Sonoma County Community Separators

UPDATE: Measure K passed by an overwhelming majority in the November 2016 election. See the results here.

The most important green measure in Sonoma County in recent years was Measure K to renew voter protections for community separators–the greenbelt lands in between the county’s cities and towns–for another 20 years. Passing Measure K protects a total of 53,576 acres of open space and farmlands from subdivision and sprawl.

For more than 20 years, Greenbelt Alliance has helped Sonoma County prevent housing tracts and shopping malls from sprawling onto rural and agricultural lands with voter protections that were passed by more than 70% in a countywide vote. Measure K required a simple majority vote and cost taxpayers absolutely nothing to protect and preserve this beautiful county for the next generation.

These critical voter protections for community separators were set to expire in 2016 but more than 80% of Sonoma County voters cast a yes vote for Measure K, renewing community separators for another 20 years. Without voter protections, community separators can be reduced and development can be intensified beyond allowable uses with a simple majority vote of the board of supervisors, so passing Measure K was a huge win.

The purpose of community separators is three-fold—they serve as green buffers between cities and towns, contain urban development, and preserve the rural charm of Sonoma County’s landscape. The county’s community separators now cover 53,576 acres of natural and agricultural lands. They complement the cities’ urban growth boundaries by safeguarding adjacent unincorporated lands.

Greenbelt Alliance led the way to renew voter protections for community separators with Measure K so that Sonoma County’s natural and agricultural landscapes remain protected for years to come.

The resulting Community Separator Protection Ordinance protects a total of 53,576 acres of natural and agricultural land from subdivision and sprawl. It extends voter protection to all green buffers designated as community separators. The ordinance prevents the conversion of these rural lands to shopping malls, housing tracts, or resort hotels without a vote of the people.

See the Results

Drag the line from right to left to see how the lands protected as community separators tripled in 2016.

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  • Ensure the passage of Measure K on the November 2016 ballot measure to keep voter protections for Sonoma County’s community separators in place for another 20 years as a key tool for protecting the county’s natural and agricultural landscapes
  • We added priority lands to existing community separators to cover more natural and agricultural lands through an amendment to Sonoma County’s general plan that will be protected by the voters with the passage of Measure K


  • December 2015: Board of Supervisors votes to develop ballot measure
  • March – June 2016: Public workshops and meetings to gather input and science on designating community separators
  • May/June 2016: Planning Commission public hearing to review draft ballot measure and general plan amendment
  • Summer 2016: Board of Supervisors public hearing to review draft ballot measure and general plan amendment
  • August 2, 2016: Board of Supervisors approved community separator designations with a General Plan amendment and finalized ballot measure for November election
  • Greenbelt Alliance partners with local allies to launch Keep Our Community Separators – Yes on Measure K campaign committee
  • November 8, 2016: Election Day, over 80% of voters said yes to Measure K


  • Sonoma County Community Separator map
  • Keep Our Community Separators, Yes on Measure K website
  • Poll results showing voter support for renewing and expanding community separators


Sonoma County Conservation Action, Sierra Club

Read More

Big Win: Sonoma County Renews Community Separators for 20 Years

Green Light for Greenbelts in Sonoma

Staff Contact: Teri Shore

Photo: Harminder Dhesi via Flickr

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