Window wells before winter: covers, leaves and where the water goes on a GTA house

Window wells before winter are one of the few exterior jobs where ten minutes per well changes what happens in the basement in March. A window well is a low spot dug against the foundation, so rain, leaves, ice and snow all end up in it, and a basement window is not built to hold back standing water. This guide covers what to clear, how high the rim should sit, which covers are safe, and what changes once the snow starts, using the federal flood-readiness guidance and the flood pages published by Toronto, Mississauga and Burlington.

What is a window well supposed to do?

A window well keeps soil away from a basement window that sits at or below grade, and lets the water that lands in it soak down instead of against the glass. The Government of Canada describes it as a dug-out space around the window, filled with gravel to help drainage, held in shape by a U-shaped metal or plastic guard installed tight against the foundation wall.

The same guidance says wells are ideally connected to the home's perimeter drain (the weeping tile) when they are installed, but that this is not always possible. That detail decides how forgiving your well is. A well with a drain under the gravel can take a heavy rain; a well that relies only on the soil beneath it drains as fast as that soil does, and clay soil is slow. A layer of gravel looks the same whether or not a drain sits under it, which is why the bucket test in the steps below is worth doing once.

What should you clear out of a window well before winter?

Take out everything that is not gravel: leaves, sticks, soil and the fine silt that settles between the stones. Leaves are the main problem in autumn, because a mat of wet leaves sits on the gravel and stops water from reaching it. The federal guidance lists a rake, work gloves and yard bags as the tools, and a wet-dry vacuum for the fine build-up.

1. 1Wait for the last big leaf drop on your streetA well cleared while the trees are still full is full again two weeks later. On a street with mature trees, do the main clean after the leaves are down, and a quick check earlier if a storm has filled it.
2. 2Pull the debris out by handWear gloves and use a small hand rake or your hands. The federal guidance notes that removal is often easier by hand when the well is filled with gravel, because a full-size rake drags the stones out with the leaves. Check for glass, nails or animals before reaching in blind.
3. 3Vacuum the finesA wet-dry shop vacuum lifts the silt and broken leaf bits sitting between the stones. This fine layer is what slows drainage year after year, even when the well looks clear from above.
4. 4Run the bucket test oncePour a bucket of water onto the gravel and watch. If it disappears while you stand there, the well drains. If it is still standing when you come back later, the drain or the soil underneath is blocked, and clearing leaves will not fix it.
5. 5Check the liner and the windowLook at where the metal or plastic liner meets the foundation. It should be snug, with no gap and no crack. Then look at the window frame from outside and from inside the basement for cracked glass, gaps and failing caulking.
6. 6Seal what you foundThe federal guidance says to seal cracks at the well edge with caulking or expanding foam insulation, to remove old caulking before applying new, and to use an exterior caulking that is weather resistant, adheres to concrete and is labelled for outdoor use. For cracks of 5 cm (2 in.) or larger, it recommends a professional.

How high should the rim of a window well sit above the ground?

High enough that surface water running across the lawn or patio cannot pour over the edge. The City of Toronto's 2026 basement flooding guidance says to install window wells that sit 10 to 15 cm above ground. Mississauga says the same thing without a number: wells should protrude sufficiently above lawns, patios or the ground surface to divert water away from basement windows, and their edges should be raised and sealed.

A rim that was installed at the right height can lose it over the years. A garden bed topped up with soil or mulch every spring, a new patio laid at a higher level, or sod added along the house can bring the ground up to the rim or over it. Measure from the top of the liner down to the soil at a few points around it. If the ground is level with the edge, or slopes into the well, water from the whole bed drains into it.

• Soil or mulch at the rim: pull it back so the liner stands clear. The earwig and sowbug post covers why a thick, wet bed against the foundation causes a second problem indoors.
• Patio stones tipping toward the well: reset them to fall away from the house. Mississauga lists patios sloped toward the house as a drainage warning sign.
• Liner too short for the new grade: an extension or taller liner is a waterproofing or window contractor's job, because the liner is fixed to the foundation.

Should a window well have a cover, and when must it open from inside?

A cover is worth considering on any well, because it keeps leaves, rain and snow out and leaves far less to clear each autumn. But on any window someone might have to climb out of, the cover must still open from inside. Mississauga's advice is to install plastic covers to keep water out and to be sure they can still open in case of an emergency. Burlington and Toronto both say to install covers where fire escape requirements permit.

The windows this matters for are bedroom windows. The Town of Oakville's building permit guidance states that a basement bedroom requires an egress window or door. If a basement room is used as a bedroom, including a guest room or a tenant's room, treat its window well as a fire exit: no screws through the cover into the foundation, no padlock, nothing heavy stored on top, and a cover light enough for the person in that room to push up and off from inside. The federal guidance says egress windows may have specific requirements for the cover and points to the provincial building code; if you are adding or changing a bedroom window, that is a building permit question for your municipality.

A clear cover is the usual choice because the basement keeps its daylight. The federal guidance's list for installing one is short: a tape measure, exterior caulking, the cover and whatever hardware it ships with, and installation according to the manufacturer's instructions.

Where is the water in the well coming from?

If a well fills during rain even after it has been cleared, look first at what is arriving from above or from the side before assuming the drain has failed. Mississauga's list of drainage warning signs includes water spilling over the eavestroughs or filling basement window wells, and downspouts draining right beside the foundation. Stand in the rain for five minutes and look straight up from the well.

1. Eavestrough overflow: a trough clogged with leaves spills over its front edge in a sheet, and if the well is under that edge, it catches the roof's water. The signs you can see from the ground post covers how to spot it.
2. A downspout emptying next to the well: extend or redirect it. Distances and slopes are in the sump pump and downspout post.
3. Ground sloping toward the house: water crosses the lawn and drops over a low rim. Raise the rim or regrade the bed.
4. A blocked drain under the gravel: water arrives normally but does not leave. This is the case where the bucket test fails even in dry weather.

Mississauga also reminds homeowners to keep private drains on their property clear, especially in spring and autumn. If there is a yard catch basin or driveway drain near the well, clear it at the same time; the catch basin post covers that job.

What changes once the snow starts?

Snow in an uncovered well is a spring flood waiting for a thaw. Mississauga's winter guidance says to keep an eye on window wells and clear out some of the snow if it builds up, because during freeze and thaw periods the extra snow inside the well can cause water to seep into the basement. Its stormwater page adds: clear snow and ice from basement window wells during thaws. The federal guidance explains why: ice and snow can clog window well drains, and when temperatures rise the melt can enter through any crack or opening.

• Do not shovel the driveway or walkway toward the wells. Mississauga's pages give two distances for piling snow away from a foundation, 2 metres in its winter flood news and at least 1 metre on its stormwater page. Use the larger one wherever the lot allows.
• Clear the well before a forecast thaw. Once the snow in the well has turned to ice over a frozen drain, it can only melt in place.
• Tell whoever clears your snow where the wells are. If you book a snow removal service, point out the wells and the bedroom window in particular when you ask for a quote, so no snow is stacked on top of them.
• Keep a bedroom well usable all winter. A cover that is frozen shut under a snowbank no longer works as an exit. Clear the snow off the top of it after each storm.

When is a window well not a do-it-yourself job?

Clearing leaves out of a window well is a job you should do yourself: it takes minutes, needs gloves and a bucket, and nobody needs to be hired for it. The point where it stops being yours is structural or below the gravel.

• The bucket test fails in dry weather after the well has been emptied of debris: the drain or its connection needs to be dug out.
• The liner has pulled away from the foundation or is rusted through.
• There is a crack of 5 cm (2 in.) or more, which the federal guidance says to hand to a professional.
• Water is coming in around the window frame even with a dry well: the window or its opening needs attention.
• You want to enlarge a well, add a window, or turn a basement room into a bedroom: that is a building permit question for your municipality.

If the well only floods when it rains hard and the eavestrough above it overflows, the fix is upstream. Clean troughs and free-running downspouts keep the roof's water away from the well in the first place.