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Water pollution from grazing cattle is the subject of an article in the Journal of Water and Health by researchers at UC Davis titled, “Reducing the impact of summer cattle grazing on water quality in the Sierra Nevada Mountains of California: a proposal.” Despite the fact that the journal is a publication is from the United Nation’s World Health Organization, the articles are not free, although I obtained a copy from the author Robert Derlet, MD. Here is the abstract. Read to the last sentence to get to their proposal.

The Sierra Nevada Mountain range serves as an important source of drinking water for the State of California. However, summer cattle grazing on federal lands affects the overall water quality yield from this essential watershed as cattle manure is washed into the lakes and streams or directly deposited into these bodies of water.

This organic pollution introduces harmful microorganisms and also provides nutrients such as nitrogen and phosphorus which increase algae growth causing eutrophication of otherwise naturally oligotrophic mountain lakes and streams. Disinfection and filtration of this water by municipal water districts after it flows downstream will become increasingly costly. This will be compounded by increasing surface water temperatures and the potential for toxins release by cyanobacteria blooms.

With increasing demands for clean water for a state population approaching 40 million, steps need to be implemented to mitigate the impact of cattle on the Sierra Nevada watershed. Compared to lower elevations, high elevation grazing has the greatest impact on the watershed because of fragile unforgiving ecosystems. The societal costs from non-point pollution exceed the benefit achieved through grazing of relatively few cattle at the higher elevations.

We propose limiting summer cattle grazing on public lands to lower elevations, with a final goal of allowing summer grazing on public lands only below 1,500 m elevation in the Central and Northern Sierra and 2,000 m elevation in the Southern Sierra.

This is the kind of public policy we need, based on peer-reviewed science and sound economics. The first author Dr. Derlet is a practicing medical doctor who became concerned about the impacts that grazing cattle have on the fragile land and water of the high Sierras. The Sacramento Bee ran a good article on the paper’s findings in April, Livestock waste found to foul Sierra waters:

As director of the emergency room at the UC Davis Medical Center, Robert Derlet always wondered what made people sick.

 Each summer, on hiking trips into the high Sierra, he brought that curiosity along, asking himself: Where do you get infections in the wilderness? The most obvious possibility, he believed, was the water.

 Now, after 10 years of fieldwork and 4,500 miles of backpacking, Derlet knows for sure. What he has learned – after analyzing hundreds of samples dipped from backcountry lakes and streams – is that parts of the high Sierra are not nearly as pristine as they look.

Nowhere is the water dirtier, he discovered, than on U.S. Forest Service land, including wilderness areas, where beef cattle and commercial pack stock – horses and mules – graze during the summer months. There, bacterial contamination was easily high enough to sicken hikers with Giardia, E. coli and other diseases. In places, slimy, pea-green algae also blossomed in the bacteria-laden water.

At issue is the tradition of cheap grazing permits from the Forest Service and Bureau of Land Management. Many think that the costs to the environment and the public exceed the benefits of cheap summer grazing for a handful of large cattlemen.

When I corresponded with Dr. Derlet, he told me, “I have a 1 hr + lecture on “Water Quality in California: A case for adding new National Parks in the Sierra Nevada” I am willing to drive to the Bay Area to give this talk if you can get a minimum of 20 people to listen.” Anyone have any ideas for an organization with a lecture series that would be interested?