The Chalk Doesn't Lie, and She Reads It Every January

Dena Windholz does not exist. The aquifer she measures does. Every number in this conversation is real.

Every January, while most of Kansas stays indoors, small crews from the Kansas Geological Survey and the Division of Water Resources fan out across 48 western counties to measure the depth of groundwater in roughly 1,400 wells.¹ The method hasn't changed in four decades: a steel tape, a lead weight, blue chalk rubbed on the last few feet, the whole thing lowered through a slit in the well casing sometimes less than an inch wide.² When the tape comes back up, the wet line tells you where the water is.

In southwestern Kansas, that water can be more than 485 feet down.³

Dena Windholz has been part of this ritual for seventeen years. She's a senior hydrologist at Groundwater Management District 4 in northwest Kansas, where she interprets measurement data, presents it to her board and to farmers, and calculates the numbers that tell communities how much pumping they'd need to cut to keep what's left. She grew up on a Thomas County farm that irrigated from the same Ogallala aquifer she now monitors. Parts of southwestern Thomas County have a projected aquifer lifespan of less than twenty-five years.⁴

We spoke in late May, over the phone. She was eating lunch at her desk, a detail she volunteered and then seemed to regret.

You grew up on a farm that pumped from this aquifer. Was there a moment when the water became a number for you?

Dena: It was always both, honestly. My dad checked the well every spring. Not with a steel tape. He'd listen to the pump and he knew what it sounded like when the draw was getting harder. That's not a number. That's a sound. Then I went to K-State, took hydrology, and suddenly there's a column in a spreadsheet that corresponds to the sound my dad was hearing. I don't think the water went away. I think the number got laid on top of it.

The measurement program runs every January. What does that work actually feel like?

Dena: Cold. [laughs] The KGS people describe it as "technically rigorous, difficult work," which is a generous way to say you're stomping through corn stubble in January trying to find wells that haven't been visited since last year.⁵ You thread a tape through a hole that's maybe three-quarters of an inch, and the tape has to make several sharp bends past the pump equipment before it drops free.⁶ In our part of the state you need a tape that reaches four hundred feet. Sometimes more. You pull it back up, read the chalk line, do the math, tag the well with a paper label. Your initials, the date, the depth.⁷ Then you walk to the next one.

I won't call it romantic. It's January in Thomas County. But there's an honesty to it I haven't found anywhere else in this job. The chalk doesn't lie. The wet line is where the wet line is.

And then the numbers leave your hands.

Dena: Right. The data goes to the GMD board, to DWR, to the KGS for their annual reports. But it also goes to banks. Banks use our measurements to appraise land value and make lending decisions.⁸ Farmers use it to monitor their own wells. The state uses it to decide whether to approve new water rights applications. Everyone reads the same column of numbers and sees a completely different thing.

What do you see?

Dena: I see a thirty-year average decline of about six-tenths of a foot per year across the High Plains aquifer in Kansas.⁹ I see GMD3, down in southwest Kansas, averaging more than a foot and a half. I see counties where the aquifer is effectively exhausted for large-scale irrigation already. Greeley. Wichita. Scott.¹⁰ I see the withdrawal-to-recharge ratio: we're pulling about 2.3 million acre-feet a year out of the Ogallala in Kansas, and natural recharge puts back maybe 750,000.¹¹

The 2025 data showed the first overall increase since 2019. How did that land?

Dena: [pause] We got good rain in 2025. That reduces irrigation demand, which reduces pumping, which lets levels recover a little. The overall number was plus 0.2 feet.¹² But the western districts still declined. My district still declined. Just less than usual. And the thirty-year trend is negative 0.57 feet per year. A wet year bought us a fraction of a foot against a half-century of decline. I know how a number like "first increase since 2019" travels, though. It travels well. I can't say the rest of that sentence in a meeting without it sounding political.

You mentioned a line you can't cross in meetings. Where is it?

Dena: I'm a hydrologist, not a regulator. GMDs don't administer water rights. That's the state, through the Chief Engineer.¹³ We provide information. We recommend. We can help develop conservation plans. But I don't tell anyone what to do with their water. I give them the Q-stable number, which is the pumping level that would stabilize water levels in a given area. In some parts of southwest Kansas, that number means reducing pumping by 17.5 percent.¹⁴ I can put that on a slide. I can answer questions about it. I cannot make it happen.

Does that bother you?

Dena: Some days.

The Sheridan-6 LEMA is in your district. First legally binding conservation plan on the Ogallala. Decline rates dropped from two feet a year to half a foot.¹⁵ People point to that as proof it can work.

Dena: It does work. Ninety-nine square miles, farmers who knew each other, four years of community meetings before anything was binding.¹⁶ But when we scaled it to the whole district in 2018, the KGS assessment found it "has yet to have a significant effect on water use or water-level declines."¹⁷ Same legal structure. Same district. Different outcome. I think about that more than I probably should.

Why the difference?

Dena: Because Sheridan-6 worked on trust. Those were neighbors deciding together. A district-wide LEMA is governance. Different animal entirely. And there's a legal question nobody wants to litigate: the LEMA reductions apply equally to all water rights, but Kansas is a prior appropriation state. First in time, first in right.¹⁸ Applying equal cuts regardless of priority is arguably inconsistent with the doctrine. Nobody's challenged it in court yet. I sometimes wonder if the reason nobody challenges it is that nobody wants the answer.

Stanford's Water in the West program found that even if every water right holder in Kansas is in full legal compliance, depletion will continue to worsen. The aquifer is over-appropriated.¹⁹ Everyone following the rules and the resource still disappearing.

Dena: The system was designed to allocate a resource. It was designed before anyone understood the recharge math. It did what it was built to do. It's just that what it was built to do and what we need it to do aren't the same thing anymore.

You drive past your family's farm. Your father still irrigates?

Dena: Some fields. He's converted a lot to dryland. He reads the annual reports. He doesn't ask me what to do.

Does anyone?

Dena: Farmers ask me how much water they have left. I can give them a range, depending on their location, their saturated thickness, their pumping rate. I can tell them what the trend line looks like. Some of them, the ones in the parts of Thomas County where we're looking at less than twenty-five years, they hear that and they nod. They already knew. They heard it in the pump before I ever ran the numbers.

What do you do with a nod like that?

Dena: I write it down. I go to the next well.

Footnotes

1. Kansas Geological Survey, "KGS and state agency to measure groundwater levels in western Kansas," December 17, 2025. https://news.ku.edu/news/article/kansas-geological-survey-state-agency-to-measure-groundwater-levels-in-western-kansas-in-2026 ↩

2. KGS, "Measuring Water Levels in Kansas." https://kgs.ku.edu/measuring-water-levels-kansas ↩

3. Kansas Reflector, "Ogallala Aquifer drops by more than a foot in parts of western Kansas," January 28, 2025. https://kansasreflector.com/2025/01/28/ogallala-aquifer-drops-by-more-than-a-foot-in-parts-of-western-kansas/ ↩

4. KGS Public Information Circular 18. https://www.kgs.ku.edu/Publications/pic18/ ↩

5. Kansas Reflector, January 28, 2025. ↩

6. KGS, "Measuring Water Levels in Kansas"; KGS Open-File Report 97-33. https://www.kgs.ku.edu/Magellan/WaterLevels/CD/Reports/OFR9733/rep02.htm ↩

7. KGS Open-File Report 96-39. https://www.kgs.ku.edu/Hydro/Levels/OFR96_39/index.html ↩

8. KGS Geophysics and Exploration Services. https://www.kgs.ku.edu/Geophysics/well.html ↩

9. KGS 2026 groundwater level release. https://kgs.ku.edu/news/article/groundwater-levels-in-the-kansas-high-plains-aquifer-see-first-overall-increase-since-2019 ↩

10. KGS Public Information Circular 18. ↩

11. KGS High Plains Aquifer overview. https://kgs.ku.edu/high-plains-aquifer ↩

12. KGS 2026 groundwater level release. ↩

13. David Barfield testimony, Kansas House Water Committee, January 2023. https://www.kslegislature.gov/li_2024/b2023_24/committees/ctte_h_water_1/documents/testimony/20230112_01.pdf ↩

14. Kansas Reflector, January 28, 2025; KWCH, "Ogallala Aquifer decline worsens in Kansas," January 29, 2025. https://www.kwch.com/2025/01/29/ogallala-aquifer-decline-worsens-kansas-hitting-southwest-hardest/ ↩

15. KGS High Plains Aquifer report, KU News, December 2023. https://news.ku.edu/news/article/2023/12/06/kansas-geological-survey-report-assesses-health-high-plains-aquifer ↩

16. Kansas Runs on Water. https://kansasrunsonwater.org/success-story/farmers/ ↩

17. KGS High Plains Aquifer report, KU News, December 2023. ↩

18. GMD4 Kansas Water Law Summary. http://www.gmd4.org/KSWaterLawSummary.html; Foulston Siefkin LLP analysis. https://www.foulston.com/resources/proposed-kansas-house-bill-would-consolidate-water-agencies-and-address-depletion ↩

19. Stanford Water in the West, "Lessons from Kansas." https://waterinthewest.stanford.edu/news-events/news-press-releases/lessons-kansas-more-sustainable-groundwater-management-approach ↩