Milltown Dam Breach Elicits Celebration, Nostalgia

By Peter Metcalf, 3-28-08

	Caption: The momentous trickle begins to flow. Photo by Matthew Frank. Click here for more photos.

This is how they breach a dam, not with a surge but a trickle.

Hundreds of people piled into viewing areas on both sides of the Clark Fork River Friday, while scores more gathered along the river’s banks to witness the historic breach of the Milltown Dam.

“I’m going to lookout there and tell those guys for the first time in 100 years, let ‘er run!” hollered Montana Gov. Brian Schweitzer, the last of a line of keynote speakers. 

With that, a lone yellow excavator worked to remove the last buckets of mud holding back the Clark Fork and Blackfoot rivers. Cheers and claps rose from the crowd a few minutes later as a trickle of water gurgled through the new pilot channel where the old brick powerhouse once stood. 

For the first time in more than a century, the Clark Fork and Blackfoot rivers began to flow freely. 

“For us it’s all back handsprings and flips. We are thrilled,” said Karen Knudsen, the executive director of the Clark Fork Coalition, the Missoula-based citizen group that spearheaded the campaign to remove the dam. “How often do we get the chance to clean-up a watershed?”

The event marks the most symbolic moment yet in the $100 million clean-up and restoration of the Milltown Reservoir. The Atlantic Richfield Company, which owns the Butte-area mines that were the source of the pollution, is responsible for 100 percent of the clean-up costs. 

Before the breach, Senators Jon Tester and Max Baucus, D-Mont. paid homage in separate speeches to the dam’s role in Montana’s history. Milltown dam was built by William Clark in 1906 to power a lumber mill in Bonner. The mill provided timbers for the mines in Butte that provided the copper for the electrification of America. Tester pointed out that ironically the Stimson mill that now sits on the site of Clark’s original lumber mill recently announced plans to close permanently. 

The dam’s removal marks years of hard work and significant collaboration by state, federal and private agencies. It also symbolizes a turning toward a new restoration economy, both Senators noted. 

“Folks have rallied around this river,” Tester said.  “Now there are a lot of other things to rally around and clean up in this state.”

Downstream from the dam, retired mill worker Jim Harrison smoked a cigar as he watched the water turn brown and timbers come floating down the driver. For Harrison, the whole clean-up has seemed like a fiasco and he questioned how the restoration would improve the economic fortunes of his neighborhood. 

Other men standing along the shore lamented the change the removal of the dam symbolized from the days of working mills and affordable homes to whitewater rafting, fly fishing and new high-end residential development.

“We’re going through change,” said Bob Johnson of Turah. “Whether its good or bad, in the end, I don’t know.”

What began as a trickle of water quickly gathered strength as the rivers cut away at the remains of the earthen coffer dam and poured muddy water into the green Clark Fork below. In the hours immediately following the breach, river levels were expected to rise by 4.5 feet immediately downstream, tapering off to a foot in Missoula and just a few inches at the confluence with the Bitterroot.

During the next few days, weeks and months, the rivers will wash 300,000 cubic yards of uncontaminated mud downstream from the mouth of the Blackfoot River. The rivers must scour through 18 feet of sediments before they reach their historical elevation. 

The release of so much sediment will have significant short-term impacts on fish, insect and other aquatic organisms, Montana Fish, Wildlife and Parks fisheries biologist Dave Schmetterling said.  Schmetterling, who has studied the dam’s impact on fish for more than a decade, expects increased fish mortality as far downstream as Superior, but added “the long term benefits to fish are enormous.”

The EPA and Envirocon made tremendous efforts to minimize impacts to the aquatic ecosystem during the remediation of the Milltown reservoir. The timing of the breach was selected to coincide with spring run-off, a time when fish are used to dealing with a high amount of sediment in the river. Boulders and other resting sites were incorporated into the pilot channel and the Clark Fork bypass channel to facilitate fish passage, Schmetterling said. 

Soon those resting places will be put to use as fish like native westslope cutthroat trout and rainbow trout begin the first natural migration upstream to spawn in over a century. 

“People need to keep this in perspective,” Schmetterling said. “This is a great thing that is happening. The long term stability of these fish populations is going to increase. The density of the fish in these areas is going to increase.”

Improving the health of the Clark Fork and Blackfoot watersheds’ fisheries, especially native bull trout which are listed as threatened under the Endangered Species Act, was one of the major reasons the EPA decided to remove the dam back in 2004, Schmetterling said.

The breach of Milltown dam marks not quite two years into a five-year project to clean up and restore the former reservoir. Attention at the dam site now turns to the spillway, which will be removed in the next eight or nine months. The removal of the 2.2 million cubic yards of toxic sediments from the old reservoir will continue for the next couple years. Then Envirocon will build a new channel for the Clark Fork River that meanders across the old reservoir and restore the wetlands in the floodplain. Long term plans include a public park and trail system. The whole project is expected to be completed sometime in 2011. 

The clean up and restoration of the old Milltown Reservoir is part of the nation’s largest Superfund site. The whole 120 mile stretch of the Clark Fork River upstream from Milltown is contaminated with toxic and other heavy metals, including arsenic, lead and mercury from the mines and smelters in the Butte and Anaconda area. Work begins to clean-up that stretch of river some time in 2009, Knudsen said.