Gap discovered in tank in LG dam fish bypass system

U.S. Army Corps of Engineers Jan. 21 found a construction joint movement, a small gap which is only one-quarter inch to 3/8 of an inch wide at the top of a 27-foot tall concrete drain tank at Lower Granite Dam.

Corps spokesman Bruce Henrickson said the corps defines it as a gap, not a crack, in an adult fish trap bypass drain tank.

The drain is part of the adult fish by-pass system and is near where adult fish are captured out of the adult fish ladder as they migrate upstream, Henrickson said.

Fish bypass operations are not expected to be affected by the drain tank joint movement. The corps pl...