KANSAS CITY, Mo. (AP) — Building a 360-mile aqueduct to reroute water from the Missouri River to irrigate crops in western Kansas where underwater stores are being exhausted would cost $18 billion and require an additional $1 billion each year to operate, a new draft report shows.

The U.S. Army Corps of Engineers estimates that building an aqueduct to transport excess water from the river would take 20 years and cost $12.2 billion, plus $5.8 billion in interest. The estimate doesn't include the costs of permits or restoring habitat lost as a result of the project, which could boost the cost "significantly higher," said John Grothaus, chief of the water planning section for the corps' Kansas City district.

The proposed concrete-lined canal and 15 pump stations would start near White Cloud, along the Nebraska border, and end near Utica. A similar 1982 analysis, undertaken at the request of Congress, estimated construction would cost $3.7 billion and interest $4.2 billion.

"Nothing materialized, and it looks like they kicked the can down the road at the very least," Grothaus said.

The Kansas Water Office posted a draft summary, which included the corps' findings, online this month and will present the complete analysis Jan. 29 to an advisory entity called the Kansas Water Authority. A state committee tasked with updating the 1982 analysis asked for the study because water levels are declining in the Ogallala Aquifer, 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.

Kansas Gov. Sam Brownback has said that Ogallala's storage could be nearly 70 percent spent in 50 years if nothing changes.

"This is a lot of money," said Kansas Senate Natural Resources Committee Chairman Larry Powell. He estimated that, with the report showing that water from the aqueduct would cost farmers $450 per-acre foot in today's dollars, it would cost upward of $90,000 to irrigate 100 acres of corn.

At that price, he asked, "is it going to be feasible to raise corn to feed cattle? It might not be."

The project already has received some pushback, with Missouri Gov. Jay Nixon calling it "ill-advised" in a November 2013 letter to Brownback. Nixon spokesman Scott Holste said in an email Wednesday that the governor's position remained the same.

Earl Lewis, assistant director of the Kansas Water Office, said, he didn't know the chances for the project being pursued and acknowledged that concerns had been raised.

"Anytime you talk about a significant amount of water and you are talking about moving water from one place to another, you are going to create some controversy," Lewis said. "Even the study of looking at it, there is controversy being created with it right now."

But he said that in Western states where water-transfer projects have been completed, the benefits are "significant." The aqueduct, he said, "becomes a policy question. What do we want to see happen in the future? And how do we want to see it happen?"