Arastradero Creek

Arastradero Creek is a perennial stream located in the San Francisco Bay Area of California, United States. It originates in the foothills of the Santa Cruz Mountains and flows northward through the cities of Palo Alto and Los Altos Hills before joining Matadero Creek. The creek and its surrounding watershed are recognized for their ecological value and are the focus of significant conservation efforts within the Midpeninsula Regional Open Space District and the Arastradero Preserve.

Course and watershed

The creek begins on the eastern slopes of the Santa Cruz Mountains within the protected lands of the Arastradero Preserve. It flows generally northward, traversing a landscape of grassland, oak woodland, and chaparral typical of the California Coast Ranges. The stream channel passes near the Stanford University foothills before its confluence with Matadero Creek, a tributary of San Francisco Bay. The approximately 4.5 square mile watershed is bounded by other local drainages like Barron Creek and lies within the jurisdiction of Santa Clara County. Key landmarks within its course include the Pearson-Arastradero Preserve and the former site of the Page Mill Road arastra.

History and etymology

The name "Arastradero" derives from the Spanish word "arrastra" or "arastra," a type of ore-grinding mill used during the California Gold Rush. Historical records indicate the presence of such a mill in the area during the 1850s, operated by early settlers like John Greer. The land was part of the historic Rancho San Francisquito and later used for cattle ranching and agriculture before being acquired for preservation. The Midpeninsula Regional Open Space District purchased the core property in the 1970s, establishing the Arastradero Preserve to protect the creek's natural environment from increasing urban development in Palo Alto and the surrounding Silicon Valley.

Ecology and conservation

The riparian corridor of Arastradero Creek supports a diverse array of native species characteristic of the San Francisco Bay Area. The canopy includes Valley Oak and Coast Live Oak, while understory plants like California Poppy and Coyote Brush are common. The area provides habitat for wildlife such as the Bobcat, Gray Fox, and Western Fence Lizard, and is a known territory for the Golden Eagle. Conservation management by the Midpeninsula Regional Open Space District and the City of Palo Alto focuses on restoring native grasslands, controlling invasive species like Himalayan Blackberry, and protecting sensitive species. The Arastradero Preserve serves as a crucial wildlife corridor between the Santa Cruz Mountains and the baylands.

Hydrology and water quality

As a perennial stream, Arastradero Creek maintains baseflow from groundwater seepage, with significant seasonal variation following the Mediterranean climate patterns of winter rains and summer drought. Its flow contributes to the Matadero Creek watershed, which is monitored as part of the San Francisco Bay regional water quality control efforts. The San Francisco Bay Regional Water Quality Control Board and local groups like the Santa Clara Valley Urban Runoff Pollution Prevention Program address challenges from urban runoff, sediment load, and potential pollutants. Projects to improve hydrologic function include bank stabilization and the installation of check dams to reduce erosion and enhance groundwater recharge.

Recreation and access

The creek's primary public access is through the trail network within the Arastradero Preserve, managed by the City of Palo Alto. Popular activities include hiking, horseback riding, and birdwatching, with trails connecting to the broader Bay Area Ridge Trail system. Key access points are located off Arastradero Road near the intersection with Page Mill Road. The preserve's Juan Bautista de Anza National Historic Trail commemorates the historic expedition of Juan Bautista de Anza. Educational programs are often conducted in partnership with organizations like the Audubon Society and Stanford University to promote environmental stewardship of the watershed.

Category:Rivers of Santa Clara County, California Category:Tributaries of San Francisco Bay Category:Palo Alto, California