Laserfiche WebLink
<br /> <br />2021 Multijurisdictional Local Hazard Mitigation Plan <br /> <br /> Colma Creek Watershed—The headwaters of Colma Creek are on San Bruno Mountain. The lower <br />reaches of Colma Creek are managed by the San Mateo County Flood Control District <br /> San Francisquito Creek Watershed—Major tributaries include Los Trancos Creek, Corte Madera <br />Creek, and Bear Gulch Creek. Los Trancos and San Francisquito form the boundary between San Mateo <br />and Santa Clara counties. <br /> San Gregorio Watershed—Major tributaries include El Corte de Madera Creek, Alpine Creek, and La <br />Honda Creek. A small lagoon forms at the mouth of San Gregorio Creek during the dry season. <br /> San Mateo Watershed—The San Mateo Creek Watershed includes three reservoirs: San Andreas Lake, <br />and Upper and Lower Crystal Springs Reservoirs, managed by the San Francisco Public Utilities <br />Commission. <br /> Belmont Creek Watershed—Belmont Creek watershed originates east of the Pulgas Ridge in the hills <br />above Hallmark Drive and covers 1,952 acres (3.1 sq mi). <br /> Atherton Creek Watershed—Atherton creek flows from headwaters just west of Interstate 280 to <br />Alameda de las Pulgas. Further downstream, the creek is highly modified and flows through a concrete <br />channel to El Camino Real and then a combination of concrete channel and culverts to San Francisco <br />Bay. Several small tributaries drain into Atherton Creek above Alameda de las Pulgas, but further <br />downstream the drainage network consists of underground culverts or storm drains. <br /> <br />4.2.4 Climate <br />The climate of San Mateo County is characterized by dry, mild summers and moist, cool winters. About <br />80 percent of the total annual precipitation occurs during from November through March. Table 4-1 summarizes <br />normal climate date from 1945 through 2016 at Western Regional Climate Center weather station at San <br />Francisco International Airport. <br /> <br />Table 4-1. Normal Precipitation and Temperatures, 1945 – 2020 <br /> <br />Precipitation (inches) <br />Temperature (ºF) <br />Minimum Average Maximum <br />Annual 19.94 49.3 57.3 65.2 <br />Winter (December – February) 11.62 42.6 50.4 59.1 <br />Summer (June – August) .19 52.8 62.6 72.0 <br />Spring (March – May) 4.65 46.2 56.0 66.7 <br />Autumn (September – November) 3.48 47.4 60.1 73.4 <br />Weather Station: San Francisco International Airport <br /> <br />4.2.5 Vegetation <br />San Mateo County’s land managing agencies and stewards have the responsibility of caring for a diverse mix of <br />ecosystems, including estuarine, marine, oak woodland, redwood forest, coastal scrub, and oak savannah. Home <br />to more than 112,000 acres of protected lands, the county’s open spaces provide community members and visitors <br />with water, recreation opportunities, scenic vistas, wildlife habitat, and vital refuges for threatened, endangered, <br />and special status species. The county’s natural resources provide numerous ecological, economic, and social <br />benefits that are vitally linked to the county’s communities. <br /> <br /> <br /> <br /> <br /> <br />4-4