ROSEBURG — A fish carcass clogged an intake pipe at Rock Creek Hatchery, shutting off the flow of water to a raceway, killing 400,000 spring Chinook pre-smolts. These fish were to be released directly from the hatchery into the North Umpqua River next spring.
Dan Meyer, Rock Creek Hatchery manager, said the water flow didn’t drop low enough to trigger an alarm. An alert employee discovered the problem within an hour but with the water temperature in the raceway at about 68 degrees and no fresh water coming in, it was too late to salvage any live fish.
“We have a new intake and a new emergency valve we can open," Meyer said. "If power to the screens is out, water to the hatchery is severed, and the emergency valve will get water to fish. It was opened for short time during a power outage a few months ago when the emergency generator failed, and we think the carcass may have gotten into the water line then.”
The hatchery spring Chinook provide a popular fishery in the Umpqua and North Umpqua rivers, with 4,000 to 6,000 returning each year. These fish return as 3- to 5-year old adults, with the majority returning as 4-year-olds. Anglers will see the impact predominately in the 2018 returns and to some degree 2017 and 2019, as well.
ODFW fish staff are looking at possible options for this fishery and will keep the public informed. Hatchery staff are refining the new alarm system testing and protocol.