UBC Theses and Dissertations
Shoreline erosion and related observations on the construction headpond at Site C, Fort St. John, BC Collier-Pandya, Beatrice
The Site C Clean Energy Project is a new dam and hydroelectric generating station that is currently being constructed by BC Hydro on the Peace River in northeastern British Columbia, near the city of Fort St. John. The Site C dam will be approximately 60 m high and will create a reservoir approximately 83 km long. A detailed geotechnical assessment was undertaken in 2012 to generate preliminary impact lines that delineate potential stability, erosion, and flood hazard areas around the future reservoir. A construction headpond currently formed by river diversion provides site-specific data to potentially improve upon initial shoreline erosion predictions. Since the impoundment of the construction headpond in September 2020, a variety of data has been collected that contributes to observations of shoreline erosion. Collected data includes headpond elevation data, wind speed and direction data, multiple aerial lidar datasets, wave characteristic data at two sites on the construction headpond, and grain size curves of soil samples take at the headpond shoreline. This data was analyzed using two quantitative methods: the digital shoreline analysis system (DSAS), and change detection analysis. The key takeaways from the DSAS tool measurements and the change detection analysis are: 1. All sites show the most material volume change in the first year of headpond impoundment, compared to the subsequent year and a half. 2. Most sites developed a notch at approximately the 416 m elevation, which corresponds with the elevation where the headpond spent the most time. The observations and analysis during the headpond impoundment led to lessons learned around monitoring, modelling, and communication. The research objectives of collecting shoreline erosion data and observations, analyzing the data with new tools and discussing the lessons learned from the headpond stage were met. The construction headpond provided a unique situation to be observed for approximately 2.5 years, but more research can be completed on the subsequent reservoir stage, as well as future reservoirs, to improve shoreline erosion prediction and monitoring methods.
Item Citations and Data
Attribution-NonCommercial-NoDerivatives 4.0 International