Nebraska groundwater levels continued to rise in the areas most affected by the 2012 drought, according to a new report from the University of Nebraska–Lincoln’s Conservation and Survey Division. Still, some portions of the state recorded levels below those of the pre-drought years.
The annual statewide report, part of a nation-leading groundwater-monitoring program, examines short-term groundwater rises and declines measured in 5,365 regional wells from spring 2017 to spring 2018. It also looks at long-term trends since monitoring began in the 1930s.
“The one-year change maps really aren’t the ones that are the most important,” said Aaron Young, survey geologist and lead author of the report. “It’s the long-term trends that illustrate the lasting effects of both our conservation measures and our water use.”
The Central Platte Natural Resources District recently hosted two meetings in Amherst and Kearney to address groundwater decline concerns in Sub-Area 9 of the NRD’s Groundwater Management Program in Buffalo and Dawson counties.
According to the CPNRD, groundwater levels in northern Dawson and Buffalo counties are down on average 12.39 feet since the 1982 baseline year. Groundwater levels have continually declined in the area since 2001. Central Platte NRD general manager, Lyndon Vogt said that the decline needs to be stabilized.
“Our preference would be for you to pump less water,” Vogt said. “It feels great to be here in front of you saying that the NRD wants to help you in whatever way we can whether it’s through funding, educational opportunities, providing speakers, or technical advice; instead of saying we have to implement regulations right away.”
Although Vogt said the Central Platte NRD would prefer landowners reach the goal to stabilize the groundwater decline in the area on their own, if groundwater levels continue to drop over the next few years then regulations would need to be implemented.
The statewide groundwater report said the long-term trends show both rises and declines in groundwater levels when compared to pre-development records.
According to the report, the greatest declines of about 122 feet were recorded in western Nebraska, particularly in areas with high irrigation-well densities in aquifers that have little or no connection with surface water and where annual precipitation is limited. The largest rises of up to 120 feet were recorded in counties in south-central, central and western Nebraska, where extensive canals and surface-water irrigation systems seep into the aquifer.
In addition to human-driven changes that alter the water levels, changes in precipitation have an effect, the report said.
“Nebraska has an excellent system in place to monitor and react to groundwater-level trends and prevent problems,” Young said.
He said it is that system that helped portions of eastern and central Nebraska, which once had rapidly declining water levels, stabilize and in some cases begin to recover.
In-depth maps in the report give visual representations of all of these changes over time, providing the information in one-year, five-year, 10-year and since-pre-irrigation (about 1950) increments. The maps are based on information collected by the Conservation and Survey Division, U.S. Geological Survey, U.S. Bureau of Reclamation, Nebraska Natural Resources Districts, and Central Nebraska Public Power and Irrigation District.