Sweetwater Authority Groundwater Desalination Facility

Groundwater Recovery

Groundwater grows as a local resource

Groundwater is a small but growing and important resource, especially in places like the South Bay where the aquifers are relatively large. Overall, it accounts for about 5 percent of the region’s water supply portfolio.

Local groundwater supplies are limited by several factors, including little recharge due to sparse rainfall. Although groundwater supplies are much less plentiful here than elsewhere in California, pockets of undeveloped brackish – or saline – groundwater could help meet more of the region’s future water demand.

While the Water Authority does not hold groundwater rights, it does provide financial and technical assistance to member agencies that are evaluating, planning and implementing groundwater recovery projects. In fact, several local water agencies have identified potential projects that could nearly double groundwater production in coming years by treating brackish groundwater to potable standards.

linkSan Dieguito Groundwater Study linkSanta Margarita River Conjunctive Use Project

Groundwater Management

Setting Sustainability Priorities

The three Sustainable Groundwater Management Act mandated basins in San Diego County are Upper San Luis Rey Valley (medium priority), San Pasqual Valley (medium priority), and Borrego Valley (high priority).

Sustainable Groundwater Management Act (SGMA)

In 2014, the California Legislature passed the Sustainable Groundwater Management Act (SGMA), making California the last state in the West to regulate groundwater. The process started with the Department of Water Resources classifying California’s 515 groundwater basins into four categories of priority:

  • High
  • Medium
  • Low
  • Very Low

SGMA requires medium- and high-priority basins to develop groundwater sustainability agencies, develop groundwater sustainability plans and manage groundwater for long-term sustainability. 

Basins By Sustainability Priority

map of san diego ground waer basin prioirity