Kansas Geological Survey presents new Ogallala data, airborne geophysics and statewide water‑quality plan to House Water Committee

Jay Cabas, director of the Kansas Geological Survey, told the House Committee on Water on Feb. 28 that KGS’ newest data show continued declines in the High Plains (Ogallala) aquifer and that new tools will help local areas plan to stabilize water levels.

The committee heard that KGS’ latest statewide water‑level campaign and a first‑in‑Kansas airborne electromagnetic (AEM) survey give much denser subsurface data than previously available and will be used with models to inform localized water‑use targets.

Cabas said the KGS map “shows the percent change in the thickness the water thickness of the High Plains aquifer since the development of large scale irrigated agriculture,” and called the product “arguably the most impactful scientific product in the history of our state.” He described a QSTABLE plot that links average annual water use to average annual water‑level change and said that, for many places, stability is achievable with a modest percentage reduction in water use: “In this case, for this area, it’s a 17.5 percent decrease in the amount of water that we have to use.”

KGS reported rapid field operations and newly available data. The agency said its annual water‑level campaign measures roughly 1,400 wells over the program (KGS crews measured 616 wells in the recent campaign in about six days), with an average measured well depth of about 162 feet and a deepest measured well of 4,458 feet. KGS described field logistics—including a handheld phone app for real‑time entry—and said crews recorded about 97,000 cumulative feet of tape in hand measurements (about 18.5 miles) and drove about 11,629 miles during the campaign.

Jim Butler, groundwater hydrologist at KGS, described the AEM work flown over Groundwater Management District (GMD) 4. The survey collects an electrical‑resistivity sounding roughly every 85 feet and, where the data quality allows, images the subsurface to about 600 feet. Butler said the project produced on the order of 155,000 soundings and that KGS discarded about 11% because of electrical interference, leaving roughly 138,000 usable soundings—vastly more control points than previous well‑based maps (previously on the order of a few hundred points in some areas).

Butler showed a 9.3‑mile line where the resistivity image revealed bedrock troughs and sharper definition of the base of the Ogallala than earlier interpolation from sparse well data. He said the new resolution has already led to policy adjustments by GMD 4’s board and that KGS plans AEM work with GMD 1 this summer and GMD 3 in 2026.

KGS also detailed a new groundwater‑quality program, developed with the Kansas Farm Bureau and the Kansas Department of Health and Environment (KDHE). Cabas said the program is currently sampling and has collected 151 samples to date, expects to ramp to about 175 in the near term, and has an initial anchor‑site target of 300 wells; long‑term expansion to “thousands of wells” would depend on partner engagement and funding. The program focuses on common contaminants cited in KGS and KDHE work—nitrate, uranium, selenium and other constituents—and KGS said it is discussing PFAS testing partnerships with Kansas State University.

KGS emphasized that the Safe Drinking Water Act does not require routine testing of private wells that serve fewer than 25 people, leaving many rural domestic wells outside federal monitoring; KGS framed the quality program as a voluntary effort to fill that information gap.

Cabas and Butler also described critical‑zone research and stream‑bank stabilization studies. KGS said local, site‑scale stabilizations reduce sediment delivery at those sites but that some analyses show increased stream power immediately downstream of such projects; KGS is using geochemical tracers and watershed‑scale studies to determine where reservoir sediment comes from and whether mitigation should focus on banks, croplands or other sources.

Committee members asked technical and planning questions. Representative Vaughn urged continued legislative support for budget items that would allow more AEM work and asked how AEM data would extend planning horizons beyond the 1–3 decades QSTABLE currently supports; Butler replied that AEM reduces structural uncertainty and should improve long‑range numerical model scenarios, though rainfall and other climate variables still require scenario ranges. Representative Buechs asked about subsurface topography and whether apparent local increases on the percent‑change map might reflect bedrock depressions or measurement anomalies; KGS said some anomalies will be field‑checked and that index wells and AEM improve calibration.

Cabas closed by summarizing KGS’ mission to provide durable, interoperable datasets—well records, index‑well telemetry, AEM soundings, WEMIS and other tools—to give local operators and decision makers the data needed to evaluate water‑use reductions and other management options. KGS plans to publish the new datasets and continue phased AEM flights and monitoring expansions.

KGS materials and slides shown to the committee include maps, the QSTABLE analysis, the AEM flight lines over GMD 4, and links to KGS web tools (WWC‑5 well database and WEMIS water‑information system). KGS said preliminary water‑level data for 2025 are available now and that Stafford/other partners’ data are expected within one to two weeks.

Next steps announced to the committee: KGS will proceed with additional AEM flights (GMD 1, then GMD 3), continue the statewide water‑quality sampling rollout, and integrate AEM products into regional groundwater models to inform local QSTABLE targets and conservation planning.