Researchers at the University of California recently highlighted a flaw in state law that may prohibit diverting streamflow to recharge groundwater. The problem is that groundwater recharge by itself is not considered a “beneficial use” under state law, and meeting that definition is a requirement to obtain a permit to divert water. Officials at the State Water Resources Control Board, which oversees water rights, say the reality is not so clear-cut. In fact, existing rules allow most groundwater recharge projects to obtain a water right.

State law does not currently allow surface water to be used for groundwater recharge if the goal is managing pollution, reversing subsidence or controlling salinity. That could be a problem as local agencies begin trying to make their groundwater use more sustainable. Groundwater depletion is a big problem in parts of California. But it is not the only groundwater problem. The state also has many areas of polluted groundwater, and some places where groundwater overdraft has caused the land to subside, damaging roads, canals and other infrastructure. Near the coast, heavy groundwater pumping has caused contamination by pulling seawater underground from the ocean.