High-Water Warning for South Fork

Coloma, California, November 29, 2012 — As of 9 a.m. today, the California Nevada River Forecast Center is predicting flows on the South Fork of the American River to reach approximately 27,000 cubic feet per second (CFS) sometime late Saturday or early Sunday, December 1-2. This is over ten times the typical summer flows of around 1500 to 3000 CFS. See the flow projections here.

Levels could be significantly higher downstream from the dam, as side creeks feed into the river. In addition, when Slab Creek dam upstream from Chili Bar starts to spill (at 1850 feet), the flows into Chili Bar exceed the reservoir’s capacity, and the flows can change quickly. See the Slab Creek release.

RV trailer crashing against Hwy 49 bridge piers, Dec 31, 2005 (©Sederquist)Lotus resident Harry Mercado points out that in the December 31, 2005, flood event (see photo right), the Chili Bar gauge underestimated the flows through Coloma. A release of 25,000 CFS indicated at the dam turned out to be closer to 40,000 in Lotus. The levels can also change rapidly. He notes that flow “jumped from 5,000 to 42,000 CFS while we slept.”

Residents are advised to remove possessions from low-lying areas. Whitewater paddlers are advised that boating is hazardous at these flows. See our South Fork Flows page for more information on river flows and how the river changes at different levels.

Thanks to Nick & Christina Pugliese and Harry Mercado for the alerts, and to Betty Sederquist for the photograph of the 2005-2006 flood event.