Future of lakes, dams in Rattlesnake Wilderness prompt debate as study continues

As members of the City Council reviewed the technical language guiding the 2019 Open Space Bond and changes to the Open Space Conservation Ordinance, it stumbled into a brief conversation on a series of lakes and dams tucked high within the Rattlesnake Wilderness above Missoula.

The lakes and dams were long owned and operated by Mountain Water Co. before the city acquired them in 2017. And while plans are in the works to remove the concrete dam on lower Rattlesnake Creek and restore the tributary to natural conditions, the upper lakes and their infrastructure remain a point of discussion.

Members of the council broached that future this week as they discussed the value of open space in regards to climate change, conservation and social equity.

“It fits in with the idea of climate resiliency,” said council member Julie Merritt. “Those lakes have the potential to mitigate some of the impacts of climate change.”

Already, members of Trout Unlimited and other state and federal partners, in conjunction with the city, are looking at the role the lakes could play in bringing clear, cold water downstream to support fish habitat during low flows late in the season.

They're also evaluating the integrity of the dams, which during the Mountain Water trial were said to be in poor condition.

According to the Rattlesnake Creek Watershed Group, Montana Power Co. built 10 dams on eight lakes in the Rattlesnake Wilderness between 1911 and 1923 to supply water to the city of Missoula. They were purchased by Mountain Water Co. in 1979, and by the city in 2017.

Donna Gaukler, director of Parks and Recreation, said the 2019 Open Space Plan, set for adoption next month, doesn't look specifically to the upper lakes, though it does address the intake dam on lower Rattlesnake Creek.

The dam is slated for removal in the coming years, followed by restoration work within the riparian zone. Gaukler said the upper lakes remain a topic of conversation and no decision about their future has been reached.

“We're taking that same look at all the lakes in the wilderness,” she said. “We will continue to do that work with Trout Unlimited and our partners in the Forest Service.”

Gaukler said those conversations beg a number of questions. Is there a recreational value in retaining the dams? Are there values in the water rights?

“If not, we'd readily come to the decision to remove the dams and do what's right for the ecosystem,” Gaukler said.

Council member Gwen Jones, who attended recent workshops on climate change and its potential impacts on water and drought in Missoula, said the upper lakes and dams were discussed by attendees.

While a decision may be years away, agreement on their future may bring a wide range of opinions.

“We discussed those lakes and dams and there's a strong conversation going on about whether the dams should be removed and go back to more natural riparian status,” said Jones. “On the other hand, they could be a powerful tool for storing water if we need that in the long term. We're learning a lot and evolving.”

Merritt suggested other solutions.

“I would push back on that removing the dams is the right thing to do,” she said. “They do have the potential to provide cool, clean water in the late season for flows into Rattlesnake Creek, which is important for the habitat there.”

Gaukler said the city and its partners are looking at those and other issues.

“That's exactly what we want to study, to make sure we protect the fishery in the riparian zones,” she said.