SummaryNumber and estimated capacity of basins with years-long aquifer declines (known as overdraft) or projected future declines. General Information about this IndicatorWhat is it?: Aquifer water is relied upon to provide consistent water supplies. As these aquifer are overdrafted, future water reliability and uses are impacted. Depending on the depth and geological context of aquifers, they may be rechargeable and available to support future reliable water supplies.