Environmental groups call for investigation of Hebgen Dam malfunction

In a citizens’ complaint filed with the Federal Energy Regulatory Commission, the groups call for swift and independent investigation into November’s dewatering of the Madison River.

By Amanda Eggert MONTANA FREE PRESS

Three environmental groups filed a citizens’ complaint today requesting a formal investigation into the Hebgen Dam malfunction that dewatered the Madison River for nearly 48 hours late last year. The groups filed the complaint with the Federal Energy Regulatory Commission, which administers the hydropower license NorthWestern Energy uses to operate the Dam.

The malfunction stemmed from the failure of part of the 108-year-old dam’s outflow gate that dropped it into a mostly closed position on Nov. 30, rapidly reducing stream flows from about 650 cubic feet per second to less than 200 cfs and generating concerns about aquatic impacts. Biologists say the sudden drop killed an unknown number of trout and sculpin that were stranded in shallow channels and pools, and that brown trout eggs on the Upper Madison may have been compromised when they were exposed to freezing temperatures.

Upper Missouri Waterkeeper, the Montana Environmental Information Center and the Madison River Foundation said in a release about the complaint that “it is critical that a formal, nonpartisan process ask [questions about long-term ecological and economic impacts] and investigate lasting solutions now.”

“This formal complaint is the means for holding NorthWestern Energy accountable for its dam’s failure, a thorough third-party investigation of impacts, and targeted action to make the river and downstream communities whole again,” Upper Missouri Waterkeeper Executive Director Guy Alsentzer said in the release.

The complaint notes that Hebgen Dam also malfunctioned in 2008, when flows jumped from 850 cfs to 3,400 cfs following a failure of the dam’s intake structure.

“Two significant flow failures in fifteen years at NorthWestern’s Hebgen Dam sound the alarm call for much needed additional monitoring and redundancy to protect the river ecology and downstream economies that are directly dependent on stable outflows,” Alsentzer said.

In addition to the request for an investigation into ecological impacts, the groups are calling for a review of the safety of the dam, which underwent a $40 million restoration in 2018. They’re also asking FERC to require NorthWestern to create and administer a fund to pay for ecological restoration and mitigate economic hardships experienced by local communities, which are heavily dependent on revenue from river-related recreation.

The complaint also asks FERC to determine and declare that NorthWestern violated the flow requirements of its license and either oversee an “alternative dispute resolution” process or appoint a judge to negotiate a settlement between the groups and NorthWestern, the South Dakota-based utility company that supplies power to about two-thirds of Montanans.

In an email to Montana Free Press, NorthWestern Energy spokesperson Jo Dee Black said the company is conducting an investigation into the malfunction and is “taking purposeful steps to ensure a thorough analysis of the gate component … to understand why this relatively new part failed and to establish corrective actions.”

“Since taking ownership in 2014 of 11 dams in Montana, NorthWestern Energy invested hundreds of millions of dollars into the system. Those investments have increased the generating capacity, improved fish passage through the dam system, modernized the infrastructure and provided more recreational opportunities,” she said.

A FERC spokesperson said “the filing is under review at this time.”