Repair Work Continues All Winter At LYIP

The last of the water may leave the Lower Yellowstone Irrigation Project (LYIP) main canal at the finish of the irrigation season, but this does not signify the end of the work for LYIP employees. In fact, many major repairs and a lot of maintenance work must wait for winter’s arrival as crews need dry ditches to move dirt, repair banks, and replace or improve structures and underground pipes within the system.

LYIP employees spend a lot of time during the winter making these repairs. One such fix occurred in January when crews replaced a structure that had blown out on the main canal last July but could not be properly remedied until winter.

“After operations began last summer, a concrete conduit failed. This conduit allowed water in Antelope Coulee to pass below the main canal,” says Jerry Nypen, former LYIP manager. “The buried concrete conduit had been there for a hundred plus years and it finally reached its yield point. The failure allowed about 90 cubic feet per second (cfs) of water to flow down the coulee. It caused some tense moments as it did some minor flooding on the highway and at Howard Harmon’s residence about a mile south of Crane.”

With the main canal full at the time of the collapse, equipment operators could not permanently fix the problem, so they made temporary repairs and hoped it would last until fall. “We tried to locate the collapse,” Nypen says. “We then put some graded material in and around the leak to slow the flow. Luckily we managed to reduce the flow to 5-6 cfs. The material held up the rest of the summer without any more collapsing or unraveling. It could have been worse had we had to shut down the canal at that time for repairs, as this would have resulted in major crop stress.”

After the canal emptied this fall, crews located the collapse. Bill Hamburg, LYIP assistant manager, and his construction crew went to work.

“We replaced the failed conduit with a new 48-inch concrete pipe,” Nypen remarks. “A complete section of the main canal bank was emptied, then a pipe trench excavated, and the pipe was installed and backfilled. The backfill is tightly compacted so we don’t lose the canal when it is put back into service.”

It takes approximately three weeks for a fix like this one. Nypen points out that his employees spend each winter completing such repairs all along the approximate 400 miles of ditches in the Project.

“The culvert replacement at Antelope Coulee is typical of how we spend our time between water seasons,” Nypen concludes. “There are numerous conduits, flumes, siphons, checks, turnouts and spillways within the Project boundaries in addition to ditch relocations and drain installations and closures that have to be kept in service. Winter construction is always slower, but it never ends.”