LAWRENCE, Kan. (AP) - Water supply issues and depletion of the Ogallala aquifer aren't just western Kansas problems, a former Kansas agriculture secretary told a group of Lawrence environmentalists.

Josh Svaty, a former three-term state representative who was named secretary of agriculture in 2009 by then-Gov. Mark Parkinson, is now a vice president at the Salina-based Land Institute, an agricultural and environmental research center.

He told members of the EcoTeam - part of an interfaith network of environmental groups known as Lawrence Ecology Teams United for Sustainability, or LET-US - that water levels in parts of western Kansas have declined rapidly because of large-scale irrigation that began there in the 1970s, the Lawrence Journal-World (http://bit.ly/1cH1WQE) reported.

"Think about the economy that transfers to eastern Kansas, coming out of western Kansas," Svaty said. "The beef industry obviously is very important to Kansas, but a huge amount of that industry is based, or has large footprints, in eastern Kansas, especially around Kansas City and Johnson County."

The Ogallala aquifer is a vast network of underground water locked in the porous limestone deep below the surface in the High Plains region of the U.S., stretching from Wyoming and South Dakota to the Texas and Oklahoma panhandle regions. It is the primary source of fresh water for the entire area.

Roughly 90 percent of the water is used for irrigation to grown corn, soybeans and milo, which are used as feed grains for the livestock industry.

Central-west Kansas, around Scott City and Tribune, is already considered a "dead zone" where irrigation has all but ceased, Svaty said. While there is more water available for feedlots and processing plants in Gaden City, Liberal and Dodge City in the southwest, he said, farmers are pumping vastly larger amounts - which consume more energy because the water is deeper below the surface.

Few people in western Kansas even speak about stopping the depletion, he said, but instead talk about "managed decline."

"Some people out there complain that they are the only mining interest in the state that is not allowed to mine out all of their resource," he said.