Water-level and recoverable water in storage changes, High Plains Aquifer, predevelopment to 2019 and 2017 to 2019

The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial groundwater irrigation (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2019 and from 2017 to 2019.

Water-level changes from predevelopment to 2019, by well, ranged from a rise of 86 feet to a decline of 265 feet; the range for 99 percent of the wells was from a rise of 42 feet to a decline of 203 feet. Water-level changes from 2017 to 2019, by well, ranged from a rise of 34 feet to a decline of 27 feet; the range for 99 percent of the wells was from a rise of 11 feet to a decline of 11 feet. The area-weighted, average water-level changes in the aquifer were an overall decline of 16.5 feet from predevelopment to 2019 and a rise of 0.1 foot from 2017 to 2019. Recoverable water in storage in the aquifer in 2019 was about 2.91 billion acre-feet, which was a decline of about 286.4 million acre-feet since predevelopment and a rise of 1.6 million acre-feet from 2017 to 2019.