From Scarcity to Surplus: A New Approach to Water Security

In California’s San Diego, United States, long-term water planning has created such strong reserves that authorities are now selling surplus supplies to support regions facing shortages.

“This reflects a shift from drought-driven conservation to a position of relative abundance,” officials from the San Diego County Water Authority said, highlighting the success of decades of investment.

After years of vulnerability to drought, the region invested heavily in desalination, recycling and storage infrastructure, including the largest desalination plant in North America. Today, those efforts are producing around 56,000 acre-feet of water annually, enough to support hundreds of thousands of people, while reduced demand has created additional surplus. New agreements with neighbouring states will enable water-sharing through exchange systems rather than physical transport, demonstrating how long-term planning, technology, and conservation can turn water scarcity into resilience and even regional support.