Livestock waste found to foul Sierra waters

Unsafe levels of livestock associated pathogens infest alpine waters

Alpine lakes and streams of the Sierra Mountains are fouled with Giardia, E. coli, and other pathogens from livestock grazing on Forest Service Lands. Dr. Michael J. Connor, the California Director of Western Watersheds Project is one of the authors of the paper.

You can read the paper here:
Derlet, R. W., Goldman, C. and Connor, M. J.: Reducing the Impact of Summer Cattle Grazing on Water Quality in the Sierra Nevada Mountains of California: A Proposal. Journal of Water and Health. 8(2): 326-333. 2010.

Livestock waste found to foul Sierra waters.
Sacramento Bee



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  1. Ralph Maughan Avatar

    So cattle are sickening backpackers, hikers, campers, hunters by spreading E. coli, Giardia, Cryptosporidium,
    Salmonella, Campylobacter, and Yersenia in the water. And they used to call Giardia “beaver fever!” This includes the very sickening E. coli strain O157:H7

    They also spread pathogenic fungus of toads from one area to the next. No doubt other animals are infected by directly or indirectly by cattle.

  2. Rick Hammel Avatar
    Rick Hammel

    My first experience with cattle in the Sierra was a backpack trip over Trail Peak in 1984. My wife and I had just crested the summit and were on the way down into a pretty valley. At least it used to be. Seems the grazing lesse had just driven 500 head of cattle into the high country. It looked like an ORV event had just occurred. There were braided trails everywhere, along with the usual cowpies all over the place,including the nice little stream, with golden trout in it.

    We hiked to the crest of the valley before camping, where we were able to get away from the stentch of many cows.

    The next day we diverted away from the cattle,and the headwaters of the Kern River up a trailless ravine, into the heaviest mosquito swarm we have ever seen. But I’ll take the mosquitos any day, over cows.


  3. JimT Avatar

    I have a great story that isn’t mine, but is too good not to share.

    Several years ago, Vermont law school in South Royalton chose a retiring tax attorney from Manhattan as its new Dean. He and his wife…who for all the world looked and talked like Julia Child and was as nice…bought a “country home” near the law school and set about rehabbing it. These are folks who never set foot in the country before, and they were very enthusiastic and eager to do the right things.

    One of the quaint things about the house was a huge antique tub that the dean’s wife adored. So, she drew a bath one time, and went to get in, and exclaimed to her husband” My word, I do believe there is a frog in my tub!” Not only that, but since moving to the house, they had several bouts of intestinal issues that remained unexplained.

    So, the dean was curious about the frog and went to discover what he could about his water system, which he assumed was a well.

    Well, it was not. Their drinking supply was a shallow cistern that was fed by a 3 inch PVC pipe. He traced the pipe back and discovered that it was simply inserted in a stream. And he walked up the hill next to the stream and disovered that the stream ran right through pasture occupied by a large number of cattle who, obviously, were enjoying the water as well.

    They took it in stride, got the right meds, and called a well drilling company the next day…..

    Ah, City folks….:*)

  4. Sal_N Avatar

    Most cattle have been taken out of the high altitute wilderness thanks to folks like Cal Trout and others. The Golden Trout wilderness is mostly cattle free on the east side and the streams are coming back nicely.

    Cattle is still mostly found in and around the Owens river and the surrounding ranches. That waters makes it way to LA (one third of our water is from the Owens). Which mean WE collectively are taking in all that crap. (can I say that on this blog?)

    I don’t think we will be able to clean up the Owens valley but at least we can have the high altitute lakes and meadows.

    1. Rick Hammel Avatar
      Rick Hammel

      Sal, that is good to hear. I know that the FS had a lot of issues with ranchers on Olacha, primarily Anheiser-Busch.


    2. Ralph Maughan Avatar


      I noticed something interesting while driving and walking in the vicinity of Bishop, CA.

      The City of Los Angeles owns most of the bottom land in Owens Valley, and they permit grazing cattle on these sensitive riparian (and less sensitive other) lands. These lands are in worse condition than the BLM lands on the mountain foothills. Some of these BLM allotments were in pretty good condition; others not. However, it’s appalling that the City of LA should be worse than the BLM, and this bad grazing is all around the city’s water supply. If the residents of LA knew, I think they would want not want cow crap on the bank of the Owens River.

    3. Elk275 Avatar

      What is the difference between cow crap and buffalo crap?

    4. pointswest Avatar

      I have lived LA for about 8 years now. I grew up in Idaho and have lived in Tri-Cities, WA; Albuquerque, NM; Denver, CO; Phoenix, AZ; and Las Vegas, NV. Of all these places, LA is, by far, the least interested in the outdoors, in wildlife, in ecology, or in preservation. You have to understand that, just to get out of this huge city is a 90 minute drive in good traffic and good traffic is usually over by about 6:00AM. The other thing is that LA is surrounded by a drab featureless pale brown desert. To get anyplace interesting where you might see interesting wildlife is a four hour drive in good traffic. If anything goes wrong and you get into bad traffic, it can take you 8 hours to get home. Many people in LA have never been anywhere else in the world except for a trip to the San Diego zoo or a few trips to Las Vegas to party.
      The other thing about LA is that American culture is on the relative decline and a diversity of foreign cultures are on the rise. Myself, being of anglo-european-american culture am in a minority here. 30% of Angelinos are Hispanic, for example, and while many Hispanics are well assimilated into American culture, the tide is turning towards a Mexican or a unique Angelino culture which has little interest in wildlife or ecology. Another predominate culture here is the Asian culture that similarly has little or no interest in the outdoors. Blacks are, in general, of an American culture but are less interested in the outdoors since they often experience extreme prejudice in areas like Idaho, Montana, and Wyoming or even the rural areas of California. Blacks have little interest in areas where they dare not tread. Then there are a multitude of other first and second generation immigrants from around the world in LA who make up nearly a third of the population. There are Russians, Iranians, Palestinians, Armenians, Ethiopians, Indians, etc., etc., all who are retaining their culture and who predominate in certain areas of town. Most of these first and second generation immigrants have little to no interest in wildlife or ecology.
      Greater Los Angeles has a population of 17 million people. The combined population of Idaho, Montana, and Wyoming is 3 million. Everyone from that tri-state area could move to LA and it would hardly be noticed. People who live in Idaho, Montana, and Wyoming assume that Americans will never completely turn their back on wolves or grizzlies or wilderness or ecology. I am not so optimistic. Ralph, believe me, most Angelinos have no idea where the Owens River is let alone that LA gets water from it.

  5. Sal_N Avatar


    I totally agree with you on the condition of the land. It is horrible. Only the occasional fisherman or dove hunter notices how bad the land is.

    LA folks probably don’t want cow poluting their waters but after a 5% hike approved yesterday, will they have the stomach to ask LADWP to remove the cattle and charge them more for the water?

    I would, now lets see if the rest will also.

    But as you know my time is limited in LA and it is off to Livingston in a few years.

    1. Ralph Maughan Avatar


      While a could be wrong, and maybe the city of LA earns a lot of grazing ree revenue, I’d bet that the actual revenues from cattle grazing are so small that they would not affect a water rate hike.

      I’m speculating on the fact that other desert cattle ranges just don’t support many cows relative to the well-watered and fertile pastures outside the desert.

    2. pointswest Avatar

      I believe only a small percentage of LA’s water comes from the Owens Valley anymore. Since they built the California Aqueduct, most comes from northern California with some from Southern Oregon. There are also several aqueducts that come from the Colorado River so LA gets water from Colorado and Wyoming too. I do not know what percentage comes from the Owens Valley but probably only something like 10 or 15%.

      In the 60’s, there was talk of pumping water from the Snake over Hoback pass into the Green River ( a tributary to the Colorado) so LA would be getting some of Idaho’s water too. Idaho succeeded in stopping them, this time, however.

  6. pointswest Avatar

    I have always wondered if cattle didn’t create more mosquitoes and horseflies. It has always seemed to me that there are more mosquitoes in areas where there are cattle. It makes sense that mosquitoes could more readily breed and reproduce where they have a food source. Horseflies, I am almost certain about. There are definitely are worse in areas with cattle…or is certainly seems like it.
    Does anyone know the answer to this? Do cattle tend to increase the numbers of mosquitoes and horseflies in an area?

  7. Tilly Avatar

    Pointswest, I have heard they do, due to both troughs and mini-puddles from hoof prints, both of which are often stagnant and good skeeter breeding grounds.

  8. Nancy Avatar

    We had a couple of 60 degree days last weekend and I saw my first mosquito but I’ve found when the neighbor is irrigating his hay meadows (as in diverting the creek) the mosquitoes are alot worse. The horseflies & flies are also bad when cattle and horses are on the property next to me.

    1. pointswest Avatar

      It may be my imagination, but there are horseflies in Island Park now the size of cigarette butts. Geese…I sure don’t remember them 40 years ago when I was a kid. I remember horseflies in the Centenial Valley and in Bechler Meadows but they where only have the size and a tenth as numerous as the ones in Island Park now (usually among the cow heards). Has some new species and moved in or has there been that much evolution in the past 40 years. The horseflies now are big and loud and buzz your head and can hurt just by striking you (let alone biting you) They are a serious anoyance I’m certain was not there 40 years ago. I spent lots of time in Island Park as a kid and only remember a few mosquitos and almost no horseflies…certinly not the dive bombers that are there now.

      …another invasive species, or my imagination?

    2. Elk275 Avatar

      Maybe, Just Maybe some fisherman who has been to the Lake District in Chile has bought back the “Tobanos”. Tobanos are a super sized horsefly that is colored like a salmon fly and is the size of a small hummingbird and bites like a snake. I have had to stopped fishing in Chile and seek indoor shelter because of them. When they bite they take a small piece of flesh. They are huge and nasty.

  9. Sal_N Avatar

    LA gets about 1/3 of its water from the Owens.

    The waters coming from the Sacremento delta have been reduced due to water needs to keep the endangered Smelt fish in plenty of waters.

    LA metro uses 25% less water today with millions more in the area than we did 10-15 years ago.

    Agro needs in the delta and surrounding areas use more water than LA.

    1. pointswest Avatar

      I do not mean to be picky (although it is in my nature) but you can read that DWP may get 30% of their water from the Eastern Sierra (Owens Valley), but DWP only serves the City of Los Anglese proper with a population of 3.8 million people. DWP might sell water to a few interior cities like Santa Monica and Culver City, but when you consider the many outlying cities in the Greater Los Angles area, Thousand Oaks, Costa Mesa, Burbank, Ontario, etc., etc., you are talking about 17 million people. The cities in the Valley and north get there water entirely from the California Aqueduct. Cites from the Pomona Valley east all get their water from the Colorado. For the Greater Los Angeles metro, it may be less than 10% that comes from the Eastern Sierra. It might be less than 5%. I am a Civil Engineer and I fly around the area quite a bit.

      The Eastern Sierra has never had the water that the San Juaquine river has had. The San Juaquin is a navitgable river and may (at one time) have had flows larger than the Columbia River. The Owens was always a small steam that once emptied into Owens Lake. Owens Lake had no outlet and inflow from the river simply evaporated into the desert air. While I do not know what the mean anual flow number are (or were before all the diversions), they are on the order of the Owens at 300 cfs and the San Juaquine 30,000 cfs.


Ken Cole is a 5th generation Idahoan, an avid fly fisherman, wildlife enthusiast, and photographer. He is the interim Idaho Director for Western Watersheds Project.

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