Confluence was contracted by the Montana Department of Transportation (MDT) to conduct annual, statewide monitoring of MDT’s stream mitigation sites. MDT is required by the U.S. Army Corps of Engineers to conduct mitigation actions to offset any permanent impacts to streams and riparian corridors resulting from highway construction projects. Confluence is responsible for collecting and interpreting monitoring data as specified in monitoring plans prepared by MDT as well as preparing annual monitoring reports for each mitigation site. Statewide monitoring in 2013 documented mitigation performance at 10 project sites.
Annual mitigation monitoring data collection includes:
- Conducting vegetation monitoring transects within the riparian corridor;
- Conducting vegetation monitoring transects along stream banks;
- Documenting all stream bank erosion occurring within the mitigation site;
- Establishing photo-documentation points;
- Documenting survival rates of planted vegetation;
- Documenting vegetative communities establishing within the mitigation site;
- Documenting noxious weed presence;
- Surveying perpendicular transects across the channel at riffle and pool features to document lateral stability and channel dimensions;
- Surveying longitudinal profiles of the channel to document vertical stability, bedform elements, and habitat complexity;
- Surveying as-built topography of recently completed projects;
Results of annual monitoring activities were summarized into technical reports documenting conditions at each site in accordance with MDT and USACE monitoring requirements. Confluence will be conducting annual monitoring at all stream mitigation sites through 2015.
The 2013 and 2014 monitoring reports may be viewed HERE: