HABITAT IMPROVEMENT. Fishery Division PROJECT PORTLAND, OREGON OREGON STATE GAME COMMISSION P. 0. BOX 3503

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1 HABITAT IMPROVEMENT PROJECT Fishery Division ottion Siam NAME COMMISSION OREGON STATE GAME COMMISSION P. 0. BOX 3503 PORTLAND, OREGON Fall Creek Reservoir Number 7

2 STATE OF OREGON OREGON STATE GAME COMMISSION FISHERY DIVISION C. J. CAMPBELL, CHIEF OF OPERATIONS FALL CREEK RESERVOIR Pre-impoundment chemical treatment to remove undesirable fish Completion report for U. S. Army Engineer Contract No. DA CIVENG-66-9 By Ralph L. Swan District Aquatic Biologist Fall Creek Reservoir Number 7

3 FALL CREEK RESERVOIR PRE-IMPOUNDMENT CHEMICAL TREATMENT TO REMOVE UNDESIRABLE FISH. 965 Abstract Fall Creek Reservoir is a unit of the comprehensive plan of the U. S. Army Corps of Engineers for flood control and multiple use of the water resources of the upper Willamette Basin. The reservoir is located on Big Fall Creek, nineteen miles southeast of Eugene in Lane County. The reservoir will cover,880 acres at maximum pool. The watershed contains approximately 200,000 acres, most of which is under administration of the United States Forest Service. Undesirable fish species that compete with anadromous fish were to be eliminated from the watershed. Rough fish problems could conceivably make expensive fish facilities useless by depleting runs. Funds for the project were provided to the Oregon State Game Commission by the U. S. Army Corps of Engineers. The dam was completed shortly after chemical treatment and was scheduled to operate for flood control purposes in October, 965. The watershed above the dam was treated with 360 gallons of synergized rotenone (Pro-Noxfish) applied at a concentration of 2.0 ppm. The chemical eliminated populations of coarse scaled suckers, squawfish, and redside shiners. Approximately twenty-four miles of Big Fall Creek and fifteen miles of tributaries were treated. Preliminary work began on August 2, 965 and the chemical treatment of Big Fall Creek and tributaries was conducted from August 3 to September t, 965.

4 Rotenone dispensing stations were established four miles apart on major streams and above barriers on, the tributaries. Small streams, sloughs, and isolated pools were treated with backpack sprayers. The upper sections of Big Fall Creek were toxic for twenty-four hours, but the duration of the toxicity increased as the rotenone moved downstream. Water flowing past the dam at a rate of 35 feet per second was toxic over eighty hours. Since water could not be impounded in sufficient volume for dilution of the rotenone, it was necessary to establish a detoxification station below the dam. Potassium permanganate was introduced at a rate of 2,0 ppm. to counteract the rotenone. A total of,200 pounds of potassium permanganate was used over a period of eighty-eight hours. Location and Past History Fall Creek Dam is located at river mile 7.2 on Big Fall Creek, a tributary of the Middle Fork of the Willamette River, The dam is in Lane County, in Township 9 South, Range I West, section, approximately one mile east of the community of Unity. Figure is a vicinity map of the Fall Creek Reservoir and drainage. Steelhead trout and spring chinook salmon enter Big Fall Creek. Facilities for handling both upstream and downstream migrants were incorporated in the dam structure. It has been estimated from redd counts that up to 00 steelhead and 600 chinook have spawned in Big Fall Creek annually. Annual trout harvest has been estimated at 2,000 fish. The stream has had an annual stocking of 0,000 rainbow trout of catchable size, that are usually stocked above the dam. (Figure 7). It had not been necessary to chemically treat the watershed prior to the construction of Fall Creek Dam because the rough fish populations were static 2

5 I CAPACITY... A.'.: I POLK CO. SALEM MARION CO. Sontiom River CLACKAMAS CO DETROIT RESERVOIR Corvallis BENTON CO. Albany Lebanon /0 Sv ->;. 0 HOLLEY DAMSITE LINN CO. BIG CLIFF REREGULATING RESERVOIR GREEN PETER RESERVOIR 5 i,,du. CASCADIA DA MSITE FOSTER River REREGULATING RESERVOIR TRUE NORTH TT -,- LANE CO. 0 FERN RIDGE RESERVOIR EUGENE Ci I_Cottage Grove DOUGLAS CO. MCK SPRINGFIELD cr- DEXTER REREGULATING RESERVOIR DORENA RESERVOIR 4_ GROVE RESERVOIR 3, L -- GATE CREEK DAMSITE Vet LANE CO. FALL CREEK HILLS CREEK RESERVOIR VICINITY MAP SCALE IN MILES I I I LOOKOUT POINT RESERVOIR BLUE RIVER DAMSITE "*----STRUBF DAMSITE COUGAR RESERVOIR TRUE NORTH SPRINGFIELD /5 MILES r- 5 FALL CREEK DAMSITE Win berry,creek - Rood Relocation / Fall Creek Rood Relocation 32 5 Peninsula Rood Location 4- i I fl/ 27 :..&:7 G 34 oximum Poo/ EI.834 USABLE RESERVOIR AT MAX. POOL 5,000 ACRE FEET LEGEND PROPOSED ROAD RELOCATION PROPOSED PUBLIC USE AREA T 8 S T 9 S -0 5 VS, Pc,/ LOOKOUT PT. RESERVOIR /are FALL CREEK RESERVOIR FALL CREEK, OREGON SCALE IN MILES 0 I I I I I U.S. AR MY ENGINEER DISTRICT, PORTLAND' CORPS OF ENGINEERS FE8. I9, FL -I

6 Defoxiccri-ion Station 0 Cot Isiatd Flow Roienorre Slat/on, Side 7.7.6cd-ary Cot Isfani- Mow Rote/70/7e Slid. POMIS /sola7lec/ From Sfream. dery oaf Forest Figure 2 B/G FALL CREEK WATERSHED Scale is= / mile

7 in a stream situation. Public access to Big Fall Creek and tributaries has been by county roads along the streams in the lower sections and by U. S, Forest Service logging roads in the upper regions. Access to the new reservoir will be provided by the U, S. Army Corps of Engineers and the Lane County Parks Department. Access to the upper portions of the watershed will remain unchanged. Figure 2 is a sketch of the Big Fall Creek watershed above the dam. Preparation Chemical treatment activities were coordinated with the U. S. Army Corps of Engineers, the construction contractor (Montag-Halvorson-McLaughlin), the Fish Commission of Oregon, the U. S. Fish & Wildlife Service, the U. S. Forest Service, and the Lane County Parks Department. Local residents were informed as to the time and duration of the treatment. Past experience with other reservoirs in the Willamette Valley indicated that, unless undesirable fish species were eliminated prior to water impoundment, they would become so numerous that they would be competitors with and predators on small salmonids. It was on that basis that plans were made to chemically treat the watershed above Fall Creek Dam, The watershed could be treated most effectively and economically when the streams were at low summer levels, Fortunately, they were at the lowest levels in many years when they were treated. Water flows in the upper portions of Big Fall Creek and tributaries were determined by field methods. The flow of Big Fall Creek at the dam was determined by U. S. Corps of Engineers personnel. The two ponds treated contained little water and their volumes were estimated. 5

8 The Big Fall Creek watershed extends from the foothills to the higher portions of the Cascade Mountains. Elevations range from 750 feet at the dam to over 5,000 feet at the headwaters. Broadleaf trees and shrubs border the streams and old-growth conifers and open logging units cover the adjacent lands above the reservoir basin. The reservoir basin was farm and pasture land. Most of Big Fall Creek is confined to a rock-walled channel which ranges from twenty to thirty feet deep. The channel contains many long, deep, slowmoving pools which are ideal habitat for suckers and other undesirable fish. Except in the reservoir basin, there were few isolated pools and slough areas. One abandoned pond was found in the reservoir basin and a private pond was found near the mouth of Portland Creek. Big Fall and Winberry Creeks were known to contain rough fish from observations made in previous years. Fish population studies, utilizing an electric shocker, were made in 964 by personnel of the River Basins Division of the Oregon State Game Commission. Data from their work is presented in Table. Figure 3 is a list of abbreviations for fish used in this report. Rotenone was used for sampling prior to the chemical treatment to determine the range of rough fish in Big Fall Creek and its tributaries. Coarse scaled suckers and whitefish were present up to the falls on Big Fall Creek, nearly twenty-four miles above the dam. Squawfish and shiners were numerous in the reservoir basin. Squawfish, suckers, whitefish, and shiners were present in Winberry Creek up to a falls approximately four miles above the mouth. Only trout, cottids and dace were found above the falls. Whitefish and dace were found in Portland Creek up to a falls about a mile above the mouth. Only dace and cottids were found in He He Creek although suckers had been reported to be present. Only dace and cutthroat were found in the 6

9 Figure 3 FISH ABBREVIATIONS AS B BB BC Bg BB BC Br BrB BSu BT C CC Ch ChF ChJ ChS Clm Co CoJ Cot Cp CRC CS CSu Dt DV F FC Gf Gr GS GSg GT Atlantic salmon bullhead catfish black bass, or bass black crappie bluegill sunfish black bullhead blue catfish brown trout brown bullhead bridgelip sucker brook trout crappie channel catfish chinook salmon chinook salmon fall chinbok salmon jack chinook salmon spring) chiselmouth coho salmon coho salmon (jack) cottid carp Columbia River chub Chum salmon coarsescale sucker cutthroat trout dace Dolly Varden trout flounder flathead catfish goldfish greenling green sunfish green sturgeon golden trout Lam LB Lc LT Mt Mu P Pk PS Rb RbF RbS Ro REIS SB SCt Sg Sh Skb Sq SS St StB StS StW Su To WC Wf Wm WSg YB YP kokanee lamprey largemouth bass lingcod lake trout madtom mullet perch pumpkinseed sunfish pink salmon rockfish rainbow trout rainbow trout fall) rainbow trout (spring) roach redside shiner smallmouth bass blackspotted cutthroat sturgeon shad stickleback squawfish sockeye salmon steelhead striped bass steelhead summel steelhead winter sucker tomcod white crappie whitefish warmouth bass white sturgeon yellow bullhead yellow perch

10 North Fork of Big Fall Creek. Table. 964 Fish Population Study on Fall Creek and Tributaries Temperature Stream Species and numbers of fish Stream Date in Degrees F mile Ct Rb Chs Cot D Wf Big Fall Creek Aug Delp Creek July He He Creek July Pernot Creek July Portland Creek July Winberry Creek July Winberry Creek July N.F. Winberry July S.F. Winberry July Table Fish Population Study Data on Fall Creek and Tributaries Species Stream Date RsS CSu Sq WF D Cot Rb Ct ChS Big Fall Creek Aug. 3 x x x x x x x x x N.F. Big Fall Creek Aug. 9 x x x x Winberry Creek Aug. 4 x x x x x x x x Portland Creek Aug. 9 x x x x x Alder Creek Aug. x x x x He He Creek Aug. x x x x Largemouth bass, pumpkinseed sunfish, white crappie, bluegill, and brown bullhead catfish were found in an abandoned farm pond in the reservoir basin approximately four miles above the dam. Fish found in various streams in the watershed are listed in Table 2. 8

11 Various agencies, both public and private, were informed of the plans to chemically treat the Fall Creek watershed prior to the completion of the dam. A helicopter flight was taken to locate ponds or other water not mapped or otherwise known to exist in the drainage. Arrangements were made with the U. S. Corps of Engineers and the U. S. Forest Service for storage space for supplies and equipment. A landowner below the dam was contacted regarding the use of his irrigation pump to introduce potassium permanganate to detoxify the rotenone. The only special equipment used on the project was a modified U. S. Forest Service slurry mixing device which was used to mix the potassium permanganate with water to obtain a liquid solution. An equipment trailer containing back-pack spray cans, tools, pumps, and miscellaneous equipment was moved to the Fall Creek Dam construction area. Lumber was purchased for use in the construction of drip barrel stands. Five new fifteen-gallon barrels were obtained for use as drip barrels on small streams. Insulation material was purchased to use on the drip barrels to maintain a nearly constant temperature of the rotenone to insure an even flow into the stream. Live-boxes containing rainbow trout were distributed throughout the treatment area prior to the application of rotenone. A box was placed above each drip station and two live-boxes were used in connection with the detoxification station. One was placed immediately above the station and the other a short distance below. (Figure 8). Replacement and control fish were held in a large live-box in Winberry Creek above five miles above the dam. It was necessary to remove the control fish during the treatment of Winberry Creek. Rotenone and some of the supplies were stored at the U. S. Forest Service

12 Guard Station about nine miles above the dam to facilitate distribution to the various waters -Co be treated. The guard station was centrally located and Forest Service personnel were present at all times to prevent theft or molestation of the equipment and supplies. Because of limited manpower and the slow movement of water in Big Fall Creek, it was decided to use twenty-four rotenone dispensing stations. The drippers could be turned on the night before the crews started downstream with the back-pack spray cans. Samples of water from Big Fall Creek and its major tributaries were sent to a commercial laboratory for analysis. Fineings are presented in Table 3. It was noted that Winberry Creek, which had the highest readings of all items tested, also had the most and largest cutthroat trout. Portland Creek, which had the next highest readings, contained mostly rainbow and the cutthroat averaged smaller in size. Table 3. Water Analysis, Big Fall Creek System August 6, 965 Test Big Fall Winberry He He Portland ph value Total Dissolved Solids in ppm Alkalinity (as CaCO 3 ) Carbonate BiCarbonate Conductivity (micromhos per cm) A temperature recording station was established on Big Fall Creek near the Fall Creek Guard Station in 962 by personnel of the Eugene office of the U. S. Bureau of Commercial Fisheries. Data from that station will be found in Table 4. 0

13 Table 4. Summary of Thermograph Readings from Fall Creek at USFS Guard Station Upstream from Proposed Fall Creek Reservoir Site 962 Day June July August September October November Max. Min. Max. Min. Max. Min. Max. Min. MR 7-77E. Max. Min * * * * * * 62 6o o o o o o o Il o o o o o o o o o o MO o o * Clock stopped

14 The data were gathered through the summer and fall months. Since the station was nine miles above the dam, the data do not reflect the rise in temperature of the lower portion of the stream where the streamside cover was limited. The weather was cooler than normal in the summer of 962. Miscellaneous temperatures were recorded by the Oregon State Game Commission River Basins personnel in connection with their fish population sampling in the drainage in 964 and are recorded in Table. Little time was available to conduct any further studies on temperatures or fish populations because of the short time between authorization of the treatment and the actual work. Samples of insect life were taken from the major streams in the drainage prior to, immediately after, and two months after the chemical treatment. Insect life was scarce in all streams because of severe erosion of the stream beds during the flood. Table 5 presents the aquatic food items collected before and after chemical treatment. Crayfish were noted but they were not numerous. The giant salamander (Dicampdedon) was numerous in Portland Creek and present in the other streams. Most of the insects collected on November 24 were very small, and were probably in the egg stage during and immediately after the chemical treatment. Chemical Treatment Procedures followed in the chemical treatment of Big Fall Creek and tributaries were similar to those used on other reservoir projects in the past. Isolated pools in the reservoir basin were treated first, followed by tributary streams and connected waters. Barriers were constructed on tributary streams near their mouths and rotenone drip stations were established above them when the main stream was treated. (Figures 4 and 5). An abandoned pond in the 2

15 Table 5. Aquatic Food Samples Collected Before and After Chemical Treatment in Fall Creek and Tributaries, 965 Stream Insects August 9 Prior Date of Collection September 9 After November 2L Later Big Fall Creek Plecoptera 3 - Tricoptera 4 Ephmeroptera 7-7 Coleoptera 2 Diptera Snails Worms Winberry Creek Plecoptera Tricoptera 2 Ephmeroptera 5 3 Odonata - - Hemiptera Diptera 2 2 Snails 2 3 Worms - - Portland Creek Plecoptera 3 - Tricoptera 5 0 Ephmeroptera 2-6 Snails 2 Worms 3 He He Creek Plecoptera - Tricoptera 4-3 Ephmeroptera 5-4 Coleoptera - Snails 5 3

16 reservoir basin and a private pond near the mouth of Portland Creek were also treated prior to Big Fall Creek (Figure 6). Even-flow rotenone dispensing apparatus was used on stations four miles apart on Big Fall Creek and Winberry Creek. Big Fall Creek contained many long, deep, slow-moving pools, which necessitated the operation of the drip stations for twenty-four hours to insure a complete kill. The rotenone was introduced at a rate of 2.0 ppm. and new stations downstream were put into operation while the water was still toxic. Winberry Creek was treated simultaneously with the lower two sections of Big Fall Creek so there would be no chance of fish escaping the chemical. The rotenone dispensing stations were activated the night before the men with the back-pack spray cans started downstream to treat standing water and minor tributaries. The actual treatment of Big Fall Creek began on August 3, 965, and once the rotenone was turned on at the headwaters, the treatment was continuous. Two crews of two men each covered eight miles of stream each day. The crews reached the dam at the end of the third day. Toxic water continued to flow past the dam for an additional three days. The Eugene office of the Bureau of Commercial Fisheries, U. S. Fish & Wildlife Service, provided two men for one of the back-pack spray crews during the final stages of the treatment. Table 6 outlines the waters treated and rotenone used on the project. 4

17 Figure 4. Upstream fish movement barrier constructed near the mouth of He He Creek, Big Fall Creek system. Figure 5. Rotenone dispensing station No. 4 on Big Fall Creek. Unit is of the constant pressure type. 5

18 Table 6. Waters Treated and Rotenone Used on Fall Creek Project Water Volume* Miles Rotenone - gals. Drip Spray 4;-* Big Fall Creek 35 cfs. 2)4.0 ) North Fork Fall Creek 3 cfs Winberry Creek 6 cfs Portland Creek 4 cfs He He Creek 5 cfs. 4.o Abandoned Pond Ppm. acre feet 3.0 Portland Creek Pond acre feet 2.5 Reservoir Basin 95 * At lowest station ** Includes pre-treatment sampling 86 7)4 360 Total Result of Treatment Rotenone dispensers were activated on upper Big Fall Creek late in the afternoon of August 3, 965. Dead and dying fish were observed three miles downstream the following morning. All fish were dead by the time the spray crews reached the next station. Over sixty spring chinook salmon adults had been transported around the dam and released upstream early in the summer, but only seven dead chinook were found in the course of the chemical treatment. It was learned later that the fish had been transported in fifty-five gallon barrels without the benefit of aeration. It is believed that survival was low. It was also possible that some of them could have been killed in the pre-treatment sampling. The only chinook juveniles observed were in a small slough at the upstream base of Fall Creek Dam. Water conditions were such that an accurate 6

19 Figure 6. Spraying rotenone on surface of abandoned pond in reservoir basin. Figure 7. Upstream view of outlet structure of Fall Creek Dam, showing fish horns for collection of downstream migrants at various water levels. -astor-.0;-'t-k 7

20 count could not be made. It was estimated that the slough contained approximately 500 juvenile chinook ranging in size from three to five inches. Coarse-scaled suckers were predominant in the numbers of large rough fish killed. They were present up to falls on Winberry and Big Fall Creeks. Squawfish were found in the reservoir basin in both of the above streams but were not found in any of the other waters treated. Dace were present in all of the streams treated. Redside shiners were confined to the reservoir basin. Pacific lamprey (Entosphenus tridentatus) and brook lamprey (Lampetra planeri) were present in all moving water treated. Ammocoetes of both forms were present in the reservoir area. Representative samples of fish were taken prior to treatment to determine percentages present in the streams. Total kill estimates of all species were not practical because of the minute sizes and varied densities of all but the larger species. Pre-treatment sampling also reduced the numbers of fish present. It was estimated from spot checks that Winberry Creek contained about 5,000 adult coarse-scaled suckers and 200 adult squawfish at the time of treatment. On the same basis, Big Fall Creek contained roughly 40,000 coarse-scaled suckers and,500 squawfish. The numbers of all rough fish decreased toward the headwaters of the streams. Table 7 is a listing of the fish population encountered in the Big Fall Creek watershed. Heavy growths of algae formed within ten days of the time the fish populations were eliminated in lower Big Fall and Winberry Creeks. It is believed that the combination of nutrients released by the dead fish and the reduction of insect life was responsible for the accelerated algae growth. 8

21 Species Table 7. Fish Population Composition of Big Fall Creek Watershed as Determined by Chemical Treatment Size range in inches Percentages Dace (3 species - Apocope & Rhinicthys) Redside shiner (Richardsonius balteatus) Coarse scaled sucker (Catostomus macrocheilus) Cutthroat trout (Salmo clarki) Rainbow trout (Salmo gairdneri) Cottids (Cottus sp.) Squawfish (Ptychoheilus oregonensis) Whitefish (Prosopium wiiliamsoni) 8-2 Chinook salmon (Oncorhynchus tshawytsha) 4 40 In addition to the fish listed in Table 7, an abandoned farm pond in the reservoir basin contained largemouth bass (Micropterus salmoides), white crappie (Pomoxis annularis), Bluegill (Lepomis macrochirus), pumpkinseed sunfish (Lepomis gibbosus), and brown bullhead catfish (Ictalurus nebulosus). project. Table 8 is a list of equipment, personnel, and chemicals used in the 9

22 Table 8. Equipment, Personnel and Chemicals Used on Big Fall Creek and Tributaries, 965 Equipment Number used Pickup I ton 2 Fourwheel drive vehicle Station wagon Flatbed truck Equipment trailer and small tools Barrel stands 5 Drip barrels - 5 gallon 5 Drip barrels - 30 gallon 2 Drip barrels - 55 gallon Even-flow drip valves 6 Live boxes 8 Rotenone pump Barrel bung opener Graduate cylinders 2 Insulating material 2 rolls Slurry mixer Five H.P. electric pump Heavy-duty drill motor One and One-half inch hose 20 feet Hose nozzle Gasoline driven pump - li" discharge (standby) Helicopter Back-pack spray cans 6 Personnel needed 7 men 80 man days * Chemicals used Rotenone gallons Potassium permanganate -,200 pounds * Based on eight-hour work day 20

23 It had been hoped that the chemical treatment of the Big Fall Creek watershed could be carried out to coincide with the closure of the gates in the dam. The procedure would have confined the toxic water in the reservoir area until it was sufficiently diluted to release downstream. The new roads around the reservoir were not completed at that time, so it was necessary to establish a detoxification station below the dam. The station was located approximately one-half mile below the dam. The system was activated when live-boxed fish, one-half mile above the dam, began to show distress symptoms. The station was deactivated eighty-eight hours later when the captive fish immediately above the station had survived over four hours. Rainbow trout, held in a live-box below the station, survived the entire operation. Potassium permanganate was used as the detoxifying agent, introduced at the rate of 2.0 ppm. The granular material was reduced to a liquid and introduced to the stream through a slurry mixing device that was designed to mix borate solutions for fire fighting. The unit was manufactured by Western Fire Equipment Company, San Francisco, California (Figure 9). The chemical was supplied in a powdered and slightly granular form, then metered through a garden-type fertilizer spreader mounted on the slurry machine hopper. A total of,200 pounds of potassium permanganate was used. The agitator in the spreader was operated by a heavy-duty, slow-speed drill motor. It was difficult to maintain an even flow of chemical through the spreader, and constant surveillance was necessary. A new hopper with motor is being designed for future operations. A five H.P. electric irrigation pump was used to supply water pressure for the slurry machine. A gasoline-driven pump was held on standby in case of a power failure or other difficulty. Figure 0 is a drawing of the slurry unit as used on the project. 2

24 Figure 8. Live-box above station number 3 on Big Fall Creek. Rainbow trout were used as test fish. Figure 9. Detoxification station below Fall Creek Dam. The slurry machine reduced the potassium permanganate to a liquid as shown by discharge hose.

25 KAIII0+ is placed into Calibrated Fertilizer Spreader A, Electric Gearma7lor B rotates.5_prectoler- Shaft ( (/Orprn) alischargin9 irhinc20 into Slurry Machine Hopper D, Efec/ric Puny, E pic,& up I-40 Throu9h /niake Screen F Perenio I.." Mrou9,4 Venturi G-(/oOpsi) which mixes the e44o,04 and NO. 74e is Men cit'schaeryea' Hose into /he s/recim. Fiqareo. DETOXICATION STATION it5l Z3

26 Testing for Completeness of Kill Stream sections of Big Fall Creek and Winberry Creek that had been heavily populated with rough fish were re-treated within a week of the initial treatment and no additional fish were killed. Observations were made on other sections,, both from shore and with the use of SCUBA equipment, and no fish were found. The pond that had contained warm-water game fish was re-treated twice to be certain that all fish were dead. An additional 25 gallons of rotenone were used in the post treatment project. Testing for Toxicity Since little impounded water was involved, the only toxicity tests necessary were those used in connection with the detoxification station. A new supply of test fish was live-boxed in Winberry Creek on September 5, l965. On the same day, a live-box containing six rainbow trout was placed in Big Fall Creek one-half mile above the dam. All of the fish died within a few minutes. September 6, new fish were placed above the dam and immediately above the detoxification station. All fish were still alive four hours later and the test was terminated. Restocking The streams in the reservoir basin were stocked with rainbow trout following the chemical treatment and before storage of water behind the dam. The stocking in the middle of September included the following rainbow trout.

27 Number Pounds Big Fall Creek 9,830 4,20 Winberry Creek 44,943 2,247 He He Creek 5, Portland Creek 0, ,773 6,992 Additional stocking of rainbow trout, coho salmon, and chinook salmon is planned for 966. Cost of Chemical Treatment Under Memorandum of Understarding by and between the Oregon State Game Commission and the United States Corps of Engineers dated 8 August 965, the Corps agreed to contribute the funds for the actual cost of treatment, but not to exceed a total of $2, March, 966 have been $7, Total costs of the project up to The cost of printing the report will be the only additional expenditure. The Willamette basin in general and the Big Fall Creek system had one of the lowest summer flows on record. The low flows were responsible for a considerable saving in the amount of chemicals necessary for the project. 25