San Francisco Group to focus on watersheds

Although the creeks that once defined San Francisco's watersheds have mostly been obliterated - forced underground into culverts and combined with both sewage and runoff - support for watershed-based planning and resource management is still very much alive.

Creeks offer some of the best habitat and wildlife-viewing opportunities. In our city, the Presidio retains some of the most natural creek conditions. The upper portion of Lobos Creek contains thriving stands of arroyo willow - until the creek flows into a culvert under Lincoln Avenue. The Presidio's other major watershed is Tennessee Hollow, but much of the watercourse has been buried or otherwise altered. The Sierra Club urges the "daylighting" and restoration of the entire stream system, all the way from the headwaters of the three major tributaries down to an expanded Crissy Marsh. This unique urban restoration project can not only provide recreational opportunities such as new hiking trails, but can serve as a wildlife corridor connecting the park's lower elevations near Crissy Marsh with the upland bluffs around Inspiration Point. The potential for restoring the watershed depends on the cleanup of remaining toxic landfills, the future of Doyle Drive, and on finding ways to relocate existing uses now on top of some of the filled-in areas.

The hydrology of the western part of the city is characterized by infiltration into the aquifer or drainage into freshwater lakes, which then feed aquifers which help sustain the lakes. The Sierra Club is concerned about depletion of the aquifer providing water to Lake Merced and Pine Lake. These freshwater lakes are important stopovers and water sources for migrating birds on the Pacific Flyway as well as habitat for local wildlife.

Four of the city's major watersheds are named for historic creeks that drained to the east. The smallest, Sunnydale, crosses the county line at Visitacion Valley. While the upper watersheds of Yosemite Creek (in McLaren Park) and the North Fork of Islais Creek (in Glen Canyon Park) are functional creeks, the greatest portions of these creeks have been transformed into conduits for the city's sewer system, with water from the creeks flowing and being pumped to the city's treatment plants. As the city's first sewer project, Mission Creek was literally turned into a sewer (at 16th Street), while Mission Bay exists now only in name. While Mission, Islais, and Yosemite Creeks have been almost completely destroyed, their names live on in the tidal inlets (sometimes called creeks or sloughs) that lie just bayward of the historic creek mouths. All three tidal inlets are affected by combined overflows (sewage and stormwater) when heavy rain causes the volume to exceed the capacity of the treatment and storage system.

The Sierra Club has recently partnered with Clean Water Action and other conservation and environmental-justice groups in an alliance, now called SWALE (for "Sustainable Watersheds Alliance"), to advocate for a more sustainable and just Wastewater Master Plan. SWALE is currently working to convince the city's Public Utilities Commission to eliminate combined overflows into the ocean and the Bay.

The Wastewater Plan should also include maximum restoration of the natural watersheds, including the creation of a tidal saltmarsh and enhancements at Islais and Mission "Creeks" and Yosemite Slough. Thanks to the incredible metabolic diversity of the microbial world, and the ability of living systems to naturally cycle and dissipate a variety of substances, constructed wetlands and vegetated swales are highly effective means of treating runoff.

The San Francisco Water System manages several important watersheds that aren't even in San Francisco, including the upper portion of the Tuolumne River watershed in Yosemite National Park, the Peninsula Watershed in San Mateo County, and various lands and waters in Alameda and Santa Clara Counties.

The city's Recreation and Park Department manages Sanchez Creek, Arrowhead Lake, and the Laguna Salada in Sharp Park in San Mateo. Thanks to the committed work of many activists, a disastrous plan by the Public Utilities Commission (PUC) to locate an irrigation watertank in the upper portions of Sanchez Creek has been narrowly averted for now. While the PUC is currently pursuing alternative locations, the Sierra Club still has concerns about the possible effects of treated wastewater on wildlife. It is also unclear whether an expensive recycled-water system is really necessary when similar conservation goals can be met by simply decommissioning the golf course and converting it to other uses.

WhatYouCanDo

In the coming months, the San Francisco Group will be focusing more on watersheds, with opportunities to participate in various habitat-restoration projects. For information on getting involved in these efforts, contact or call (415) 200-8975

Steven Chapman, conservation chair, San Francisco Group