Quincy, WA - Modifications of the left-bank fish ladder at Wanapum Dam and location 1 on the right bank of Rock Island Dam are now in place for migrating adult fish. The installation of pumps, a weir box and an exit flume at the fish ladder are all complete at Wanapum. At Rock Island, two 30-foot denil baffled extensions were added to the existing fish ladder with a resting pool in between the extensions. About 80-percent of fish at migrating past Wanapum Dam use the left-bank ladder and about 70 percent of the migrating fish use the right side of Rock Island Dam. Modifications on the right-bank ladder at Wanapum are expected to be finished next week, as is location 2 on the right bank of Rock Island Dam.

Upon request from stakeholders and agencies, Grant PUD and the Washington Department of Fish and Wildlife began a program today (Tuesday, April 15, 2014) to trap migrating adult spring chinook salmon at Priest Rapids Dam and haul them above Wanapum Dam until the ladder modifications are evaluated under working conditions. For Rock Island Dam, the fish ladders are ready for the arriving adults. The extensions are deemed necessary for the expected low river elevations on the downstream side of the dam later this season.

Using the modified Off-ladder Adult Fish Trap at Priest Rapids Dam -- a facility that until now was used to primarily trap adult steelhead and sockeye salmon -- experienced WDFW workers, under contract with Grant PUD, will capture returning spring chinook and haul them in specially-designed tanker trucks up the river to designated release points above Wanapum Dam.

About 15,000 spring chinook are expected to come through Priest Rapids Dam this year, with as many as 1,500 arriving per day during peak times. If necessary, Grant PUD can trap and haul every spring chinook expected at Priest Rapids Dam this year. However, the trap-and-haul process will not accommodate the summer and fall salmon and steelhead runs, with as many as 12,000 fish arriving in a single day.

The utility expects that the Wanapum Dam fish ladder modifications will prove to be an effective method for fish passage. To test the modified fish ladders, 150 hatchery-program adult spring chinook salmon captured at Priest Rapids Dam will be tagged with computer chips and radio transmitters (known as PIT tags and acoustic tags) before being released below Wanapum Dam. The progress of the tagged fish will be monitored as they advance up the river and past the fish ladders at Wanapum and Rock Island dams. The test data will be used to prove the effectiveness of the ladder modifications. When the ladders are proven effective, the trap-and-haul procedure will end.

For additional information, visit: http://www.grantpud.org/your-pud/media-room/wanapum-dam-spillway-response or www.chelanpud.org “Wanapum Response” on the home page.