Five major systems

US Aquifers, Ranked by Risk

The five aquifer systems in this analysis serve roughly 24.5 million people and underpin about $110B of agriculture. They are not equally at risk, and the ranking by probability is not the ranking by economic exposure.

AquiferP(crisis) 2100Expected crisisDeclinePeopleAgriculture
EdwardsTexas53.2%20580.05 ft/yr2.5M$5B
FloridanFL, GA, SC, AL36.3%20660.02 ft/yr10M$8B
Central ValleyCalifornia17.3%20683.07 ft/yr6.5M$50B
Mississippi EmbaymentAR, MS, LA, MO, TN0.226%20740.99 ft/yr3M$12B
OgallalaNE, KS, TX, OK, CO, NM, WY, SD0.0%0.96 ft/yr2.5M$35B

Crisis probabilities are modelled output from 100,000 Monte Carlo paths per aquifer; decline rates are measured from USGS monitoring wells. A low system-wide probability can still contain individual wells already past threshold — see each aquifer page for well-level detail.