California gets about 30 percent of its total water supply from groundwater.  Overdraft threatens California’s continued access to this scarce resource, and the state does not presently have an effective way of allocating and managing groundwater.  In this paper, the fourth in the Emmett Center's Pritzker Brief Series, Rhead Enion evaluates the adjudicatory process used to resolve groundwater use disputes in California, and recommends a number of reforms that could be implemented by the legislature or courts to address problems in the adjudication and post-adjudication management of groundwater resources.

California’s water supply system depends heavily on groundwater use, but its overuse threatens the reliability of the state’s future water availability. In our inaugural Pritzker Brief, Rhead Enion describes the importance of groundwater and the advantages of realigning California's water rights system to better manage groundwater. According to Under Water, the state should establish enforceable standards and goals for monitoring, data reporting and management of groundwater basins, to be implemented by regional and local entities. Under Water recommends, among other things: comprehensive groundwater monitoring, including groundwater use metering and groundwater quality screenings; the availability at a statewide level of monitoring data from regional and local agencies; and the implementation of statewide rules for regional regulation of groundwater, with mandatory management goals.