Sonoma County is a county located in the U.S. state of California. As of the 2020 United States Census, its population was 488,863. Its seat of government and largest city is Santa Rosa.
Arroyo Hondo is a northwestward-flowing 13-mile-long (20.9 km) river in Santa Clara County, California, United States, that lies east of Milpitas. The area is privately owned by the San Francisco Water Department and is closed to public access because of its usage as drinking water. Bounded to the east by Oak Ridge and to the west by Poverty Ridge, Arroyo Hondo empties into the Calaveras Reservoir where it joins Calaveras Creek. It is formed by the confluence of Smith Creek and Isabel Creek which drain the west and east slopes of Mount Hamilton, respectively.
Coyote Creek is a river that flows through the Santa Clara Valley in Northern California. Its source is on Mount Sizer, in the mountains east of Morgan Hill. It eventually flows into Anderson Lake in Morgan Hill and then northwards through Coyote Valley to San Jose, where it empties into San Francisco Bay.
Lagunitas Creek is a 24 miles (39 km)-long northward-flowing stream in Marin County, California. It is critically important to the largest spawning runs of endangered coho salmon in the Central California Coast Coho salmon Evolutionary Significant Unit.
Alameda Creek is a large perennial stream in the San Francisco Bay Area. The creek runs for 45 miles (72 km) from a lake northeast of Packard Ridge to the eastern shore of San Francisco Bay by way of Niles Canyon and a flood control channel. Along its course, Alameda Creek provides wildlife habitat, water supply, a conduit for flood waters, opportunities for recreation, and a host of aesthetic and environmental values. The creek and three major reservoirs in the watershed are used as water supply by the San Francisco Public Utilities Commission, Alameda County Water District and Zone 7 Water Agency. Within the watershed can be found some of the highest peaks and tallest waterfall in the East Bay, over a dozen regional parks, and notable natural landmarks such as the cascades at Little Yosemite and the wildflower-strewn grasslands and oak savannahs of the Sunol Regional Wilderness.
Sonoma Creek is a 33.4-mile-long (53.8 km) stream in northern California. It is one of two principal drainages of southern Sonoma County, California, with headwaters rising in the rugged hills of Sugarloaf Ridge State Park and discharging to San Pablo Bay, the northern arm of San Francisco Bay. The watershed drained by Sonoma Creek is roughly equivalent to the wine region of Sonoma Valley, an area of about 170 square miles (440 km2). The State of California has designated the Sonoma Creek watershed as a “Critical Coastal Water Resource”. To the east of this generally rectangular watershed is the Napa River watershed, and to the west are the Petaluma River and Tolay Creek watersheds.
Crystal Springs Reservoir is a pair of artificial lakes located in the northern Santa Cruz Mountains of San Mateo County, California, situated in the rift valley created by the San Andreas Fault just to the west of the cities of San Mateo and Hillsborough, and I-280. The lakes are part of the San Mateo Creek watershed. Crystal Springs Regional Trail runs along the reservoir.
San Andreas Lake is a reservoir adjacent to the San Francisco Peninsula cities of Millbrae and San Bruno in San Mateo County, California. It is situated directly on the San Andreas Fault, which is named after the valley it is in.
San Francisquito Creek is a creek that flows into southwest San Francisco Bay in California, United States. Historically it was called the Arroyo de San Francisco by Juan Bautista de Anza in 1776. San Francisquito Creek courses through the towns of Portola Valley and Woodside, as well as the cities of Menlo Park, Palo Alto, and East Palo Alto. The creek and its Los Trancos Creek tributary define the boundary between San Mateo and Santa Clara counties.
San Leandro Creek is a 21.7-mile-long (34.9 km) year-round natural stream in the hills above Oakland in Alameda County and Contra Costa County of the East Bay in northern California.
San Mateo Creek is a perennial stream whose watershed includes Crystal Springs Reservoir, for which it is the only natural outlet after passing Crystal Springs Dam.
Tolay Lake is a shallow freshwater lake in southern Sonoma County, California, United States. The lake, nestled within the southern vestiges of the Sonoma Mountains, is the site of significant Native American prehistoric seasonal settlement. In 2005, Sonoma County acquired the entirety of the lake and virtually its whole drainage basin from the Cardoza family for the sum of $18 million; the county's intention is to utilize the property as Tolay Lake Regional Park for ecological and archaeological preservation, as well as public use and enjoyment. Tolay Lake and its immediate drainage area is home to several nesting pairs of golden eagles, Aquila chrysaetos, and a number of rare, threatened or endangered species including the California red-legged frog, Rana draytonii; Western pond turtle, Actinemys marmorata; and Western burrowing owl, Athene cunicularia.
Lake El Estero is a U-shaped body of water that is the anchor of the El Estero city park in Monterey, California. It is close to Del Monte Beach and Monterey Bay. Two bridges connect downtown Monterey with the Oak Grove residential neighborhood and the Naval Postgraduate School. The 24.7-acre (100,000 m2) El Estero park complex has dedicated spaces for recreation with a baseball field, skatepark, and the Dennis the Menace Playground. It is also popular with migrating birds and bird watchers.
The Hydrography of the San Francisco Bay Area is a complex network of watersheds, marshes, rivers, creeks, reservoirs, and bays predominantly draining into the San Francisco Bay and Pacific Ocean.
Laguna Creek is a perennial stream that flows northwesterly for 2.6 miles (4.2 km) along the San Andreas Fault from Woodside in San Mateo County, California and, after crossing the Phleger Estate and Filoli, enters Upper Crystal Springs Reservoir, where it is a historic tributary to San Mateo Creek. San Mateo Creek then carries its waters over Crystal Springs Dam northeast to San Francisco Bay.
San Felipe Creek is a 14 miles (23 km) stream that originates in the western Diablo Range in Santa Clara County, California. It flows south by southeast through two historic ranchos, Rancho Los Huecos and Rancho Cañada de San Felipe y Las Animas before it joins Las Animas Creek just above Anderson Reservoir. One of the nine major tributaries of Coyote Creek, the creek's waters pass through the Santa Clara Valley and San Jose on the way to San Francisco Bay.
The Laguna Creek watershed consists of 25.1 square miles (100 km2) of land within northern California's Alameda County. The watershed drains the foothills of the Diablo Range south of Niles Canyon. To the southeast, the area of Mission Peak Regional Preserve around Mission Peak is included. Agua Caliente, Canada del Aliso, Mission, Morrison, Sabercat, Vargas, and Washington creeks drain the area of the watershed. They drain into Laguna Creek and eventually Mud Slough.
