However, the slow recovery of groundwater to a dynamic equilibrium state means withdrawal can easily surpass replenishment and lead to groundwater depletion. Over-drafting, especially in the regions that are becoming heavily dependent on groundwater, weakens its buffering effect, potentially making agriculture even more fragile to longer drought duration. Groundwater intensive use also can lead to major environmental externalities, from saline intrusion to land subsidence (OECD, 2015a).