Peninsula Watershed – protect it! August 24, 2016

Posted by GGAS in Conservation, Golden Gate Audubon

By Noreen Weeden

On September 12, the San Francisco Board of Supervisors’ Land Use Committee will hear a proposed resolution seeking expanded public access to the Peninsula Watershed Lands. It urges the San Francisco Public Utilities Commission (SFPUC) to provide enhanced public access to existing roads and trails in the Watershed Lands, consistent with the goals of protecting the water supply and the environmental quality of the area.

Sounds like a wonderful idea … except when you look into what this means for our drinking water supply, native plants, and wildlife.

Golden Gate Audubon Society opposes this resolution or, at a minimum, calls for postponing any decision until the SFPUC has completed its study on the impacts, costs, and funding for opening the watershed. We believe the wording of the resolution itself is contradictory. How exactly does opening up the watershed lands protect the water supply and the environmental quality? It will not. Opening public access to our watershed will have environmental impacts – especially impacts on our drinking water, native plants, birds, and other wildlife – that must be considered.

Pilarcitos Reservoir in the Peninsula Watershed / Photo by Emma Leonard, Bay Nature

Pilarcitos Reservoir in the Peninsula Watershed / Photo by Emma Leonard, Bay Nature

Protected since the 1860s

The Peninsula Watershed is a 23,000-acre area surrounding Crystal Springs Reservoir, bordered by Pacifica and San Bruno in the north and Woodside and Redwood City in the south. (See map at bottom of this article.) As a source of drinking water for the city of San Francisco, it is owned by the PUC and has been closed to the public since it was originally set aside in the latter half of the 1800s. The watershed is part of a regional water system serving 2.6 million people in four San Francisco Bay Area counties. About five percent of San Francisco’s drinking water comes directly from rainfall and run-off into the Peninsula Watershed reservoirs. In addition, some Hetch Hetchy water (which makes up 85 percent of the city’s water supply) is stored in the Peninsula Watershed reservoirs on its way to the city.

The watershed is critical, intact habitat for 800 plants and trees, 165 bird species, 50 mammal species, and other wildlife – many of which have been extirpated from other parts of the Bay Area. This watershed has the highest concentration of special status (rare, threatened and endangered) species in the entire nine-county Bay Area.

The Peninsula Watershed is a California-designated Fish and Game Refuge and protected under the UNESCO Golden Gate Biosphere. Over the years, as other Bay Area parks and lands have become urbanized and altered, the Crystal Springs Watershed has remained the single most pristine tract of Peninsula land, and it has some of the highest conservation value of any land in our area.

Peninsula Watershed: Important bird habitat

With respect to birds, the Peninsula Watershed is within the Pacific Flyway, a major migratory route birds use each spring and fall. Many bird species come to the watershed to spend the winter while other birds use this as an important migratory stopover site where they can rest and feed. Other birds including Bald Eagles breed within the protected areas of the watershed. The Marbled Murrelet, a bird federally listed as threatened, relies on this watershed as breeding habitat. [1] The official bird of San Francisco, the California Quail, no longer breeds within city limits but currently lives and breeds in this watershed.

Peninsula Watershed / Photo by SFPUC

Peninsula Watershed / Photo by SFPUC

Increased use will take a toll

Our water, these habitats, and the species that depend upon them will be threatened by increased public and recreational activities. Humans harm wildlife by leaving food, trash, and human waste. Recreational activities cause erosion, unwittingly transmit weed seed, and potentially spread damaging diseases such as sudden oak death to these habitats. Fires in the region are primarily started by humans.

Increased recreational use will create conflicts between humans and wildlife. The watershed is truly a wilderness, one of few remaining on the Peninsula.   Last summer, the California Department of Fish and Wildlife Service relocated a mountain lion there from a residential area in San Mateo. In California, mountain lions are legally classified as a specially protected species and CDFW strives to protect their habitat and minimize conflicts between these mammals and humans. The SFPUC is required to maintain habitat for wildlife including mountain lions, yet safety guidelines in mountain lion territory include not hiking, biking, or jogging alone. These recreational activities pose a potentially dangerous situation and liability. The proposed resolution sets up a conflict between their mission of maintaining habitat for wildlife and recreation.

Peninsula Watershed in the spring / Photo by SFPUC

Peninsula Watershed in the spring / Photo by SFPUC

Looking west across the Peninsula Watershed to Montara Mountain and Pacifica / Photo by K. Glavin/Wikipedia

Looking west across the Peninsula Watershed to Montara Mountain and Pacifica / Photo by K. Glavin/Wikipedia

Wildfire and water quality risks

Increased recreational use will also raise fire danger and threaten water quality. In 2015, after several years of drought, the Peninsula Watershed was closed due to fire danger in order to protect the watershed. With climate change, severe storms and additional droughts are anticipated in our future. Wildfires present a huge threat to the area since it has not burned for many decades and there is much fuel on the forest floor. Without significant planning and clearing, we will face unusually severe wildfires that could do great damage to wildlife and plants. Fires also contribute to sediment build-up in the lakes by increasing both erosion and the potential for debris flow. (Increased hiking and biking on trails will also contribute to erosion and sediment build-up.)

The chief concern of the SFPUC in its 2002 Peninsula Watershed Plan was fire: “Studies in the FEIR demonstrate an increased chance of fire ignition once the public is allowed into a formerly closed area. Should a devastating fire occur, the resulting erosion and sedimentation would make treatment of the water using direct filtration a difficult (if not impossible) endeavor.” The devastating Big Sur Soberanes Fire — still burning as we go to press — was started by an illegal campfire. Such a disaster in the Peninsula Watershed would create a huge financial burden to San Francisco taxpayers.

Existing public access is adequate

This watershed already has public access with a surrounding trail used for hiking, biking, horseback riding, and birdwatching. This fenced 16-mile trail, operated by San Mateo County Parks and open every day of the year, is more than sufficient to support the estimated 325,000 current annual visitors.

Hikers in the watershed / Photo by Emma Leonard, Bay Nature

Hikers in the watershed / Photo by Emma Leonard, Bay Nature

Peninsula Watershed / Photo by Emma Leonard

Peninsula Watershed / Photo by Emma Leonard

The SFPUC reviewed opening the watershed in 2002 and it — along with U.S. Fish and Wildlife Service, California Dept. of Fish and Game (now Wildlife), and the California Department of Health Services — all “expressed concern with permitting unrestricted public access to the interior of the watershed due to the unique assemblage of habitats and species that occupy the watershed and potential for public health impacts.”

These agencies recommended the use of a docent program which “minimizes or eliminates the impacts related to unrestricted public access, such as unauthorized off trail use and ignition of fire.” [2]

The SFPUC implemented a docent program in 2002, which has been very successful at educating the public about our water supply while providing guided access to Fifield-Cahill Ridge. We support expanding this program with more training and resources.

Oppose opening the watershed!

The resolution to open up the watershed – resolution # 160183 – was proposed by Supervisors John Avalos, Scott Wiener, and David Campos.

The potential impacts on water quality and wildlife have not been identified, mitigated, or budgeted within the current city spending plans. Without a thorough plan that addresses the threats associated with increased use, it is premature to consider opening the watershed.

GGAS joins other organizations including Sequoia and Santa Clara Audubon, the Bay Area chapters of Sierra Club, Yerba Buena and Santa Clara chapters of California Native Plant Society, Native Plant Conservation Campaign, and Committee for Green Foothills in opposing opening the watershed while supporting the expansion of the docent-led program.

Please contact Supervisors Malia Cohen, Scott Wiener and Aaron Peskin (who sit on the Land Use Committee), your district supervisor, and the SFPUC contacts below to urge them to vote no on this resolution.

Protect San Francisco’s water while also protecting this unique habitat for rare, threatened, and endangered species and other wildlife!

Email contacts

(Click here to find out who is your district supervisor. When you send an email, please consider including us as a BCC so we can track the impact we’re having! Send the BCC to  District 1  District 2  District 3   District 4   District 5   District 6  District 7  District 8  District 9  District 10    District 11   San Francisco Public Utilities Commission   Steve Ritchie, Asst. General Manager, SFPUC  Tim Ramirez, Manager of Natural Resources, SFPUC



[1] See Fifield-Cahill Ridge Trail brochure by City and County of San Francisco and SFPUC

[2] See page 327-334 in

Map of Peninsula Watershed by SFPUC

Map of existing Peninsula Watershed trails by SFPUC

Tags: Crystal Springs Reservoir, Peninsula Watershed, S.F. Public Utilities Commission, San Francisco Watershed.


  1. Dan Richman
    August 24th, 2016 at 1:32 PM

    There have been attempts in the past to open up this precious area to increased public access, and they were foiled. If anything, the current situation cries out for this proposal to be turned down also. With increasing population in the Bay Area, a great wild and restricted place like this is even more vital as wildlife habitat. And considering the ongoing drought, the very last thing we need is endangering an already protected area around an important watershed. This proposal goes against common sense to say the least.

  2. Dave Wade
    August 29th, 2016 at 8:27 AM

    My understanding is the resolution would trigger the very studies you suggest. A yes vote wouldn’t simply open up any areas without restrictions.

    My personal feeling is that given there are many acres that don’t actually flow towards the reservoirs, and there are maintained fire roads in these areas, some of these corridors could be opened for regional connectivity between other open spaces.

  3. David Michaels
    August 29th, 2016 at 11:44 AM

    Isn’t this area currently heavily used for residences by employees of the water district? I understand that employees have homes in this area and use it for a variety of purposes. There is some real hypocrisy involved here. In addition, this belies any claim that “the watershed is truly a wilderness”
    I wouild suppport keeping this area closed if in fact it could be maintained as a true wilderness, without homes and roads with trucks being driven back and forth.

  4. Andy Howse
    August 29th, 2016 at 4:04 PM

    The fears allayed are not only highly speculative. Each one and many others are required by CA CEQA law to be analyzed and addressed through scientific review. From that standpoint the sentence below quoted in the article is little more than anti-science fear mongering:

    “The potential impacts on water quality and wildlife have not been identified, mitigated, or budgeted within the current city spending plans. Without a thorough plan that addresses the threats associated with increased use, it is premature to consider opening the watershed.”

    Totally ignored in this article, are all of the benefits opening that Watershed will provide. Including protecting the wildlife and habitats in the Watershed itself. Remember it was only a few years ago that Pilarcitos Quarry acquired the rights to expand. Breaking the scenic easement on the property set by the GGNRA and eating away at the mountain forever. There was no public outcry because the public is proscribed from having any engagement (docent or not) anywhere near Pilarcitos valley. The Audubon Society, Sierra Club, chapters and CGF were all totally silent or endorsed that enviornmental tragedy. Why? Pragmatism when monied interests eat the mountain, but vitriol when the nature loving public requests access to public land.

  5. GGAS
    September 1st, 2016 at 1:18 PM

    Actually, the Peninsula Watershed is NOT heavily used for residences. There are eight cottages in the watershed that have been there for decades and are occupied by SFPUC “watershed keepers” — their version of park rangers. They are uniformed personnel who manage safety in the watershed and are the first responders in events such as fires, fallen trees, medical emergencies, problems with the water system, and trespassing.

    The fact that this small number of SFPUC rangers live in the watershed doesn’t make it any less of a wilderness. Our national parks and national forest lands also have rangers, fire lookout people etc. living within their boundaries. This helps protect the land and keep it secure from natural disasters and trespassers.

  6. Susannah Marriner
    September 10th, 2016 at 4:08 PM

    For God’s sake, keep this beautiful natural area just the way it is!!!!!!! We are NOT the only species on this planet. We have encroached on the habitat of wildlife with very little regard as to where they have to go. Please leave this watershed alone!!!!!!

  7. Lee Ellis
    September 11th, 2016 at 1:24 AM

    I do not live in SF, so cannot vote on (against) this measure.

    I have been privileged to spend considerable time at Crystal Springs as an environmental consultant, so am quite familiar with its ecology. I agree 100% with the Golden Gate Audubon Society’s assessment of the negative risks of opening the area for public use. I cannot think of any beneficial impacts.

    First and foremost, this is a CDFW (CDFG) Refuge. The long term data on plant and wildlife species serve as a valuable baseline against which to measure the affects of future human impacts on surrounding environments.

    The increased danger of human-caused fire to wildlife and their habitat, as well as to nearby residences is a major concern.

    Secondly, the reservoirs are the source of drinking water for SF. Hetch-Hetchy water serves 33 Bay Area communities. Contamination by human feces and parasites is inevitable.

    There are ample opportunities for public recreation at existing Mid-Peninsula Regional Open Space areas and County Parks, several of which are under-used. Although the forbidden has always held an attraction for humans, there is nothing at Crystal Springs that cannot be seen or experienced at these existing areas.

    Environmental groups may obtain permission to conduct plant and wildlife studies at Crystal Springs. Docent-led tours allow the general public supervised access.

    Could I vote, I would oppose this measure.

    Lee Ellis

    The increased danger of human caused fire is a major concern.

  8. GGAS
    September 11th, 2016 at 10:25 AM

    Thank you for sharing this informed opinion, Lee!

    As an environmental professional, you opinion might carry some weight with the Boardf of Supervisors even if you don’t live in the city. We encourage you to send them an email!

  9. x
    September 13th, 2016 at 8:41 AM

    That the watershed has been Protected (from the public) since the 1860s is news to me; my understanding is that the Spring Valley Water Company allowed and encouraged visitors, and that the land was closed to the public only when the City bought it in 1930.

    Is my impression incorrect?

  10. GGAS
    September 13th, 2016 at 12:30 PM

    It was a very different era in the late 1800s or early 1900s. This wasn’t a metropolitan area of 7 million people. I hope you’re not arguing that we should manage our water resources and watersheds as if this were 1870, when there were a relative handful of people here.

  11. x
    September 21st, 2016 at 5:32 PM

    I’m not suggesting we manage our watershed as if this were 1870. I am asking that we manage it based on facts and science. My understanding is the watershed *was* open to the public until 1930, so arguing it has been closed since the 1860’s is arguing based on fiction.