Corps expected to award bid for Pipestem project by end of month
The Pipestem Dam safety modification project consists of building a concrete terminal structure on the downstream end of Pipestem Creek.
JAMESTOWN – The U.S. Army Corps of Engineers is expected to award the bid to a contractor by the end of the month for the Pipestem Dam spillway modification project, according to Chris Fassero, project manager for the corps.
Fassero wrote in an email that the bid opening for the construction contract was held Aug. 15. Barnard Construction Co. out of Bozeman, Montana, was the low bidder.
“We expect that they will begin mobilizing to the site this fall and begin construction work next spring,” he wrote.
The Jamestown Sun reported in November the cost of the project’s construction is between $100 million and $200 million. The plan was for the project to be fully funded for the 2022 federal fiscal year so the Corps of Engineers can award a construction contract before Sept. 30.
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. Fassero said in November 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.
Fassero said the Corps of Engineers is planning some additional public outreach regarding the construction.