Your Estero Americano Watershed
The majority of Estero Americano’s 49 square mile watershed is in Sonoma County. Just 9 square miles of the watershed are in Marin. Americano Creek and Estero Americano form a portion of the northern boundary between Marin and Sonoma Counties where it drains into Bodega Bay.
Almost the entire watershed is on private property, but sections of Estero Americano can be viewed along the county line on Middle Road and Marsh Road just south of Valley Ford. The best view is from the bridge at the county line on Valley Ford Franklin School Rd. Land use within the watershed is primarily dairy operations, beef and sheep grazing, and residences. The small communities of Valley Ford and Bloomfield are within the Sonoma County portion of the watershed.
The Estero Americano is a coastal estuary at the base of Americano Creek, the estuary's sole tributary. In some years, a seasonal sand bar at the mouth restricts tidal exchange. When the mouth is open, the tidal influence ranges up to 4 miles upstream.
The Estero Americano contains 301 acres of open water and 412 acres of wetland habitat. This includes mudflats, seasonal brackish marsh, and freshwater marsh. The California Department of Fish and Game identified Estero Americano and its southern neighbor, Estero de San Antonio, as among the most significant habitat areas in the State. Streamside habitat along Americano Creek consists of grazed pastures with few trees interspersed with dense willow thickets. Coastal oak woodland occurs in the upper watershed.
Special-status species in the watershed include Northwestern pond turtle, Steelhead trout, California red-legged frog, Myrtle’s silverspot butterfly, Tidewater goby, and the Tricolored blackbird. Other noteworthy species identified in and surrounding the Estero include 71 species of water and marsh-associated birds, 66 species of terrestrial birds, and 44 marine and freshwater fish species. Over 70 species of benthic invertebrates and 30 species of epibenthic invertebrates were also collected in the Estero in the late 1980s.
Remember, storm drains connect streets to creeks. Simple changes can make a big impact. Estero Americano Watershed is Ours to Protect.