Proposed repairs to bolster Montana's Fort Peck Dam following epic flooding along the Missouri River last year would cost more than $225 million, according to estimates released Wednesday by the U.S. Army Corps of Engineers.
But with money short, Corps officials acknowledged they are able to afford only $46 million for damage assessments and repair work for now. Most of that will be spent on repairs to the dam's spillway.
Record snowfalls and massive spring rains in Wyoming and Montana last year prompted the release of unprecedented volumes of water from the Corps' six Missouri River dams.
The torrent damaged Fort Peck's spillway gates and eroded areas downstream from the dam, located at the top of the Missouri River system.
The most expensive repairs outlined by the Corps' engineering consultants would bolster the spillway so it could handle releases of 265,000 cubic feet of water per second. That's more than four times the peak release of almost 66,000 during last year's flooding.
Fort Peck Project Manager John Daggett said the proposed repairs are needed to ensure the spillway can be used to safely release water.
Montana Gov. Brian Schweitzer said Wednesday that the state would support any work that improves safety and storage capacity for the dam.
But the Democrat added that the high-end estimates offered by the Corps appeared unrealistic given federal budget constraints.
"The Army Corps of Engineers oftentimes has grandiose plans. But the checks are written by Congress and there seems to be a diminishing appetite for borrowing more money from China and giving it to the Corps of Engineers," Schweitzer said. "In tough times, you don't buy another ranch and build a new barn. You just make sure the roof keeps water out of your hay."
The 2,341-mile Missouri River is managed by the Corps and flows from Montana through the Dakotas, Nebraska, Kansas, Iowa and Missouri. The agency has earlier estimated that last year's flooding caused $630 million in damage to levees, dams and channels built to control the river.
At the lower end of the cost alternatives for Fort Peck's spillway, Daggett says $25 million would allow for repairs to damaged concrete along the spillway chute and along the "wing walls" where the structure drains into the Missouri.
Work on damage to the spillway gates already is under way.
The most expensive option from the consultants entails the construction of a huge concrete "stilling basin" below the spillway. That would capture released water, reduce erosion and better protect against an uncontrolled release that could destroy the dam, Daggett said.
"We're going to have to seek additional funding for the ultimate fix, but we're going to have to do as much as we can with the money we have."
The $245 million figure does not include any work that could be needed on a concrete drainage system beneath the spillway. Testing to determine whether that drainage system is working properly is planned for the week of Sept. 4.
As part of the testing, the Corps plans to release water at between 3,000 and 30,000 cubic feet per second at periodic intervals over four days.