Digging deeper wells

Groundwater makes up 40% of California’s water supply, and in dry years that rises to 60%. The overwhelming majority of that groundwater — 79%, on average — goes to agriculture.

During the last drought, thousands of wells, mostly in poor farm communities in the Central Valley, went dry. But thousands of new wells are constructed every year, and existing wells are modified to increase pumping capacity. Depletion of groundwater is a growing concern, particularly in the central part of the state, as growers and others dig deeper and deeper wells.

A 2014 state groundwater law has had little to any effect on reducing depletion so far. Most local water suppliers are still working on their plans for how to regulate pumping. Six draft plans, mostly in the San Joaquin Valley, have been deemed insufficient and sent back by state water officials. The goal of the law is to make groundwater pumping sustainable within 20 years — a long time off when almost-back-to-back droughts are becoming the norm.