Black bitumen lakes spread all over towns and villages, parking lots increasingly represent a battlefield in the fight against climate change. Some options make the greenery bloom among these large asphalt surfaces, but regulations are slow to take root to standardize the development of greener, more attractive and more user-friendly parking lots.
Where it reigns, the realm of the automobile seems endless. Laval had, in 2019, more than half a million parking spaces on the whole of Jesus Island, or three spaces for each car – not counting residential entrances. On average, more than 80% of these parking lots remained unoccupied at all times of the day, and 90% of their surface had no trees.
Another example: Drummondville calculated, a few years ago, that mineralized surfaces occupied nearly 50% of its downtown area. Between the roadways and the parking areas, the ground occupation of the buildings was limited to a meager 18.5% in the heart of the city.
These large asphalt surfaces where cars come to nap while waiting for their master pose several problems. First, parking lots generate heat islands, to such an extent that the perceived temperature can easily rise by 10°C compared to other urban areas within the same perimeter. A mercury that jumps in the city increases, by ricochet, the use of air conditioners, which are often energy-intensive, to the point that “a 2°C increase induced by urban heat islands can increase energy consumption by 5%”.
As early as 2009, the National Institute of Public Health (INSPQ) sounded the alarm: “on hot days, asphalt surfaces can reach temperatures of 80°C”, wrote the INSPQ in its Measures to combat urban heat islands. The document pointed out that these conditions contribute to the formation of smog and mold, in addition to exacerbating a whole range of chronic diseases.
Another hitch: parking areas around schools, grocery stores, hospitals, arenas, warehouses, shopping malls, etc. do not absorb rainwater. As soon as it hits the ground, it stagnates or rushes into the municipal aqueduct networks, which are already struggling to absorb the increasingly frequent torrential rains in Quebec, as the deluge that fell on Montreal last September showed. .
“Climate change is changing the frequency of extreme events,” explains Professor Sophie Duchesne, researcher at the National Institute for Scientific Research (INRS) and expert in hydrology and urban infrastructure. When it rains on a highly mineralized surface, this water falls on an impermeable surface and it flows quickly to join the municipal network. It creates flash floods very quickly. »
“We are still investing a lot of financial resources to enlarge the roads and to concrete, observes the interim director general of Nature Québec, Cyril Frazao, but not enough to revegetate and revitalize the paved areas. »
Other promising options
However, other options to traditional parking lots exist and allow municipalities to save significant amounts of money, in addition to creating more user-friendly areas for the population.
A few cities have adopted more thoughtful parking lot designs to reduce heat absorption and increase rain absorption. Professor Duchesne notably worked on the development of the eco-responsible Pierre-Laporte parking lot located in downtown Victoriaville. Formerly a sea of asphalt like Quebec has so many, this parking lot has undergone a green treatment in 2020.
A honeycomb paving gives a glimpse, in summer, of grass growing under the axles of automobiles. Water retention islands, provided with freshly planted plants and trees, make it possible to soak up surface rainwater before it runs off to the sewer. Picnic areas have also taken root, and even pedestrians and cyclists find their way thanks to walking corridors and bicycle garages.
“Parking becomes a sponge,” explains Professor Duchesne. In addition, adds Romain Coste, coordinator at the Regional Council on the Environment of Montreal (CRE), the new car park encourages a mix of uses. “Traditional parking lots are designed solely around the automobile, never for active and public transport,” he laments. The layout is car-centric, and we forget about other ways of getting around. »
The improvements made to the Pierre-Laporte parking lot required a few million and the sacrifice of 20 car parking spaces. However, there are still 141 left today, not counting those added for bicycles.
This expense was well worth the effort, according to the Town Hall. “It costs a little more at the time, explains the mayor of Victoriaville, Antoine Tardif. On the other hand, in the medium and long term, we get back our money by avoiding having to excavate to enlarge our sewers and by reducing the quantity of water to be filtered in our purification centers. »
Victoriaville is, along with Drummondville and Pointe-aux-Trembles, one of the few municipalities in Quebec to have adopted a by-law governing the design of more user-friendly and greener parking lots. “In the future, each time we have to repair a parking lot,” underlines Mayor Tardif, “we will have to fulfill requirements for it to become more ecologically responsible. »
The private challenge
Since 2017, Romain Coste, from the CRE de Montréal, has been leading a campaign set up to support the conversion of parking lots and encourage best practices. He believes that the example of Victoriaville must be generalized sooner rather than later in Quebec.
“The pace is quite slow, and we still have some challenges in our approach,” he says. Everyone agrees on the importance of greening our cities, but as soon as we touch on the number of parking spaces, some elected officials rebel for fear of popular discontent. People are always crying disaster, and each time the worst never happens. »
In Montreal, certain boroughs, such as Saint-Laurent or Le Sud-Ouest, are at the forefront of parking issues. In others, there are sometimes no standards for tree planting or stormwater management, laments Romain Coste.
The CRE believes that regulations are one of the keys to standardizing the construction of green parking lots. Taxation can represent another, according to Romain Coste, by promoting good practices and taxing bad ones.
Taxation could also encourage the private sector to embark on the movement to demineralize parking lots, he explains. The CRE lists in Montreal about 500 parking lots with at least 100 spaces which together cover a few thousand mineralized square kilometres. A quarter of them belong to the industrial sector, another to public institutions, while half depend on the commercial sector.
“There are many more greening opportunities in private parking lots than in public parking lots,” says Cyril Frazao, from Nature Québec. The hunger to do things better, however, does not yet grip the large private owners.
“In new shopping centres, observes Mr. Frazao, there will be one tree for every 10 parking spaces… It’s a bit of a greenwashing. »
For the past few years, the CRE has been rewarding the most inspiring parking lots in Quebec by giving them an eco-responsible certificate. So far, 10 have obtained the mention.
“Municipalities are aware of these issues; on the other hand, it lacks a lever to generalize the practice. The next step, concludes Romain Coste, is to review the regulations to establish new standards for the development of parking lots. »
To prevent the climate of cities from drifting in asphalt seas with no other use than parking cars.