Shoreline Erosion and Geomorphology of Canyon Ferry Lake
Canyon Ferry Lake, east of Helena, Montana, in Broadwater County, was formed in 1954 when Canyon Ferry Dam was constructed. Lakeshore residents have reported excessive erosion during recent years. Montana Power produced a management report, with recommendations for erosion mitigation, but no studies have been done on Canyon Ferry of actual erosion rates and areas at high risk of erosion along the shore. This study will be a comprehensive analysis of shoreline erosion around Canyon Ferry Lake. The first component of this work involves mapping shoreline retreat using time series remote sensing imagery. Emphasis will be on the White Earth Unit, where Tertiary sedimentary rocks are located. Detailed stratigraphic analysis of the White Earth Unit will be conducted to determine geologic factors that could be leading to differential weathering and erosion. The results of this phase of the study will allow us to identify areas of highest erosion in the last 50 years as well as geomorphic patterns. Using geomorphic patterns, such as shape and direction of cuspate beaches, initial analysis on current direction in the new dammed regime will be performed.