"An analysis of federal data found the Ogallala aquifer shrank twice as fast over the past six years compared with the previous 60, The Denver Post reports.
The drawdown has become so severe that streams are drying at a rate of 6 miles per year and some highly resilient fish are disappearing. In rural areas, farmers and ranchers worry they will no longer have enough water for their livestock and crops as the aquifer is depleted.
The aquifer lost 10.7 million acre-feet of storage between 2013 and 2015, the U.S. Geological Survey said in a June report."
https://en.wikipedia.org/wiki/Ogallala_Aquifer
Saturated thickness of the Ogallala Aquifer in 1997 after several decades of intensive withdrawals. The breadth and depth of the aquifer generally decrease from north to south.
Regions where the water level has declined in the period 1980-1995 are shown in yellow and red; regions where it has increased are shown in shades of blue. Data from the USGS
Groundwater withdrawal rates (fresh water, all sources) by county in 2000. Source: National Atlas
The Ogallala Aquifer is a shallow water table
The Ogallala hasn't been in the news much lately, other than occasional mentions when somebody is running an oil pipeline across it. The USGS summary is at https://www.usgs.gov/news/usgs-high-plains-aquifer-groundwater-levels-continue-decline
The southern Kansas through Texas part - where the levels are seriously low - is still in severe drought, so the reduced draining of 2013-2015 may not be continuing.
There is nothing wrong with this world that having less people on it, wouldn't take care of.