Pilarcitos Creek (Spanish for: Little Pillars or Pillaries Creek) is a coastal stream in San Mateo County, California, United States, that rises on the western slopes of the Santa Cruz Mountains and descends through Pilarcitos Canyon to discharge into the Pacific Ocean Half Moon Bay State Beach.
The Pilarcitos Creek watershed is a significant area of ecological, cultural and economic diversity. It is a source of clean drinking water for residents of the central coast and San Francisco Bay Area and supports several natural-resource based economies – including agriculture and recreational tourism. The watershed is also experiencing increased competition for water between agricultural, domestic, recreational, commercial and environmental uses.
History
The Portolà expedition camped on the creek on October 28, 1769, and Father Juan Crespí named it Arroyo de San Simon y San Judas in honor of the Catholic Feast day for the Apostles Simon and Jude. The name Arroyo de los Pilarcitos meaning "creek of the little pillar-like rocks" was recorded in land grant papers as early as 1836.
In recent history, public and private stakeholders in the watershed have been working together intermittently since 1992, when two separate pollution discharge events occurred. Settlements from pollution discharge events initiated a trust fund for restoration activities. Associated money was used to develop the 1996 Pilarcitos Creek Restoration Plan. The Pilarcitos Creek Advisory Committee (PCAC) was created as a citizens advisory committee to provide input on the development of the Plan, and to provide advice and guidance to the Project Manager, the San Mateo County Resource Conservation District (RCD).
In 2005, a group of over 20 local and regional agencies and advocacy groups gathered with nearly 200 members of the community at a water summit to discuss watershed-based approaches for balancing the beneficial uses of water in Pilarcitos Creek.
In January 2007 watershed stakeholders established the Pilarcitos Creek Restoration Workgroup to guide the development of an Integrated Watershed Management Plan (IWMP) to promote balanced solutions to effectively manage the Pilarcitos Creek watershed that satisfy environmental, public health, domestic water supply, and economic interests.
Watershed description
The Pilarcitos Creek watershed drains . The creek begins at on the south slope of Whiting Ridge east of the North Peak of Montara Mountain, flows east-southeast, to Pilarcitos Reservoir where it is joined by Spring Valley Creek. Pilarcitos Dam was built in 1864 and two miles downstream Stone Dam was built in 1871. Further downstream, Pilarcitos Creek is joined by Albert Gulch in Albert Canyon at Highway 92. Albert Gulch is named for the ranch of the William C. Albrecht family, who lived here from the 1870s until 1954. Here Pilarcitos Creek turns to flow southwest for to the community of Half Moon Bay. Along the way it is joined on the right (heading downstream) by Nuff Creek, Corinda Los Trancos Creek, and Apanolio Creek, then from the left by Madonna Creek and Arroyo León before heading and west-northwest for to enter Half Moon Bay and the Pacific Ocean at Elmar Beach. The maximum rate of discharge was recorded as .
As early as 1860 a major diversion of Pilarcitos Creek was constructed to supply water to the burgeoning population of San Francisco. Two different tunnels carry water east from Pilarcitos Lake Reservoir and Stone Dam Reservoir, respectively. At the present time Pilarcitos Creek not only continues to supply water to San Francisco and the Peninsula via the Crystal Springs Reservoir, but it is also the principal source of potable water for the city of Half Moon Bay and coastside vicinity.
Jurisdiction over land use decisions in the lower creek regions is under the city of Half Moon Bay. Land use decisions in the upper reaches are with the San Mateo County. Both entities administer provisions of California's Local Coastal Program.
Watershed condition
The Pilarcitos Creek watershed is host to a number of plant and animal species, including anadromous steelhead trout (Oncorhynchus mykiss) which are listed as "threatened" by the Federal government. Over recent history, physical and biological impacts resulting from human activity have degraded the overall watershed condition, threatening native plant and animal species including steelhead. In addition, water demand has increased with the growth of residential, agricultural, and industrial development in the Pilarcitos Creek watershed, decreasing the amount of water available for surface flow in streams.