IDAHO
FISH GAME DEPARTMENT
Joseph C. Greenley, Director
FEDERAL AID IN FISH AND WILDLIFE RESTORATION..
JOB FINAL REPORT
LAKE AND RESERVOIR INVESTIGATIONS
Project F-53-R-8
Job No. VI-a Survival, Distribution and Use of Mysis relicta by Game
Fish Species
Job No. VIII-a Priest River Fisheries Study (Survey) March 1, 1972 to
February 28, 1973
by
Richard A. Irizarry Fishery Research Biologist October, 1973 Table of Contents
Job No. VI-a Page
ABSTRACT ...... 1
RECOMMENDATIONS ...... 3
OBJECTIVES ...... 3
TECHNIQUES USED ...... 3
FINDINGS ...... 3
Coeur d Alene Lake ...... 3 Pend Oreille Lake ...... 3 Priest Lake ...... 4 Upper Priest Lake ...... 4
LITERATURE CITED ...... 4
List of Tables
Table 1. Kokanee size at spawning time, Lake Pend Oreille, Idaho, 1950-present ...... 5
Table of Contents
Job VIII-a
ABSTRACT ...... 6
INTRODUCTION ...... 8
RECOMMENDATIONS ...... 9
OBJECTIVES ...... 10
TECHNIQUES USED ...... 10
Cross-Sections ...... 10 Stream Depth ...... 10 Temperature ...... 11 Water Quality ...... 11 Stream Habitat ...... 11 Float Trips ...... 11
i Table of Contents (Cont.)
Job VIII-a Page
Fish Species Composition ...... 12 Insects ...... 12 Kokanee Spawning ...... 12
FINDINGS ...... 12
Cross-Sections ...... 12 Stream Depth ...... 12 Temperature ...... 13 Water Quality ...... 14 Stream Habitat ...... 14 Float Trips ...... 16 Fish Species Composition ...... 16 Kokanee Spawning ...... 16
LITERATURE CITED ...... 17
List of Tables
Table 1. Percent reduction of wetted area (stream width) by station, Lower Priest River, Idaho, 1972 ...... 19
Table 2. Stream depth measurements by station, Lower Priest River, Idaho, 1972 .....20
Table 3. Thermometer readings ( F) at seven stations, Lower Priest River, Idaho, 1972 21
Table 4. Thermograph readings at three stations; Lower Priest River, Idaho, 1972 ...... 22
Table 5. Water temperatures ( F) at four sites near the mouth of Outlet Bay, Priest Lake, Idaho, August 5, 1972. . . . 23
List of Figures
Figure 1. Field stations, Lower Priest River, Idaho, 1972 . . . 24
Figures 2A and 2B. Minimum temperatures ( F) and monthly mean, Priest Lake Dam and Saddler, Lower Priest River, Idaho, 1972 ...... 25
Figures 2C and 2D. Minimum water temperatures ( F) and monthly mean, Dickensheet, Lower Priest River, Idaho, 1956 and 1972 ...... 26
ii List of Figures (Cont.)
Job VIII-a Page
Figures 3A and 3B. Maximum temperatures ( F) and monthly mean, Priest Lake Dam and Saddler, Lower Priest River, Idaho, 1972. . 27
Figures 3C and 3D. Maximum water temperatures (0F) and monthly mean, Dickensheet, Lower Priest River, Idaho, 1956 and 1972 ...... 28
Figure 4. Water temperatures ( F) at 17 sites in Outlet Bay and vicinity, Priest Lake, Idaho, August 12, 1972 ...... 29
Appendix I
Station 1. Photo taken on east bank. About one mile above mouth - deep pool, too deep to measure. Back up water from Albeni Falls Dam maintains pool level all summer. Housing development on both sides of river. Some livestock usage on east bank ...... 30
Station 2. Photo taken on east bank. About one mile above Lower West Branch. Riffles with four to five foot pools. Stagnant pools on west bank below clay cliff. Old ranch land on east bank. No cattle usage observed . . 30
Station 3. Photo taken on west bank. At Eight-Mile Rapids. Forested land on both banks of gorge. Good white water trip at flows over 500 cfs ...... 31
Station 4. Photo taken on east bank. Near the McAbee Falls. Deep pool, too deep to measure. Large debris jammed into both banks. Large populations of rough fish. Livestock usage on both sides ...... 31
Station 6. Photo from west bank. About two miles above East River. Uniformly flat streambed. Good spawning gravel throughout. Bank cutting quite evident on west bank ...... 32
Station 7. Photo taken from west bank. Near Whitetail Butte. Deep pool and run. Heavy cattle usage on east bank. Banks cutting and slumping. Housing development on west bank ...... 32
Station 10. Photo taken on west bank. At Chipmunk Rapids. Steep hillsides. Erosion potential high. No cattle usage observed ...... 33
iii Appendix I (Cont.)
Job VIII-a Page Station 12. Photo taken on west bank. One-half mile below dam. Highway 57 on west bank. One area of better fishing for hatchery rainbow ...... 33
Station 13. Photo from west bank. Immediately below the dam at Kokanee Resort. Deep pools and runs. Receives angler pressure from locals and overnighters. Mainly hatchery rainbow caught ...... 34
Appendix II
Thermograph readings at Dickensheet (1/2 mile above bridge), Lower Priest River, Idaho, 1956 ...... 35
Appendix III
Kokanee Spawning Survey (Chronological Data) ...... 36 37
iv JOB FINAL REPORT RESEARCH
PROJECT SEGMENT
State of Idaho Name: LAKE AND RESERVOIR INVESTIGATIONS
Project No. F-53-R-8 Title: Survival, Distribution, and Use of Mysis relicta by Game Fish Job No. VI-a Species Period Covered: March 1, 1972 to February 28, 1973
ABSTRACT:
Department personnel examined 428 stomach samples from kokanee collected at Coeur d Alene, Pend Oreille, and Priest lakes and found no Mysis.
Project personnel trawled for Mysis in sections of Priest, Upper Priest, Pend Oreille, and Coeur d Alene lakes. Net catches of shrimp per haul averaged 2,250 at Priest Lake, 327 at Upper Priest Lake, and 108 on the south end of Pend Oreille Lake. No Mysis were captured in Coeur d Alene Lake or in the north end of Pend Oreille Lake. A 1-ounce sample of shrimp caught at Priest Lake contained about 2,688 individuals.
Submitted by:
Richard A. Irizarry Fishery Research Biologist RECOMMENDATIONS:
The time devoted to the Mysis studies was somewhat limited during 1972 and consequently, no correlations were developed between limnological and physical characteristics of the various lakes and Mysis abundance. During 1973, a more intensive effort is needed to fulfill this job objective.
Priest Lake is the only body of water that contains mysids in sufficient numbers to significantly contribute to the game fish diet. Therefore, stomach sample collection and analysis should be intensified at this lake.
OBJECTIVES:
To make trawl net hauls in major bays and sections of Priest, Upper Priest, Pend Oreille, and Coeur d Alene lakes to determine the relative survival and population growth of Mysis introduced in recent years.
To correlate the limnological and physical characteristics of various lake areas with Mysis abundance.
To measure the relative volume of Mysis in game fish diets and correlate abundance of Mysis with fish growth. TECHNIQUES USED:
Project personnel made a survey of major sections of the four lakes, using the same trawling techniques employed at Kootenai Lake (Heimer, 1969) to ascertain the relative abundance of Mysis shrimp.
We trawled at a rate of ten minutes per haul between a depth of 10 to 40 feet. Personnel bottled the shrimp after each haul in preparation for analysis (counts and volume displacements) the following day.
Kokanee stomachs were collected from all lakes except Upper Priest.
FINDINGS :
Coeur d Alene Lake
On May 26 and June 25, I collected and examined a total of 54 kokanee stomachs and found no shrimp present. Samples mainly contained Dipteran larvae.
On August 23, we made 9 five-minute trawls from Tubbs Hill east to Wolf Lodge Bay, including Blue Creek and Beauty bays. No shrimp were collected but Leptodora kindti were plentiful. An average five-minute trawl produced a 3-ounce sample of these invertebrates.
Pend Oreille Lake
We examined 358 kokanee stomachs collected on May 25 and May 28 and found no shrimp present. The natural diet consisted heavily of Dipteran
-3- larvae; however, we found large amounts of corn in most samples.
Between September 3 and September 6, we trawled at Garfield Bay, Anderson Point, and Blackwell Point. No shrimp were collected in 6 ten-minute trawls at the north end of the lake near Garfield Bay and Anderson Point. On the south end, 3 ten-minute trawls at Blackwell Point produced 324 shrimp or 108 shrimp per haul.
Kokanee spawners in 1972 showed little deviation from the average size of the past seven years (Table 1). Apparently Mysis have not yet contributed significantly to the kokanee diet.
Priest Lake
A total of 16 kokanee stomachs were collected on June 18 at the Outlet Resort but produced no shrimp. In November, a local sportsman reported catching three Dolly Varden in Kalispell Bay, all exceeding nine pounds, whose stomachs contained Mysis. However, the stomach contents were not verified.
On September 1, we collected shrimp in six net trawls on the west side between Distillery Bay and Kalispell Island. We collected 13,518 shrimp in one hour of trawling time or 2,250 shrimp per haul. A 1-ounce sample of shrimp contained about 2,688 individuals.
Although unverified, a few residents of Priest Lake reported several 15-inch kokanee either in the catch or on spawning grounds.
Upper Priest Lake
On August 30, we collected shrimp in 12 net trawls between Trapper Creek and Plowboy Campground. We collected 3,928 shrimp in the two hours or 327 shrimp per haul. The majority of the shrimp were caught near the mouth of Trapper Creek with none caught in the vicinity of the Plowboy Campground.
LITERATURE CITED:
Heimer, John T., 1969. Lake and reservoir investigations. Federal Aid to Fisheries Project. Annual Completion Report. Idaho Fish and Game Department, 29pp.
Prepared by:
Richard A. Irizarry Fishery Research Biologist
-4- Table 1. Kokanee size at spawning time, Lake Pend Oreille, Idaho, 1950-present.
Average size at Year spawning (inches)
1950 10.9
1951 11.2
1952 12.0
1953 11.9
1954 9.9
1955 -
1956 9.8
1957 -
1958 10.5
1959 10.7
1960 11.2
1961 11.2
1962 11.0
1963 10.7
1964 9.9
1965 10.3
1966 10.4
1967 10.2
1968 -
1969 10.2
1970 10.5
1971 10.5
1972 10.2
-5- JOB FINAL REPORT RESEARCH
PROJECT SEGMENT
State of Idaho Name: LAKE AND RESERVOIR
Project No. F-53-R-8 Title: Priest River Fisheries Study (Survey) Job No. VIII-a Period Covered: March 1, 1972 to February 28, 1973
ABSTRACT:
I conducted studies in 1972 on the regulation of impounded waters at Priest Lake which, in previous years, has been at the expense of summer flows down Lower Priest River. In addition, I monitored the duration and peak of kokanee spawning in relation to reservoir levels and outflow.
As flows in Lower Priest River declined with the addition of stoplogs at the dam, a reduction in wetted area of 2 to 12 percent occurred at selected stations. This decrease in stream width occurred between July 27 and August 4. Stream depth averaged nearly 18 inches and stream width averaged 135 feet at a recorded flow of 190 cfs.
In August, minimum and maximum water temperatures in the river averaged 65 F and 71 F, respectively. Lake temperatures in Outlet Bay read 68 F or higher in the top 20 feet with temperatures decreasing to 50 F below 45 feet. Neither minimum air temperatures nor increased releases from the lake s epilimnion noticeably cooled river waters.
I found the recreational potential of floating the river by raft handicapped at flows less than 500 cfs.
During two float days, five men fished 21 hours on 18 miles of stream and caught 14 trout or 0.7 fish per hour.
Studies by Forest Service personnel indicated that increased fall discharges are of sufficient velocity to erode bank material and redistribute the small particles of bed material on the stream bottom, even on riffles.
Kokanee spawning occurred between October 29 and December 29 with the peak between November 13 and November 20. Lowering of the lake to minimum pool consumed 51 days (October 14 to December 3) with the last 10 inches removed during the bulk of the spawning activity. Shoreline observations indicated potential egg losses at Reeder, Kalispell, and Granite bays.
-6- However, the magnitude of egg loss is not known.
Submitted by:
Richard A. Irizarry Fishery Research Biologist
-7- INTRODUCTION:
.The manipulation of the outlet dam on Priest Lake and its effect on Lower Priest River has been an item of controversy, discussion, and partial evaluation since 1952. In 1972, local interest prompted the Department to research the problem.
A stoplog dam built by Washington Water Power in 1949 stores water in Priest Lake. The present elevation of the lake is 2435.0 feet when at zero on the outlet gauge. Stoplogs are dropped into slots each summer as the lake rises, storing 3.0 feet of water above minimum pool elevation.
By law, the water is to be maintained at the 2438.0 foot level until "the end of the recreation period." The top 3.0 feet are drained off over a two-month period ( ) between mid-October and mid-December.
In practice the regulation of the lake surface is crude and the level is often held at 2438.1 feet to 2438.3 feet until October. It appears that the fractions over 2438.0 feet are added in mid-summer, August and September, at the expense of flows down the river.
Pre-1949 minimum flows over 23 years averaged about 230 cfs at the dam and in only four years did the minimum flow fall to less than 150 cfs. Tributaries along the 44- mile length of Priest River below the dam approximately double summer flows but much of this is added in the lower river and the upper stream channel (20-30 miles) has less than half the flows of the lower section.
The stream channel, width, gradient, and pool structure are formed by normal spring flows as high as 8,000 cfs. When reduced summer flows move through this channel, stream temperatures no doubt rise above pre-dam norms. Stream biota could be adversely effected by these abnormally high temperatures.
Below normal flows also result in lowered stream velocities, slower water replacement (turnover) in pools, a reduction in wetted streambed, and probably increased silt deposition. These physical-chemical changes would adversely affect coldwater species (trout and whitefish) and possibly benefit squawfish and other rough fish. Increased rough fish numbers would also adversely affect game fish. Increased minimum water flows during the summer could increase raft and canoe use in the 44-mile long river which is quite scenic and isolated.
A second major problem results because the lake level is held at, or near, the 2438.0 foot level until approximately October 1. Drainage to the 2435.0 foot level generally takes place over two months ( ). Kokanee in Priest Lake are primarily beach spawners and, as at Pend Oreille Lake, we have a conflict since the Priest Lake level drops 2.0 feet to 2.5 feet after November 1, the start of the kokanee spawning season. Water withdrawals to the 2435.0 foot level before November 1 would benefit kokanee production. Kokanee are an important game fish and are the principal food item of Priest Lake mackinaw and Dolly Varden. -8- A "problem" of unknown consequence is the rapid release of large volumes of water in the fall. This sometimes amounts to increases from less than 200 cfs to over 1, 000 cfs within a few days. The maximum fall release varies between 2,000 and 2,500 cfs, less than half high spring flows, but disruption of the "steady state" with sudden dislodgement and movement of stream sediments and aquatic organisms may be damaging.
Local residents report that cutthroat spawners move down into the outlet in the spring and cannot get back over the dam. Movements of spawners takes place in May before dam boards are in place. Once the boards are installed, movement back to the lake of adults and juveniles is blocked. This may have reduced cutthroat populations in the lake, but again the magnitude of the problem is unknown.
Normal lake levels of 2439.0 to 2440.0 feet are common in the spring and so man- made structures along Priest Lake shoreline must now withstand these levels.
A major conflict is the desire of boatowners to maintain a high lake level in the fall to permit boat passage in the "Thorofare" to Upper Priest Lake.
RECOMMENDATIONS:
The fall drawdown should commence immediately after Labor Day and conclude by November 1 in order to minimize loss of kokanee eggs on Priest Lake shoreline. The kokanee spawning survey should continue in 1973.
The fall drawdown should not exceed 900 cfs per day in order to reduce sand deposition and still evacuate 36,000 second-feet days of water in 51 days. Two release gates should be installed to provide more sophisticated regulation of the outflow.
A minimum flow of 200 cfs to the river should be maintained at all times during the summer to afford more cover for fish and to provide reasonable raft passage in a number of sections of the river.
The proposed siphoning of cooler lake waters from a 40-foot depth beyond the outlet mouth should not be undertaken because it would create an unnatural water temperature state in the river. In addition, the effect on the lake s "steady-state" is unknown, not to mention the prohibitive installation costs. The present stocking rate of hatchery rainbow is adequate for the localized summer angling pressure and should be continued.
It appears that the best approach to improving the river s habitat is by reducing fall discharge velocities and minimizing man s impact on the surrounding watershed. Although the river appears unsuitable for a sustained native trout fishery, tributary streams could be of importance in maintaining fishing values in the vicinity. Future management should preserve the habitat and fish populations of tributary streams.
-9- OBJECTIVES:
To record water flow, temperature, and other water quality characteristics at selected intervals in Priest River and to relate these to fish populations.
To measure and describe the characteristics of the streambed and banks and erosion-siltation areas.
To measure and assess fish food abundance in selected stream sections and relate this to the abundance and well being of fish in these areas.
To provide a general assessment of the recreational access and sport fishery of Priest River for U.S. Forest Service and fisheries management personnel.
TECHNIQUES USED:
Cross-Sections
Between June 30 and August 19, field personnel marked fluctuating stream widths each week at five stations (1, 4, 7, 10, and 13) along Lower Priest River (Figure 1 and Appendix I). I selected these stations because of favorable access to either bank during high flows. I standardized stream widths as the wetted area between stream banks.
We checked these stations each week throughout the summer and inserted new stakes along the water s edge as the flows receded. Horizontal measurements were taken between stakes and converted to percentage to determine the reduced amount of wetted area. Initial width measurements were made by use of a surveyor s transit and triangulation formula: a = b x Tan A. Measurements between stakes, to account for receding water levels, were made to the nearest 1/2 inch. Measurements were correlated with flows recorded at the stream gauge at the Dickensheet Campground.
We planned regulated river flows at 100, 200, and 300 cfs in August to note changes in wetted cross sections. However, a late summer runoff forced the evacuation of impounded waters as the lake level rose. Only four days were available for study of flows at 200 cfs. Flows were never lower than 190 cfs during the study.
Stream Depth
We measured stream depths at six stations (2, 3, 6, 7, 12, and 13) at a gauged flow of 190 cfs. Areas selected for depth measurements at stations 7 and 13 were adjacent to our cross sections. Deep pools prevented depth measurements at stations 1, 4, and 10. By stretching a marked nylon rope, I measured stream depths to the nearest 1/2 inch at 10.4 foot increments.
-10- Temperature
We recorded water temperatures from Taylor minimum-maximum thermometers placed at seven stations (1, 3, 5, 6, 8, 10, and 13) during the spring and early summer ( 6/22 to 8/19). These thermometers were calibrated with pocket thermometers to 1/2 F. Field personnel checked the Taylor thermometers for deviation after each reading. We secured the minimum-maximum thermometers to either rocks, man-made structures, or fallen timber to minimize vibrations and provided shade to reduce sunlight exposure. The thermometers were secured in water depths varying from 12 to 18 inches.
In late summer, I replaced the minimum-maximum thermometers with three thermographs. Two were located near the gauging stations with the third at the dam.
On August 5, we recorded lake water temperatures by electronic thermometer at four sites near the outlet mouth when outflow was 190 cfs. Temperatures were recorded at five-foot intervals to a depth of 60 feet. On August 12, temperatures were recorded at 17 different sites in Outlet Bay.
Water Quality
Dave Rosgen, U.S. Forest Service Water Hydrologist, conducted separate studies on Lower Priest River to determine the effects of the fall release of water from Priest Lake. He employed the following techniques:
To help determine the changes in the stream environment, metal link chains were installed prior to the 1971 fall discharge in two different stream reaches below Priest Lake outlet. One station is located 1/2 mile above Dickensheet Campground and another several miles downstream.
Chains were buried vertically in the bottom materials with one link left uncovered. The size of the links were closely aligned to the average particle size of bed material. This was to prevent a velocity barrier creating accelerated deposition or scour around the chains.
Stream Habitat
I reviewed stream habitat work that has been reported for Lower Priest River since 1952 and listed excerpts from each study that indicated the relative stream habitat conditions that prevailed throughout the years. I related these stream conditions to trout production and/or well being.
Float Trips
Department personnel floated two sections of Lower Priest River in Avon Red Shank boats to determine difficulties encountered in floating the river at selected flows.
-11- Fish Species Composition
We used underwater observations and fishing gear during the float trips as sampling techniques to determine the relative abundance of game and rough fish populations. I made comparisons of fish observed or caught by upper and lower stream section.
Insects
I planned to collect 40 insect samples from the Lower Priest River at 200 cfs flow. This was not accomplished owing to the short duration of flows at 200 cfs.
Kokanee Spawning
During November and December, I contacted local residents and visited lakeshore areas and tributary streams to record the location and abundance of kokanee spawners. Techniques used included boat and foot surveys supplemented by aerial flights. I noted the duration and peak of spawning. In addition, I related reservoir levels to lakeshore kokanee spawning.
FINDINGS:
Cross-Sections
Flows at the dam decreased from 2,970 cfs on June 30 to 190 cfs on August 4. By August 11, flows had increased to 460 cfs and continued to rise to 880 cfs on August 16.
The percent of wetted area at all stations except station 1 declined as flows receded ( Table 1). The wetted area was least affected in the lower segment of Priest River as reflected at stations 1 and 4. Tributary inflow and channel conformation helped maintain higher water levels on the lower river channel despite reductions in flow at the dam.
Reductions in stream flow from 460 cfs to 190 cfs only affected the wetted area or stream width at two of the five stations. Such a reduction in flow had no affect at stations 1, 4, or 10 and only a 2 percent reduction in wetted area at station 13. However, a flow reduction of this magnitude had a severe effect at station 7, reducing the wetted area by 12 percent.
Reductions in flow from 880 to 460 cfs had the greatest effect on wetted area at stations 4, 10, and 13 but very little effect at station 7.
Stream Depth
On August 5, the average stream depth from measurements at six stations was nearly 18 inches (Table 2). Stream width averaged 135 feet. We found it difficult to wade the stream at 190 cfs only at station 3, the lower end of Eight-Mile Rapids. We would have encountered difficulties in crossing the stream at all stations except number six if flows had neared 300 cfs.
-12- Between August 5 and August 19, 1971, Price and Keniston found an average depth of 24 inches and an average width of 136 feet from measurements at 38 transects. Stream flow averaged 242 cfs.
Temperature
As early as July 5, maximum water temperatures ranged between 64 and 70 F. and after August 2 exceeded 70 F. at all stations (Table 3).
Generally, minimum water temperatures at the three thermograph sites ranged between 65 and 68 F. from August 19 to August 30 (Table 4). Maximum water temperatures exceeded 66 F. for 19 days. Minimum water temperatures at all three stations in August averaged 65 F. (Figure 2 a-c) while maximum water temperatures averaged nearly 71 F. (Figure 3 a-c). Water temperatures recorded by thermograph in 1956 depict similar patterns (Figure 2d, 3d, and Appendix II).
Maximum water temperatures at the dam reflected air temperatures throughout the summer (Figure 3a). In late September, cooling air temperatures did little in lowering water temperatures substantially in lower Priest River, emphasizing the temperature impact of lake outflow. Minimum air temperatures did not cool river waters near the dam (Figure 2a). Not until late September did flows at the Dickensheet and Saddler gauges reflect cooling air temperatures.
During warm summer days, water temperatures generally rise between 9 and 11 a. m., peak at 70 F. or higher between 1 and 3 p.m. and remain near peak till late evening. Temperatures decrease (4 to 6 degrees) to a minimum by midnight.
On August 5, temperatures read 68 F. or higher near the outlet mouth between 0 and 20 feet (Table 5). Surface waters were near 75 F. at all sites while temperatures decreased to 50 F. below 45 feet. On August 12, water temperatures at 9 sites in Outlet Bay exceeded 67 F. in the top 16 feet (Figure 4). Temperatures at 8 sites in the adjacent lake were similar. Cooler readings, 63 F. or less, were attained at a 30-foot depth.
The inability to regulate stream flows prevented testing whether river temperatures cooled with increased flows from 100 to 300 cfs. However, as flows increased from 190 to 810 cfs between August 4 and August 19, river temperatures showed little cooling response with increased volume. Apparently increased outflow from the lake s epilimnion during summer has no major cooling effect.
In 1956, Bjornn reported that lake releases into the river water were very near the upper temperature tolerance for cutthroat trout. His investigations showed that fishing for cutthroat trout was best during and immediately after the spring runoff and that after July 15 fishing was quite poor. Further indications showed that the fishery was supported by fish migrating from the lake for reproductive purposes. He acknowledged that poor fishing after July 15 was possibly due to river temperatures becoming undesirable, hastening fish migration from the river. -13- Water Quality
Dave Rosgen s preliminary results indicate that approximately 4-6 inches of fine sands are deposited on the stream bottom in several portions of Priest River as a result of increased fall discharges. The velocity of these discharges is sufficient to erode bank material and redistribute the small particle size bed material. The carrying capacity of the stream is reduced as the concentration of sediment exceeds the ability of the stream to adequately transport it. The result is deposition of fine sands on the stream bottom, even on riffle areas. This affects permeability and composition of spawning gravels, food availability to overwintering fish, fry emergence and stream equilibrium changes which affect sediment discharge relationships during snow melt or storm flow runoff. As this aggradation continues, the stream scours more channel bank providing higher sediment concentration per unit discharge.
Lower Priest River is characterized by peak snow melt runoff in June. Following spring runoff, the chains. indicated approximately a 5-6 inch scour and deposition of bed material. This is not unusual in these types of glacial landform streams. What does change the situation, however, is the fall discharge sometimes equal to two-thirds of the spring smow melt peak runoff. This very definitely can effect the stream morphological conditions and stream fishery.
Stream Habitat
In 1952, Paul Jeppson, Area Fisheries Biologist, described Lower Priest River as having a slight gradient. . .from 20 feet per mile in the upper extremity to 10 feet per mile near the mouth. The river has a somewhat meandering course, but the flow is confined to a single channel. Water temperatures range from 60 to 70 F. throughout most of the summer.
He noted that, ". . .the river does appear to have increased in velocity as a result of blasting boulders and out-cropping bedrock (to prevent log jams during drives) and the grinding action of logs on riffle areas. The disrupting of the stream bed has resulted in predominantly rubble bottom on the riffles and mud and silt in the pools and lower courses. Silting, poor cover and increased water temperature are closely associated and have contributed to decreased trout populations and increased numbers of squaw-fish and chubs. Spawning area for salmonid species has not been eliminated by the scouring and silting, but it has been greatly reduced."
Jeppson concluded that, "logs dumped in at various points along the river jammed throughout the summer and fall. These jams were often impassable to migrating fish during low water and may have contributed to the low numbers of Dolly Varden in the stream."
The 1954 report of activities for the Priest Lake Sportsmen s Association and the Priest River Wildlife Federation provides further evidence of the reduced quality of the river habitat.
-14- Sportsmen reported that, "habitat conditions were drastically changed in Priest River. . .to facilitate log drives in the river and access to a mill located at the outlet of Priest Lake. Priest River. . .has no obstructions except at a rapids known locally as Eight-Mile. The bottom is oval-shaped, with silted pools, and small gravel bottom riffles. It s singularly free from overhanging banks, boulder obstructions, and deadheads. There are few trout shelter areas except those provided by deep water. During periods of extreme low water. . .the water temperature rises rapidly past the point where trout can or will tolerate it. At such times, they migrate downstream or into tributaries."
Forest Service personnel (Price and Keniston, 1971) described the condition of Lower Priest River watershed in 1971 as follows:
"The Lower Priest River has a history of heavy land use; especially the southern half of the river. South of McAbee Falls, farming and ranching is quite common to both banks. Much of the area of active farming and ranching shows evidence along river banks. The water appears milky due to suspended materials in it. The bank shows cutting and slumping. The pool bottoms are either covered with sand or silt. At the present time, land development corporations are constructing roads to the river and are selling house lots on it. Most of the developments are found on old farm or ranch land. Development could be a future source of pollution due to sewage and materials washed from the roads."
"North of McAbee Falls forested land predominates. Most of the instability problems here exist because of old fires and logging. South of Chipmunk Rapids, the forest type is more xeric. The hillsides are bare or have scattered brush vegetation with less brush under trees to help hold the soil. Heavy rains here could cause more sedimentation than more mesic sites in the northern sections of the river."
"Generally, the river system is old as is evidenced by the meanders, oxbows, and lagoons left from channel changes. Areas of many oxbows are for the most part swampy with abundant wildlife. The upper and lower west branches carry heavy sediment loads in the spring. This is due to old fires and logging areas in these drainages. Quartz Creek is also rather muddy due to heavy cattle usage. Land development is also heavy in the Quartz Creek area."
Jim Cooper, U.S.F.S. Fisheries Biologist, sorted two samples of stream bed gravel from sites considered desirable for salmonid spawning. He passed the samples through a 6.35 mm sieve and converted the amount of materials passed to percent.
He selected one site near the Dickensheet Campground and another one mile below the Upper West Branch confluence and he found that 34 and 30 percent, respectively, of the materials (fines) had passed through the sieve at these sites. Certain salmonid studies have shown high mortality in 30 percent sand.
-15- Float Trips
We floated the river between station 4 and station 2 on August 8, a distance of nine miles in six hours. The Saddler gauge recorded a 460 cfs flow. The main difficulty encountered on an otherwise pleasurable trip was Eight-Mile Rapids. Exposed boulders and rocks caused numerous hang-ups.
On August 9, the river between the Dickensheet Campground and station 8 was floated, a distance of nine miles in 7.5 hours. The Dickensheet gauge recorded a 470 cfs flow. Passage was hindered only at Chipmunk Rapids. Our rafts constantly scraped or hung up on nearly exposed bedrock.
Although I didn t float the river between station 8 and station 4, an aerial flight over this area showed no major obstacles. The only untested obstacle, 2 1/2 miles above the Dickensheet Campground, was Binarch Rapids.
A leisurely float of the 44-river miles could be accomplished without excessive difficulty in 3-5 days at a minimum flow of 500 cfs.
Fish Species Composition
Between station 4 and station 2, we caught 25 squawfish, 9 cutthroat, and 2 hatchery- released rainbow. While snorkeling, divers observed abundant schools of redside shiners and fingerling squawfish. Suckers were noted frequently with whitefish rarely seen.
Between the Dickensheet Campground and station 8, we caught 9 squawfish, and 3 hatchery rainbow. One cutthroat and 2 rainbow were hooked, but lost. Abundant schools of whitefish were observed in the deeper pools. We observed suckers occasionally, but schools of shiners and fingerling squawfish were few.
During the two days, 5 men fished 21 hours on 18 miles of stream and caught 14 trout or 0,7 fish per hour. We averaged less than one fish per mile. Only in the lower section were native cutthroat caught in any number.
Past reports indicate that the operation of the dam diminished the number of outlet spawners. The present stocking rate of rainbow appears adequate for the localized fishing pressure which occurs heavily at the outlet dam, Dickensheet Campground and McAbee Falls. The most consistent angler pressure occurs on whitefish during the fall near the mouth of Big Creek.
Kokanee Spawning
Kokanee spawning in Priest Lake and tributaries occurred between October 29 and December 29 with the peak between November 13 and November 20 (Appendix III). Observations by local residents indicated fewer kokanee spawned on the Granite Creek delta in 1972.
-16- The majority of the kokanee spawned in water six feet and over with fewer redds in shallower water. Shallow water redds were noted in Kalispell, Reeder, and Granite bays.
I did not ascertain spawning abundance because I saw beach spawners only at Grandview Lodge. I observed spawners in Kalispell Creek, but none in Granite or Soldier Creeks. In 1966, based on intuitive estimates, Leusink found that 80 percent of the spawners used shoreline areas and the remaining 20 percent used the tributaries.
Dam boards were initially pulled on October 14, 1972, at 9 a.m. when the lake level was 2.82 feet above minimum pool. The last boards were removed on October 28 at a lake level of 2436.82 (1.82 feet above minimum pool).
Between October 14 and October 27, the lake level dropped one foot with an average flow of 1,180 cfs going down the river. Between October 28 and November 9, the lake level dropped another foot. Gauged flow information was not available from the U.S. Geological Survey after October 27. The remaining 10 inches flowed out by December 3 at which time minimum pool elevation, 0.0 on the gauge, was attained.
It took 14 days to release the first foot of water, 13 days for the second, and 24 days for the last 10 inches.
In previous years, the Priest Lake level dropped 2.0 to 2.5 feet after November 1, the generally accepted start of the kokanee spawning season. Local residents, however, have observed spawning kokanee as early as October 15 in years past.
In 1972, lowering of the lake to minimum pool consummed 51 days (October 14 to December 3) with the last 10 inches removed during the bulk of the spawning period. Shoreline observations indicated potential egg losses at Reeder, Kalispell, and Granite bays. However, the magnitude of egg loss is not known.
If drawdown would commence immediately after Labor Day, with all stored waters evacuated by November 1, egg losses would be minimal.
LITERATURE CITED:
Bjornn, Ted C., 1957. Priest Lake fisheries investigations. Idaho Fish and Game Department. 176 pp.
Cooper, James L., 1971. Personal communication on Priest River intragravel surveillance. United States Forest Service, Sandpoint, Idaho.
Jeppson, Paul, 1952. Personal communication on effects of log driving on Lower Priest River. Idaho Fish and Game Department, Idaho Falls, Idaho.
-17- Leusink, Wayne, 1968. Lake and reservoir investigations. Federal Aid to Fisheries Project. Annual Completion Report. Idaho Fish and Game Department. 30 pp.
Price and Keniston, 1971. Stream habitat survey summary and analysis of Lower Priest River. United States Forest Service. 16 pp.
Priest Lake Sportsmen s Association and Priest River Wildlife Federation. 1954. Annual report of the Joint Fish Committee. 29 pp.
Rosgen, Dave, 1972. Personal communication on Priest River water quality survey. United States Forest Service. Sandpoint, Idaho.
Prepared by: APPROVED BY:
Richard A. Irizarry IDAHO FISH AND GAME DEPARTMENT Fishery Research Biologist
-18- Table 1. Percent reduction of wetted area (stream width) by station, Lower Priest River, Idaho, 1972.
Stream Station 1 Station 4 Station 7 Station 10 Stream 13 Date flow Width Percent Width Percent Width Percent Width Percent Width Percent
June 30 2,970 196 100 190 100 145 100 160 100 193 100
July 7 1,800 No change 188 99 138 95 150 94 186 96
July 14 1,560 No change 187 98 137 95 146 91 184 95
July 21 1,380 No change 185 97 136 94 144 90 183 95
July 27 880 No change 183 96 133 92 136 85 178 92
August 4 810 No change 183 96 134 92 152 95 182 94
August 11 460 No change 179 94 135 93 116 73 170 88 August 19 190 No change 179 94 117 81 116 73 166 86 Table 2. Stream depth measurements by station, Lower Priest River, Idaho, 1972.
Average Stream Depth in inches by ten foot increments depth width Stations 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 in inches in feet
2 7.5 25 25 27 23 12 25.5 35 29 20.5 5 21.3 118 3 11.5 11.5 14 15 19 17.5 21 25.5 27.5 27 18 15.5 3 2.5 16.3 151
6 7 12 14.5 17 12 10 14.5 19 17.5 17 15.5 16.5 11.5 3.5 0 5.5 12.1 170
7 12 20 23.5 26 30 37.5 14 6 4.5 19.2 98
12 21.5 36.5 47 30.5 20.5 17 20.5 30.5 28.5 19.5 10 25.6 116
13 15.5 10.5 20 36.5 27 13.5 15.5 25 22.5 6 1 4.5 0 9.5 14.9 154
Total average depth 17.6 Total average width 134.5
Stream outflow at the dam was 190 cfs at the time these measurements were taken. Table 3. Thermometer readings ( F) at seven stations, Lower Priest River, Idaho, 1972.
Thursday Wednesday Wednesday Wednesday Wednesday 6/22 6/28 7/5 7/12 7/19 Station Min Max Min Max Min Max Min Max Min Max
1 52 58 52 58 60 64 54 68 56 66
3 52 58 48 58 60 68
5 ------60 74
6 52 66 50 68 58 70 58 74 60 74
8 48 60 52 66 46 68 60 68
10 38 58 54 64
13 56 58 58 58 62 66 62 64 62 64
Wednesday Wednesday Tuesday Wednesday Saturday 7/26 8/2 8/8 8/16 8/19 Min Max Min Max Min Max Min Max Min Max
1 60 60 60 70 60 74 62 74 60 70
3 62 64 70 74 68 74 - -
5 60 68 62 74 68 76 - -
6 62 72 64 76 68 80 70 80 66 76
8 59 59 66 74 - - - -
10 52 61 52 74 62 70 58 78
13 62 62 66 74 66 72
Indicates thermometer exposed as water receded. -Indicates no reading.
-21- Table 4. Thermograph readings at three stations, Lower Priest River, Idaho, 1972.
Priest Lake Dam Dickensheet Campground Saddler Creek August September August September August September Date Min Max Min Max Min Max Min Max Min Max Min Max
1 64 69 61 70 59 66 2 64 69 61 69 59 65 3 64 68 62 70 59 66 4 64 68 63 70 59 66 5 63 66 62 66 60 64
6 60 61 59 64 57 61 7 57 63 56 63 57 61 8 59 61 57 63 55 61 9 58 62 55 63 55 60 10 54 63 54 63 - -
11 55 63 52 64 - - 12 57 61 55 61 - - 13 57 63 53 64 - - 14 55 64 54 66 - - 15 55 63 54 70 - 60
16 54 64 53 65 55 63 17 52 61 50 63 50 66 18 - 68 52 57 - 70 50 57 - 72 46 64 19 63 70 50 57 66 70 50 56 68 72 46 57 20 64 72 46 55 65 70 43 61 68 72 37 63
21 65 72 48 50 66 70 48 59 68 72 48 50 22 65 68 46 57 66 68 46 - 68 70 47 - 23 61 67 52 58 65 68 - - 66 70 - - 24 63 70 54 56 65 72 - - 66 72 - - 25 68 72 55 57 66 71 - - 64 72 - -
26 68 72 55 55 64 72 - - 64 71 - - 27 68 72 54 56 65 72 - - 65 72 - - 28 68 72 55 55 65 73 65 72 - - 29 66 70 54 55 64 72 - - 65 72 - - 30 65 68 52 55 64 70 - - 64 69 - -
31 64 69 - - 61 68 - - 60 66 - -
-Reading not recorded by thermograph.
-22- Table 5. Water temperatures ( F) at four sites near the mouth of Outlet Bay, Priest Lake, Idaho, August 5, 1972.
Depth in feet #1 #2 #3 #4 73.5 0 75 74 75
5 72 72 72 72
10 71 71 71 70
15 70 71 70 69
20 68.5 69 68 68 59.5 25 61 60 59
30 61 57 57 57
35 56 56 55
40 52.5 53 52 51.5 45 50.5
50 50 49
55 48
60 47
Sites not similar to those used on August 12, 1972.
-23-
Figures 2A and 2B. Minimum temperatures ( F) and monthly mean, Priest Lake Dam and Saddler, Lower Priest River, Idaho, 1972. Figures 2C and 2D. Minimum water temperatures ( F) and monthly mean, Dickensheet, Lower Priest River, Idaho, 1956 and 1972. Figures 3A and 3B. Maximum temperatures ( F) and monthly mean, Priest Lake Dam and Saddler, Lower Priest River, Idaho, 1972. Figures 3C and 3D. Maximum water temperatures ( F) and monthly mean, Dickensheet, Lower Priest River, Idaho, 1956 and 1972. Figure 4. Water temperatures ( F) at 17 sites in Outlet Bay and vicinity, Priest Lake, Idaho. August 12, 1972.
Site Min ( F) Max ( F) Depth (in feet)
1 67 70 8 2 68 70 6 3 68 71 12 4 63 70 33 5 67 70 16 6 70 70 9 7 71 71 8 8 71 71 7 9 70 70 5 10 66 71 15 11 66 71. 15 12 68 71 15 13 68 71 15 14 63 71 24 15 66 71 15 16 63 71 24 17 61 70 30 Appendix I Station 1. Photo taken on east bank. About one mile above mouth deep pool, too deep to measure. Back up water from Albeni Falls Dam maintains pool level all summer. Housing development on both sides of river. Some livestock usage on east bank.
Station 2. Photo taken on east bank. About one mile above Lower West Branch. Riffles with four to five foot pools. Stagnant pools on west bank below clay cliff. Old ranch land on east bank. No cattle usage observed.
-30- Station 3. Photo taken on west bank. At Eight-Mile Rapids. Forested land on both banks of gorge. Good white water trip at flows over 500 cfs.
Station 4. Photo taken on east bank. Near the McAbee Falls. Deep pool, too deep to measure. Large debris jammed into both banks. Large populations of rough fish. Livestock usage on both sides. -31- Station 6. Photo from west bank. About two miles above East River. Uniformly flat streambed. Good spawning gravel throughout. Bank cutting quite evident on west bank.
Station 7. Photo from west bank. Near Whitetail Butte. Deep pool and run. Heavy cattle usage on east bank. Banks cutting and slumping. Housing development on west bank.
-32- Station 10. Photo taken on west bank. At Chipmunk Rapids. Steep hillsides. Erosion potential high. No cattle usage observed.
Station 12. Photo taken on west bank. One-half mile below dam. Highway 57 on west bank. One area of better fishing for hatchery rainbow.
-33- Station 13. Photo from west bank. Immediately below the dam at Kokanee Resort. Deep pools and runs. Receives angler pressure from locals and overnighters. Mainly hatchery rainbow caught.
-34- Appendix II Thermograph readings at Dickensheet (1/2 mile above bridge), Lower Priest River, Idaho, 1956.
July August September Date Min Max Min Max Min Max
1 66 68 62 65 2 63 68 62 64 3 62 64 60 67 4 61 69 59 66 5 62 71 59 68
6 64 70 60 68 7 64 72 60 67 8 64 67 62 72 60 68 9 62 68 63 72 60 69 10 62 69 64 72 60 66
11 64 69 64 72 60 66 12 65 68 64 72 59 67 13 63 68 65 74 60 66 14 62 66 65 74 59 65 15 61 67 66 71 - 66
16 62 68 66 73 59 67 17 62 68 64 72 58 66 18 65 70 65 73 58 67 19 66 73 66 74 61 67 20 68 71 66 74 61 64
21 67 74 66. 74 22 67 74 66 74 23 66 74 67 73 24 67 75 66 69 25 68 75 66 68
26 66 74 64 66 27 67 74 64 65 28 65 72 64 68 29 66 74 63 66 30 66 73 61 66
31 66 74 62 66
-35- Appendix III Kokanee Spawning Survey (Chronological Data)
November 1, I checked for shoreline spawners between Elkin s Resort and Hagman s Resort. Bob Benscoter, owner of Grandview Lodge, said the first fish appeared west of his boat docks on Sunday, October 29. On November 1, I didn t observe any fish near his lodge, but I did uncover. four redds in the area west of his docks. I found two eggs in 1 redd, 6 in another, and 4 eggs in each of the last 2 redds. Further observations disclosed no beach spawners, but a few redds near Hagman s Resort. All observed redds were near docks, pilings, or breakwalls. A snow storm moved in hindering further observations.
November 6, I flew over Priest Lake and Upper Priest Lake. I observed no shoreline spawners except at Grandview Lodge where they were visible from a 600 foot height. However, more redds were noted south of the mouth of Granite Creek near man-made structures. Later, Benscoter reported the kokanee by his lodge had returned on November 4.
November 12, I checked the spawners at Grandview Lodge from shore and counted over 200 fish spawning or guarding nests on the shoreline. I observed many others in 8-10 feet of water, but could not obtain a good count because of poor water clarity (reflection). I launched the boat at Priest Lake Marina and spent 3 1/2 hours carefully checking the shoreline between the marina and west Twin Island. Many appealing beaches were heavily sanded while others had very small littoral zones (10 to 20 feet) available for spawning. No redds were observed in the delta north of Granite Creek.
November 21, via aerial flight with Earl Smith, Department of Public Lands, I observed high concentrations of redds at Mosquito Bay, and the Granite Creek and Soldier Creek deltas. Other redds were present at Distillery, Bear Creek, Indian Creek, and Hunt Creek bays with scattered redds noted adjacent to Eight-Mile Island. Although redds were noticed quite readily, intensive searching showed no kokanee on the beach areas. I saw only five redds at Upper Priest Lake immediately south of the Trapper Creek mouth. I took a short walk down Soldier Creek, but observed no spawners or redds.
November 30, I checked for spawners at Kalispell Creek and Grandview Lodge and found 18 spawners just below our incubation channel on Kalispell Creek. No fish were found near Grandview Lodge. According to Benscoter, the kokanee had left this beach area on November 28.
December 4, I spent the day with Vern Kidd checking out portions of Kalispell Creek, the Kalispell Bay shoreline, and two springs for spawning kokanee. Vern reported observing several hundred kokanee in a multi-channeled area of Kalispell Creek on November 19. However, when we checked this area on December 4, it was completely iced over. There was no indication of mortality in the area due to the freeze.
-36- Near Vern s home (Kalispell Bay) there s a 42 F. spring that flows year-round. This year the kokanee moved into the spring on November 8 according to Vern with the first mortality occurring on November 20. Considerable predation occurs at this spring. ( Later he reported the last fish died in the middle of December.) We observed several nearly exposed redds on the Kalispell Bay shoreline, but we ended our search because of darkness.
December 5, Vern Ellis and I collected spawning kokanee from Kalispell Creek and Foster s Spring. We measured the kokanee in fork and total (when possible) lengths. All listed measurements are fork length inches.
Males Females
10 1/2 9 1/2 9 1/4
10 1/2 9
9 3/4 9 1/4
9 3/4 10
9 3/4 9 3/4
9 3/4 9 1/4
9 1/2 10 The water temperature was 33 F. in Kalispell Creek and 36 F. in Foster s Spring. Seven kokanee were taken from each area. The lone male in the sample was captured on the Granite Creek delta. No other beach spawners were observed. Ten of the females were spawned out and the other four were ripe. The male was in his last death throes. Kokanee collected from Kalispell Creek were collected in an 18-inch hole at the mouth of the incubation channel.
December 15, Chuck Troxel (U.S.F.S.) and I checked for shoreline spawners at Kalispell and Granite Creek bays and found none. Streams were still frozen over.
December 29, I flew over Priest and Upper Priest Lake. Upper Priest Lake and the upper portion of Priest Lake were frozen over. I saw 9 or 10 new redds in the Thorofare and at least that many on the Soldier Creek delta. It appears the some kokanee spawn late in the year, but the number is minimal. Older redds that had been observed on November 21, were not discernible on this date.
-37-