Get reliable rangeland science

Livestock grazing is one potential contributor to non-point source contamination of water bodies, and is commonly assumed to reduce water quality. In some cases, cessation of grazing activities is proposed in areas with impaired water quality. However, recent research in California has shown that grazing can be a land use compatible with state and federal water quality requirements. Escherichia coli (E. coli), a common fecal bacterium, is used as an indicator of microbial water quality and risk to human health. We quantified E. coli concentrations throughout the Willow Creek watershed of the Sierra National Forest in Madera County, California, to characterize E. coli concentrations in the watershed and assess whether current land uses are compatible with state and federal water quality requirements. Twenty-one sampling locations were identified by their primary association to one of three primary land use activities in the watershed: public recreation areas, federal public grazing areas, and rural residential areas. Sampling was conducted during July and August, to capture peak human and livestock use of the watershed. Water samples were collected weekly from each of these sampling locations and E. coli concentration determinations were completed within 6 � 1 hours of collection, following established protocols. Preliminary results indicate that these multiple land uses are compatible in the Sierra National Forest under current management protocols, as E. coli concentrations were below the EPA threshold for recreational water use in 97% of our samples.