Mariposa News - Streamflow Measurements Resume on Clavey

Clavey River Streamflow Gauge Location

Sonora, Calif., (May 2, 2010)…The Forest Service today announced the Stanislaus National Forest, in partnership with the City and County of San Francisco Hetch Hetchy Project, has re-installed a stream flow measurement gauge on the free-flowing lower Clavey River. Reinstatement of Clavey River flow measurement operations will provide scientists with a rare opportunity to gather data on natural, undisturbed stream flows in a large Sierra Nevada watershed.

The new stream gauge replaces the original historic gauge once operated by the United States Geological Survey until its termination in 1995. At the time, budgetary constraints required the discontinuation of several of the agency’s stream flow measurement operations in California, including the Clavey River. Re-installing a stream flow gauge on the Clavey River was first recommended in the Forest's 1997 Clavey River Wild and Scenic River Review.

The partnership project jelled quickly since the City of San Francisco is interested in gauging all major streams in the Tuolumne River system to better understand how to improve releases from Hetch Hetchy Reservoir to better meet multiple, downstream beneficial uses of the river, including water supply, hydroelectric power generation, recreation activities, and protection of aquatic species.

A key benefit of the Clavey gauge is that it adds to the history and understanding of natural flows in the Sierras, and it also provides real-time data for anyone interested in flow information. Those members of the public interested in the information include anglers as well as expert kayakers who rate the Clavey as an extreme run in the spring when flows are within a range that offers high challenge. The information is valuable because the flows of most other Sierra Nevada Rivers are regulated by dams and diversions.

Now that the stream flow gauge is again in operation, Clavey River stream flow data is easily available on the California Data Exchange Center website at: CDEC.water.ca.gov, real-time data, code “CBU” to access the Clavey flow information.

For more information on the Clavey River stream flow and watershed data, contact Forest Hydrologist Jim Frazier at jfrazier@fs.fed.us or (209) 532-3671 ext. 205.