Manhattan ? Gov. Sam Brownback says Kansas has to make changes to address concerns over the state’s water supply.

Brownback told about 600 water conference attendees Wednesday in Manhattan that the time has come to make changes to extend life of the underground Ogallala Aquifer and to rehabilitate silted reservoirs to preserve the state’s water resource.

Brownback said “We know this aquifer. We know these reservoirs. You can’t say, ‘No, we need to study it more.’ Now is the time.”

The Topeka Capital-Journal reports that Brownback says he intends water preservation to be part of his legacy as governor.

He also says wells that enable irrigation of crops, withdrawal for business use and pumping for the drinking supply were depleting the aquifer at an unsustainable rate and that work begins soon on a $25 million project to dredge the John Redmond Reservoir in Coffey County, which has lost considerable water storage capacity to silt.

State-financed dredging at the reservoir had to be approved by the U.S. Army Corps of Engineers.

Brownback also told participants that the state had formalized the first voluntary water conservation area created under a law adopted in April by the 2015 Legislature. Holders of water rights would be allowed to collaboratively set a target for water consumption. The voluntary approach is a part of the administration’s plan to restrain water that is drawn from the Ogallala Aquifer.

“We’ve just got to use a lot less of it, but still maintain the economic activity and viability of western Kansas,” Brownback said.