Downspout Connected to Ottawa Storm Sewer? What You Need to Know

If your downspout is still connected to Ottawa's storm sewer system, you could be in violation of the City of Ottawa's sewer use by-law and may face enforcement action. Ottawa has been actively working to separate storm and sanitary sewers for decades, and many older neighbourhoods — particularly in Centretown, the Glebe, Old Ottawa South, and Sandy Hill — still have homes with legacy downspout connections to the municipal system.

Why Ottawa Requires Disconnection

The core issue is combined sewer overflow. When heavy rainfall floods the combined system, raw sewage mixed with stormwater can overflow directly into the Ottawa River and Rideau River. Ottawa's climate makes this worse — major summer thunderstorms can dump 50 to 75 millimetres of rain in an hour, overwhelming systems that are also handling rooftop drainage from thousands of connected homes. During spring snowmelt, the problem compounds further as the deep snowpack Ottawa accumulates over winter rapidly drains into the system.

The City of Ottawa's Residential Protective Plumbing Program has been encouraging and in some areas requiring disconnection for years. Under the current by-law, homeowners in designated areas must disconnect downspouts from the sanitary or combined sewer system. Failure to comply can result in fines, and the city can order disconnection at the homeowner's expense. If your home was built before the 1970s and you have not verified your downspout connections, there is a reasonable chance at least one downspout still ties into the underground system.

Disconnecting a downspout from the storm sewer is a relatively straightforward project. The downspout is cut or redirected to discharge onto a splash pad, downspout extension, or rain barrel at ground level, with water directed at least 1.8 metres away from the foundation as required by the Ontario Building Code. The cost in Ottawa typically runs $200 to $600 per downspout for professional disconnection, including capping the old underground connection and installing a proper above-ground discharge.

There are a few important considerations for Ottawa specifically. The city's clay-heavy soil drains poorly, so simply dumping water next to your foundation without a proper extension or splash block can create basement moisture problems. If your lot has poor grading, you may need to extend downspouts further or install a dry well or underground drainage pipe that directs water to a more suitable area of your property. In neighbourhoods with tight lot spacing like Sandy Hill or Lowertown, directing water away from both your foundation and your neighbour's requires careful planning.

For homeowners unsure whether their downspouts are connected, a professional can run a camera inspection or simply trace the downspout path. If the downspout goes straight into the ground with no visible discharge point, it is almost certainly connected to the underground system. You can also contact 3-1-1 to check whether your property is in a designated disconnection area. Browsing eavestrough and drainage contractors through the Ottawa Construction Network directory at justynrookcontracting.com is a good starting point for finding someone experienced with Ottawa disconnection requirements.