LYIP Deals With Unusual Situations

Thanks to historic high water levels on both the Yellowstone and the Missouri rivers this spring, the Lower Yellowstone Irrigation Project (LYIP) faced unusual problems this season. Crews not only dealt with collapsed banks and washouts, but they also had to take steps to prevent the flooding of 1500 acres that lie below the river bank in the Nohly area. LYIP closed off three open drains in that area this spring to prevent water from flooding farmland.

“We’ve never had this situation before,” says Jerry Nypen, LYIP manager. “1500 acres in the Nohly area lie below the historically high river levels that prevailed for the last 40 years. There are three open drains in this area; two drain to the Yellowstone and one drains to the Missouri. All three drains were plugged to keep river water from inundating that 1500 acres.”

He adds, “This is a unique situation in river bottom lands where the river banks are higher than the adjacent land.”

Water continued to drain off the farmland but could not return to the river due to the blocked drain. LYIP crews set up pump sites at the plugged off portion of each drain to pump water across the plugged spots so it could drain back to the river. “Irrigated land in this area drains by gravity through the intentionally plugged drains, so it became necessary to pump the water back to the river,” says Nypen.

LYIP did not have this option in other areas of the irrigation district, so many low-lying fields did flood along both rivers. “This opportunity did not exist along other areas along the Yellowstone,” Nypen comments.

The flooding south of Savage completely washed away a lateral, so LYIP will look for alternate ways to irrigate that portion of land. “We had a 1,000 feet of Lateral HH1 that dropped into the river,” Nypen remarks. “The river consumed it, so we will set up an emergency pump station to provide water to the lateral that was severed. The river movement is so dynamic that another permanent service route must be constructed. A pipeline route from another direction is a likely solution.”

Richard and Terry Cayko at the northern edge of LYIP experienced the worst of the flooding. “The Caykos lost a lot of their sugarbeet land to flooding,” Nypen says. “They were the worst hit in the entire Project, and suffered extensive damage.”

Even though the water situation along the length of LYIP is slowly returning to normal, water levels remain high on both the Missouri and the Yellowstone. “Normally by the third week of July the Yellowstone runs at 16,000 cubic feet per second,” Nypen notes. “On July 21 it was still running at 45,000 cubic feet per second, nearly three times normal.”

He concludes, “We expect the Yellowstone to start collapsing by August, but the Missouri will stay high because the Army Corps of Engineers will continue to draw down the excessive flood pool behind Fort Peck dam. They are extracting 40,000 cubic feet of water per second and report that releases will be reduced to 30,000 by Aug. 1; here again about three times the normal flow.”