Across Canada, many municipalities have mandatory, volunteer or rebate programs to encourage homeowners to disconnect their downspouts from the sewer system. Directing rainwater away from sewers has economic and environmental benefits. Here's how to disconnect your downspouts.

What Are Downspouts?

Downspouts are the vertical pipes that drain water from the roof down to the ground. They clear the rainwater that collects along the edge of the roof in the eavestroughs and direct it away from the building's foundation. The water is then typically piped to the storm sewer system, piped to a combined storm and sanitary sewer system, or diverted into the ground through natural seepage.

Benefits of Disconnecting Downspouts

Sudden, heavy rainstorms can cause combined sewer systems to overflow. When sewers overflow, basements and waterways can be flooded with untreated stormwater and wastewater.

According to the Canada Mortgage and Housing Corporation, homeowners and municipalities can derive economic and environmental benefits by disconnecting downspouts. These benefits include:

  • Reduced likelihood of basements flooding due to unsanitary sewer backups and leaking downspout connections
  • Less stormwater in the sewer system, decreasing the chance that untreated water will overflow into local streams and lakes
  • Cleaner watercourses and a replenished groundwater table
  • A reduced chance of flash flooding in rivers
  • Lower energy requirements to run the sewer system and wastewater treatment facilities, resulting in fewer greenhouse gas emissions
  • Increased availability of water for lawns and gardens if it's collected in rain barrels1 2 3

Across Canada, many municipalities have downspout disconnection programs. These programs may be mandatory, voluntary or supported by consumer rebates. Visit your public works website for more information.

5 Tips for Disconnecting Downspouts

Many municipal websites offer advice on disconnecting downspouts. Consider the following:

  1. Ensure that the rainwater will flow onto your grass or into your garden.
  2. Direct the downspout so the rainwater will flow away from your foundation walls, not cross a driveway or walkway, and not negatively affect a neighbour's property.
  3. Make sure your eavestroughs and nearby municipal catch basins are free of debris, such as leaves.
  4. Position the downspout so there is a minimum slope of 1 metre (3 feet, 4 inches) away from your house.
  5. Consult a knowledgeable and licensed roofer, eavestrough contractor or civil engineer for expert guidance.3

How to Get Disconnected – A Step-by-Step Guide



1Canada Mortgage and Housing Corporation (CMHC)

2City Farmer, Canada's Office of Urban Agriculture

3City of Hamilton Downspout Disconnection