You gotta admit it’s nice when the bad dam system fails and the GOOD one moves in. Check out this story from Idaho where a hydroelectric company lost their permit and have to restore a creek. Things were going not so well until they got a certain flat-tailed helper.

Z. Tuana transformation

In 2004, when Idaho Power’s federal license for hydroelectric production at nearby Bliss Dam expired, the utility began an effort to restore the riparian habitat of Tuana Creek — a requirement of its Bliss Dam relicensing.

Past land use in Tuana Gulch had left a landscape with little value to wildlife, said Utz, the Idaho Power senior biologist who leads the company’s habitat mitigation from Milner Dam to Swan Falls.

“The bulk of what you’re looking at now is native,” Utz said, scanning the creek’s vegetation-lined beaver ponds from a footpath on the slope above its south bank. “This is a much more lush, green, useful area for wildlife. And they seem to be responding to it.”

Idaho Power didn’t accomplish this alone.

The company killed Russian olive trees and planted willows, cottonwoods and wildlife-friendly trees that produce fruits, berries and nuts. The plantings didn’t do well.

But a few isolated locations elsewhere on Tuana Creek had beavers, and beavers are territorial creatures whose young must disperse to colonize new areas. Finally, just enough of Idaho Power’s willow and cottonwood plantings survived to attract beavers.

Their dams impounded the creek, slowed it down, broadened the water’s zone of influence and created the conditions that allow native riparian plants to flourish.

“The beavers kind of did what we struggled to do,” Utz said.

Beaver ponds drowned many of the original willow plantings — “which is a nice problem to have,” Utz said — but new growth stretched up the reshaped banks.

“There’s a nice little cottonwood getting started,” Utz said, pointing to a sapling beside the creek. “See it? If it survives, it’ll be a 120-foot tree someday.”

Okay, now the cynic me has to point out that at least part of this story is about a power company fixing a problem with as little money as possible that they were quite content to spend a great deal of money to cause in the first place. But never mind that they’re doing this on the cheap. It’s Idaho and they could use a reminder of how much transformation beavers can bring. I’m sure they killed a peck of beavers back in the days of the hydro was running, but now they’re finding out what happens when you let them live.

Beavers can do this.

Beside a C-shaped beaver dam less than five years old, he watched dragonflies flit above the pond and named off the cattail, goldenrod, stinging nettle, common teasel, veronica, duckweed, sedges and bulrush. He pointed out the viceroy butterfly wings left behind after a bird’s meal and an empty duck eggshell left by a skunk, raccoon, snake or other hungry nighttime prowler.

“There’s a lot going on here that you can’t normally see,” he said.

Sure, you could build artificial ponds with berms and dikes and equipment. But that’s short-term and can be wrecked by flooding. Engineering can’t mimic the natural dynamic. Flood a beaver dam, he said, and the beavers just rebuild.