FISHING -- Improvements in operating Rock Island Dam will allow survival of at least 93 percent of the young salmon and steelhead migrating downstream, according to the Chelan County PUD.

The utility had to be able reach the 93-percent survival goal to meet federal criteria for boosting spring chinook, steelhead and sockeye runs.

The fish-survival debate regarding the region’s Columbia River dams began in the late 1970s and ’80s, with federal and state agencies and tribes mandating what PUDs had to do to improve fish survival numbers.

Each dam has its own plan for reaching the goals.

Rock Island Dam is fitted with fish ladders that mature fish use to get around the dam on their homeward migration to spawn. But it has no bypass system for young, ocean-bound fish. Spill is the method used to transport the fish downstream.