Water in the basement after rain: where it comes from

I don't even know where it's coming from

Start with where the water is, not how much. The City puts it plainly: "Where the water comes from will help identify the type of flooding, and how to address it."

Next rain, go down while it's happening. Note the wall, the corner and how high it sits.

Source: City of Hamilton, Basement Flooding Preparedness. Checked October 15, 2026.

It came up the floor drain

Or out of a toilet or sink downstairs. The City calls this a sewer back-up. It isn't a wall problem.

Call the City first. Its words: "Please call the City of Hamilton 905-546-2489 to report if you are experiencing water or sewage coming up a floor drain."

One of those is the City's Protective Plumbing Program. What it is and how it works: 2026 storm damage? Start here.

It comes in at the basement window

That's overland flooding: rain running toward the house instead of away from it. The City says water "may enter basements through windows, doors, vents and other openings," often "due to improper grading, exposed window wells."

Go outside and look at that window. Does the ground slope toward it? Is the window well open, or full of leaves?

It's coming in at the bottom of the wall

Or a damp line creeps up the wall, or water seeps across the floor. That's infiltration. The City explains it: "When soil around your home becomes saturated or when the ground water level rises higher than your basement, water will get into your basement through cracks in the foundation walls and floor."

This is the one most people mean when they say the basement leaks. It's also the one we fix. We find where the water gets in, then fix it there.

It only happens after a big rain

That's the clue. A light shower soaks in. A long, heavy rain fills the ground around the house, and the water pushes in. Spring snowmelt does the same.

Damp counts too. A musty smell, a dark corner or a tide line on the drywall after every storm is water, just slower.

I want to check a few things myself first

Good. These come from the City's own list:

• The ground. "Check that the ground around your house slopes away from your foundation."
• The downspouts. "Direct your downspouts away from the home where water can be easily absorbed, such as your lawn or garden."
• The eavestroughs. "Keep your eavestroughs clean so they can direct water away from your house."
• The window wells. The City suggests you "minimize points of entry for overland flooding such as window wells and window well covers."

If it still comes in after all that, the water is getting through the wall or floor.

Who do I call first?

Who to call about water in the basement after rain depends on where it came in. In this order:

1. The City, if it came up the floor drain. Call 905-546-2489 to report a sewer back-up.
2. Your insurer. If there's damage and you might claim, call your insurer first.
3. Us, if it comes through the walls or floor. Albany Contracting Group finds where the water gets in and fixes it at the source.

We just want it to stop

That's the job. We come to the house, look at the basement and the outside walls, and find where the water gets in. You hear what it needs, and the price, at the free consultation in your home, before any work starts.

Here's more on how we do basement waterproofing in Hamilton. Got an old fieldstone foundation? Read why old stone foundations leak.

Family-owned. Renovating Hamilton homes since 1999. Insured. 4.8 on Google, 49 reviews · 5.0 on HomeStars, 9 reviews · checked October 15, 2026.