Flows on the American River through Sacramento will increase by 50 percent tonight to ensure enough flood-control capacity in Folsom Lake.
The U.S. Bureau of Reclamation, which operates Folsom and Nimbus dams, will boost flows from 4,000 cubic feet per second to 6,000 cfs between 6 and 8 p.m.
The increase is enough to fill an Olympic-size swimming pool every 45 seconds and is expected to raise water levels in the American River by one foot. This is not enough to cause flooding problems. But people traveling or recreating along the river are advised to use caution near the water and watch for rising water levels and faster flows.
Folsom Lake is the primary flood-control reservoir for the Sacramento metro area. With more storms forecast this week, there is a need to open more storage space in the reservoir.
At this time of year, officials are required to maintain the reservoir at about 59 percent of capacity to ensure enough storage for storm runoff from the American River watershed upstream. As of 2 p.m. Monday, the reservoir was about 62 percent full.
Additional flow adjustments may be needed as storms move through the area this week.