Is Montreal ready for emergencies?

City deserves credit for getting ready to cope with weather extremes, but Chicago shows it might be wise to do even more


The Gazette May 26, 2011

The Richelieu Valley’s freak flooding, causing mayhem for hundreds of homeowners, shows what can happen when municipalities don’t anticipate the sort of extreme weather events that climatologists say could become much more common.

Chicago, having learned its lesson from a 1995 heat wave that contributed to the deaths of about 500 people, has become a leader among North American cities in preparedness against various kinds of extreme weather. Is Montreal doing enough?

This city’s vulnerability to weather extremes is plain. Last July’s heat wave, according to public-health authorities, precipitated the deaths of 106 people. Also last summer, tornadoes – ultraweak and undestructive – were spotted in Ste. Anne de Bellevue and the northern suburb Mascouche. No one will forget the 1997 rainstorm and the 1998 ice storm. And lest anyone smugly assume that the city’s remoteness from the coast gives it immunity to those increasingly severe hurricanes, bear in mind that Hurricane Hazel in 1954 blasted a city far more inland than us, Toronto, drenching it with 11 inches of rain and causing 83 deaths.

To be sure, no single weather event, including the Richelieu River’s overflow, can be blamed on human-made greenhouse-gas emissions, but most scientists say increasing emissions contribute to the overall trend.

The Tremblay administration – in particular, the executive committee’s Alan DeSousa – deserves credit for taking various steps to adapt to changing weather conditions (as distinct from taking steps to reduce greenhousegas emissions). The city is:

–Building four water-retention basins to keep sewers from overflowing during storms. (The four are in Ahuntsic, Lachine, Griffintown and St. Laurent.)

–Banning construction of new buildings on Montreal Island within 10 metres of the St. Lawrence River and the Rivière des Milles Îles. (Time will tell if 10 metres is enough.)

–Extending water-intake pipes farther into the St. Lawrence River in anticipation of lower water levels.

–Repairing leaking under-ground pipes carrying drinking water. This will, among other things, help in the event of future water shortages. DeSousa estimates that leakage caused the loss of 40 per cent of water a decade ago, that this is now down to 30 per cent, and that it should be at about 20 per cent by 2015.

–Obliging all new-building and renovated basements to install backwater valves, according to a bylaw effective in July. At times of heavy rain, these devices prevent sewers from backing up.

–Planting more shade trees to cool the territory and absorb rainwater, and encouraging vegetation on roofs.

–Bracing for the latest in-vasive species, the ash borer beetle, by ceasing as of last spring to plant its favourite food, ash trees, along Montreal streets. The insect has already killed tens of millions of such trees in the U.S., and warmer weather has brought it to southern Quebec. Ash trees are second only to maples as the most common tree on streets and in parks.

–Imposing new rules for off-street parking spaces in St. Laurent, where DeSousa is borough mayor. Asphalt parking lots absorb heat and don’t absorb rainwater, contributing to flooding. A 2009 borough bylaw reduces the number of parking spots required per building (thus also encouraging use of public transit), shrinks the size of each spot by five per cent, requires shade trees to cover 40 per cent of new spots and authorizes the use of permeable paving to replace asphalt.

Chicago is doing some of the same things as Montreal, such as building underground storage tanks for rainwater. But, as the New York Times reports, it is also doing a lot of other things.

In anticipation of a hotter future, it has stopped planting native Illinois species of trees and is replacing them with varieties from the southern U.S. It is planting those trees a foot or so below the surface sidewalks so that rainwater can readily drain into them. It is also seeding these sunken areas with special weeds that resist drought, absorb water and filter de-icing salts.

Most ambitiously, Chicago is also redesigning its streets. When it builds bike lanes and parking lanes, it introduces light-reflecting surfaces that reduce heat. Fragments of recycled tires are in this asphalt, allowing the pavement to contract in winter without cracking, and expand in summer without buckling.

Chicago gets a lot hotter than Montreal, which helps explain its being in the vanguard. But if the climatologists are right, Montreal can expect to get much, much hotter, too. Getting more prepared is a sound investment; Millions spent today can save billions down the road.