SP0158: Sustainable Rainwater and Flood Management

In Montreal, during heavy rainfall, overflow of sewage and rainwater is dumped directly into the St-Lawrence river without treatment as the City does not have independent drainage systems. As a means of addressing this issue, the City now requires that all new exterior construction projects capture rainwater on site during a storm, and slowly release the water to the municipal system to avoid overwhelming it. The simplest and most commonly used approach to this mandate is to store the water in underground plastic/concrete basins and slowly release it into the municipal sewage system. This project will develop a much more sustainable approach for McGill water management by developing and testing a master plan (of water retention and transmission) which will involve evaluating different low cost sustainable rainwater and flood management options for McGill's downtown campus using state-of-the art hydraulic models and by studying the flood consequences, taking into consideration McGill's infrastructure and the Montreal storm water system. 

The Project will explore an integrated strategy for rain and flood water harvesting to provide water for campus irrigation, urinals, etc. The introduction of these eco-based approaches can both increase biodiversity and restore natural hydrological cycles on campus. These approaches also reduce the wasted resources that go towards treating rainwater when it is combined with sewage, and they present an opportunity to reuse rainwater on site, in addition to reducing potable water consumption in a significant way. Sustainable rainwater management alternatives that will be evaluated (of which some will be implemented for testing and demo purposes) may include land hilling, stream creation and/or channeling, infiltration trenches, vegetation planting, small detention ponds, etc. 

Without this project, McGill would be required to hire an external civil engineering firm to develop the management system mandated by the City. These firms, who generally have very limited knowledge of ecosystem-based design, will very likely implement a traditional concrete/plastic rainwater system in which they are familiar. By developing the master plan with key stakeholders while simultaneously educating them in the process, we can ensure a consistent application of much more sustainable strategies across all future projects. The implemented strategies can then also be used as hands-on teaching tools for students, staff, and the broader public to learn about water systems and management. This project will also contribute to LEED certification on all projects across campus. 

The main results of the implementation of ecosystem based rainwater management practices are: reduction in construction material use; reduction of GHG emissions, reduction in waste water creation; more sustainable land use; reduction of potable water use; reduction in energy use; creation of a living lab for experiential learning; increasing staff, student and sub-contractors' knowledge and skills related to sustainable water management; increasing biodiversity and human-health related impacts; and, reducing the cost and increasing the sustainability of rain and flood management on campus. 

Funds from the SPF will primarily be used to compensate two Project Associate positions. Resources and additional funding from the SPF will also be used for data collection, calibration and validation of a Personal Computer Storm Water Management Model, GPS, transportation, mapping/printing and field measurements.