Port Credit Storm Drainage Master Plan

The Storm Drainage Master Plan is a study to identify the potential drainage system issues in the Port Credit Neighbourhood. The study will evaluate existing drainage system capacity. It will also identify impacts related to infill and intensification development, as well as climate change.

A plan will be created to mitigate any identified deficiencies.

In recent years, the Port Credit Neighbourhood has been subject to infill and intensification development, and is likely to see more. However, recent assessments or evaluations of the drainage system capacity have not yet been completed. For this reason, the City is undertaking this project to address current and future requirements of the City’s storm drainage infrastructure.

When rainwater hits the ground or when snow melts, it generates stormwater as it runs off the surface. Hard surfaces like asphalt or concrete generate more stormwater than soft surfaces like grass. This is because stormwater cannot soak into the natural ground and flows off of the land more rapidly. This ultimately increases the potential to cause flooding and erosion.

• Urban growth and development alter the amount of runoff and pollution.
• Infrastructure such as pipes, culverts and outfalls have limited life expectancy.
• Stormwater facilities must be actively maintained throughout their expected life. This includes watercourses, storm sewers, catch basins, stormwater ponds, pump stations, culverts and outfalls.
• Climate change could affect the intensity and frequency of storm events that stormwater management programs must respond to.
• Appropriate resources, assets and improvement projects must be proactively planned to address needs and problems.

These are most often structural measures that municipalities use to manage stormwater. For example, the City may build a detention pond such as a stormwater management facility to temporarily hold back water to reduce the impact of peak stormwater flows during heavy rain events. The City may also use measures like rain gardens to clean stormwater before it is released to creeks and watercourses.

River or Riverine flooding is associated with excessive rainfall or snowmelt that results in rivers exceeding their capacity. As a result, water flows outside of the river banks. Urban flooding is associated with excessive rainfall that cannot be absorbed into the ground and overwhelms the urban drainage system. For example, when there is more water than the sewers can convey, this results in flooding on roadways.

Infill housing is housing that fits within an existing neighbourhood. Infill can mean a variety of things, such as filling in a gap between houses to build a new house or severing a lot to build a new house. Sometimes infill results in intensification (when one house is replaced with two new houses), or sometimes it does not (when one house is replaced with one new house).

Intensification is the intensification of a property, building or area that results in a net increase in residential units. It does not include replacing a small house with a larger house or an old house with a new house. Intensification can include a variety of things such as developing on a vacant lot, infill development on small sites or expanding residential buildings to create more units.

Infill and intensification are important as they provide more housing using less land, which is good for the environment as well as affordability. In the context of the Storm Drainage Master Plan, the Study will allow the City to evaluate existing stormwater infrastructure to plan for and provide enough capacity to support infill and intensification development.