In some cases, downspouts may be connected to the municipal storm sewer system through a separate storm sewer lateral. If your downspout leads to an underground pipe, you should contact the department responsible for urban drainage in the municipal government. They should be able to tell you if your downspout should be connected to the sewer system, or if it should be directed over your lot. Identifying what the downspout is connected to should be part of the detailed plumbing investigation in your home (
see Option 3).
When the downspout is disconnected from an underground pipe, the remaining exposed pipe leading underground should be capped to stop extra water from entering the sewer system. A 1.8 metre extension should be placed on the downspout to ensure that water is kept away from the home, and splash pads should be used help prevent erosion at the discharge point. Downspout water should be directed over a permeable surface, including lawns and gardens. A pipe can be used to direct flow to a lawn if the area surrounding the downspout is paved.
When downspouts are directed over a lot’s surface, they create the potential for damage, including flooding, erosion and ice build up, for neighbouring properties. You should consult your municipal government to ensure that downspouts are directing flows in a manner that does not negatively affect neighbouring properties.
A further benefit of disconnecting downspouts is that water from downspouts can be directed over permeable surfaces, thereby reducing the amount of water that enters municipal sewer systems. Reducing water that enters these systems can decrease the risk of flooding for you and your neighbours, and can reduce the environmental impacts of stormwater flows.
You may also consider installing a rain barrel when you are disconnecting your downspout. This will allow you to store some of the water that flows off of your roof so that you can use it during dry periods in the summer. If a rain barrel is to be installed, consider the following points:
• Rain barrels are not designed to capture a large volume of water during a storm, and will overflow during heavy downpours.
• Make sure that, when the barrel has filled with water during prolonged rain events, overflow is directed away from your foundation wall and onto a splash pad at least 1.8 metres away from
your home.
• During the winter, the rain barrel should be disconnected from the downspout to prevent damage from ice build-up in the barrel.
• Some municipalities will provide a partial subsidy for installing a rain-barrel, as they can help to reduce water use during the dry summer months.
• Water collected in rain barrels is unsuitable for drinking or other domestic uses, and should only be used to water gardens and lawns.
Follow manufacturer’s instructions for installation, operation and maintenance for the rain barrel.
