Drinking Water

Santa Margarita Water District provides more than 6 billion gallons of high-quality drinking water a year to more 165,000 residents. The District places the utmost importance on its role in delivering safe drinking water. 

Your Drinking Water Supply

All of the drinking is imported from Northern California and the Colorado River. 

Regardless of source, all of the drinking water meets or surpasses all federal and state regulations, and is tested by both the wholesaler, Metropolitan Water District of Southern California, and the Santa Margarita Water District at it's very own laboratory to ensure that all drinking water meets or surpasses all federal and state regulations. Every year, the District produces a Water Quality Report to share the results of the extensive water quality analysis performed on the water being provided to homes and businesses throughout the service area.   

Santa Margarita Water District is investing in projects and infrastructure to reduce its dependence on imported water, and securing water supplies that are local, reliable and sustainable. 

What is the Colorado River Aqueduct?

The Colorado River Aqueduct is a 242 mile long aqueduct built in the 1930's by Metropolitan Water District of Southern California. It conveys water from the Colorado River at Lake Havasu across the desert to Southern California. If water is available in the region, it can pump more than 400 billion gallons of water to Southern California. 

What is the State Water Project?

The State Water Project is a series of aqueducts that stretches more than 700 miles. It conveys water from Northern California to Central and Southern California. If water is available in the region, it typically pumps 800 millions of water. California Water Fix is a major initiative which is underway to increase the reliability of this important resource.

How does SMWD get its drinking water?

Santa Margarita Water District is a member of the Municipal Water District of Orange County (MWDOC), which wholesales water within Orange County and is a member of the Metropolitan Water District of Southern California. 

The Santa Margarita Water District delivers drinking water provided from two treatment plants: 

  • Robert B. Diemer Treatment Plant 
    • Located in Yorba Linda and operated by Metropolitan Water District of Southern California 
    • Typically fed with a blend of State Water Project and Colorado River Aqueduct water depending on regional conditions 
  • Baker Water Treatment Plant 
    • Located in Lake Forest and operated by Irvine Ranch Water District (IRWD) 
    • Fed by the Colorado River Aqueduct 
      • Can be operated with Irvine Lake as a water source in case of an emergency

The treated drinking water is sent through large transmission pipelines and then into the Santa Margarita Water District distribution system where it is delivered to your home.

Domestic Water, By the Numbers

The District's Drinking Water System: 

  • 56,000 drinking water connections
  • Average annual demand of 6.5 billion gallons 
  • 600+ miles of distribution pipeline
  • 30 reservoirs
  • 2 emergency storage reservoirs
  • 400 million gallons of storage capacity
  • 21 pump stations