Improving Stormwater Drainage for SW Communities

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The Community Drainage Improvements program was launched in 2010 to mitigate flooding in areas throughout the city. Drainage studies were undertaken to identify solutions for communities frequently hit by flooding due to extreme rainfall. Such solutions can include adding additional storm drainage pipes, increasing the size of pipes, and adding wet or dry storm ponds to help manage stormwater.

In recent years the communities of Woodlands, Woodbine, Cedarbrae and Braeside have experienced an unusually high number of high volume rainfall events.

These communities currently have a storm level service of a one-in-five-year rainfall event or less. That means that there is a 20 percent chance (or greater) that the storm system will not handle rainfall events causing local flooding in any given year.

Drainage improvements being looked at for these communities target a 1-in-50-year level of service. Once upgrades are in place there will be a two percent chance in any given year that rain events would overwhelm the storm system.

Installation of a dry pond

The City of Calgary will be constructing a new dry pond in the fields located east of the John Ware and St. Benedict schools. This dry pond will greatly reduce flooding during extreme rain events, specifically the flooding that occurs at the intersection of Southland Drive and Braeside Drive. Construction is expected to begin in the fall of 2017 with completion by fall of 2018. The fields will remain inaccessible to the public for the entire duration of construction.

Construction impacts

Construction of the dry pond consists of earthworks (excavation and grading), underground piping and landscaping. Construction impacts will include:

  • Increased traffic to site (construction crews, trucks hauling materials to and from site) on Southland Drive and on Palliser Drive
  • Construction noise
  • Fields will remain fenced off and closed to the public for the duration of construction
  • Traffic and sidewalk detours

Community benefits

The dry pond will significantly reduce flooding that occurs at Southland Drive and Palliser Drive, and along Braeside Drive. During heavy rainfall, overall vehicle and

pedestrian safety will be improved, traffic congestion reduced and emergency vehicle access unimpeded by flooding. John Ware and St. Benedict schools will each receive a new soccer field (two in total) and a new baseball diamond will be built allowing for more recreational opportunities for the community.

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