CGF: News: Pilarcitos Creek — a Restoration Challenge

Participants at the Pilarcitos Creek Water Forum included John Muller (Farmer John), Half Moon Bay City Councilmember; Tim Frahm, Director of Conservation, San Mateo County Farm Bureau; and Chris Fischer with the Pilarcitos Creek Advisory Committee and The Nature Conservancy

— photo April Vargas

The ecological challenge of restoring Pilarcitos Creek, through a collaborative watershed approach, was the focus of the Pilarcitos Creek Advisory Committee’s February Forum made possible through grants to Committee for Green Foothills from the San Francisco and Peninsula Community Foundations.

Pilarcitos Creek originates along the Skyline Ridge above Half Moon Bay and flows west through forests, farms, fields, and urban subdivisions until it meets the ocean. The creek was a reliable source of water for Half Moon Bay for many years.

Pilarcitos Creek nearly dry at the mouth
Today, Pilarcitos creek needs help. Dams and water diversions, groundwater wells, and water-hogging exotic species, such as Eucalyptus, cause the creek to become entirely dry in summer near its mouth. At its headwaters, San Francisco built an earthen dam in the late 1880s, which still supplies some of the City’s municipal water. In two of its tributaries, the natural, free-flowing creek has disappeared entirely — diverted around the landfill operated by Allied Waste (BFI) in Corinda Los Trancos Canyon and culverted under the working area of the Pilarcitos Quarry in Nuff Canyon. All of these human alterations have contributed to the decline of the creek’s once robust year-round flows and pristine water quality.

Despite these impairments, several impor-tant wildlife species are still found in Pilarcitos Creek and its other tributaries, including the federally-threatened steelhead trout, threat-ened California red-legged frog, and the endangered San Francisco garter snake.

Dam break funds creek restoration
In the fall of 1992, the dam on a sediment basin broke below the BFI landfill in Corinda Los Trancos canyon and released massive quantities of sediment into Corinda Los Trancos and Pilarcitos Creeks. The sediment destroyed habitat by filling pools, covering gravels used by spawning steelhead, and creating a flat and shallow sandy substrate many miles downstream. Fines of over $1 million resulted, and the Pilarcitos Creek Restoration Plan was developed to improve habitats in the creek.

A committee composed of various stakeholder groups, called the Pilarcitos Creek Advisory Committee (PCAC), was formed to recommend projects identified in the Plan, and to work with the affected landowners, farmers and residents in the watershed to improve water quality, quantity, and habitats. The PCAC members included farmers and landowners, agency representatives, commercial and recreational fishing interests, environmental groups (CGF), and several dedicated experts who gave generously of their time in addition to conducting studies that furthered knowledge about the creek and its habitats.

Community Forum restoring Pilarcitos Creek
In February, over 80 interested people attended the community Forum on restor-ing Pilarcitos Creek. A variety of studies and projects funded by the Pilarcitos Fund over the past ten years were showcased, including geological studies, fisheries habitat surveys, water quality sampling, characterization of sediment sources, removal of barriers to fish passage, and streambank stabilization projects in the watershed.

The forum enlisted community support for several key future projects, including removal of barriers to fish passage in Apanolio Canyon, which will restore the pristine upper canyon to annual steelhead runs. This canyon in the past was identified as the future site for San Mateo’s garbage, once Corinda Los Trancos is filled. If the historic steelhead fishery can be restored soon, this canyon and free flowing stream may be spared the fate of burial under several hundred feet of garbage.

In November 2005, Half Moon Bay voters endorsed the use of treated wastewater for irrigation of golf greens, cemeteries, and non-food crops by a wide margin that could result in more year-round flows in the creek. It will be important to ensure that as recycled water goes on line, the wells currently pumping near the creek for irrigation of Ocean Colony golf courses are put into inactive status.

CGF will continue to work with interest-ed stakeholders to ensure the restoration of the creek while maintaining other beneficial uses.