DAM BREACH STUDY FOR THE CORRA LINN HYDROELECTRIC FACILITY

摘要

Fortis BC owns and/or operates five hydroelectric facilities with dams on the Kootenay River downstream of the Kootenay Lake: the Corra Linn, Upper Bonnington, Lower Bonnington, South Slocan, and Brilliant Hydroelectric Projects. An analysis was undertaken to determine the extent of potential inundation that may result in the event of a dam failure at the Corra Linn Hydroelectric Project, which is the most upstream facility of the five. The study was completed using the dam breach component of HEC-RAS with the HEC-GeoRAS interface used to transfer modelled water surface elevations to ESRI ArcGIS. Two failure scenarios were examined in this study: failure due to a Probable Maximum Flood (PMF) event, and failure due to a Maximum Design Earthquake (MDE) event. It was assumed that failure of the Corra Linn Dam would be associated with the failure of all of the Kootenay River dams downstream. In the PMF case each dam was failed successively as the peak flood wave reached it; in the earthquake case all dams failed simultaneously. Inundation maps that show peak water surface elevations were prepared for all areas downstream of the Corra Linn Dam on the Kootenay River and all areas along the Columbia River from the Hugh Keenleyside Dam down to the Canada/US Border. The model results indicate that some residential areas along the Kootenay and Columbia Rivers may be inundated in the event of failure of the Corra Linn Dam. The results from this study can be used to update Emergency Preparedness Plans and to determine the Dam Safety Consequence Category for the Corra Linn Dam.