While there鈥檚 simply no way to handle 1.4 metres of water falling on a city, one disaster reduction expert says there are other measures that Canadian and American cities can take to avoid the current fate of hurricane-swamped Houston, Texas.
Good urban planning is ultimately the best way to avoid flooding caused by heavy rainfall, according to Glenn MacGillivray, managing director of the Toronto-based Institute for Catastrophic Loss Reduction. MacGillivray says many cities fall prey to the financial lure of allowing urban sprawl, which often leads to wetlands and green spaces being paved over in the name of growth. But MacGillivray says those natural spaces are vital for absorbing heavy rainfall, and their absence can leave cities vulnerable.
鈥淲e鈥檙e paving over everything,鈥� he told CTV鈥檚 Your Morning on Tuesday. 鈥淭here鈥檚 just nowhere for the water to go.鈥�
Tropical storm Harvey has dumped an estimated 76 centimetres of rain on Houston, with another 61 centimetres expected to come before the storm lifts.
MacGillivray acknowledged that there鈥檚 鈥渘ot a city on Earth鈥� that could endure that amount of rainfall. However, there are plenty of lessons to be learned from Houston鈥檚 current predicament.
For instance, he says Houston has made itself more vulnerable to flooding in recent years by paving over an estimated 227 square kilometres of wetlands and green space, which would otherwise have helped with the flooding. He says the city has taken other measures to protect itself from heavy rainfall, but ultimately, there is no replacing the relief of having wetlands nearby.
鈥淗ow would that city perform right now if those wetlands were still in existence?鈥� he wondered.
MacGillivray laid part of the blame at the feet of city officials who are 鈥渆ntranced by the lure of development,鈥� and who often do not have to foot the bill after a disaster. 鈥淭hey don鈥檛 have to pay for it,鈥� he said. 鈥淭he more senior levels of government come in and pay for the disaster, so there鈥檚 a disconnect there that I think needs to be corrected.鈥�
He says sprawling urban development only makes a city more vulnerable to intense weather brought on by climate change. A better alternative would be for cities to focus on building denser housing and better infrastructure, rather than spreading out into natural spaces. 鈥淲e really have to look at the long view and what we鈥檙e going to do with this water, particularly as climate change grabs hold even more,鈥� he said.
And while it鈥檚 unlikely that Canada would ever face 1 metre of rainfall in a short period of time, MacGillivray is quick to point out that it doesn鈥檛 take nearly that much water to cause a flood. Toronto, Gatineau, Ottawa and communities in southern Alberta have all felt the effects of flooding in recent years, and none of them faced nearly the same amount of rainfall that fell on Houston.
鈥淚 don鈥檛 think we should be too smug in Canada,鈥� he said. 鈥淲e don鈥檛 get 50 inches of rain, but we get enough.鈥�
With files from The Associated Press
