Flood maps off limits in this city

Flood maps off limits in this city

Flood maps off limits in this city Flood maps that could assist homeowners in more than 100 neighborhoods to buy the correct coverage are not being released to Edmonton homeowners.

The maps, a product of a $2.4-billion project, provide predictions of which areas are likely to be most vulnerable in the case of the storm of the century hitting, down to the level of which basements will flood and where water will pool.

Officials are not releasing the maps over concerns that doing so before measures are in place to address a one-in-100-year deluge would cause panic.

"Instead of giving residents half a solution, I want to give them a whole solution. Because it's more than just an individual homeowner can take on,” said acting head of utilities infrastructure, Todd Wyman.

The maps were created using stereoscopic photos of the ground taken by low-flying aircraft. The topographical charts thus created were then fed into a computer model that compared that data with the locations of underground stormwater pipes and the possibility of approximately 5 centimetres of precipitation in an hour and a half.

According to Wyman a plan should be in place this summer, with all maps for vulnerable areas and a prioritization of solutions should be complete by the end of 2017.
“We want to build awareness,” he says. “We don't want to create anxiety. We need to be very sensitive about personal information."

Alberta director of government relations for the Insurance Bureau of Canada, Heather Mack, has seen how contentious the release of Calgary's updated flood maps was and says. "It's a tough call. I don't envy the city's position.”

"It's climate change that's causing a lot of these problems. These raging cloud bursts that we get and all the sudden dump a ton of water and our infrastructure just wasn't built for that climate. Huge problem."

Edmonton residences built prior to 1980 are particularly vulnerable as their sewer systems allowed for only a one-in-10-year storm; conversely newer neighbourhoods have been constructed in such a way that the roads function as small rivers in the case of large storms, acting as a back-up system keeping water away from houses until such floodwaters subside.