By Helena Dore, Bozeman Daily Chronicle
Three nonprofits are requesting an independent investigation into a Hebgen Dam gate malfunction that led to an abrupt drop in flows along the upper Madison River in late November.
Upper Missouri Waterkeeper, Montana Environmental Information Center and the Madison River Foundation filed a complaint with the Federal Energy Regulatory Commission on Wednesday.
Guy Alsentzer, executive director of Upper Missouri Waterkeeper, said the organizations are asking FERC to take a hard look at the circumstances surrounding the dewatering event and address the economic and ecological consequences, which are still largely unknown.
A broken metal coupler on a gate stem at Hebgen Dam caused flows to plunge from 648 cubic feet per second to 278 cfs in the wee hours of Nov. 30. The sudden change stranded fish in some side channels and exposed brown trout redds.
NorthWestern Energy, the utility that controls the dam, didn’t learn about the loss of flows until 12:19 p.m., according to a Dec. 23 letter from FERC addressing the incident.
“As a public utility, NorthWestern Energy must be held accountable for mismanagement of Montana’s natural resources, especially our water,” said Derf Johnson, staff attorney and clean water director at the Montana Environmental Information Center, in a news release.
“NorthWestern needs to fully cooperate with a comprehensive and transparent investigation, mitigate the impacts to the environment, community, and economy, take measures to ensure that this never happens again, and pay to fix the problem out of its shareholders’ pockets,” Johnson said.