IDAHO CITY -- The largest stream restoration project in the state is underway near Idaho City.

Troy Colson-KTVB

Work is underway to restore about a half-mile of Mores Creek near Idaho City.

Dredge mining has damaged miles and miles of Mores Creek north of Idaho City.

On the banks of Mores Creek, crews are using heavy equipment to help restore the stream.

From the 1870s to the 1950s dredge mining piled up what are called "tailings," leftover material from the mining process.

“In order to dredge the entire valley, they pushed the creek over to one side and essentially just channelized it. It’s like a canal, there's nothing to slow that water,” said Hana West, Boise National Forest hydrologist.

Those tailings have caused numerous problems in the creek - from flooding to killing fish.

Removing the tailings will change all that.

“We’re recreating a flood plain that used to exist before the dredging that occurred here at Mores Creek, oh 100 years ago. We’re allowing a space for water to seep back into the soil instead of rushing down to the reservoir,” said West.

Not only does the current situation cause flooding downstream, but the tailings have also reduced the water temperature so badly that it has killed fish.

“What happens is, it will interact with the gravels that are right against the water and it heats up terrible in the summer, and yeah we've had fish kills on Mores Creek because of that. So removing these tailings, just pushing them back will do a lot for the creek,” said Pam Smolczynski, Trout Unlimited.

Trout Unlimited and the Boise National Forest hope that this project to remove the tailings will help restore bull trout habitat that already exists upstream and downstream.

Later this fall, volunteers will come back here and plant trees and bushes.

The project covers a half-mile area, which organizers hope will serve as a model for others to come. 

The officials involved on this project area hoping to secure grant money to do more restoration work on Mores Creek, and also on Grimes Creek south of Idaho City.