Abstract: Session D 2:45 pm (Back to Session D)
Reconnection, Restoration and Enhancement of Elbow Coulee in the Sun River Watershed, Augusta MT
Robert L Sain
The Elbow Coulee Reconnection, Restoration and Enhancement Project is in progress at the Broken O Land and Livestock (Broken O) near Augusta, Montana. The Broken O that surrounds and contributes to over 50 miles of tributary streams and 26 miles of the Sun River, has a unique opportunity to improve fish passage, fish habitat and reduce sediment influence on the Sun River. The watershed goal for enhancement and restoration activity is to increase trout habitat and cold-water refuge by removing fish passage barriers and ensuring native flow to coulee tributaries of the Sun River. The objective for Elbow Coulee is to reconnect (5.2 miles); enhance and restore 8 miles to its confluence with School Section Coulee and further downstream to the Sun River.
A three phased project, Phase I of the Elbow Coulee addresses a unique set of problems that encompass ranch irrigation and cattle operations, altered watershed hydrology and fish passage. Phase I construction was completed in 2017. A soup-to-nuts and design/ build operation whereas the in-house restoration program planned, surveyed, designed, permitted and performed construction on a 1,750-foot-long stream channel re-alignment under a large irrigation canal. The new floodplain and realignment reconnects fish passage to 5.2 miles of Elbow Coulee after over 100 years of disconnection. The design approach and challenges to consider for this type of project will be discussed. Drone monitoring presented as well.