Basement Flooding in Milton: Untested Sump Pumps in the New Subdivisions, Groundwater Under the Old Town

New subdivisions: the untested house

A new Milton house comes with a sump pit and pump, weeping tile that may or may not be connected to the storm sewer, and a lot graded to the plans. In the first years the lot settles, downspouts end up discharging next to the foundation, window wells sit below the new grade, and the pump has never been asked to run. Then a storm arrives: water over the window wells, water at the wall-floor joint, and a pump that either works or does not. Sewer backup at the floor drain happens too, when the subdivision’s sewers surcharge in a storm larger than they were designed for.

Photograph where the water first appeared and when. Clear water at the walls or over a well is groundwater or surface water; sewage from the floor drain is the sanitary sewer.

Halton Region’s subsidy and Tarion

Halton Region has run a Basement Flooding Prevention Subsidy Program that contributes toward a backwater valve on the sanitary lateral, a sump pump and pit, and disconnecting the foundation drain from the sanitary sewer, at eligible homes in Milton, Oakville, Burlington and Halton Hills. The work must be done by a licensed plumber under a Town of Milton plumbing permit and inspected, and the subsidy is claimed after completion. The terms change; read the Region’s current page before signing a quote.

Separately, a foundation leak in a new house may be a Tarion warranty matter: water penetration through the foundation is covered for the first years of the warranty, and a basement leak reported in writing to the builder and Tarion within the deadlines is the builder’s to fix. A repair you pay for before reporting is not reimbursed.

• Closing date and Tarion warranty forms, for a newer house
• Halton Region program eligibility checked
• Licensed plumber and Town of Milton permit number
• Sump pump tested under load, backup and alarm
• Grading and downspouts corrected around the foundation

Who owns which pipe

In Milton the owner is responsible for the sanitary lateral on private property up to the property line, and Halton Region for the sanitary sewer beyond it and the water supply. The Town of Milton owns the storm sewers and catch basins, and Conservation Halton regulates Sixteen Mile Creek and the escarpment valleys. A camera inspection with a locate tells you which side a break or blockage is on. Keep the recording; an insurer will want it, and sewer backup and overland water are usually separate add-ons on an Ontario policy.

The old town and the escarpment

Houses along Main Street and in the old town from the 1880s to 1950s have clay weeping tile that silted up decades ago and stone or block foundations that groundwater passes through; waterproofing there is excavation, a membrane and new drainage, sometimes with a mason. Lots against the escarpment on the west side sit over springs and seeps, and a sump system there runs in every season. Extend downspouts, correct grading and get a waterproofer and a plumber to look together before spending on anything underground.