Groundwater Levels Decline Slightly, Remain Above Allocation Trigger

Groundwater Levels Decline Slightly, Remain Above Allocation Trigger

During March and April 2025, NRD staff measured roughly 500 observation wells throughout the district to determine the average water level change, based on a weighted change from each well. For spring 2025 water level measurements, the NRD has determined that the average groundwater level change shows a decline of 0.39 feet from last spring. The spring 2025 average groundwater level is now 3.21 feet above the “Allocation Trigger.” Thus, there will be no allocation restrictions enacted at this time. 

Observation wells are measured in the spring of each year, allowing the water table to rebound from the previous irrigation season. The wells that are measured are uniformly distributed throughout the district to provide an accurate profile of the average groundwater level change. Each well measured is assigned an area of the district based on distances from other measured wells. This method gives the average groundwater level change a weighted average. 

In spring 2024, the NRD reported an average groundwater decline of 3.08 feet. Spring 2023 showed a decline of 2.21 feet on average. Fluctuations from year to year are common throughout the district, however we have seen several dry years in the district with sustained declines. The Upper Big Blue NRD sits above the High Plains Aquifer, which stretches from South Dakota to Texas. This portion of the aquifer is dynamic and factors like rainfall and pumping affect how the aquifer reacts. 

In addition to the average change, the NRD also provides a more detailed look at water levels across the district. Water levels declined most in Adams and Seward Counties, each with a drop of about 1 foot. On the other end of the spectrum, Butler County saw a groundwater level increase of 1.19 feet. Fillmore and Polk Counties also saw marginal increases.

Water use records enable informed management decisions and practices

Producers in the district continue to do an exceptional job of managing the use of district water resources and cooperating with the NRD on conservation activities and monitoring. Along with NRD staff measuring observation wells, all groundwater users are required to annually report their water use. This is how the NRD maintains records on historic groundwater usage. Groundwater use records are very important to the district for making informed management decisions. The 2024 district average groundwater usage was 5.65 inches/acre. The district average groundwater usage is 6.1 inches/year since 2007. 

The district’s goal is to hold the average groundwater level at or above the 1978 level. In 2005, the district average groundwater level reached the “Reporting Trigger,” initiating mandatory reporting of annual groundwater use to the district and certification of irrigated acres. If the district average water level falls below the 1978 level (“Allocation Trigger”), groundwater allocation will begin. 

 

Click maps/graphs to enlarge

groundwater levels 2025level trendswithdrawal map