The City of Montréal is planning to develop its first water square. Inspired by the Netherlands, this urban planning concept consists of building a floodable public square, using water as a central, attractive and playful element.

The feasibility study conducted by the borough of Le Plateau-Mont-Royal found that it was possible to build a multifunctional public space that could sustainably manage rainwater and improve citizen quality of life. This means that instead of investing in two separate structures, it is possible to invest in a single structure that combines two functions that were once incompatible.

The Fleur de Macadam Water Square will be built in the heart of the borough, on Mont-Royal Avenue East between Boyer and Mentana streets. It will have a surface area of about 1,000 m2. Serving as a gradual transition zone between the commercial artery and the residential neighbourhood through the use of vegetation and by providing a welcoming atmosphere, the future public square will also improve resilience against climate change.

The water square will make it possible to slow down water runoff, reduce flooding and backups in the event of intense rainfall, and reduce the frequency of overflows while improving the built environment and the population’s well-being. The facilities will be of higher quality than those of traditional parks, since the money invested in water management, which is usually handled underground, will be invested in surface structures. The presence of water will also have a beneficial impact on fauna and flora by transforming a heat island into a green public square.

The water square project could have a snowball effect. The City of Montréal is currently looking into projects for the sustainable management of runoff water in order to reduce the number of overflows at various locations in its jurisdiction. Providing a retention capacity for 100‑year rainfall events at no additional cost is a major asset for reducing the city’s vulnerability to climate change.

This approach is especially interesting for large cities where there are few opportunities to build traditional retention ponds and where urban densification is leading to increased sanitary flows. It will surely inspire other cities that also need to find additional runoff water storage volumes to protect people, property and the environment.

Project details

  • Project name: Water Square: A Good Way to Mitigate the Impacts of Intense Rainfall in Urban Quebec?
  • Sector: Adaptation
  • Type: Feasibility study
  • Grant amount: $110,480
  • Location: Montreal, QC

Primary objectives

  • Transform a heat island into a green public square with structures that are able to capture a maximum volume of rainwater from the main system;
  • Ensure the compatibility of retention usages and recreational usages;
  • Limit system overload in the event of intense precipitation through temporary retention and controlled discharge;
  • Guarantee of zero water discharge into the sewer system for 1-in-10 year events;
  • Limit the risks associated with intense rainfall for up to 1-in-100 year events;
  • Filtering and treating rainwater so it can be reused for recreational and refreshment purposes;
  • Promote the presence of water to add an educational vocation to the square;
  • Raise public awareness about sound water management through information signs, educational workshops and works of art;
  • Propose a user-friendly public square that can be used for relaxation and contemplation.

“As part of its major goals of improving the quality of facilities, the safety of users, active transportation and the equitable sharing of public spaces, the Borough is putting a lot of efforts in improving the quality of life of its citizens. Often recognized for its leadership, the Borough has stood out with this project by proposing an innovative, audacious, durable and resilient approach to confront climate change. By offering and multiplying the number of these types of multifunctional spaces, the City will be able to face climate variations while continuing to provide citizens with quality experiences and adequate facilities.”

–Michaël Tremblay, Director, Territory Development and Technical Studies
City of Montréal

By the numbers

  • The water square will have a surface area of 1,000 m2;
  • The square will limit the risks associated with intense rainfall for up to 1-in-100 year events;
  • The infrastructure will be able to absorb 19 mm of rainwater without any discharge;
  • The infrastructure’s maintenance costs are estimated at $15,900 per year.

Project activities

  • The feasibility study was completed in fall 2019;
  • A contract will be awarded soon following a public call for tenders for the design of the permanent site structure;
  • The final draft should be completed in summer 2020;
  • A second call for tenders will be launched in winter 2020 for the construction;
  • The goal is to start construction work in spring 2021.

Resources

Borough of Le Plateau-Mont-Royal
The Berthemplein water square in Rotterdam, Netherlands

Contact

Borough of Le Plateau-Mont-Royal 
communicationplateau@gmail.com

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