NHC was retained by Brookfield between 2016 and 2018 to perform dam breach hydraulic analyses and inundation mapping of Lois Lake Dam, Horseshoe Dam, and Collett Dam. The first phase involved providing technical specifications for LiDAR survey, compiling and reviewing existing information for the sites, and determining the adequacy of hydrographs from recent hydrologic studies for performing hydraulic analyses. Then, two-dimensional hydraulic models were developed for flood routing downstream of each dam to estimate the downstream inundation extents, depths, and flood wave arrive times. Scenarios analyzed included flood‑induced and sunny day scenarios, as well as a cascade breach of Horseshoe Dam located upstream of Lois Lake Dam. The modelling results were then applied to evaluate the hypothetical impacts on the population at risk, environmental, cultural, infrastructure, and economic losses. Based on these analyses, NHC recommended updates to the consequence classification for each dam.