This structure would allow for natural stream characteristics to occur while flowing through the structure. These structures typically encompass the bankfull width and have substrate composition equivalent to a natural stream.

The culvert is a fish barrier between the headwaters of the Roaring River and its connection to the Middle Fork Boise River. The culvert is located on National Forest System (NFS) Road 255 located in Elmore County on the Mountain Home Ranger District of the Boise National Forest.

Replacement of the culvert will provide fish access to the upper subwatershed and will restore connectivity to an isolated bull trout population located above the culvert. The work is scheduled to occur between August 1st to October 1st 2007 and a corresponding road closure would be in place until completion of the project.

Bull trout (Salvelius confluentus) were listed as threatened under the Endangered Species Act on June 10, 1998 (63 FR 31647). The US Fish and Wildlife Service draft Bull Trout Recovery Plan identified the Roaring River population as depressed because of the migration barrier. The draft Plan also identified restoring connectivity as one of the seven recovery criteria for bull trout.

Specialists with the Boise National Forest identified spawning habitat above the existing culvert. The bull trout patch contains 4.5 miles spawning and rearing habitat, all located upstream of the culvert, and limited to the 4.5 miles because of natural barriers on the Middle Fork and East Fork Roaring River.

The 2003 and 2004 ³Fish Passage at Road Crossings Assessment, Boise National Forest², identified the Roaring River culvert to be a barrier to fish passage for all life stages of bull trout and rainbow/redband trout. The existing culvert constrains the stream channel increasing water velocities through the culvert at a rate unattainable by bull and rainbow/redband trout for its length (76 feet). The current culvert with the constrainment of the stream channel has caused downcutting which has consequently developed an outfall barrier.

Ted Trueblood volunteers will be involved in the bank stabilization and streamside planting work following the heavy construction activity.

Questions or comments? tutedtrue@aol.com
Ted Trueblood Chapter of Trout Umlimited