TUESDAY, September 8, 2026|

Photo – Image of Seminoe Pumped Storage Project – Courtesy rPlus Hydro

Wyoming lawmakers expressed their disapproval of the federal government’s handling of the proposed Seminoe Pumped Storage Project.

On August 18th, the members of the Wyoming Joint Travel, Recreation, Wildlife, and Cultural Resources Committee submitted a letter to the Federal Energy Regulatory Commission, or FERC. In its letter, the Committee questioned the environmental analysis, or NEPA review, FERC conducted on the Seminoe Pumped Storage Project. NEPA is the National Environmental Policy Act, which requires federal agencies to study and disclose environmental impacts before making major decisions.

Utah‑based rPlus Hydro, also known as Black Canyon Hydro, has proposed constructing a pumped storage facility at Seminoe Reservoir. Plans call for a 13,000‑acre‑foot man‑made lake on a mountaintop above the existing reservoir, connected to Seminoe by an underground electrical powerhouse. During periods of high wind‑energy production, water would be pumped into the upper lake and stored until needed. When demand outpaced production, the water would flow downhill through the underground turbine, generating roughly 900 megawatts of electricity for up to 12 hours. The cycle would repeat as needed.

Project opponents say construction of the facility, which involves five years of blasting and frequent heavy truck traffic, will disrupt the nearby Seminoe‑Ferris bighorn sheep herd, the last known population free from domesticated livestock diseases. In its Rawlins Resource Management Plan, the Bureau of Land Management limits construction to a four‑month period from May through August to avoid disturbing the herd. rPlus Hydro would need BLM to amend the plan to allow at least a nine‑month season.

Opponents further contend that transferring water between Seminoe Reservoir and the proposed upper lake will change conditions in the downstream ecosystem, particularly the Miracle Mile. They argue that any changes to dissolved oxygen or sediment levels have the potential to negatively affect the blue‑ribbon trout fishery.

Despite those concerns, the Wyoming Department of Environmental Quality issued a Clean Water Act Section 401 Water Quality Certification for the project earlier this year. DEQ found that when the Seminoe Pumped Storage Facility is operating, discharged water used for power generation may briefly change temperatures in Seminoe Reservoir, Kortes Reservoir, and the Miracle Mile. The state agency recommended real-time monitoring of water temperature, dissolved oxygen, and turbidity to ensure the project does not exceed allowable thresholds.

On June 12th, the Federal Energy Regulatory Commission released its final Environmental Impact Statement, or EIS, for the Seminoe Pumped Storage Project. FERC concluded the project would have little to no impact on the Miracle Mile blue‑ribbon trout fishery if certain restrictions were put in place, including scaling down pumping during periods of high temperatures.

In its letter to FERC, the Wyoming Joint Travel, Recreation, Wildlife, and Cultural Resources Committee raised concerns with how the federal agency conducted the National Environmental Policy Act, NEPA, review. The Committee members wrote that after hearing from stakeholders, local officials, agency directors, and residents, they recognized the significance of the impacts, many of which appear negative, the project will have on Wyoming’s people, natural resources, and wildlife.

Federal law requires FERC to evaluate “a reasonable range of alternatives to the proposed action” when conducting an environmental review. The Joint Travel Committee members wrote that FERC did not appear to consider an alternative closed‑loop system proposed by Trout Unlimited in its public comments. A closed-loop system would prevent water used for power generation from entering the North Platte River. The letter continues, stating that FERC declined to analyze any closed‑loop water‑use option, adding that “concerned citizens, stakeholders, and agencies have raised such issues throughout the NEPA review process and have not been appropriately engaged with and considered.”

The Wyoming Joint Travel, Recreation, Wildlife, and Cultural Resources Committee wrote that FERC also failed to recognize the potential negative impacts to fish and wildlife in the area. Representatives from the Wyoming Game and Fish Department testified that construction may harm the Seminoe-Ferris bighorn sheep herd. In its letter, the Joint Travel Committee stated that rather than address those comments, FERC “ignored” them.

Continuing, the Committee wrote that the Seminoe Pumped Storage Project, in its current state, has no method to monitor or prevent harm to the local bighorn sheep population. The Joint Travel Committee stated that by requesting special waivers to bypass herd protections, including amending the Rawlins Resource Management Plan, rPlus Hydro and FERC were disregarding Wyoming Game and Fish’s concerns.

The Joint Travel Committee also wrote that FERC relied on outdated information, including data from ten years ago, to complete its environmental review.

In conclusion, the Committee expressed frustration that the federal agency has “chosen not to fully engage with Wyoming’s officials and stakeholders to develop a reasonable alternative to ensure that the Project can proceed and succeed while minimizing the impacts on Wyoming’s water, wildlife, and natural resources.”

With its final Environmental Impact Statement now complete, FERC has until next Thursday, September 17th, to approve or deny the project.

Even if the federal agency grants approval, the Seminoe Pumped Storage Project must receive authorization from the state and Carbon County before construction can begin. Speaking at the August 4th Board of Carbon County Commissioners meeting, Commissioner Sue Jones said the Board of Commissioners has the final say on the project. Even though many feel their opposition is being ignored, she assured residents that the Board is aware of their concerns.