Longitudinal streambed profiles along the sides of piers at selected bridge sites in Montana

The U.S. Geological Survey (USGS), in cooperation with the Montana Department of Transportation (MDT), collected longitudinal streambed profile data along the sides of piers at selected bridges in Montana. The streambed profile data extends upstream and downstream of piers so that local pier scour effects might be distinguished from more general geomorphic scour processes. Two or more streambed profiles were obtained on each side of piers at each bridge site. Contraction scour was not considered a factor mainly because none of the bridges reflect a substantial contraction of flow, given the spring runoff conditions that were experienced. The purpose of the data collection is to determine if scour and channel instability occur in the vicinity of the bridge structures. Data were processed, analyzed, and compiled for bridge scour monitoring, facilitating better understanding, documentation, and prediction of scour processes.