Mundy Watershed Modelling

Water Street was retained by the City of Coquitlam to carry out the hydraulic modelling of Mundy Watershed, which totaled 476 ha. Due to ongoing development of the watershed, the City wanted an updated stormwater model to assess how different levels of impervious surfaces in residential areas impact the stormwater infrastructure. The purpose of the project was to understand the implications of further densification in the region.

The stormwater model for this project was developed using PCSWMM. This model was then used to analyze how the existing stormwater infrastructure performed under existing and future IDF curves at various levels of imperviousness in residential areas. A cost estimate was completed for each scenario to estimate the costs of the required upgrades for each scenario.

The analysis indicated that some of the upper storm sewers in the Mundy Watershed were modelled to flood in all scenarios, while a large portion of the storm sewers were predicted to flood during the future and high imperviousness conditions.

Based on the findings of the analysis, Water Street recommended multiple solutions ranging from guideline and policy development to infrastructure investment.