… The Colorado River and its reservoirs are not sufficient to meet the regional demand for water, so groundwater has been extracted from the aquifers. … In a recent study published in Geophysical Research Letters, a research team used gravity data from NASA’s Gravity Recovery and Climate Experiment and GRACE Follow-On to determine how much water has been withdrawn from Colorado River Basin aquifers since 2002. … The results indicate that the reservoirs and the aquifers have lost a combined 52 cubic kilometers of water since 2002. The reduction of groundwater was 65% of that total, about 34 cubic kilometers. 

Other Colorado River Basin news:

• John Fleck at Inkstain: Blog: Autumn rains delay Colorado River basin-wide reservoir depletion
• Lake Powell Chronicle: Colorado River Indian Tribes grant historic personhood status to namesake river
• KTAR (Phoenix): Opinion: Colorado River crisis — time is running out
• Arizona Department of Water Resources: News release: Interior Secretary Burgum tours Arizona water systems with ADWR, CAP and SRP leadership
• FOX10 (Phoenix): Video: Feb. 14 deadline set for Colorado River water agreement