Bigger water flows to help salmon; move seeks to entice fish up Clear Creek
Dylan Darling
Redding.com
05/24/2011
More water is flowing down Clear Creek south of Redding this week in an effort scientists hope will lure salmon upstream.
The increased releases out of Whiskeytown Dam will aid spring-run chinook salmon as they swim to the upper reaches of the revitalized creek, said Matt Brown, a fish biologist with the U.S. Fish and Wildlife Service. There the fish will find pools up to 20 feet deep, perfect for them to stay over summer as they wait to spawn.
"It's those big pools that are higher up in the creek that we want to get them up to," Brown said.
The pools are the perfect place for the federally protected fish to spend their summer as they wait to spawn in September or October, Brown said. For nearly a century the pools were out of reach because of an old diversion dam midway through Clear Creek's 18-mile run from Whiskeytown Dam to the Sacramento River.
In 2000 the U.S. Bureau of Reclamation removed the Saeltzer diversion dam, reopening 10 miles of salmon spawning habitat. Since 2003, Brown said, scientists experimented with "pulse flows," attempts to show the fish the habitat is there by enticing them there with temporary releases of extra water.
Flows Monday hit 1,040 cubic feet per second, more than four times than normal for this time of year, he said.
They were set to drop down to 600 cfs Tuesday and then stay there until 4 p.m. Thursday, according to bureau data. The bureau, which regulates releases from Whiskeytown Dam, will then slow flows down to 175 cfs by Sunday.
Another pulse, up to 600 cfs, is planned for June 6 to 9, Brown said. He said the high flows are stretched over three days each so fish have time to go up the creek.
"That's designed so the maximum number of fish in the Sacramento River will sense that water and find their way in," Brown said.
Before, between and after the pulses, Fish and Wildlife Service scientists snorkel stretches of Clear Creek and count the salmon, he said. Since the Saeltzer Dam came out a decade ago, the spring run usually has about 100 fish. Scientists estimate that the stream could handle a run of about 1,000 fish. The National Marine Fisheries Service listed spring run chinook salmon on the Sacramento River as threatened in 1999.
Finding the right number, timing and water amount for the pulse flows will be key to increasing the current run tenfold, Brown said.
