Ville de Gatineau
Eavestroughs and runoff
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Eavestroughs and runoff
Eavestroughs and runoff

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Manholes and catch basins are designed to capture rainwater only. The water is then redirected to a waterway, generally without treatment. Thus, discharging into them any substance that could alter the quality of the environment is prohibited.

Heavy rainfall may result in runoff saturating the sewer system, which may lead to:

  • additional costs for wastewater treatment plants;
  • overflow into waterways, causing significant harm to wildlife and vegetation due to pollutants such as fertilizer, oil, grease and pesticides carried by the runoff; and
  • damage to properties due to flooding.

The benefits of managing water runoff on your property

  • Reduced risk of damage to properties from sewer backups and flooding
  • Healthier lawns requiring less maintenance
  • Less erosion on the property
  • Attractive rain gardens or green driveways

Ways to limit water runoff

Modify eavestroughs

Eavestroughs that are directly connected to the foundation drain or that direct rainwater to an impermeable surface increase the amount of runoff going into the sewer system, which can overload the system.

Properly modifying eavestroughs can help divert, on average, 100,000 litres of rainwater annually from the sewer system per home.

Proper eavestrough installation

Rain barrel:

A standard 200-liter rain barrel can save close to 6000 litres of tap water annually. The water collected can be used to water gardens, lawns and flower beds, wash cars, and even top up wading pools and swimming pools. If you cannot divert the water from your eavestroughs to a permeable surface, this is a good option. Just cut the downspout and attach it to the rain barrel.

Rainwater diverter:

A rainwater diverter connected to a downspout redirects the rainwater to a grassy area located at least 1.5 m from the building foundation.


Water from eavestroughs must at all times remain on the property, and must never be diverted to a neighbouring property or onto the road.

Examples of improper eavestroughs

Connected to the foundation drain:

the building's eavestroughs are connected to an underground pipe that takes the water to the foundation drain, which leads to the sewer system.

Directly to the street:

the building's eavestroughs are connected to an underground pipe that takes the water to the street, which leads to the sewer system.

Drainage onto an impermeable surface or less than 1.5 m from the foundation:

the building's eavestroughs take the rainwater to a paved surface, which leads to the sewer system.

Less wasted tap water

Did you know that washing your car with a hose uses close to 400 litres of tap water? Using tap water outdoors can overload the sewer system. By wasting less tap water outside, you reduce the amount of water runoff, and therefore the amount of water running into the sewer system.

Practice bioretention

There are a number of landscaping arrangements that maximize the absorption of stormwater into the ground and their percolation to water tables. Esthetic and effective, the solutions presented here help reduce the amount of water running into the sewer system.

Rain gardens

Rain gardens are landscaping arrangements that are designed to collect stormwater. They are located in depressions in the ground that stormwater tends to flow into and then sit. You can direct water from eavestrough downspouts to them!

Did you know that trees, shrubs and plants intercept and retain surface water better than a lawn? A single tree can intercept 6,600 litres of water annually.

Ecological lawns

An ecological lawn refers to the use of indigenous plants that are naturally adapted to local conditions. Those species are more resistant to bad weather, and therefore require less maintenance than a traditional lawn and less artificial watering. Thus, they help reduce the use of tap water and, possibly, runoff.

Green driveways

Paved driveways are impermeable surfaces that prevent the absorption of stormwater, which increases runoff. There are a number of innovative and esthetic solutions. In addition to minimizing runoff, they reduce heat islands.

Grassy strips

Grassy strips help minimize paved surfaces by including green surfaces, which help refill the water table and reduce runoff. This solution percolates 17 times more water into the ground than a paved driveway, and lasts longer.

Permeable asphalt

With a proper initial design and winter maintenance, permeable asphalt can sustain freeze-thaw cycles and help absorb runoff. According to the Cement Association of Canada, every square metre of permeable asphalt allows 200 litres of water to percolate into the ground per minute.

Alveolated pavement

A rigid alveolated membrane is spread and seeded with resistant cover greenery such as clover to create an alveolated driveway that withstands winter conditions and can last up to 20 years. Alveolated pavements allow stormwater to drain naturally and percolate into the ground.

Permeable pavement

Permeable pavements use blocks spaced out on a layer of stone. Similar to traditional prefabricated pavements, permeable pavements allow stormwater to drain and percolate into the ground.

The measures proposed on this page are general and do not apply to all properties. In special cases, such as high clay content or steep slopes, property owners should seek the opinion of a qualified contractor before starting a project.

About Gatineau

Recognized for its quality of life, Gatineau is a city of 292,000 inhabitants. It is located on the north shore of the Ottawa River, and extends east and west of the Gatineau River.

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