Kansas Geological Survey presents aquifer loss maps and tools to help manage groundwater use

The Kansas Geological Survey told the Kansas House Committee on Agriculture and Natural Resources that parts of the High Plains aquifer have lost more than 60% of their original thickness and described new measurement and modeling tools intended to help irrigators, agencies and local governments manage groundwater.

KGS Director and Kansas State Geologist Jay Kalbus said the survey’s map of percentage change in aquifer thickness is “a window into one possible future based on empirical data” and that the product is delivered promptly to farmers, ranchers and state agencies to inform local decisions. He said the map is based on repeated, hand‑measured water‑level data and quality‑assured processing.

Kalbus described several measurement and data programs the survey operates or supports: annual hand measurements of roughly 1,400 wells; a network of continuously monitored wells that provide near‑real‑time hydrographs; an app that allows irrigators to report pumpage electronically so the Division of Water Resources receives near‑instant water‑use data; and airborne electromagnetic surveys to map aquifer thickness and lithology in three dimensions.

The survey said its crews measured 97,500 feet of wells by hand in the most recent campaign and drove about 11,600 road miles in western Kansas to complete the winter measurements. Kalbus noted the seasonal timing is deliberate: measurements are taken in winter to avoid irrigation effects.

Kalbus also outlined how the survey combines water‑level and water‑use data to estimate a local “stable” pumping level for a parcel or region. Using an example graph that plots annual water use against annual water‑level change, he said the survey can identify a pumping reduction that would halt further water‑table decline at that location; in the example shown, stability would be achieved with about a 17.5% reduction in pumping for that specific parcel and geologic setting.

On water quality, Kalbus said KGS has stood up a statewide groundwater quality program in partnership with the Kansas Water Office, Kansas Department of Health and Environment (KDHE), and Kansas Farm Bureau. He said the program will use an analytical suite that includes dozens of chemical tracers and will revisit roughly 300 historical sites as a baseline; building the analytical capability will take about a year. He said the program will be paired with additional, higher‑resolution sampling where hotspots are identified.

Kalbus described the survey’s airborne electromagnetic (AEM) reconnaissance flown with a helicopter and geophysical array, funded in part by the state water plan fund and local groundwater management districts (GMDs). He said the first AEM survey covered GMD 4 and that KGS plans additional surveys over GMD 1 (planned for 2025) and GMD 3 (2026–2027). He described the AEM cross‑sections as providing high‑granularity views of aquifer thickness and resistivity that help interpret lithology and how quickly water moves through the subsurface.

Kalbus emphasized the time lag between surface actions and aquifer response, noting that in many places a surface reduction in pumping does not immediately produce an uptick in the aquifer because recharge and lateral flow occur over long time scales. He urged that the combined datasets — water levels, water use, AEM and continuously monitored wells — provide practical tools for local managers and irrigators to evaluate tradeoffs and plan.

Representative Roth and others asked questions about map symbology and whether local wells — including wells near Dodge City with elevated nitrate levels — are included in KGS datasets. Kalbus said the survey aggregates clusters of closely spaced wells in some map symbologies and that its teams perform QA/QC and repeat measurements when results look anomalous.

Nut graf: The KGS presentation combined long‑term aquifer monitoring with newer remote sensing and digital reporting tools; staff said those integrated data products are designed to give irrigators and local managers actionable, parcel‑level information about how pumping reductions would change local water‑table trajectories and to identify water‑quality hotspots that require follow‑up sampling.

KGS provided additional context on repositories and data access: the survey houses large archives of well cuttings and cores used for subsurface interpretation and said it facilitates about 672,000 industry well‑log and file downloads annually. Kalbus said the survey’s data and its GIS infrastructure support agencies ranging from the Kansas Water Office to county tax appraisal districts and 9‑1‑1 systems.

Ending: Kalbus closed by urging use of integrated data to inform long‑term policy decisions. Committee members followed with questions about mapping symbology, nitrate plumes and the feasibility of local pump‑management plans; Kalbus said the survey will continue work with GMDs, agencies and landowners to refine tools and support site‑specific follow‑up sampling where needed.