JAMESTOWN, N.D. (NewsDakota.com) – A draft environmental assessment (EA) for a Dam Safety Modification Study on Pipestem Dam is currently available for public review.

Right now, the U.S. Army Corps of Engineers is seeking the public’s comments and input on the draft EA.

“The draft EA evaluates the environmental impacts of modifying the emergency spillway to address the risk of erosion during spillway flow,” the U.S. Army Corps of Engineers states. “The proposed project would include modifications to the emergency earthen spillway to reduce erosion risk in the event the spillway would need to be used to pass flows.”

Modifications include a stepped chute structure to convey spillway flow from the higher elevation to the lower elevation. It would then install a stilling basin to reduce the hydraulic energy of flow exiting the spillway before it enters the creek.

“Dikes [would then be installed]on either side of the spillway channel to direct flow into a chute structure to prevent erosion of the spillway,” the Corps states.

The Corps says there’s a need to address risks associated with erosion of the emergency spillway.

“Although the ungated, earth channel spillway has never discharged, there is significant concern regarding the potential for erosion. The risks are high due to the combination of life, economic, or environmental consequences in the event of failure.”

Estimated incremental direct property damage from failure of Pipestem Dam would be in excess of $450 million. Annual lost benefits for flood risk management, recreation, water supply, and hydropower are estimated at over $2.2 million.

Pipestem Dam is located about four miles Northwest of Jamestown. The project is about seven miles above the confluence of Pipestem Creek and the James River.

For more on the draft environmental assessment for Pipestem Dam Safety Modification, click here.