Corps receives $136.5 million to complete Pipestem project
The spillway modification project consists of building a concrete terminal structure on the downstream end of Pipestem Creek and filling in the eroded areas with concrete.
JAMESTOWN – The U.S. Army Corps of Engineers received $136.5 million to complete the Pipestem Dam safety modification project.
Sens. John Hoeven, R-N.D., and Kevin Cramer, R-N.D., announced the funding for the project on Thursday, May 26. The funding comes in addition to the $40 million the Corps of Engineers received last year to initiate construction of the Pipestem Dam safety modification project.
“Improvements are currently underway to help prevent erosion at the Pipestem Dam. This funding will help keep this important project on schedule, ensuring the dam can continue to effectively prevent flooding in the Jamestown region,” Hoeven said. “This is part of our broader efforts to help North Dakota communities manage their water resources and improve opportunities for recreation … .”
The Pipestem Dam safety modification project consists of building a concrete terminal structure on the downstream end of Pipestem Creek and filling in the eroded areas with concrete. The downstream end of Pipestem Creek is where erosion could happen because of a drop-off.
A terminal structure is located at the downstream end of the outlet works - which controls the release of water from a reservoir - to dissipate the energy of rapidly flowing water and protect the riverbed from erosion, according to the Federal Emergency Management Agency’s website.
The emergency spillway is located west of the paved road across the top of Pipestem Dam. Immediately south of the spillway is a broad relatively level area that had previously been used as a shooting range. From that area, there is a steeper slope with nearly a 90-foot vertical drop to Pipestem Creek below. The area where the steeper drop is located is at risk of eroding away.
The Corps of Engineers identified a risk of the spillway flowing in the event of a large storm, which could cause erosion, said Chris Fassero, project manager for the corps, in November. He said the worst-case scenario is the spillway getting eroded up to the crest and causing the reservoir to be released.
In areas with existing erosion, there are areas where more serious erosion could occur. When the safety modification project is complete, the eroded areas will be filled in and a terminal structure will be built over the drop-off at the end of the spillway.
Since Pipestem Dam was built, the water has never been high enough to flow over the spillway crest.
The Jamestown Sun reported in November the cost of the project’s construction to be between $100 million and $200 million, which depends on the accepted contractor bid. The plan was for the project to be fully funded this fiscal year so the Corps of Engineers can award a construction contract before Sept. 30, Fassero said in November.
Fassero previously said construction on the project could start in spring 2023 but could start sooner than that.