Pre-design report: Pointe-Saint-Charles blue-green alley project

This report presents the 2020 blue-green alley project for the Montreal borough of Pointe-Saint Charles. The project involves disconnecting roof drains from municipal networks in order to redirect rainwater to green infrastructure located in alleyways. This project explores three themes: (1) infrastructure sharing, (2) identification of a cost effectiveness threshold for this type of development; and (3) creation of differentiated incentives to encourage investment by various stakeholder groups. The document promotes innovative models that build on local appropriation (i.e., integrating and taking ownership) of nature-based solutions. It is aimed at finding solutions for the use of rainwater from the roofs of neighbouring buildings, with the objective of retaining and treating runoff on site, demineralization and increasing vegetation cover.

Understanding and Assessing Impacts

This report is further to the feasibility study conducted in 2018 by Alliance Ruelles-Bleues-Vertes (ARBV) and its consultants to assess the project’s potential and feasibility. The feasibility study assessed the impacts and demonstrated the interest in the project. It focused on two alleys in order to accommodate the pilot project, which proposes to disconnect roof drains from municipal networks to redirect the rainwater to green infrastructure located in alleys. One of the two sites selected is the alleyway on the south side of Building 7 in the borough of Pointe-Saint-Charles.

Identifying Actions

  • Various strategies were considered through an iterative and collaborative process:
    • Mobility and traffic strategy
    • Rainwater strategy
    • Vegetation strategy
    • Lighting and electrical strategy
    • Furniture strategy
    • Materiality strategy
    • Sharing strategy – winterization


The analysis and feasibility studies were followed by public outreach and engagement workshops to enhance social acceptability of the project. Visioning workshops on the project design were then held. Temporary facilities were installed. Lastly, validation workshops were held and project plans and specifications were developed. Permanent facilities were created and planting events were held. All of these activities were steps towards the inauguration of the project in 2020.

Outcomes and Monitoring Progress

The objective was to move from a pilot project to a replicable model. The project is currently being implemented.

Next Steps

The key objectives of ARBV are to replicate this type of project, in whole or in part, so that they are no longer considered pilot projects. In addition, this project focuses specifically on the built environment, as it has considerable potential for action, as opposed to waiting for new constructions. To this end, innovative models will be promoted that build on integrating and taking ownership of this type of approach by a wider variety of stakeholders. The field of water management has traditionally been the purview of engineering and natural science experts. Although such experts are critical, the RBV project promotes the integration of non-traditional stakeholders, such as community groups, citizens and those working in the social sciences in order to explore new methods of collaboration with the view to moving the practices forward.


Link to Full Case Study (in French only)