With a study in April suggesting the state is in a megadrought, researchers at the Public Policy Institute of California (PPIC) looked into what that means for water management.

Their analysis of precipitation over the last 20 years shows a cumulative deficit “comparable to the extended dry period that included the Dust Bowl,” they explained in a blog post Tuesday. Add in a pattern of warming temperatures under climate change – accelerating snow melt and evaporation while making wet years less frequent – and the situation looks more like a megadrought.

The situation is limiting the state's ability to refill reservoirs and recharge aquifers. The deficit grows bigger over time, leading to groundwater overdraft issues, as is happening in the San Joaquin Valley.

In response, the PPIC research fellows call for a change in drought planning, using the last two decades as a guide rather than the prior two wet centuries.