Water management is expected to cost Montreal billions; the city wants your input | CBC News

Aging infrastructure, climate change and population growth are putting significant pressure on Montreal’s water resources. Faced with the magnitude of the issues and the cost of planned investments, the city is launching a public consultation on the future of water on its territory.

Montreal wastes too much drinking water, dumps too many pollutants into the St. Lawrence River, its aging infrastructure is unable to cope with the ever-increasing quantity of water spilled during torrential rains, and the city does not have enough money to update and adapt its water management infrastructure.

These are some of the findings raised in a report prepared by the Commission sur l’eau, l’environnement, le développement durable et les grands parcs.

Wasted drinking water

Canada is among the countries that wastes the most drinking water, and the city of Montreal is one of the worst cities in the country for this, according to the commission’s report.

Montrealers consume 367 litres per person per day for residential purposes, according to 2020 data. The average consumption for the rest of Canada is 220 litres.

“In Paris, it’s 120 litres a day, and in London, it’s 140 litres,” said Maja Vodanovic, responsible for consultation with the boroughs and water on the city of Montreal’s executive committee.

Water leaks in the distribution network are partly responsible for this poor track record. The municipal administration estimates that a quarter of the water wasted comes from leaks.

“There are leaks in the public network, but there are also a lot of leaks in homes,” Vodanovic told The Canadian Press, adding that “there are still a lot of businesses that air-condition using drinking water.” 

She invited the public to take part in the public consultation to find solutions to these problems.

Protecting resources

Industrial discharges into the river and the island’s water bodies are constantly evolving, according to the commission, and only 38 per cent of waterways have “satisfactory quality.”

“We now know that the St. Lawrence River is one of the most polluted rivers in terms of microplastics. It is in the same categories as the highly polluted rivers of Asia,” said Vodanovic, referring in particular to per- and polyfluoroalkylated substances (PFAS), which are found in many consumer products and which can cause health problems.

She said it is necessary to act at the source, to reduce the quantity of this type of pollutant in the water, in particular when washing clothes in washing machines that do not contain the appropriate filter.

Cross connections of buildings, where sanitary and storm sewers intersect, are also a major source of pollution. When flooding occurs in areas where buildings have crossed connections, sanitary wastewater flows into the Rivière des Prairies and the St. Lawrence River without treatment. 

Adapting to climate change

Montreal has received 20,000 reports of flooded residences since 2013 and “this number is going to increase,” Vodanovic said.

“Even if we redid all the sewers, which would cost between $7 billion and $8 billion, there would still be flooding.”

She pointed out that adapting to climate change also involves “modifying the built environment of some houses, by putting walls, valves, drains.” It is necessary “to make concrete basins” and “to change the geometry of certain streets so that the water is routed to vacant lots.”

Adapting to climate change also requires green infrastructure. More vegetation is needed to absorb rainwater, to prevent it from overloading the city’s aging infrastructure and underground network.

This includes the use of green roofs, rain gardens, water retention ponds and permeable surfaces to capture and store water.

“According to projections for 2050, critical rainfall intensities will increase by an average of 15 per cent compared with today, and the frequency of flooding is likely to double,” the commission’s report said.

Vodanovic, who is also Lachine’s borough mayor, estimates that $1 billion a year is needed to finance water management.

“This is one of the reasons why all the cities are asking the Quebec government to set up a green pact of $2 billion a year for the next five years,” she said.

The public consultation on water management will take place until Oct. 4, and the recommendations will be presented and adopted at a public meeting on Dec. 5.