OBC DIVISION B · PART 9 · SECTION 9.14 — DRAINAGE

Where must foundation drains and weeping tile discharge in Ontario?

Foundation drains must discharge to a storm sewer, a drainage ditch or dry well where soil conditions allow, or to a sump from which water is pumped away from the building. Discharge into sanitary sewers is not an acceptable design for new work.

Code reference
The OBC requires foundation drains to drain to a sewer, drainage ditch or dry well. Where gravity drainage to those points is not practical, drainage must be directed to a covered sump, and the sump must be pumped so that water discharges in a way that does not return to the foundation or create a nuisance on adjacent properties.
OBC Division B, Subsection 9.14.5.

Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.

What this means in practice

In most new Ontario subdivisions, weeping tile runs to an interior sump pit with a pump discharging to grade or a storm connection, because municipalities have largely eliminated gravity connections to sanitary sewers to reduce inflow and infiltration. Key details that get flagged: sump lids must be sealed where soil gas control applies, pump discharge must be directed well away from the foundation and not onto neighbouring lots, and dry wells only work in permeable soil above the water table. Always confirm the local municipal standard before roughing in.

Plain language

The water your weeping tile collects has to go somewhere safe: a storm sewer, a ditch, a dry well, or most commonly a sump pit with a pump that pushes it out and away from the house, never back toward your foundation or a neighbour's yard.

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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.