Local Supplies Enhance Supply Reliability
Coordinating with 22 member agencies to develop local water resources is a key component of the Water Authority’s mission to provide a safe and reliable water supply. In fact, a growing number of local water sources across the San Diego region are managed by member agencies — and they are critical to ensuring long-term water supply reliability. Local projects reduce demand and reliance on imported supplies and provide local agencies with more control over costs.
Before 1947, the San Diego region relied heavily on local surface water runoff in normal and wet years, and on groundwater pumped from local aquifers during dry years when stream flows shriveled. As the economy and population grew exponentially, local resources became insufficient to meet the region’s water supply needs and the region increasingly turned to imported water supplies.
Local Sources
In recent years, local water agencies have increasingly invested in local supplies such as brackish groundwater, recycled water and water purification. The Water Authority has also invested in seawater desalination. Water supplies from these projects is considered drought-resilient since the projects are primarily independent of precipitation. Today, about 30 percent of the water used across the region is from local supplies – and that number is expected to grow as more water purification projects come online.
Groundwater
Groundwater is a small but growing and important resource, especially in places like the South Bay where the aquifers are relatively large.
Seawater Desalination
The Claude “Bud” Lewis Carlsbad Desalination Plant produces up to 54 million gallons per day of locally controlled water for San Diego County, helping to minimize the region’s vulnerability to statewide drought conditions.
Surface Water
Runoff from local rainwater that flows into reservoirs represents a vital but small portion of San Diego County’s water supply needs.
Potable Reuse
Advanced water purification for reuse — also referred to as potable reuse — relies on a multi-barrier treatment process to make recycled water safe to drink.
Water Recycling
Water and wastewater agencies across San Diego County are developing or expanding water recycling projects, because every gallon of recycled water reduces the need to import or develop other supplies.