“Everything manmade is going:” Lt. Gov. Cooney tours Rattlesnake Dam

Posted at 3:30 PM, Jun 24, 2019
and last updated 2019-06-24 17:58:08-04

Morgan Valliant, the conservation lands manager with the city of Missoula, and Lt. Gov. Mike Cooney, discuss plans to remove a dam in Rattlesnake Creek and restore the tributary to historic conditions during a field tour on Friday, June 21, 2019. (Martin Kidston/Missoula Current)

-Martin Kidston reporting for the Missoula Current

MISSOULA – A year after touring the Missoula Valley floods, Lt. Gov. Mike Cooney returned to the water’s edge on Friday, this time to study the city’s plans to remove a dam on Rattlesnake Creek and restore the tributary to historic conditions.

Gathered on the first day of summer, project partners toured the site while noting the benefits that a full restoration will have on wildlife, the natural environment and planned public access.

But it was the ability of endangered bull trout to return to their native spawning grounds high in the wilderness for the first time in more than a century that won much of the praise.

“We have a barrier to fish passage here that’s been 115 years in the making,” said Rob Roberts, the Clark Fork restoration director with Trout Unlimited. “Bull trout, cutthroat and whatever else hasn’t moved up this creek ever since then.”

The lower end of Rattlesnake Creek has been a problem for decades, and efforts have been made to overcome the concrete dam blocking the tributary. A fish ladder was installed nearly 20 years ago, and portions of the dam itself have been removed.

But the structure continues to deteriorate, and it continues to hinder the passage of fish. The city and its partners, including Trout Unlimited, local businesses and Montana Fish, Wildlife and Parks, plan to remove the structure and begin what represents a monumental restoration effort starting next July.

Logs washed down with high water flows sit lodged against Rattlesnake Dam. The city plans to remove the structure and restore the creek to native conditions. (Martin Kidston/Missoula Current)

“Everything that’s manmade is going to go – fences, buildings, concrete,” said Roberts. “After that, this whole area becomes a restored stream and floodplain and hopefully look more or less like it did before this ever happened. We’re certainly turning back the clock in a major way.”

The dam was constructed in 1901 and the adjoining retention pond followed in 1904. The site served as a source of domestic water until 1983, when an outbreak of giardia ended its use.

The site was maintained as an emergency water sources after the giardia outbreak, though with the addition of new wells it’s no longer needed, according to former Mountain Water Co. employee Dennis Bowman, who now leads Missoula Water.

FWP has collected detailed information on how and when fish navigate the creek. It led to the installation of the fish ladder and at times, it prompted operators to open the dam’s sluice gates.

But still, Bowman said, additional efforts are needed. Recent studies have shown that bull trout still don’t access the wilderness, and that’s likely due to low flows and warm water temperatures at higher elevations.

“We’re working with (FWP) to collect data on the temperature of the water coming out of the (wilderness) lakes,” said Bowman. “We’re opening up valves on the lakes so we can increase the flow and pull the water off the bottom of the lake, which is colder. If we can change the temperature 4 degrees in the stream, we think it can really help the bull trout.”

Portions of the restoration project will also look to public access, something Morgan Valliant, the city’s conservation lands manager, is eager to begin. The finished product will cater to both wildlife and migration, as well as public viewing and access.

Rattlesnake Creek runs alongside a concrete retaining pond just above the dam. The pond will be removed, filled in and converted to natural stream channels. (Martin Kidston/Missoula Current)

“Not only are we dealing with the maintenance issues and costs and doing this habitat restoration, but we’re also looking at that whole process of planning how the public will use this site,” said Valliant. “It’s something we struggle with in balancing recreation and conservation. Being able to design that in concert is really a unique thing.”

The project will require a large amount of earth moving – materials needed to fill in a large holding pond located on the property. Concrete structures will be removed, as will the fencing and a log cabin on the site. Channels will be constructed and the creek itself will be cleared of manmade structures.

During that process, Valliant said, a viewing platform and loop trail for all abilities will be installed. A partnership with NorthWestern Energy could also see the utility tackle restoration on its adjacent property.

“This is a really good opportunity for us to have a natural area in this beautiful riparian area and to have this creek open to everyone,” Valliant said. “This 45-acre chunk sits between federal land to the north and 120 acres of the city’s Rattlesnake greenbelt. It will really be a critical link for wildlife and people through this whole site.”

The project, estimated at $1 million, has already secured funding from several sources. That includes a $125,000 grant from the Montana Department of Natural Resources and Conservation.

The city also has applied for a Hazard Mitigation Grant of $475,000 from FEMA. The grant has passed the first round of approval and could help fund the project when combined with other campaign efforts.

Several local businesses, including Stockman Bank, have already given to the effort.

“We’re looking at the environment, the ecology of the area, and how that’s going to improve, and the people ultimately will be the ones who benefit from it,” said Cooney. “Not everywhere do these kind of projects come together this well.”