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COVID-19 Updates: Get the latest public information related to coronavirus disease 2019 (COVID-19) at

Public Works will re-open our front counter to the public on July 6 and start providing some modified services.  Our hours will be 8 – 5, with closure from 12 – 1:30 for sanitation. Masks are mandatory in our building, and we ask that you adhere to physical distancing protocol. We will have limited services at our front counter and will not be accepting drop in meetings.  Please contact 805-781-5252 to make an appointment with staff.  Bus passes can be purchased at the Kiosk on the corner of Osos and Palm or by phone via Follow us on Twitter @SLOCountyPWD for the latest updates.

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Public Works

County of San Luis Obispo

Watershed Sanitary Surveys

Watershed Sanitary Surveys are required byt the State Water Resources Control Board Division of Drinking Water for all surface water influenced water supplies. The surveys must be updated every 5 years, with 4 main goals:

  1. Identify existing sources of water contamination.
  2. Identify potential future sources of water contamination.
  3. Provide a baseline of water quality and watershed condition for identification of trends in future survey updates.
  4. Recommend watershed management practices that will protect raw water quality of this valuable local water source and minimize the need to import water.

Click on each location below to view their Watershed Sanitary Survey:

Lopez Lake and Terminal


Santa Margarita Area


Salinas Reservoir


Nacimiento Lake


Nacimiento Water Project


Whale Rock Reservoir