Water flow reduced on American River
Officials: Flow to be cut in half by Friday
Water flowing into the American River was reduced overnight as part of a plan to conserve dwindling water storage in Folsom Lake.
At 11 p.m. Monday, water was flowing out of Nimbus Dam at a rate of 1,063 cubic feet per second, according to U.S. Bureau of Reclamation sensors.
At 5 a.m., water flowing through the dam's hydroelectric turbines had been reduced to 862 c.f.s.
Officials said the gradual reduction in flows would continue through the week until the outflow from Nimbus Dam reached 500 c.f.s.
The flow will equal levels not seen since the drought of 1990, according to water officials.
Tom Gohring, of the Water Forum, a coalition of Sacramento-area water agencies and environmental groups, said the process would be done in steps, beginning with a reduction of 300 cubic feet per second at midnight between Monday and Tuesday.
The Bureau of Reclamation said it would then reduce the flow by 100 c.f.s each day until the target of 500 c.f.s is reached on Friday.
He said a team of six biologists would be stationed on the river to monitor the effects on wildlife, including Chinook salmon, which recently laid eggs in the river bed.
"We have an estimate of how many eggs will be dewatered. And our estimate is about 12 percent," said Gohring.
However, Gohring said lowering the river level now will help guarantee that there is enough water for steelhead trout, which are just beginning to spawn.
Levels on the lower American River are determined by water releases from dams on Folsom Lake and Lake Natoma.
The U.S. Bureau of Reclamation, which controls those dams, confirmed the planned reductions.
"We have a lot of different objectives we have to weigh and the consequences of making the different actions. So it wasn't something we came to very easily," said Paul Fujitani, deputy operation manager for the Bureau of Reclamation.
Fujitani estimated the flow reduction would lower the river's level by an average of 6-8 inches.
The city of Roseville, the city of Folsom and the San Juan Water District pump water out of Folsom Lake to supply tens of thousands of residents.
Last month, water agency officials expressed concern that if current dry weather conditions persist into spring, the lake level may fall below the intake valve in the face of Folsom Dam.
The city of Sacramento's utilities department said it was still evaluating the situation and was not yet sure if the planned reductions would effect its water pumping facility on the American River.
Utilities spokeswoman Jessica Hess called the situation unprecedented and urged residents to conserve water.
Hess said sensors near the water pumping facility showed the river depth of 16 feet.
She said if the river falls below 14 feet of depth at that location, engineers will have to find an alternative way to use the intake.
"Fortunately, the city of Sacramento has an alternate intake on the Sacramento River, and they have a fairly substantial groundwater supply," said Gohring.