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Tolay Lake Regional Park -Background

Tolay Lake view from park entrance

Master Plan Background

Sonoma County Regional Parks Department has completed the Tolay Lake Regional Park Master Plan and it has been approved by the Board of Supervisors. 

Read the Press Release:  

Supporting Documents to the Master Plan & Environmental Impact Report

  1. Biological Resources Study – Tolay Lake Regional Park(PDF: 5.94 MB)
    Prepared by LSA Associates, Inc., April 2009
  2. Biological Resources Study – Tolay Creek Ranch(PDF: 5.95 MB)
    Prepared by LSA Associates, Inc., May 20, 2009
  3. Tolay Lake Regional Park Rangeland Resources Study(PDF: 6.08 MB)
    Prepared by LSA Associates, Inc., March 13, 2009
  4. Baseline Geomorphic Assessment of Tolay Creek(PDF: 1.22 MB)
    Prepared by Joan Florsheim, Geology Department, University of California, Davis, June 2009
  5. Report of Investigation – Tolay Lake Ranch(PDF: 11.81 MB)
    Prepared by EBA Engineering, September 8, 2004
  6. Feasibility Analysis for the Restoration of Tolay Lake – Final Report(PDF: 6.16 MB)
    Prepared by Ducks Unlimited, Inc., March 2005
  7. Tolay Lake Regional Park Interim Access & Resource Management Plan – Initial Study(PDF: 40.91 MB)
    Prepared by Sonoma County Regional Parks, August 2008
  8. Tolay Lake Regional Park Initial Study – Conceptual Master Plan & Water-Right Application(PDF: 34.42 MB)
    Prepared by Sonoma County Regional Parks, September 05, 2006
  9. Tolay Creek Riparian Enhancement Plan(PDF: 60.18 MB)
    Developed by West Coast Watershed with assistance from Rob Evans & Associates, November 2009
  10. Building Inspection Report - 5869 Cannon Lane, Petaluma, California 94954(PDF: 643 kB)
    Prepared by American Home Inspection, May 24, 2004 Inspection Date
  11. Petition to Amend Water Right Application – September 21, 2006(PDF: 2.47 MB)
  12. Notice of Petition for Change in Points of Diversion, Points of Rediversion, Purpose of Use and Place of Use(PDF: 86 kB)
    Petition Filed September 25, 2006
  13. Water Availability Analysis Appropriative Application 30558 (PDF: 7.58 MB)
    Prepared by Napa Valley Vineyard Engineering, April 1, 2008; Revised February 18, 2009
  14. Tolay Lake Regional Park Baseline Documentation(PDF: 46.37 MB)
    Prepared by Circuit Rider Productions, Inc., June 2006
  15. Tolay Lake Regional Park Grazing Plan(PDF: 96 kB)
    Prepared by Stephanie Larson, Ph.D., UC Cooperative Extension, Sonoma County


Project Funding


The Sonoma County Agricultural Preservation & Open Space District provided more than half of the $18 million needed for the acquisition of Tolay Lake. These funds are from the ¼ cent sales tax approved by voters in 1990.

The remaining $6.8 million for the purchase included grants from the Department of Fish and Game, Wildlife Conservation Board, State Coastal Conservancy, Land and Water Conservation Fund, National Oceanic and Atmospheric Administration, State Proposition 12 Funds, and private foundations, businesses, and individual donors. 

The 1,665 acre Tolay Creek Ranch property was acquired and managed by Sonoma Land Trust and transferred to Regional Parks in 2017.

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