Topeka ? Attorneys for Kansas and Nebraska will argue before the U.S. Supreme Court next week in a longstanding dispute between the states over using water from the Republican River.

Kansas farmers and officials accuse Nebraska of using more than its share of water from the Republican River in 2005 and 2006, but Nebraska has argued any overuse was the result of drought conditions.

A special master appointed by the Supreme Court to oversee the dispute concluded last year that Nebraska owes Kansas a combined $5.5 million for overusing water during those two years, the Topeka Capital-Journal reported.

Special master William Kayatta Jr. rejected Kansas’ demand for $80 million and a request for an order that would permanently shut off irrigation pumps that service about 300,000 acres in Nebraska.

A 1943 compact has long divided the use of the Republican River water among Colorado, Kansas and Nebraska. Under that agreement, Colorado is entitled to 11 percent of the water, Kansas gets 40 percent and Nebraska gets 49 percent.

Despite Nebraska’s argument that drought forced its hand on overusing the water, Kayatta found that the state failed to take proper steps to conserve use of the waters in recommending his penalties to the high court.

Kansas Attorney General Derek Schmidt’s office said the Supreme Court also will be asked on Tuesday to decide whether provisions of the water-use compact should be changed to account for groundwater from the Platte River basin that feeds into the Republican River basin, which Kayatta also recommended.

Kansas Solicitor General Stephen R. McAllister will present the state’s case before the court, Schmidt’s office said.