Projects > Flathead & Swan River Bridges Biological Resource Report


Confluence completed a biological resources report to analyze potential impacts to existing biological resources associated with proposed rehabilitation to a bridge spanning the Swan River. Confluence examined soils, vegetation, wetlands, noxious weeds, hydrology, and habitat in the affected area. Confluence wetland scientists identified threatened and endangered species use of the project reach including bald eagles and bull trout.

Confluence wetland scientists utilized the Montana Department of Transportation Montana Wetland Assessment Method (MWAM) to determine wetland functions and values of several wetland areas within the project area. This methodology is commonly used to document functional trends in wetland habitats targeted for restoration and enhancement. The method includes documenting and scoring 14 functional characteristics of each wetland assessment area, resulting in an overall functional score. Future monitoring efforts using this methodology can determine whether the wetland assessment areas are maintaining their functional value, trending upwards (functional uplift), or trending downward (functional loss).

The biological resource report included conducting a formal wetland delineation to identify and map boundaries of aquatic communities/resources. The delineation included documentation of hydrologic indicators including soil saturation/inundation, water marks, drift deposits, and water-stained leaves. The delineation also included mapping wetland vegetation communities to determine the extent of wetland habitat in the project area.