LAWRENCE, Kan. -- In a dark, dank room on the University of Kansas-West Campus, one can find some of the best kept, hardest won and most thoroughly analyzed mud in the state of Kansas.

The room houses row after row of meter-long tubes, which resemble fluorescent light tubes of office buildings but are made of translucent, super-hard plastic. And the stuff inside has known only the dark of underground, until now.

Each tube holds a  piece of a sample from the sediment below Harvey County in central Kansas. And each tells a small part of the story of not only geologic history but, scientists hope, the future of the subterranean water system on which the region's economy, farmers and communities depend.

The filling in some tubes is so fine and sandy it looks as if it was taken from a beach. And in some sense, it was. Ancestral rivers to modern river systems in central and western Kansas dumped the sand onto the plains hundreds of thousands or even millions of years ago.

Greg Ludvigson, a sedimentary geologist with the Kansas Geological Survey, points to a tube holding a heavy granular sand -- bright auburn grains mixed in with browns and grays.

"That's almost something you could put in an aquarium," he said.

Fish might like that sort of sediment, but humans do, too, whether they realize it or not. Water moves more easily through grainy sediment, which makes the wells above it more productive.

It takes a geologist to glean much knowledge from mud, sand and rock. Two years into a five-year project, Ludvigson and the survey team already can tell us more than we have ever known about the layers of earth that house aquifers in the state.

This vertically preserved sample of sediment was taken from the Ogallala Aquifer, a massive underground water system stretching from Nebraska to Texas.

The Ogallala is hugely important to the economy and communities of the Midwest. Farmers have long tapped it to irrigate crops, and as water-needy corn has gained popularity among farmers because of its market value, the Ogallala has been under more pressure than ever.

In 2012, aquifer water tables in Kansas dropped by 3 1/2 feet, the second greatest dip on record. With the depletion rate so much higher than what nature can replenish, parts of the aquifer could be tapped out in fewer than 25 years.

But such projections are not as precise as they could be. They are based on a limited understanding of the sediment that houses the underground reservoir.

Ludvigson notes that previous studies have used techniques that smash up the sediment in the process of extracting it. Extrapolating from broken sediment yields results with high margins of error. And that adds vagueness to those very important projections about the Ogallala's ability to produce water.

That's where Ludvigson and the Kansas Geological Survey team come in.

Using two drills, they have been able to pull preserved core samples from central and southwestern Kansas. The drills -- great gear-filled mechanical beasts that vaguely resemble oil rigs -- were imported from Europe because the machinery isn't produced anywhere in the United States. To give an idea of the kind of sophisticated technology needed to get a core sample, one of the drills uses sonic vibrations to help cut through the deepest layers of sediment, which helps keep them intact.

That makes the process difficult and expensive, one of the reasons understanding of the Ogallala and other aquifers in the plains is so incomplete. As Ludvigson puts it, "The point of doing a core sample is to stop guessing and start knowing."

The team began drilling the Harvey sample in 2011 and has come away with 98 meters, with 100 feet of harder rock left to go. They have a multimillion-dollar budget, cobbled together from the survey's budget plus grants from the U.S. Geological Survey, U.S. Bureau of Reclamation, National Science Foundation and Kansas Water Office -- all of that to produce five or six core samples, which Ludvigson said was a pretty good start.

After drilling, he said, the team has "thrown the kitchen sink" at the samples it has collected, running sediment through a battery of tests to analyze everything from isotope records and calcium carbonates to gamma radiation and signs of weathering.

From all those tests, researchers can learn about the layers of earth, where they came from and how old they are, as well as the composition down to the finest detail. All that goes toward providing an incredibly precise description of the sediment's layers that researchers then can compare to samples from other areas.

Already, the team has made important findings about the state's aquifer system. Along with the Harvey sample, the team extracted most of a core from Haskell County in southwestern Kansas, an area most had assumed was part of the Ogallala, though an especially low-flowing section of it.

But samples show that sediment is tens of millions of years older than thought, meaning it probably couldn't have been formed at the same time as the Ogallala. By getting a precise gauge on the core's age, the team concluded the sediment from Haskell might belong to a completely different water system, the White River Group that extends to Nebraska.

These are all fairly big discoveries in the world of geology and hydrology. More modest discoveries found through comparing samples can yield a more detailed picture of the sedimentary makeup of the aquifers under the plains and how it all connects. That information then can be used to make more accurate and specific predictions about the Ogallala and aquifers under the Great Plains.

The promise of the research is that it can be of direct use to water managers and farmers in central and western Kansas. Understanding the Ogallala more deeply can lead to better decisions about pumping from it. Or so Ludvigson and his fellow geologists hope.