Environmental flow limits to global groundwater pumping

Already, unsustainable groundwater pumping exceeds recharge from precipitation and rivers4 leading to significant groundwater level drops and losses of groundwater from its storage, especially for intensively irrigated regions. When groundwater levels drop, groundwater discharges to streams decline or possibly reverse in direction or even completely stop, decreasing streamflow with likely devastating effects on aquatic ecosystems.

Here, we link groundwater level declines that result from groundwater pumping, to decreases in streamflow globally and estimate where and when environmentally critical streamflow, required to maintain healthy ecosystems, will no longer be sustained. We estimate that by 2050 environmental flow limits will be reached for approximately 42% - 79% of the watersheds with groundwater pumping worldwide and that this generally occurs before significant groundwater storage losses are experienced.