Seminoe Hydropower Plan Sparks Pushback Over Wildlife and Fishing Risks

The original story by Dustin Bleizeffer for WyoFile.

A big hydro project planned for Seminoe Reservoir is running into equally big resistance from anglers, hunters and wildlife advocates who say the proposal could put some of central Wyoming’s most iconic species and outdoor experiences at risk.

At the center of the clash is a request from developers rPlus Hydro and Black Canyon Hydro, who want to lift seasonal wildlife restrictions so they can keep construction moving for the full three-to-five year buildout. Opponents say those protections exist for a reason — especially for the region’s bighorn sheep.

“I’m all for energy development,” said Blake Jackson, fishing guide and co-owner of the Ugly Bug Fly Shop in Casper. “I just think this is a really poor project that puts so many things at risk.”

Jackson helps lead Friends of the North Platte, a group formed specifically to fight the proposal.

“They’re asking for all of those wildlife stipulations to be waived, and we’re basically saying, ‘No.’”

Developers want to create a massive pumped-storage hydropower system by building a 10,000-acre-foot reservoir high in the Bennett Mountains above Seminoe. Water would be pumped uphill using cheap daytime electricity from wind and solar, then released downhill during high-demand evening hours to generate power.

They argue the $3–$5 billion project would boost grid reliability and bring millions in tax revenue to local counties.

County leaders in both Carbon and Natrona counties have formally urged federal regulators to slow down — or even shut down — the project as proposed. They say it threatens world-class fishing, vital big game habitat, and local tourism dollars.

“This project will have a substantial impact on the health, safety, welfare, custom, culture and socio-economic viability of not just Carbon County, but also Natrona County,” Natrona County Commission Chair Dave North wrote to the Federal Energy Regulatory Commission (FERC).

Carbon County Commissioner Sue Jones said she worries FERC might “fast-track” approval without fully considering how much the project would disrupt the area.

“We see $7 to $9 million annually just from fishing at Seminoe,” she said. “I have not encountered one person who has told me they’re for this.”

The Wyoming Game and Fish Department is pushing back as well, opposing the developer’s request for wide-ranging exemptions to winter wildlife protections. Those rules shield big game, including a uniquely important bighorn sheep herd, from disturbance during the most vulnerable part of the year.

“Something of that magnitude — construction for five years or greater — a blanket variance for the entire winter, that is not something that we support,” said Will Schultz, Habitat Protection Program supervisor for Game and Fish.

Conservation groups share the concern. The proposed construction zone sits inside crucial winter range for the Ferris–Seminoe bighorn sheep, the only herd in the state that has not tested positive for the devastating respiratory disease M. ovi.

“All of that blasting and hauling would happen during the time of year when sheep are conserving energy,” said Katie Cheesbrough of the Wyoming Wild Sheep Foundation. “If you degrade the air quality on top of that, it doesn’t help.”

Because the herd is used to bolster other bighorn populations, protecting it is considered essential to the species’ future in Wyoming.

Even after construction ends, anglers warn that pumping and releasing huge volumes of water could increase sediment and raise temperatures — both serious threats to trout.

“We’re often near dangerous water temperature levels currently,” Jackson said. “Add sediment, add heat, and it becomes a really big issue.”

rPlus Hydro says it is committed to minimizing impacts and following federal permitting rules. Meanwhile, the project remains under review, with FERC accepting public comments on its draft environmental impact statement through Jan. 2.

Those interested in weighing in can find the draft EIS and comment portal on FERC’s website.