An Environmental Impact Statement (EIS) has identified the construction of a bypass channel as the best option for fish passage at the Lower Yellowstone Intake Diversion Dam in Montana, US.

The US Army Corps of Engineers and Bureau of Reclamation, serving as Federal co-leads, prepared the Final EIS to evaluate and disclose the impacts of improving fish passage at the Intake Diversion Dam while also maintaining the viable and effective operation of the Lower Yellowstone Project.

"The lower Yellowstone River is considered by the US Fish and Wildlife Service to provide one of the best opportunities for recovery of Pallid Sturgeon," said Col. John W Henderson, Omaha District commander for the Corps.

The Final EIS evaluates and discloses the potential effects of a No Action alternative and five action alternatives for improving fish passage at the Intake Diversion Dam. Action alternatives analyzed include; rock ramp, bypass channel, modified side channel, multiple pumps and multiple pumps with conservative measures. Each alternative includes a monitoring and adaptive management plan.

The Bypass Channel was identified as the preferred alternative based upon it best fulfilling statutory mission and responsibilities for both agencies along with the consideration of economic, environmental, and technical factors.

Both agencies believe the Bypass Channel Alternative could be constructed, operated, and maintained to meet the physical and biological criteria identified by the Fish and Wildlife Service's Biological Review Team, and therefore would provide passage for pallid sturgeon and other native fish. Additionally, the Bypass Channel Alternative is a cost effective means of providing fish passage and is estimated to have the lowest annual cost for long term operations and maintenance of the action alternatives considered, the EIS says.

"The Bypass Channel provides a balance of fish and agricultural community needs," said Reclamation's Great Plains Regional Director Mike Ryan. "The alternative provides the pallid sturgeon a chance at recovery and allows for the continued viable and effective operation of the Lower Yellowstone Project."