METHODS FOR INVENTORY AND ENVIRONMENTAL RISK ASSESSMENT OF ROAD DRAINAGE CROSSINGS

Road-stream crossings and ditch-relief culverts are commonly sites of ongoing or potential erosion. Erosion from failures of these structures can be a source of significant impacts to aquatic and riparian resources far removed from the initial failure site. The inventory and assessment of culvert installations are necessary for locating sites with potential impacts to aquatic and riparian environments for possible treatment. Locating those sites that have the greatest likelihood of causing adverse impacts is necessary to prioritize the expenditure of funds to reduce or eliminate risks. This guidebook discusses procedures for assessing the erosional hazards and risks to aquatic and riparian ecosystems of road-stream crossings, ditch-relief culverts, and other road-drainage features.