardsonius balteatus, northern squawfish
Ptychocheilus oregonensis , speckled dace Rhinichthvs osculus,
longnose dace R. cataractae , chiselmouth chub Acrocheilus
alutaceus and mottled sculpin Cottus bairdi (Tables 1-5) .
Smallmouth bass were present up through site 2. Brook trout were
only sampled in the upper two sites. Although wild rainbow trout
were not sampled at Balanced Rock, they were found in all other
sites. Wild rainbow trout were observed below Balanced Rock at
Magic Water pump site in April, 1993 (Warren and Partridge, In
Press). Nongame fish were sampled at all sites except site 4.
Fish sampling efforts at Balanced Rock park were not
effective enough to collect a suitable sample for population
estimates because of the excessive depth (> 2m) and dense aquatic
vegetation. Population density estimates for wild rainbow trout
ranged from 0.8 to 14. 2 /100m 2 at sites 1-4 (Table 6). Brook
trout density estimates in sites 3 and 4 were 0.8 and 35.0/ 100m 2 ,
respectively. Smallmouth bass density which was only estimated
at site 1 due to sampling efficiency, was 2.6/100m 2 . Population
Table 1 . Fish sampled by electrofishing at the Balanced Rock site of Salmon Falls Creek with total length
frequency in each 1 mm length group, percent of total, mean weight of hatchery rainbow trout
and smallmouth bass, and total numbers of each species, collected July, 1994.
Hatchery rainbow
Smallmouth
Largescale
Redside
Northern
trout
bass
sucker
shiner
squawfish
Length
Range _
.Length Weight
Length Weight
Length
Length
Lenqth
(mm)
no. % no. avg.
no. % no. avg.
no. %
no. %
no. %
0-9
10-19
20-29
30-39
40-49
50-59
60-69
70-79
80-89
2 33.3
90-99
1 16.7
100-109
3 50.0
110-119
120-129
1 50.0 1 20
130-139
140-149
150-159
160-169
170-179
180-189
190-199
200-209
210-219
1 50.0 1 90
220-229
1 50.0
230-239
1 100.0 1 124
240-249
1 500
250-259
260-269
270-279
280-289
290-299
300-309
310-319
320-329
330-339
340-349
350-359
360-369
370-379
380-389
390-399
400-409
410-419
420-429
430-439
440-449
450459
460-469
1 50.0
470-479
480-489
490-499
500-509
1 50.0
510-519
520-529
530-539
540-549
Number;
1 1
2 2
2
6
2
Avg.
length:
235
165
483
S5
233
Total
collected:
1 1
2 2
2
6
2
Table 2 Fish sampled by electrofishing at site 1 of Salmon Falls Creek with total length frequency in each 10 mm length group, percent of total, mean weight of wild rainbow trout and
smallmouth bass and total numbers of each species, collected July, 1994.
CO
Wild rainbow
Smallmouth
bass
Northern
squawfish
no. %
Speckled
dace
Mottled
SCUlPJtL
Length
no. %
Bridgelip
sucker
Length
no. %
Chiselmoulh
chub
Longnose
dace
Largescale
sucker
Length
no. %
Redslde
shiner
Length
Range
Length
no. %
Weight
no. ava.
Length
no. %
Weight
no. avg.
Length
no. %
Length
no. %
no. %
.. Length
no. %
0-9
10-19
20-29
30-39
40-49
3 20.0
50-59
60-69
70-79
80-89
90-99
1
1
1
1
3.2
3.2
3.2
3.2
1
3
4.3
13.0
1
3
8
11
2 13.3
4 26.7
5 33.3
9 243
6 162
2 5.4
100-109
110-119
120-129
130-139
140-149
1
2
3.2
6.5
1
2
20
30
1
4.3
1
20
1 2.9
2 5.7
3 8.6
4 11.4
2 100.0
1 6.7
1 14.3
1 14.3
6 33.3
S 44.4
1 50.0
1 50.0
1 16.7
1 16.7
2 33.3
1 16.7
11 29.7
8 21.6
1 2.7
150-159
160-169
170-179
180-189
190-199
1
1
2
4
4
3
1
3
3.2
3.2
6.5
12.9
1
1
4
45
54
77
1
1
3
3
1
4.3
4.3
13
13
4.3
1
1
3
3
1
50
60
65
72
94
3 8.6
6 17.1
9 25.7
4 114
1 14.3
1 14.3
2 286
3 16.7
1 5.6
1 16.7
200-209
210-219
220-229
230-239
240-249
12.9
9.7
3.2
9.7
4
3
1
3
84
97
98
125
4
1
1
1
17.4
4.3
4.3
4.3
4
1
1
1
107
138
148
180
2 5.7
1 2.9
1 14.3
250-259
260-269
270-279
280-289
290-299
2
1
1
1
6.5
3.2
32
32
1
1
1
1
158
176
1
1
4.3
4.3
1
1
252
260
300-309
310-319
320-329
330-339
340-349
258
355
350-359
360-369
370-379
380-389
390-iqq —
Number:
Avg.
length:
Total
Collected:
31
192
31
24
23
177
23
23
35
166
70
2
113
2
15
68
15
7
173
7
18
143
18
2
115
2
6
138
6
37
89
179
Table 3 Fish sampled by electrof.shing at site 2 of Salmon Falls Creek with total length frequency in each 10 .mm ttengtn i group, percent of total,
mean weight of wild rainbow trout and smallmouth bass and total numbers of each species, collected October, 1994.
to
Wild rainbow
Smallmouth
bass
Bridgelip
sucker
Length
no. %
Mottled
sculpin
Length
no. %
Redside
shiner
Speckled
dace
no. %
Northern
squawfish
Length
Range
(mm)
0-9
10-19
20-29
30-39
40-49
Length
no. %
Wek
no.
bt_
_Lenglb
no. %
_WeigM_
no. avg.
Length
no. %
Length
no %
1
7.7
6
5
50.0
41.7
2 66.7
50-59
60-69
70-79
80-89
90-99
1
1
12.5
12.5
3
4
1
3
1
23.1
30.8
7.7
23 1
77
1
8.3
1 33.3
100-109
110-119
120-129
130-139
140-149
2
14.3
2
37
1
125
1 11.1
1 11.1
2 22.2
150-159
160-169
170-179
180-189
190-199
200-209
210-219
220-229
230-239
240-249
1
1
1
11.1
11.1
11 1
1
1
1
56
54
66
2
1
4
1
1
143
71
286
7.1
7.1
2
1
4
1
1
45
59
63
84
86
2
2
25.0
25.0
2 22.2
3 333
3
33.3
3
84
1
1
7.1
7.1
1
1
142
164
1
12.5
250-259
260-269
270-279
280-289
290-299
1
2
11.1
22.2
1
2
142
180
1
7.1
1
216
300-309
310-319
320-329
330-339
340-349
350-359
360-369
370-379
380-389
390-399
Number:
Avg
Lgth:
Total
Collected
9
217
9
9
14
181
14
14
8
141
8
13
65
13
12
39
12
3
43
3
9
158
9
Table 4 Fish sampled by electrofishlng at site 3 of Salmon Falls Creek with total length frequency in each 1 mm length group, percent of total, mean weight of wild
rainbow trout and brook trout, and total numbers of each species, collected July, 1 994
Wild rainbow
trout
Brook
trout
Bridgelip
sucker
Length
no %
Chiselmouth
chub
Longnose
Length
no. %
Mottled
sculpin
Length
no. %
Redside
shiner
Length
no. %
Speckled
dace
Length
no. %
Northern
squawfish
Length
Range
Length
no. %
We
gbl_
avg.
Length Weight
no. % no. avg.
Lengtb_
no %
Length
no. %
no.
0-9
10-19
20-29
30-39
40-49
1
25
1 2.6
2 18.2
2 100
7 350
1
1
1
20
20
2.0
50-59
60-69
70-79
80-89
90-99
3
2
1
1
7.5
5.0
2.5
2.5
1 125
4 500 1 5
1 125
1 91
2 18.2
1 91
3 273
1 91
1 50
2 100
2 10.0
4 20.0
2 10.0
1
2
19
13
20
4.1
38.8
265
1 50
1 50
100-109
110-119
120-129
130-139
140-149
1 12.5 1 12
1 2.6
7 18.4
11 28.9
2 53
11 28.9
1 250
2 50.0
1 25.0
1 9.1
11
22.4
1 10.0
2 20.0
2 20.0
150-159
160-169
170-179
180-189
190-199
6
3
4
6
9
1
2
15.0
7.5
10.0
15.0
22 5
5
2
2
2
4
35
43
55
57
74
1 12.5 1 45
3 7.9
1 2.6
1 2.6
1 10.0
2 20.0
1 10.0
1 10.0
200-209
210-219
220-229
230-239
240-249
25
5.0
1
2
78
92
250-259
260-269
270-279
280-289
290-299
1
2.5
1
138
300-309
310-319
320-329
330-339
340-349
350-359
360-369
370-379
380-389
390-399
Number:
Avg
length:
Total
Collected
40
157
40
40
8 8
96
8
38
129
38
4
125
4
11
68
11
20
60
20
49
85
49
2
75
2
10
155
10
10
Table 5. Fish sampled by electrofishing at site 4 of Salmon Falls Creek with total length
frequency in each 10 mm length group, percent of total, mean weight offish
sampled, and total numbers of each species sampled, August, 1 994.
Wild rainbow
Brook
gth
trout
trout
Len
Range
Lenqth
We
ght
Lenqth
Weiqht
(mm)
no.
%
no.
avg.
no.
%
no.
avg.
0-
•9
10-
■19
20-
•29
30-
■39
40-
•49
1
2.0
50-
■59
1
2.0
60-
•69
3
1.8
70-
-79
14
8.3
80-
-89
i
18
10.7
1
4
90-
-99
21
12.4
100-
-109
27
16.0
4
13
110-
-119
1
2.0
1
18
15
8.9
3
15
120-
-129
1
0.6
130-
-139
3
6.0
2
22
1
0.6
140-
-149
1
2.0
1
0.6
150-
-159
3
6.0
2
41
1
0.6
160-
-169
4
8.0
1
36
170-
-179
5
10.0
2
56
180-
-189
6
12.0
3
60
1
0.6
190-
-199
3
6.0
1
92
13
7.7
1
84
200-
-209
2
4.0
11
6.5
3
99
210-
-219
4
8.0
2
112
15
8.9
3
117
220-
-229
4
8.0
2
113
10
5.9
230-
-239
1
2.0
8
4.7
2
142
240-
-249
3
6.0
1
140
6
3.6
2
175
250-
-259
2
4.0
1
162
2
1.2
2
198
260-
-269
1
2.0
1
0.6
270-
-279
4
8.0
4
205
280-
-289
290-
-299
300-
-309
310-
-319
320-
-329
330-
-339
340-
-349
350-
-359
360-
-369
370-
-379
1
2.0
1
500
380-
-389
390
-399
Number:
50
23
169
21
Avg
length:
194
141
Total
Collected:
50
169
11
Table 6. Salmon Falls Creek game fish population estimates,
standard errors, and densities for sites electrof ished,
Site
Date
7/13/94 10/18/94 8/16/94 8/22/94
Wild rainbow trout
Population estimate
Standard error
Density (no./ 100 m 2 )
32
1.03
3.2
12
6.00
0.82
88
68.69
7.88
131
120.99
14.2
Brook trout
Population estimate
Standard error
Density (no./lOO m 2 )
'.
-
8
0.82
322
93.34
35.04
Smallmouth bass
Population estimate
Standard error
Density (no./lOO m 2 )
25
2.55
2.57
_b
-
-
* Standard error of population estimate of brook trout at site 3
not calculable with second removal pass catch equal to 0.
b Both first and second removal pass catches were equal to 7
smallmouth each at site 2.
12
estimates were not made on nongame fish due to sampling
inefficiencies on small fish.
Length-at-age estimates for some of the game fish sampled
are given in Tables 7 and 8. There is no length-at-age estimate
table for wild rainbow trout from site 1 or brook trout from
sites 3 or 4 because only age + and 1 + fish were sampled from
these sites. Mean back calculated length to age 1 for 15 rainbow
trout sampled from the 1993 year class at site one was 145 mm
with a standard deviation of 33.59. Mean back calculated length
to age 1 for 5 brook trout sampled from the 1993 year class at
site 4 was 134 mm with a standard deviation of 26.48. Of scale
samples taken from brook trout at site 3, only one was age 1 + and
the rest were age + .
Fish health laboratory test results for BKD were positive-
low utilizing the ELISA procedure and negative utilizing the FAT
procedure on both rainbow and brook trout. Whirling disease
samples were negative for brook trout but presumptive positive
for rainbow trout. The presumptive positive designation was
given since Myxobolus sp. spores were found by digestion method
although no M. cerebralis were confirmed present in histological
samples. Also, whirling disease positive fish were stocked into
Salmon Falls Creek in Nevada upstream of Salmon Falls Creek
Reservoir in the 1980' s.
Instream substrate consisted mainly of fines (sand and
organic silt) and boulder. These two groups accounted for 85 to
95 percent of the substrate in sites 1-4 (Table 9) . The highest
gradient measured was within site 4 which was 5% over the entire
98 m reach. Due to the areas of boulders, the stream gradient is
a stair step system of flat pool/run areas above boulder areas
with steeper gradients. Stream channel type for all sites
surveyed was confined. Total stream discharge as measured at
Lily Grade on August 4, 1994 was 11.87 cfs. Maximum water
temperature at Lily Grade between May 14 and September 22, 1994
was 25.8 C (Table 10). Above the Lateral 10 hydro inflow between
June 11 and October 17, 1994, it was 22.2 C. Daily average water
temperatures averaged 1.6 C warmer at Lily Grade than downstream
near Lateral 10 hydro, with a maximum difference of 3 C on August
6, 1994.
DISCUSSION
The Salmon Falls Creek fishery indicates that water quality
is relatively good within the reach between Salmon Falls Creek
Dam and Lily Grade. Instream and riparian habitat conditions,
however, have been significantly altered by the decrease in
stream flows from the diversion of water at Salmon Falls Creek
Dam. Within this reach there exists a gradient in fish community
13
Table 7. Back calculated length-at-age (mm) for smallmouth
bass sampled from Salmon Falls Creek. Standard
deviation is in parenthesis.
Site 1, July 13, 1994
Year
Number
Mean lengt
h
at annulus
class
of
fish
1
2
3
4
1993
3
62
(0.96)
1992
9
88
(7.33)
148
(17.70)
1991
2
82
(8.08)
153
(19.62)
218
(17.25)
1990
1
65
(-)
102
(-)
153
(-)
193
(-)
Weighted
average
length
80
145
196
193
Weighted
average
length
Site 2, October 18, 1994
Year
Number
Mean
length at
annu
lus
class
of fish
1
2
3
1993
7
105
(12.23)
1992
9
72
(2.33)
117
(6.51)
1991
2
81
(18.47)
142
(6.22)
199
(7.16)
91 125 199
14
Table 8. Back calculated length-at-age (mm) for wild rainbow
trout sampled from Salmon Falls Creek. Standard
deviation is in parenthesis.
Year
class
Number
of fish
Site 2, October 18, 1994 ^_
Mean length at annulus
1993
117
(15.83
1992
124
(35.68)
171
(89.75)
Weighted
average
length
120
171
Site 3, August 16, 1994
Year
class
Number
of fish
Mean length at annulus
12 3
1993
17
128
(14.74)
1992 (none sampled)
1991
Weighted
average
length
114
(-)
127
168
(-)
168
223
(-)
223
15
Table 8. Continued.
Site 4, August 22, 19 94
Year
class
Number
of fish
14
Mean
1
length at
2
annulus
3
1993
98
(16.71)
1992
6
110
(17.02)
199
(26.56)
1991
1
129
(-)
220
(-)
297
(-)
Weighted
average
length 103 202 297_
16
Table 9. Habitat data collected from all sites surveyed in the
Salmon Falls Creek drainage, 1994.
1
2
Site
3
4
Reach length (m)
Mean width (m)
190.6
5.1
150.0
9.7
147.0
7.6
97.8
9.4
Mean depth (cm) 49.1 20.8 36.4 43.5
Habitat (%)
Pool
43.3
0.0
67.0
80.0
Run
43.3
29.0
8.0
0.0
Pocket
3.3
25.0
0.0
0.0
Riffle
6.7
8.0
25.0
20.0
Backwater
3 .3
21.0
0.0
0.0
Dry
0.0
17. a
0.0
.0
Substrate Class (%)
Sand
41.0
50.0
54.6
22.3
Gravel
6.7
3.8
4.6
4.0
Rubble
8.3
0.4
0.0
5.0
Boulder
44 .0
45.8
40.8
68.7
Bedrock
0.0
0.0
0.0
0.0
Exposed rock outcroppings .
17
Table 10. Daily minimum, maximum and average water temperatures
(Celcius) recorded at Lily Grade and immediately
upstream of the Lateral 10 hydropower outflow.
Salmon Falls Creek
Grade
May 14 - Sept. 22,
at Lily
1994
Salmon Falls Creek
upstream of Lateral 10
hydropower outflow
June 11 - Oct. 17, 1994
MAXIMUM
MINIMUM
AVERAGE
25.8
10.3
18.9
MAXIMUM 24.0
MINIMUM 13 .
AVERAGE 18.2
DATE
MAXIMUM
MINIMUM
•AVERAGE
MAXIMUM
MINIMUM
AVERAGE
14-May-94
18.2
13.3
15.9
15 -May- 9 4
16.9
15.0
15.8
16-May-94
14.8
13.1
13.9
17-May-94
14.1
11.5
12.8
18-May-94
13.6
11.4
12.5
l9-May-94
13.1
10.9
12.2
20-May-94
13.2
10.7
12.0
21-May-94
16.5
10.3
13.4
2 2 -May- 9 4
18.4
12.3
15.3
23-May-94
20.2
13.9
17.0
24-May-94
21.1
15.0
18.1
25-May-94
21.8
15.6
18.7
26-May-94
21.9
16.5
19.4
27-May-94
19.6
17.2
18.4
28-May-94
18.7
15.0
17.0
29-May-94
20.2
15.1
17.6
3 0-May-94
21.1
15.2
18.3
31-May-94
19.3
16.2
17.2
01-Jun-94
19.3
14.8
16.6
02-Jun-94
20.3
14.4
17.5
03-Jun-94
21.5
16.8
19.1
18
DATE
MAXIMUM
MINIMUM
AVERAGE
MAXIMUM
MINIMUM
AVERAGE
04-Jun-94
21.4
16.2
19.0
05-Jun-94
22.4
16.5
19.5
06-Jun-94
20.4
16.2
18.1
07-JUT1-94
16.5
13.1
15.0
08-Jun-94
18.3
12.3
15.3
09-Jun-94
19.9
13.7
| 16.8
10-Jun-94 21.1
14.8
18.0
ll-Jun-94
21.4
16.5
19.2
21.3
15.3
18.3
12-Jun-94
22.0
18.0
20.1
20.7
16.5
18.7
13-Jun-94
20.9
17.8
19.3
19.1
15.7
17.7
14-Jun-94
18.9
14.4
16.7
18.8
13.2
15.7
15-Jun-94
18.7
13.3
16.1
19.1
13.1
15.5
16-Jun-94
18.0
13.4
15.8
18.3
13.0
15.4
17-Jun-94
19.3
13.3
16.4
19.6
13.0
16.1
18-Jun-94
21.0
15.3
18.1
20.8
14.3
17.3
19-Jun-94
22.0
16.2
19.1
21.6
15.0
17.9
20-Jun-94
22.8
17.4
20.2
22.2
15.8
18.6
21-Jun-94
22.0
18.6
20.5
20.6
16.7
18.6
22-Jun-94
22.8
18.2
20.6
22.0
16.5
18.9
23-Jun-94
23.6
18.0
20.8
22.5
16.2
19.0
24-Jun-94
23.2
17.8
20.6
21.8
15.7
18.5
25-Jun-94
24.1
18.3
21.3
22.8
15.9
19.0
26-Jun-94
22.3
18.8
20.8
20.6
15.9
18.0
27-JUT1-94
21.0
16.4
19.0
20.0
14.1
17.1
28-Jun-94
22.6
17.1
19.9
22.0
15.3
18.5
29-Jun-94
24.0
18.9
21.3
22.5
16.6
19.3
30-Jun-94
23.6
19.0
21.4
22.6
16.3
19.2
Ol-Jul-94
24.1
18.7
21.5
23.0
16.2
19.2
02-Jul-94
22.1
19.1
20.8
1 21.3
16.6
18.7
19
Table 13. Continued.
DATE
MAXIMUM
MINIMUM
AVERAGE
MAXIMUM
MINIMUM
AVERAGE
03-JU1-94
21.4
17.3
19.4
20.0
14.8
17.3
04-JU1-94
20.8
16.0
18.4
20.0
14.1
16.8
05-JU1-94
19.5
16.9
18.1
18.2
15.2
16.6
06-Jul-94
18.5
15.0
16.6
19.1
13.6
16.0
07-JU1-94
21.2
15.3
18.1
21.2
14.6
17.8
08-Jul-94
22.8
17.1
19.9
22.1
15.7
18.9
09-JU1-94
22.0
18.4
20.5
21.6
16.4
19.0
lO-Jul-94
22.6
18.3
20.2
21.4
16.3
18.5
ll-Jul-94
22.3
17.0
19.7
20.9
14.7
17.7
12-JU1-94
22.4
17.1
19.7
21.4
15.0
17.8
13-Jul-94
22.8
17.5
20.1
21.2
15.3
18.1
14-JU1-94
23.2
18.1
20.6
21.9
15.8
18.6
15-JU1-94
23.7
18.3
21.0
22.5
15.9
19.0
16-Jul-94
24.1
19.5
21.8
22.4
16.4
19.3
17-JU1-94
24.9
20.2
22.5
22.6
17.1
19.8
18-JU1-94
24.5
20.2
22.3
22.4
17.1
19.7
19-JU1-94
23.5
19.4
21.5
21.6
15.9
18.8
20-Jul-94
23.8
18.6
21.2
22.3
15.8
19.0
21-JU1-94
24.3
19.4
21.8
23.4
16.5
19.9
22-JU1-94
24.1
20.2
22.2
23.4
17.0
20.1
23-JU1-94
23.3
20.8
22.1
22.1
18.5
20.0
24-JU1-94
24.0
19.6
21.8
22.7
17.1
19.8
25-Jul-94
25.3
20.5
22.8
23.8
17.4
20.5
26-JU1-94
25.8
21.1
23.4
23.9
18.0
20.8
27-JU1-94
25.1
21.7
23.4
24.0
18.6
20.9
28-JU1-94
24.6
21.1
22.7
23.5
18.0
20.5
29-JU1-94
23.0
20.4
21.8
22.0
17.4
19.8
30-JU1-94
23.5
20.8
22.0
22.0
18.0
19.9
20
Table 13. Continued.
DATE
MAXIMUM
MINIMUM
AVERAGE
MAXIMUM
MINIMUM
AVERAGE
31-JU1-94
23.5
20.4
21.9
22.6
17.6
20.0
Ol-Aug-94
23.3
20.1
21.7
22.6
17.6
20.0
02 -Aug- 9 4
23.1
19.6
21.4
23.0
17.1
19.9
03-Aug-94
24.2
19.3
21.7
22.8
17.0
20.0
04-Aug-94
25.3
20.5
22.8
23.1
17.0
20.1
05 -Aug- 9 4
25.6
21.0
23.2
23.2
17.4
20.2
06 -Aug- 9 4
24.6
20.4
22.4
22.3
16.5
19.4
07 -Aug- 9 4
24.4
19.9
22.2
22.4
16.3
19.4
08 -Aug- 9 4
22.5
20.8
21.7
20.7
17.2
19.0
09 -Aug- 9 4
23.2
19.1
21.1
21.4
16.2
18.7
10 -Aug- 9 4
21.8
20.0
21.0
20.2
17.1
18.7
ll-Aug-94
23.3
19.1
21.2
22.2
16.4
19.1
12-Aug-94
23.6
20.1
21.8
21.2
17.3
19.4
13-Aug-94
24.1
20.2
22.1
22.4
16.8
19.6
14-Aug-94
24.3
20.3
22.2
22.3
16.8
19.8
15-Aug-94
23.9
20.2
22.0
21.6
16.8
19.4
16 -Aug- 9 4
23.2
19.1
21.1
20.8
15.8
18.4
17-Aug-94
22.6
18.4
20.5
20.9
15.5
18.2
18 -Aug- 9 4
22.6
18.7
20.6
21.0
15.6
18.4
19-Aug-94
22.3
18.9
20.5
20.5
15.6
18.2
20-Aug-94
22.1
19.0
20.5
20.7
15.9
18.5
21-Aug-94
22.6
19.5
21.0
21.2
16.4
18.8
22-Aug-94
21.3
18.5
20.0
19.3
15.3
17.5
23-Aug-94
20.7
16.8
18.8
19.6
14.3
17.0
24-Aug-94
21.3
17.4
19.3
19.9
14.7
17.4
2 5 -Aug- 9 4
21.3
17.5
19.4
20.1
15.0
17.6
26-Aug-94
20.8
17.6
19.3
19.9
14.8
17.5
27-Aug-94
20.4
17.5
18.9
19.4
15.3
17.4
21
Table 13. Continued.
DATE
MAXIMUM
MINIMUM
AVERAGE
MAXIMUM
MINIMUM
AVERAGE
28-Aug-94
21.3
17.7
19.5
20.3
15.6
17.9
29-Aug-94
20.4
17.7
19.1
19.2
15.2
17.2
30-Aug-94
19.3
16.2
17.8
18.2
14.1
16.2
31-Aug-94
19.3
15.5
17.4
18.7
13.7
16.3
Ol-Sep-94
19.5
16.0
17.7
19.0
14.2
16.6
02-Sep-94
19.0
16.1
17.6
18.6
14.5
16.6
03-Sep-94
19.3
16.1
17.7
18.7
14.8
16.7
04-Sep-94
18.6
15.6
17.1
18.1
14.1
16.0
05-Sep-94
18.4
14.7
16.6
18.1
13.2
15.7
06-Sep-94
19.3
15.3
17.2
18.9
14.0
16.3
07-Sep-94
19.9
16.5
18.1
19.2
14.9
17.0
08-Sep-94
20.2
16.9
18.5
19.2
15.0
17.1
09-Sep-94
19.2
16.5
17.9
18.1
14.4
16.2
10-Sep-94
17.7
14.8
16.3
17.4
13.4
15.3
ll-Sep-94
16.8
14.1
15.5
16.8
13.2
15.0
12-Sep-94
15.7
13.9
14.9
16.3
13.4
14.8
13-Sep-94
16.0
13.6
14.8
16.6
13.5
14.9
14-Sep-94
15.7
13.6
14.6
16.8
13.4
14.8
15-Sep-94
16.4
13.2
14.8
17.1
13.3
15.0
16-Sep-94
16.8
13.4
15.0
17.4
13.3
15.3
17-Sep-94
17.1
14.0
15.6
17.6
13.6
15.5
18-Sep-94
18.0
14.4
16.1
17.6
14.1
15.7
19-Sep-94
17.9
14.7
16.2
17.9
13.9
15.8
20-Sep-94
17.6
14.7
16.1
17.6
14.1
15.7
21-Sep-94
17.2
14.6
15.9
17.4
13.9
15.6
22-Sep-94
16.8
13.7
15.1
17.4
13.6
15.3
23-Sep-94
17.4
13.3
15.2
24-Sep-94
17.3
13.2
15.1
22
Table 13. Continued.
DATE
MAXIMUM
MINIMUM
AVERAGE
MAXIMUM
MINIMUM
AVERAGE
25-Sep-94
17.2
13.2
15.1
26-Sep-94
16.8
13.4
15.0
27-Sep-94
16.8
13.4
14.9
28-Sep-94
16.8
13.3
15.1
29-Sep-94
15.7
14.9
15.3
30-Sep-94
15.0
14.5
14.7
Ol-Oct-94
16.8
14.2
15.3
02-Oct-94
15.8
13.1
14.6
03-Oct-94
13.1
11.8
12.5
04-Oct-94
12.8
11.1
11.9
05-Oct-94
13.7
12.1
12.9
06-Oct-94
13.4
11.6
12.6
07-Oct-94
13.4
11.4
12.4
08-Oct-94
13.7
11.1
12.4
09-Oct-94
14.3
11.6
12.9
10-Oct-94
14.3
12.1
13.2
ll-Oct-94
14.6
12.4
13.4
12-Oct-94
13.6
11.8
12.8
13-Oct-94 1
13.1
12.1
12.6
14-Oct-94
12.4
11.0
11.7
15-Oct-94
11.1
9.5
10.4
16-Oct-94
11.6
10.0
10.7
17-Oct-94
12.1
10.4
11.3
23
types ranging from a cool water fish community with significant
numbers of smallmouth bass at the Lily Grade site to a cold water
fish community dominated by brook trout at the dam site.
Habitat and water temperature conditions at the Lily Grade
site are well within the range of conditions reguired for
smallmouth bass survival and reproduction. Carlander (1977)
cites numerous sources stating that smallmouth bass egg laying
begins when rising water temperatures reach 13° - 15°C. This
temperature had already been reached at site 1 by the time the
thermograph was put in on May 14, 1994. Substrate reguirements
for smallmouth bass egg laying varies enough to probably not be a
significant limiting factor to the species within this reach.
The absence of smallmouth bass upstream of site 2 can only be
speculated on. There is either a natural fish barrier possibly
in the form of cascades or flow becomes subterraneal through rock
slides, or water temperatures are modified enough from spring
flows to favor only cold water fish species. Most likely it is a
function of both since the aerial video tape does reveal narrow
sections of the canyon with enough rocks in the bottom to obscure
the stream course. If smallmouth bass are capable of migrating
upstream, growth and reproduction may be limited by the cooler
water temperatures.
Cooler downstream water temperatures just above Lateral 10
hydro are probably the result of significant spring inflows that
occur along canyon walls below Lily Grade. Warmer temperatures
in the Lily Grade area are a result of relatively low flows and
the radiator effect of large black boulders in the stream
channel. Water temperatures in sites 3 and 4 were not monitored,
but the numerous brook trout indicate that temperatures are
probably not excessively high. Temperatures are probably cooler
and more stable as you approach the dam since water sources come
mainly through the rock strata.
The high variability in densities of trout among sites
indicates that the population may be limited by natural
recruitment from younger year classes. Considering the lack of
clean gravel at most sites, wild rainbow trout recruitment may be
limited by a lack of successful spawning habitat. Although there
is no significant influx of sediments from upstream sources, the
modified flows below the dam no longer flush out silt from the
areas of low velocity. Fine materials continue to enter the
stream along the canyon due to natural erosion levels. As a
result many of the pools and shoreline areas are laden with a
deep layer of silt favoring the encroachment of shoreline
vegetation. Since there is also no annual flooding there are few
willows and cottonwoods thus very little instream woody debris.
Most of the instream cover is provided by large boulders from the
canyon walls.
24
Two fish species of special concern, bull trout and
leatherside chub Gila cooei that might of been in Salmon Falls
Creek were not found. High water temperatures, lost of migration
due to Salmon Falls Dam and brook trout introductions may have
all played a part in the loss of bull trout from this portion of
the drainage. Brook trout and altered flows may be the reason
nongame fish were not found at site 4 . Leatherside chub may
never have been in the drainage but have been documented further
up the Snake River drainage (Simpson and Wallace 1978) .
25
LITERATURE CITED
Carlander, K.D. 1977. Handbook of Freshwater Fishery Biology,
Vol. II. Iowa State University Press, Ames, Iowa.
Harenberg, W.A. , H.G. Sisco, I. O'Dell, and S.C. Cordes. 1987.
Water Resources Data, Idaho, Water Year 1985. U.S.
Geological Survey, Water Resources Division, Boise.
Harenberg, W.A., M.L. Jones, I. O'Dell, T.S. Brennan, A.K.
Lehmann, and A.M. Tungate. 1993. Water Resources Data,
Idaho, Water Year 1993. U.S. Geological Survey, Water
Resources Division, Boise.
Idaho Department of Fish and Game. 1992. Anadromous Fish
Management Plan 1992-1996, Boise.
Platts, W.S., W.F. Megahan, and G.W. Minshall. 1983. Methods
for evaluating stream, riparian, and biotic conditions.
USDA Forest Service, Intermountain Forest and Range
Experiment Station. General Technical Report INT-138.
Rosgen, D.L. 1985. A stream classification system. Presented
in: Riparian Ecosystems and their Management: Reconciling
Conflicting uses. First North American Riparian Conference,
USDA Forest Service, Rocky Mountain Forest and Range
Experiment Station. General Technical Report RM-12 0.
Seber, G.A.F. and E.D. LeCren. 1967. Estimating population
parameters from catches large relative to the population.
Journal of Animal Ecology 36:631-643.
Simpson, J.C. and R.L. Wallace. 1978. Fishes of Idaho.
University Press of Idaho, Moscow, 237 pp.
Warren, CD. and F.E. Partridge. In Press. Regional Fisheries
Management Investigations. Job 4-c. Idaho Department of
Fish and Game, Job Performance Report. Project F-71-R-18.
Boise.
26
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