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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />., <br />I <br />I. <br />I <br />I <br /> <br />00231)0 <br /> <br />METHODS <br /> <br />Fish transport was measured using a large net which sieved waters <br />being released through one of the turbine outlets. The facility <br />has two turbines. Each with three exhaust ports measuring 3 by 3 <br />meters. At the designed head (101 m). generating 43.2 megawatts <br />at 47.6 cubic m per second (m3/s), the water velocity through <br />each opening is estimated to be about 1.6 m/s. The net was <br />attached to a steel frame that traveled within the bulkhead gate <br />channels (Figure 2). Rollers were installed on the frame which <br />reduced friction and stress, allowing the net to be easily set <br />and retrieved. An existing 4-ton overhead electric winch and <br />bulkhead lifting device was used to operate the net. <br /> <br />The net was constructed of 6 mm, knotless, heavy delta mesh and <br />was 9.1 m in length. The cod end was constructed of 5 mm mesh <br />and designed with a zipper to remove its contents. The net was <br />attached to a heavy metal frame which traveled vertically inside <br />the bulkhead channels. A choke line was attached 2 m above the <br />cod end to trap its contents during retrieval, and to help <br />prevent net entanglement during placement. Net length and mesh <br />size evolved during 1994, due to problems with net abrasion <br />against the concrete structure. A heavy chafe collar (1.5 wide) <br />was installed around the net to reduce net abrasion against the <br />concrete apron. The net opening was designed smaller <br />(2.7 x 2.4 m) than the outlet port to reduce net abrasion. The <br />small buffer area between the net and concrete provided a cushion <br />of water which reduced net abrasion and wear. These and other <br />small modifications were made, and by the end of summer 1994, we <br />had a reliable fish sampling apparatus. <br /> <br />Samples were collected by lowering the net and frame into the <br />discharge flow. Recorded data included: time, date, number of <br />turbines in use, megawatts being generated, reservoir elevation <br />and any bypass flow through the hollow-jet valves. On retrieval, <br />the choke line was set, closing the cod end, and the net and <br />frame was lifted by the winch. <br /> <br />Samples were only taken during uninterrupted power generation <br />cycles. Due to the facilities design, interruptions in releases <br />could allow resident, downstream fish access to outlet structures <br />which could possibly "contaminate" the sample. Powerplant <br />generation is continuously monitored so we could determine if <br /> <br />6 <br />