Prospect No. 3 Hydroelectric Project FERC Project No. P-2337 Fish Passage Facilities Study Report: Biological Evaluation
Study Objectives Determine if Project fish passage facilities are biologically functional Test upstream passage success rate and travel time by PIT tagging wild trout and installing a PIT tag detection system in the fish ladder Test entrainment, injury, and travel time through the fish screen return system using hatchery test fish releases
Study Site
Upstream Fish Passage Methods Install PIT tag detection array in fish ladder PIT tagged 30 naturally produced trout from downstream of fish ladder PIT tagged 5 additional naturally produced trout from upstream of fish ladder Introduced PIT tagged trout in Pool 1 of the fish ladder Operated PIT tag detection array continuously for 1.5 months (June 11 to July 31, 2015)
PIT Tag Detection Array
PIT Tag Detection Array
Upstream Passage Test Fish 66% (n=23) of test fish ranged from 100 to 149 mm (min = 89 mm, max = 215 mm) All naturally produced rainbow trout All abdominally implanted with 23 mm half duplex PIT tags (Oregon RFID)
Upstream Passage Test Results 4 of 5 (80%) upstream origin test fish successfully ascended the fish ladder; upstream travel time = 12 to 25 hours 1 of the upstream origin test fish made 2 successful ascents through the fish ladder 3 of 30 (10%) of downstream origin test fish successfully ascended the fish ladder; upstream travel time = 2 fish @ 7 hrs, 1 fish @ 88 hrs) Smallest successful upstream fish = 110 mm Largest fish (215 mm) did not ascend the ladder
Summary of Successful Upstream Fish Ladder Passage Events
Downstream Fish Passage Safety and Effectiveness Test Methods 2 trial releases of hatchery-reared rainbow trout 150 fish 70 to 99 mm, 150 fish 100 to 160 mm Fish released upstream of fish screen Trap installed in fish bypass return pipe (same as 1999 test ) to re-capture screened fish Canal dewatered and fish salvaged upstream of screen at end of test
Downstream Fish Passage Safety and Effectiveness Test Results After a 4-hour test period, 22 hatchery fish were re-captured in the bypass trap No apparent injury was noted on recaptured fish and all were alive All fish salvaged from the canal upstream of screen were alive and in good condition No fish were found impinged on the fish screen No potential screen surface irregularities or gaps observed that could cause injury or entrainment
Summary of Fish Passage Safety and Effectiveness Test Results Size Class Number Released Number Caught in Bypass Trap (A) Number Salvaged Upstream of Screen Total Recaptured Total Uncaptured (B) Effectiveness (A/(A+B)) 70-99 mm 150 13 129 142 8 61.9% 100-160 mm 150 9 111 120 30 23.1% Based on visual observation of fish swimming in the canal upstream of the screen and in the impoundment after release, it is likely that some of the fish not captured during the test migrated upstream and out of the canal
Downstream Fish Passage Time Test Methods 30 hatchery rainbow trout 80 to 123 mm fork length PIT-tagged abdominally with 23 mm half duplex PIT tags Released immediately upstream of the fish screen bypass pipe entrance Migration time determined using same fish ladder PIT tag detection array Fish release occurred on June 12, 2015
Downstream Fish Passage Time Test Results 3 fish were never detected at an antenna (10%); 5 (17%) apparently remained in the fish ladder during the study period; and 22 fish (73%) were determined to have exited the downstream end of the fish ladder Median travel time = 195 hours (min = 8 hrs, max = 1108 hrs) Of 22 fish that exited the downstream end of the fish ladder, one fish moved back upstream all the way through the fish ladder (a successful upstream passage event)
Overall Conclusions Upstream passage rates likely influenced by fish behavior: upstream origin fish = 80%, downstream origin fish = 10% passage rate Fish as small as 110 mm ascended the ladder; passage time was generally less than 24 hours Fish screen impingement and injury were not observed Fish screen bypass effectiveness rates were relatively low (23 and 62 %), and appear biased low due to test fish moving upstream and out of the canal Median downstream travel time >1 week, but maybe biased by using hatchery trout as test fish