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Water quality and continued grazing can coexist at Pardee Reservior

The Issue

California rangelands provide many important functions. They are grazing lands, provide wildlife habitat and are also valuable watersheds around drinking water reservoirs. In one particular instance, at the Pardee Reservior in Calaveras County, two uses of the rangeland were perceived to be incompatible with one another - grazing and clean drinking water.

What Has ANR Done?

Cooperative Extension advisors in three county offices were contacted for assistance when the grazing lessees around Pardee Reservoir were told to remove their cattle within three months. This action was being taken due to concerns about risk of Cryptosporidium parvum, a protozoa common to all warm-blooded mammals, entering the drinking water supply. East Bay Municipal Utility District (EB MUD) owns and manages the land around Pardee Reservoir, which supplies drinking water to the residents of the East Bay. The possible contamination concern was pushing the leadership in EB MUD to eliminate grazing during the winter months, the time of year when rainfall could cause overland water flow to washC. parvum from manure into the reservoir. ANR researchers have been investigating C. parvum for many years and have developed an extensive base of knowledge on the protozoa. The current research shows that there is a minimal risk of C. parvum contamination from cattle, especially from older cattle, and by revising management practices ranchers can further reduce the risk of contamination. Research also shows that there is a greater risk of C. parvum occurrence in wildlife species common on rangelands. Other rangeland management issues also were addressed, such as invasive weeds in the watershed. Cooperative Extension advisors worked with EB MUD staff to find a solution that would satisfy all parties.

The Payoff

A win-win solution - maintain a healthy rangeland and protect drinking water quality

Working with EB MUD staff, ANR Cooperative Extension specialists and advisors were successful in providing research-based information to help develop policies concerning rangeland management around Pardee Reservoir. The new policies included a requirement to change grazing practices to reduce the risk of C. parvum contamination while largely maintaining cattle numbers on the rangeland. EB MUD also established a water quality sampling program to alert them of any early signs of problems and to allow them to make future management changes to safeguard the drinking water supply. With maintenance of winter livestock grazing, the vegetation management benefits of grazing continue, including reduction of invasive plants that are common in the area (such as Medusa head), reduction of fuel loads before fire season, and maintaining a rural area with a viable industry. The end result was a win-win situation: a healthy rangeland producing an economic product and protecting drinking water.


Supporting Unit:

Alameda, Calaveras, Contra Costa, El Dorado, Santa Clara, Stanislaus and San Joaquin Counties, and Veterinary Medicine Extension
Theresa Becchetti, Livestock/Natural Resource Advisor, tabecchetti@ucdavis.edu; Bill Frost, Natural Resource Advisor, wefrost@ucdavis.edu; Sheila Barry, Livestock/Natural Resource Advisor, sbarry@ucdavis.edu; Rob Atwill, CE Specialist in Veterinary Medicine Extension, ratwill@ucdavis.edu; Ken Churches, Farm Advisor, cdcalaveras@ucdavis.edu