(Image taken from the NASA page mentioned below) Several African basins, such as the Congo, Zambezi and Nile, show significant drying over the past five years. In the United States, the Mississippi and Colorado River basins show water storage increases during that time. Such information is vital for managing water resources in vulnerable parts of Africa and Southeast Asia, since increasing populations and standards of living place demands on water resources that are often unsustainable. The data can be used to make more informed regional water-management decisions. 

The twin Grace satellites monitor tiny month-to-month changes in Earth's gravity field that are primarily caused by the movement of water in Earth's land, ocean, ice and atmosphere reservoirs. Hydrologists are analyzing Grace data to identify possible trends in precipitation changes, groundwater depletion and snow and glacier melt rates, and to understand their underlying causes.Read More: https://www.nasa.gov/vision/earth/lookingatearth/grace-20061212.html