Characterization of Fish Passage Conditions through a Francis Turbine and Regulating Outlet at Cougar Dam, Oregon, Using Sensor Fish, 2009?2010

Abstract

Fish passage conditions through a Francis turbine and a regulating outlet (RO) at Cougar Dam on the south fork of the McKenzie River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions, identifying potential fish injury regions encountered during passage via specific routes. The RO investigation was performed in December 2009 and the turbine evaluation in January 2010, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc.Sensor Fish and live fish for both turbine and RO passage were conveyed through a pipe injection system that terminated at elevations approximately 2 ft above the respective intake midpoints. Release depth and position were established to introduce the fish and sensors into flows of approximately 5 feet per second (fps). Turbine passage through unit 2 was evaluated at minimum wicket gate opening, peak efficiency, and maximum wicket gate opening; RO passage was evaluated through 1.5-ft and 3.7-ft gate openings. Each study was conducted at one operational head.Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision, strike, and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates.For the turbine evaluation, three operational conditions through turbine unit 2 were tested: the minimum wicket gate opening of 13.6 degrees; maximum wicket gate opening of 24.5 degrees; and wicket gates set to the peak efficiency setting of 19.1 degrees. The corresponding turbine discharges were 340 cubic feet per second (cfs), 550 cfs, and 455 cfs, respectively. Sensor Fish were injected into turbine intake flows about 2 ft below the penstock ceiling at an elevation of approximately 1426 ft above mean sea level (MSL), into water velocities of approximately 5 fps.Sensor Fish experienced at least one significant strike, collision, or shear event during passage through the turbine runner; more than 92% experienced multiple events. The average value for all turbine events was 149.4 g (n = 13). The highest significant event magnitudes (166.2 g) occurred during passage through the maximum wicket gate opening condition followed by those at the minimum and peak efficiency settings (143.2 g and 140.3 g, respectively). Mean pressure nadir values obtained during turbine runner passage at Cougar Dam were the lowest observed to date; mean value observed during the maximum wicket gate opening condition was 3.66 pounds per square inch absolute.Passage through the RO was evaluated at two test conditions-gate openings of 1.5 ft and 3.7 ftwith corresponding approximate discharges of 440 cfs and 1040 cfs, respectively. The injection system pipe terminus was positioned at approximately elevation 1487.0 ft MSL, 2 ft above the RO centerline elevation.More than 97% of the Senso...

Passage and survival probabilities of juvenile Chinook salmon at Cougar Dam, Oregon, 2012

“…Monzyk and others (2011) estimated passage survival based on fish with passive integrated transponder (PIT) tags, and reported survival estimates for the RO route similar to those of the balloon-tagged fish and survival estimates for the powerhouse route greater than those of the balloon-tagged fish. Duncan (2011) passed sensor packages through the two routes and found more severe conditions within the powerhouse route than in the RO route, corroborating the results described by Normandeau and Associates, Inc. (2010) and Monzyk and others (2011). In November 2011, Beeman and others (2012) estimated that dam passage single-release survival of radio-tagged subyearling Chinook salmon from entry into the temperature control tower to detection at a site 3 km downstream was 0.3860 for fish passing through the powerhouse and 0.4247 for fish passing through the RO (expressed as probabilities rather than percentages).…”

“…The differences in the allocation and magnitudes of the discharge led to differences in the RO gate openings between years with an average of 1.21 ft during the day and 3.18 ft at night in 2012 and 1.25 ft (assumed constant during day and night) in 2011. Previous studies have shown survival and passage conditions to improve with RO gate opening size at Cougar Dam (Duncan, 2011;Monzyk and others, 2011). Thus, the greater RO gate opening during the night in November 2012 may be one reason for the higher survival in 2012 compared to 2011.…”

“…This premise is supported for the RO at Cougar Dam by results from sensor packages passed through the RO during the balloon tag and PIT tag studies. Duncan (2011) reported that the minimum exposure pressures of sensor packages passed through the RO were about 14 pounds per square inch absolute (psia) and they occurred near the downstream side of the RO gate. Thus, the acclimation and minimum exposure pressures will be very similar and the differences in head among the studies are not likely to result in differences in survival through the RO due to barotrauma.…”

Synthesis of downstream fish passage information at projects owned by the U.S. Army Corps of Engineers in the Willamette River Basin, Oregon

“…Fish in the RO study were a mean length of 172 mm (range 127-209 mm), and in the powerhouse study were a mean length of 179 mm (range 124-230 mm; Normandeau Associates, Inc., 2010b). Study conditions included a 1.5-ft RO opening at 440 ft 3 /s and 3.7-ft RO opening at 1,040 ft 3 /s when the reservoir elevation was near winter low pool (1,532-1,541 ft; Normandeau Associates, Inc., 2010b;Duncan, 2011). The turbine evaluation included three separate treatment conditions for unit 2: (1) minimum wicket opening and 340 ft 3 /s, (2) maximum wicket opening and 550 ft 3 /s, and (3) peak efficiency wicket opening and 455 ft 3 /s (Normandeau Associates, Inc., 2010b).…”

“…The turbine evaluation included three separate treatment conditions for unit 2: (1) minimum wicket opening and 340 ft 3 /s, (2) maximum wicket opening and 550 ft 3 /s, and (3) peak efficiency wicket opening and 455 ft 3 /s (Normandeau Associates, Inc., 2010b). Duncan (2011) used sensor fish and reported a high incidence of one or more significant strike, collision, or shear events (acceleration magnitude greater than 95 g) in the RO and powerhouse outlets (more than 92 percent). Nearly 86 percent of trials resulted in multiple significant events during passage through the powerhouse and RO.…”