As a result of historical volcanic activity, the Panoche-Silver Creek Watershed in the State of California contains some of the largest deposits of selenium in the world. The watershed comprises approximately 300,000 acres and ranges in elevation from 100 to 5,000 feet above sea level. The Panoche-Silver Creek Watershed is located in the Coastal Range and San Joaquin Valley, 35 miles west of Fresno, California.

Unfortunately, the natural selenium deposits and similar deposits of boron and other salts contribute to contamination of the watershed’s surface water. Development of the lower watershed has virtually eliminated the creek channel and, as a result, continual flooding and sediment transport has deposited the selenium, boron and other salts into the region’s waters. This flooding also increases already excessive levels of streambed and streambank erosion and sedimentation in the watershed. Flooding damages the watershed’s agricultural land and industry, an important component of the local, county and state economies. A 1998 survey estimated damage costs to be $370 per acre.

Controlling the Floods

In 1989, a joint effort between federal, state and local agencies, landowners and water districts created the Panoche-Silver Creek Coordinated Resource Management and Planning (CRMP) Program. After completing a sedimentation study of the 30,000-acre confluence of the Panoche and Silver Creeks, program partners developed a watershed management plan to address flood and erosion control and sediment transport.

While most program initiatives are either in the planning phase or underway, some projects have been completed. For instance, in two "Clinic Programs," watershed stakeholders worked with the California State University Fresno School of Agricultural Sciences and Technology to construct a riparian area along Panoche Creek. A gauging station was also installed on Panoche Creek to support monitor ing and assessment aspects of the CRMP program.

Current projects include the installation of riparian filter strips, revegetation, revetment and stabilization of the channel bed. Additionally, an erosion control structure is being developed to reduce the flow and velocity of runoff. A project is also taking an inventory of the regional population of tamarisks, an invasive species of salt cedar, as a first step toward the development of an eradication program.

Future CRMP Projects

Future actions include restoring riparian pastures and corridors, revegetating filtration zones and constructing an erosion control structure in the Panoche drainage for flood control purposes. CRMP program partners will also support the activities of another Panoche-Silver Creek Watershed partnership, the Central Valley Project. The Central Valley Project and the Bureau of Land Management have designated the watershed as an Improvement Area and plan to purchase a 9-mile-long, 1-mile-wide corridor for land retirement and flood control.

By concentrating on flood, erosion and sedimentation concerns, partners in the Panoche-Silver Creek Watershed hope to improve water quality and wildlife habitat. Those improvements, in turn, will benefit the regional economy and all of the watershed’s inhabitants.

State and Federal Partners The Panoche-Silver Creek CRMP program receives financial support from the federal government, State of California, City of Mendota, Central Valley Project, Westside Resource Conservation District and Silver Creek Drainage District. Partners in state government include the Department of Water Resources, Department of Transportation, Regional Water Quality Control Board, Department of Fish and Game, University of California Cooperative Extension Service, CALFED Bay-Delta Program and California State University Fresno School of Agricultural Sciences and Technology. Federal support comes from the EPA, DOI Geological Survey, DOI Bureau of Land Management, DOI Bureau of Reclamation and USDA Natural Resources Conservation Service.

Table of Contents

http://water.usgs.gov/owq/cleanwater/success/panoche.html
Created October 13, 2000