Transforming an industrial area of Toronto into a vibrant and modern community

The Cowdray Court project faced several significant challenges due to constraints with the existing infrastructure, which was originally designed for commercial and industrial uses. These challenges had to be addressed to make the high-density residential development viable: 

• Floodplain issue: The redevelopment potential of the site was significantly constrained by an unresolved floodplain issue and couldn’t proceed to the next approval stage without accurate floodplain mapping and adjustments. 

• Environmental Assessment (EA) constraints: The Municipal Class Environmental Assessment governing the Southwest Agincourt Transportation Connections Study required all engineering design for the subdivision (road layout, grading and servicing) to be fully compatible with future municipal roads and a railroad underpass in the EA. 

• Railroad setback constraint: A 30-meter setback along the site’s south boundary required special design considerations for grading and servicing. 

• Sanitary sewer capacity: The existing sanitary sewer was not large enough to handle future demand. Designing a new sewer system with minimal disturbances to the existing infrastructure was essential. 

• Inadequate water pressure: A study by Hydratech for the City of Toronto found that water pressure in the Agincourt District was insufficient for future development, so pressure zones had to be adjusted.  

• Stormwater infrastructure issues: The existing industrial subdivision was developed when stormwater management standards were lower or non-existing. A comprehensive stormwater treatment train approach was required to meet current standards.

GHD provided civil, servicing and stormwater management engineering design services to aid in the rezoning, draft plan of subdivision and site plan applications.  

Addressing the challenges required innovative engineering solutions and close collaboration with various stakeholders including: 

• Floodplain adjustments: We supported Gemterra Developments in amending the West Highland Creek floodplain map through technical revisions to the TRCA’s  HEC-RAS model. The amendments were approved in 2023. 

• EA and railroad setback: We developed a subdivision grading plan that was compatible with future municipal roads. This plan also included a safety berm and crash wall along the south boundary to address the railroad setback constraint. 

• Sanitary sewer upgrade: We designed a new sewer system to accommodate the increased demand from the new development. This design minimized disturbances to the existing trunk sewer along the east boundary. 

• Water pressure improvements: We completed a local study that was compatible with Hydratech’s pressure adjustment recommendations to demonstrate that the Cowdray Court project could be serviced as per the City of Toronto’s criteria. 

• Stormwater management (SWM): We designed a comprehensive SWM solution for the subdivision and each of the proposed development blocks and roads. This included both minor and major drainage systems, water quality, water balance and water quantity approaches using best management practices and nature-based solutions. 

• Green infrastructure: Our proposed SWM system incorporated green infrastructure features such as green roofs, Silva cells, infiltration galleries and greywater reuse to manage water balance, quality and quantity effectively. The design of green roofs and Silva cells required extensive coordination with the project's landscape architect  to integrate these features seamlessly into the development. 

• Advanced Hydrological Model: We developed a fully-integrated hydrological and hydraulic model to demonstrate the effectiveness of the proposed minor and major drainage systems, emergency overland drainage route to West Highland Creek, water quality objectives, water balance targets and water quantity controls under prescribed single event and continuous modelling simulations. 

The Cowdray Court redevelopment project shows how thoughtful urban planning and innovative engineering can create a sustainable and thriving community. Gemterra’s commitment to sustainability and green infrastructure is demonstrated by the implementation of best management practices and nature-based solutions like green roofs, Silva cells, infiltration galleries and greywater reuse systems to manage stormwater, enhance air quality and promote a healthier living environment. These initiatives align with the environmental goals of the City of Toronto and TRCA, setting a benchmark for future developments. 

The project also addresses critical infrastructure challenges through innovative and collaborative efforts. Floodplain adjustments, water pressure improvements and sanitary sewer upgrades have contributed to the development’s viability while enhancing the surrounding area’s infrastructure. New municipal roads and improved drainage systems will provide better connectivity and reduce flooding risks, setting the community up for success for generations to come.