Estero Americano land use and habitat


The Estero Americano contains 301 acres of open water and 412 acres of wetland habitat. This includes:

  • Mudflats
  • Seasonal brackish marsh
  • 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
  • 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
  • 44 marine and freshwater fish species

Over 70 species of benthic invertebrates and 30 species of epibenthic invertebrates were collected in the Estero in the late 1980s.

Land use

Land use within the watershed is primarily:

  • Dairy operations
  • Beef and sheep grazing
  • Residences

The small communities of Valley Ford and Bloomfield are within the Sonoma County portion of the watershed.

Changes to the watershed

Historic activities in the watershed have contributed excessive amounts of sediment to the Estero. Periods of hypersalinity have been recorded in the Estero. This has changed the shape of the Estero which in turn changes:

  • Tidal circulation
  • Nutrient circulation
  • Salinity

Restoration and conservation

Restoration efforts in the watershed included the Sonoma County Coastal Wetland Enhancement Plan. This is an erosion survey of the Estero Americano and several coastal watersheds to the north. It was completed in 1987 by Circuit Rider Productions for the Gold Ridge Resource Conservation District (Gold Ridge).

With funding from the State Coastal Conservancy, Gold Ridge repaired many of the erosion sites identified. Gold Ridge continues to be active in the watershed. They sponsor workshops to assist agricultural landowners in developing ranch plans and implement projects to improve water quality and reduce erosion. More recently, the Gold Ridge produced the 2007 Estero Americano Watershed Management Plan.

There are also significant land conservation efforts in the watershed. The Sonoma County Agricultural Preservation and Open Space District and Marin Agricultural Land Trust are both active in the watershed. They protect agricultural land use through conservation easements.

The Sonoma Land Trust owns the 127-acre Estero Americano Preserve. This includes salt marsh habitat and some grazing lands.

For more information on the Estero Americano, contact the Gold Ridge Resource Conservation District:


  1. The Natural Resources of Esteros Americano and de San Antonio
  2. Estero Americano and Estero de San Antonio Monitoring Program: 1988-1989 Results. Long-term Detailed Wastewater Reclamation Studies: Santa Rosa Subregional Water Reclamation System. Draft Technical Memorandum No. E8.
  3. Sonoma County Coastal Wetlands Enhancement Plan
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