The Twisp-Power Ditch existing fish screen is located on the Twisp R. adjacent to Douglas County PUD's Twisp River smolt acclimation/release pond. A single, paddlewheel-driven 3 foot diameter x 6 foot long drum currently screens 10 cfs resulting in an average approach velocity of 0.8 feet/sec (fps) or twice the maximum 0.4 fps allowed by the NMFS/WDFW screening criteria. The bypass systems is undersized & poorly designed by current standards resulting in potential injury to fish. The concrete structure is very old & needs to be replaced. Worn woven mesh was replaced with 3/32' stainless steel perforated plate in 1995 to reduce fry entrainment. Impingment is still a problem for fingerlings until they can swim for sustained periods at 0.8 fps or greater. Large numbers of juvenile spring chinook, steelhead & resident trout (including bull trout) use the ditch upstream of the screen for summer rearing habitat and are at risk of impingment or injury in the fish bypass system. The engineering drawings for a new screen facility based on the 10cfs design flow was completed in early 1999. The new design consists of a single, 3.5 foot diameter X 12 foot long, paddlewheel, hydraulics driven rotating drum screen covered with 3/32" stainless perforated plate.