The majority of the Hamlet of Bragg Creek is located on the south side of the Elbow River, within a low terraced area. Since the establishment of first settlements in the Bragg Creek area, the Elbow River has been prone to flooding. These floods have caused widespread property damage, including destruction of buildings and bridges. In one instance, the death of one inhabitant was attributed to flooding on the Elbow River.
Flooding in the Elbow River basin may be caused by snowmelt, rainfall and snowmelt, or rainfall alone. The largest floods have occurred during a combined rainfall and snowmelt event. Flood events due to rainfall alone are not common, but that’s what occurred in 2013, the worst one so far.
Historic floods have been observed on Elbow River from as early as 1915. This was particularly evident with the washing out of the bridge crossing at Bragg Creek in 1915, 1916, 1929 and 1932.
The 1932 flood was the largest recorded flood, with an estimated peak instantaneous flow of 836 cubic metres per second (m3/s) at Bragg Creek. (That record was broken in 2013 when the river flow reached 842 m3/s). The 1932 flood had a severe impact on property and residents in the study area. In addition to the wrecked bridge, the flood also destroyed the post office, a two story store and resulted in the death of one inhabitant. Since 1932, peak instantaneous flows on the river have been reported at 267 m3/s in 1948 and 268 m3/s in 1963.
The 2013 flood destroyed commercial buildings, homes, roads, bridges and other infrastructure. No one died, but the impact was devastating to residents and business people in the hamlet. As of 2017, we’re still recovering – many commercial spaces remain unoccupied, two restaurants are gone forever, another in the Shopping Centre, is still closed. About an acre of riverfront land is gone, along with the homes that were there. The Old Trading Post, which was all but destroyed has been rebuilt. The county says they’ll open a second exit (the only exit is the Balsam Ave. bridge) for residents of West Bragg and Wintergreen, but they’ve done nothing. Some flood mitigation projects have been done and more are planned (when?). Alberta Transport rebuilt the wrecked roads and bridges, but the government is mired in a complex debate over whether/if they’ll build a dry dam near McLean Creek or in Springbank.
Following the 1963 flood, an artificial levee was constructed on the south bank of the river to protect the Bragg Creek Trading Post from future flooding and to protect the bank from erosion. This levee was constructed by piling up river gravel and covering it with a 1.5 m blanket of 0.5 m diameter riprap material. This levee acts as a. deflector dike on the main channel and has, to date, protected the. Trading Post from flooding.
There have not been as many reported incidents of flooding on Bragg Creek. Flooding has occurred over the left (north) bank both upstream and downstream of the Elgin drive bridge. Subsequently, a dike was constructed on the left bank, upstream of the bridge, to contain flood waters.
In recent years, the largest floods on the Elbow River have occurred in 1967 and 1990. Other than these two years, the annual spring runoff flood has not been unusually high in comparison with flows recorded in the first half of the century. The 1967 flood is the largest flood in recent history and was observed to have an estimated instantaneous Peak discharge of 283 m3/s at Bragg Creek corresponding to about a 10 year flood event.
The 1990 flood was observed to have a peak instantaneous discharge of 172 m3/s. This is equivalent to approximately a 5 year flood event, and was not observed to impact on any property in the area. However, this is the most recent flood for which good flow and depth data arc available.
Ice jam floods on either the Elbow River or Bragg Creek have never been reported.