About Our Water

Water Sources

Currently, the City of Paso Robles relies on a combination of surface water supplies and groundwater to provide potable water to our water customers. In a normal year, over 50% of the City’s water is supplied by seven relatively-shallow wells located along the Salinas River corridor. Surface water from the Nacimiento Water Project and groundwater from the Paso Robles Groundwater Basin is used to supplement the Salinas River wells.

Nacimiento Lake Water

The City is a participant in the Lake Nacimiento Water Project (PDF) and has secured a 6,488 acre-feet per year water entitlement. The water connection fees and water rates provided the funds needed to construct, operate and maintain the City's surface-water treatment plant. In addition to the water treatment plant, connection fees and water rates provide for the ongoing operations and maintenance of all City water infrastructure.

The use of Lake Nacimiento water allows the City to reduce its dependency on the Paso Robles Groundwater Basin, and provide a reliable long-term water supply for the City. 

Urban Water Management Plan

The City's  2020 Urban Water Management Plan documents the City’s sources of water supply, defines water demands, presents a water shortage contingency plan, describes implementation of water demand management measures and guides conservation efforts.

Water Quality

Over the years, the City has dedicated itself to producing drinking water that meets or exceeds all state and federal drinking water standards. You can download the entire Water Quality Report 2022 (PDF) or pick one up at Water Services in City Hall at:

1000 Spring Street
Paso Robles, CA 93446


Water-quality samples are taken throughout the City are tested regularly. The samples are sent to an independent laboratory for analysis, insuring compliance with all state and federal regulations. On a weekly basis tests are conducted for coliform bacteria as an early indicator for pathogenic contamination.

The City’s water is regulated by numerous agencies under many laws. Some of the agencies that monitor are: