Riparian habitat plays a critical role in determining the condition and sustainability of native fish populations. The vertical and horizontal arrangement of riparian vegetation (living and dead) provides cover for fish, influences pool development, maintains streambank stability and leads to cooler water temperatures that are more conducive to native fish populations. Roads that parallel or cross streams commonly produce some of the most negative effects on aquatic resources. Fundamental impacts include floodplain constrictions, vegetation loss, and sediment sources. Roads can reduce floodplain capacity and restrict natural stream channel migration and meander patterns. Besides vegetation loss from initial construction, roads also occupy corridors where shrubs and trees would normally grow and contribute to stream function. Fine sediment inputs affect interstitial spaces between stream bottom particles, which negatively influences spawning and habitat conditions for small fish and macroinvertebrates. Larger sediment inputs from bank erosion events can fill pools and consume channel capacity, thus increasing flood frequency and contributing to habitat loss.
TU and the Lolo National Forest developed a partnership agreement and began with a coarse level GIS analysis of fish bearing streams in the Middle Clark Fork River area of the Lolo National forest. Tributaries were prioritized within the Middle Clark Fork watershed on their present capacity to support native fish, especially bull trout and westslope cutthroat. In April of 2008, TU and the Lolo National Forest partnered on a demonstration project involving revegetation of riparian roads in the Cedar Creek watershed -a tributary of the Clark Fork River - by using stinger technology, a modified excavator attachment, to install plants along 500 feet of rip-rapped road that impinged the stream channel. Cedar Creek is one of four primary bull trout spawning tributaries in the Middle Clark Fork River and also maintains a strong native westslope cutthroat population. Monitoring results from this project have indicated some willows have grown 5 feet after two growing seasons. Building on the success of this project Trout Unlimited and Lolo National Forest have planted more than 8,000 feet of rip rapped lined streambanks in Rock Creek, Fish Creek and Trout Creek drainages.
