MGS Engineering applied the SEFM model to the Campbell River Project, which consists of a cascade system of three dams (Strathcona, Ladore, and John Hart). The UBC Watershed Model (UBCWM) was used to simulate the rainfall, snowmelt and runoff response from each watershed. A flowchart of the SEFM simulation procedure using the UBCWM is shown in the accompanying figure.
Reservoir elevation-frequency estimates were developed for each reservoir for scenarios that assumed 100-percent floodgate reliability and with gate reliability based on qualitative analyses and consultations among engineers involved in the BC Hydro Gate Reliability Program. Magnitude-frequency plots for reservoir elevation comparing cases with and without spillway gate failures for John Hart Dam are shown in the figure. The results show that dams are much more likely to be overtopped (and consequently fail) due to an unusual combination of otherwise somewhat common individual events than due to a single extreme flood event.