NINEMILE — On what he called “a scenic death march through the bomb zone,” Paul Parson cheerfully pointed out how looks can deceive in the stream restoration business.
The results of some million-dollar-a-mile geoengineering looked suspiciously like a toddler was at the controls of the bulldozer. Every tree for 50 feet on either side of the little creek was knocked over. Scraggly willow shoots poked out of No-Man’s-Land rock piles. Weird reddish-orange scum floated on stranded ponds.
“When I saw that, I panicked,” said Parson, who oversaw the restoration project for Trout Unlimited.
The project was supposed to restore 7,000 feet of stream bed that had been forced into an artificial channel by gold miners a century before. He called a consultant, certain that mine waste was leaking into the watercourse intended to host trout. She informed him that no, it was a kind of bacteria that only grows in places returning to natural conditions.
For much of the early 20th Century, this creek drainage west of Missoula crawled with gold miners using pressure hoses and dredging machines to gouge their way 20 feet down to the bed of Glacial Lake Missoula, where deposits of raw gold had accumulated.
They moved millions of cubic yards of gravel and rock into long tailing piles, raising parts of the valley floor 15 feet above its original level. Meanwhile the creek had its curves ironed out. The resulting straight stream bed had no floodplain to slow it down, and eroded down another 10 feet below its pre-mining elevation.
Decades later, trees and shrubs have grown along the ramrod Ninemile Creek in a pleasant appearance of normality, aside from the mini-canyon it flows through on its way to the Clark Fork River. In fact, it tears through the landscape like a firehose, washing tons of sediment into the river, blowing away fish and beaver habitat and frequently running nearly dry in late summer.
With habitat mitigation money from the Bonneville Power Administration, abandoned mine programs and other environmental restoration accounts, Trout Unlimited helped organize a major reconstruction of Ninemile Creek in 2008. The project quickly attracted the interest of the National Wildlife Federation and the Clark Fork Coalition. That’s because fixing an old stream benefits far more than just trout.
NWF saw an opportunity to showcase some natural restoration methods, specifically the engineering prowess of beavers. Former Ninemile District Ranger Greg Munther had done extensive beaver transplanting in the drainage during his tenure in the 1980s and 90s. Some careful stream grading could encourage those remaining beavers to add their efforts.
But that required overcoming a lot of misperceptions about beavers. Lewis and Clark hadn’t even made it back east to St. Louis in 1806 with their report of the Voyage of Discovery when they met beaver trappers heading west. Barely 50 years later, almost all the beaver in the West were trapped out.
The remainder got constant bad reps from cattle ranchers who dried their ponds for grazing pasture, farmers who hated their meddling with irrigation canals, anglers who thought their dams prevented fish from moving around, and road builders who thought they created unnecessary drainage problems.
Older Missoula residents remember when beavers in Rattlesnake Creek got the blame for giardia showing up in the municipal water supply in 1983, prompting Mountain Water Co. to switch to well water.
Better biology dismissed all those concerns. Beaver ponds do take up grazing space, but they also keep cattle from degrading stream banks and promote a much wider range of plant and tree growth. The ponds actually make refuges for many species of fish, which have evolved for eons to move through them in summer and survive ice scouring in winter. As for giardia, many animals including domestic dogs can infect a waterway with the intestinal parasite, and municipal water systems have to treat for it whether the water comes from a surface or underground source.
Beavers do mess with irrigation systems and present road construction challenges. But both can be overcome inexpensively. Meanwhile, the benefits they provide turn out to be stupendous.
Trout Unlimited researcher Christine Brissette studied the Ninemile water flows before and after the stream restoration and beaver activity occurred. She found more natural floodplains, enhanced by beaver ponds, stored much more water and kept tons of sediment out of the Clark Fork.
In late summer, when some parts of the stream had shrunk down to six cubic feet of water per second, the improved water storage added one more cubic foot of flow. That’s a 15 percent addition that would have been lost to spring runoff, but instead was keeping fish alive in late August.
“Without it, the streams were going dry,” Brissette said. “This allows them to connect to the river below. It was really exciting to see that it works.”
That could become crucial as climate change brings smaller snowpacks, warmer summers and changing rainfall patterns. The restored stream channel stores water in side channels, ponds, underground aquifers and other refuges, acting like a giant sponge that releases cold flows late in the year.
The Clark Fork Coalition got involved by buying water rights to that extra flow, ensuring Ninemile Creek had enough flow to keep fish populations healthy and the riparian areas growing. Otherwise, irrigation calls would frequently dewater the creek by late summer, crippling the restoration efforts.
So while the section of Ninemile Creek that Brissette and Parson toured on Wednesday looked like a disaster area, an upstream reach finished two years ago already had 6-foot-high stands of flowering dogwood, alder and willow covering a maze of beaver-flooded channels.
“We tried to take a beaver dam out in one area to let it dry out so we could work there,” Parson recalled. “Overnight, the beavers put it back. That thing about ‘busy as a beaver?’ It’s real. They just don’t quit.”