Stormwater

Stormwater DrainStormwater Drain

When precipitation occurs, several things can happen to the water. Through the hydrologic cycle, natural landscapes, such as forests and wetlands, trap rainwater and snowmelt, and filter it as it percolates into the ground. In contrast, an urban environment consisting of paved surfaces such as roads, buildings, bridges and parking lots, and other impermeable areas such as airports and building sites, interrupt the natural hydrologic cycle by preventing percolation and thereby decreasing the water available to recharge groundwater. Instead of seeping slowly into the ground, water remains on the surface, accumulates and runs off in large amounts, creating the potential for flooding and erosion. This runoff is referred to as stormwater.

Adapted from Pollution Probe's Source Water Protection Primer

Why Should I be Concerned about Stormwater?

As the stormwater flows, it also picks up and carries away contaminants lying on the impermeable urban surfaces, such as oil, gasoline, road salts, pet droppings, and other potential hazardous chemicals.  This polluted stormwater flows directly into waterways, or into drains (also called catch basins), and then into city storm sewer systems. 

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Stormwater Management

In much of Canada, urban stormwater infrastructure falls within the jurisdiction of municipalities however, provincial and federal governments have historically assisted with research, guidelines, data and information, and provided capital funding. However, the level of provincial and federal involvement will likely decrease over the next decade and possibly beyond because of the current trend towards delegating services and associated responsibilities to lower levels of government.

Rainbow over OttawaRainbow over OttawaProvincial Government Stormwater Responsibilities

The primary areas where senior government agencies are involved include research; development of stormwater management guidelines; collection, analysis and provision of hydrometric data; and targeted funding programs for infrastructure renewal. In addition to governments, the urban development and the insurance industries play major roles in stormwater management, in terms of investment costs and covering potential weather-related and other damages.

The Provincial Government of Ontario

The Ontario Ministry of the Environment initiated the development of a Stormwater Management Practices Planning and Design Manual and have updated it with the help of the Government of Canada's Great Lakes Sustainability Fund, Credit Valley Conservation, and other agencies.

The 2003 manual provides technical and procedural guidance for the planning, design, and review of stormwater management practices. The manual is intended as a tool for understanding the performance requirements of stormwater management projects. The manual provides practical guidance that has been found to be effective in specific circumstances. The manual will also be used as a baseline reference document in the review of stormwater management applications for approval under section 53 of the Ontario Water Resources Act as administered by the Ministry of the Environment.

See here to learn more about the Ontario Ministry of the Environment Stormwater Management and Design Manual

The Provincial Government of Quebec

In the majority of cases, water services in Québec come under the municipalities, which own many of the infrastructures related to wastewaters. The municipalities plan, finance, maintain, and control most of the activities related to these services.The provincial government works with the municipalities providing support through finances and establishing terms of reference governing the exercise of municipal responsibilities for water management.

Through the Québec Water Policy the government of Québec has committed to undertake the following action related to stormwater management:

  • Urge and assist municipalities to reduce the frequency of overflows by 20% in combined sewer systems during rainstorms, by 2007.
  • Establish a strategy to govern urban discharges in Québec.

By taking this course of action they expect to see:

  • a reduction in the frequency of overflows of wastewaters into the environment for improved protection of watercourses, especially for swimming and other recreational uses;

For more information on stormwater management in Québec see the Québec Water Policy, and the MDDEP's Wastewater webpage

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How to Reduce the Effects of Stormwater

Pick up after your pet to prevent pollutionPick up after your pet to prevent pollution

  • Pick up after your pet to prevent harmful bacteria from polluting stormwater.
  • Use rain barrels to collect stormwater from your roof to reduce runoff of rainwater.
  • Use the water on your lawns and gardens.
  • Hand weed to avoid the use of herbicides.
  • Eliminate the use of pesticides and fertilizers.
  • Sweep soil and vegetation away from pavement and storm drains to reduce silt from entering rivers and streams.
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