Big Meadows Culvert

This project is the first phase of a three phases to complete the removal of the Big Meadows Creek culvert fish passage barrier located approximately 1/4 mile east of Troy, Idaho.

Approximately six miles of stream was assessed for instream habitat condition, salmonid presence/absence, fish passage barrier inventory and habitat use by salmonids. Three miles of stream were identified as in need of restoration.

A habitat survey field data collection was completed on 36 acres and 18 acres were identified to be in need of restoration Discharge measurements were regularly recorded beginning in March 2013 and turbidity measurements were recorded in the spring of 2014.

The IDFG fisheries engineers coordinated with the Idaho Transportation Department (ITD) to draft three alternative designs and cost estimates for replacement/retrofitting of the Big Meadow Creek culvert. Big Meadows Creek flows south through a culvert under Highway 8 before draining into the West Fork Little Bear Creek. All three designs would improve passage to a degree but the bridge option would most effectively solve fish passage and provide the lowest future maintenance for ITD.

These alternatives are: 1) Install baffles on existing culvert 2) Culvert replacement with stream simulation arch culvert, and 3) Culvert replacement with bridge (preferred alternative). Technical reviews of these designs were conducted by two independent consultants who both provided comments supporting culvert replacement with a bridge. A Hydrologist/Watershed Restoration representative from the United States Forest Service visited the site and provided comments. Bonneville Power Administration (BPA) conducted a field review of the project and determined that it is a high risk project requiring engineering and technical oversight from BPA as implementation and permitting proceeds.

Additional funding will be solicited to conduct phase two (final design) and three (implementation of the selected alternative to remove the fish passage barrier.

Benefits will include improved access to spawning and rearing habitat and summer refugia for steelhead within the Big Meadows Creek tributary. This project will provide passage to over 9 miles of habitat that is currently unavailable due to passage constraints. Improved passage at this site will allow access to higher drainage habitat and may provide better flow and lower temperatures for additional spawning and rearing habitat within this productive drainage. This project will serve to proved a collaborative approach to steelhead population improvements as a sister project is being implemented on the West Fork Little Bear (Dutch Flat Dam Removal - PCSRF project 010 11 CW).