MONDAY, June 1, 2026 |
Photo – Seminoe Dam – Bigfoot99 file photo
State and federal officials discussed their ongoing concerns with the Seminoe pumped storage project.
On Thursday, May 28th, the Wyoming Joint Travel, Recreation, Wildlife, and Cultural Resources committee met to hear testimony about the proposed Seminoe Pumped Storage Project. The Salt Lake City‑based developer, rPlus Hydro, plans to build a variation of a hydroelectric power plant called a pumped storage facility at Seminoe Reservoir. The project would require the construction of a lake above the existing reservoir, an underground powerhouse, and a bridge over the North Platte River to access the tunnels. During periods of high energy production, such as late at night, excess electricity will be used to pump water from Seminoe Reservoir into the upper lake. When additional power is needed, that water would flow downhill, through an underground turbine, generating electricity.
Speaking to the Joint Travel, Recreation, Wildlife, and Cultural Resources committee, rPlus Hyrdo General Council Kevin Baker explained the scope of the project.
Baker said Wyoming will need additional electrical energy in the near future. Over the next eight years, he predicted the Rocky Mountain region will see demand rise from 14 gigawatts to 17. Over the same period, Baker said Wyoming’s power output will drop by two gigawatts.
Baker said the Federal Energy Regulatory Commission, or FERC, which oversees all hydroelectric power generation, reported that the Seminoe pumped storage facility would save Wyoming taxpayers $200 million compared with other forms of electrical generation needed to support the grid.
Opponents of the project say the pumped storage facility is likely to have unintended negative consequences on local fish and wildlife. Baker said FERC’s draft environmental impact study concluded that the project would not affect the Miracle Mile blue‑ribbon trout fishery or undermine existing water rights.
Baker said FERC also found that the public benefits of the project will outweigh any potential negative environmental impacts. He said the pumped‑storage facility is expected to generate millions of dollars in property tax revenue for Carbon County and create up to 35 permanent jobs.
Baker said rPlus Hydro worked with the Wyoming Department of Environmental Quality to determine the facility’s potential impact on water quality in Seminoe Reservoir and the Miracle Mile. Using DEQ’s water data from 2013 through 2016, Baker said the study concluded that the facility will have no effect on water temperature in the trout fishery except during periods of extremely low water.
In fact, Baker said studies indicated that the project could improve water temperatures and increase dissolved‑oxygen levels in Seminoe Reservoir.
Even during a once‑in‑a‑decade drought, Baker said DEQ found that the project, operating at full capacity, may exceed water‑quality standards in the Miracle Mile by one‑tenth of a degree Celsius for a short period of time. He said even a small violation is not permitted under DEQ regulations, and rPlus will ramp down production when water temperatures begin to approach the agency’s limits.
Baker said construction of the underground powerhouse and tunnel system will take five years, with the heaviest activity occurring during the first three years. The Wyoming Game and Fish Department found that the work is likely to disturb the nearby Ferris‑Seminoe bighorn sheep herd. In November, one month before FERC was set to issue its draft environmental impact statement, rPlus moved its tunnel spoils storage area closer to the construction site. Baker said the change shortened the distance trucks must haul the material, further reducing the impact on the herd.
The Ferris‑Seminoe herd is the only known group of bighorn sheep in Wyoming still free of domestic‑livestock pathogens such as pneumonia. As a result, the animals are used to bolster other herds around the state.
Baker said rPlus has also limited construction of the upper reservoir to a nine-month window, from March to November, to further protect the sheep.
Following Baker’s testimony, Joint Travel, Recreation, Wildlife, and Cultural Resources committee member Senator Larry Hicks noted that Wyoming exports roughly 25 percent of the energy it produces. Senator Hicks said power generated by the Seminoe pumped storage facility will be sent out of state and is unlikely to benefit Wyoming residents.
rPlus Hyrdo General Council Kevin Baker acknowledged that some of the power will go out of state but said the pumped storage facility is designed to supplement all forms of energy production, including coal and nuclear.
Next, Representative Elissa Campbell asked why rPlus used decade‑old data to conduct its water‑quality study. Baker responded that the Wyoming Department of Environmental Quality directed the company to use the 2013 through 2016 dataset due to its inclusion of a large range of water conditions.
Later in the meeting, Trout Unlimited Government Relations Director Patrick Harrington said the low-water data Wyoming DEQ and rPlus Hydro used in the study was higher than levels recorded during 22 drier years.
Harrington said the open‑loop system proposed for the Seminoe pumped storage facility, which would be connected to the North Platte River, may be more harmful than a closed‑loop design where both reservoirs are isolated from natural waterways. He said the Federal Energy Regulatory Commission failed to consider any alternative designs for the project.
Harrington also refuted Baker’s earlier claim that in its draft environmental impact statement, FERC concluded that the Seminoe pumped storage facility would benefit the public. He said FERC made no such statement and claiming they did appears to be purposely misstated.
Wyoming Game and Fish Deputy Director Jeff Davis said his agency is worried about the effect construction will have on the Ferris-Seminoe bighorn sheep herd. Davis said he is unsure whether his agency and rPlus Hydro can develop a plan that permits construction and still safeguards the herd.
Davis stressed the value of the Ferris‑Seminoe bighorn sheep herd and said further strain on the animals, including noise and vibration associated with tunnel blasting, may reduce the herd’s health.
Representative Julie Jarvis asked if the Miracle Mile fishery can be fully protected from the effects of the pumped storage facility. Game and Fish Director Angi Bruce said her department has not found a way to do so.
Wyoming State Parks Planning and Grants Manager Carly‑Ann Carruthers said her agency is concerned that construction of the pumped storage facility may limit public access to Seminoe State Park. Like Game and Fish, Carruthers said she is also worried the project will reduce wildlife‑viewing and fishing opportunities.
Carruthers said outdoor recreation is a major economic driver in Wyoming. She added that despite the closer material storage site, heavy truck traffic in the area, particularly on Seminoe Road, will continue to produce significant dust and noise.
Bureau of Land Management Wyoming State Director Kris Kirby said rPlus needs an amendment to the Rawlins Resource Management Plan to allow for year-round construction, which would disturb the local bighorn sheep herd, and to change the visual character of Seminoe Reservoir. Kirby added that BLM is working with the company on the required amendments, and she expects the agreements to be in place by next April.
Bureau of Reclamation Wyoming Area Manager Lyle Myler said all the hydroelectric powerplants on the North Platte River generate approximately 240 megawatts of electricity combined. He said increasing that output would require a new dam, as turbine upgrades can only produce modest gains.
The Federal Energy Regulatory Commission is expected to issue its final environmental impact statement later this month. Even if the project is approved, rPlus Hydro cannot immediately begin construction, as it must still complete two years of water‑quality studies on the Seminoe and Kortes reservoirs and secure a buyer for the electricity produced by the pumped storage facility.
