Downspouts and Sump Pumps in London, Ontario: Rules and Grants
In London, Ontario, downspouts must discharge at least 0.7 m from your foundation and can't be aimed so they damage a neighbour's property. Sump pumps can't drain into the sanitary sewer. The City recommends extending downspouts about 2 m (6 ft) toward a lawn or garden that can soak up the water. If you've had flooding, the City's Basement Flooding Grant Program may cover most of the cost of a sump pump, backwater valve or related work.
Fall is the right time to sort this out. Gutters fill with leaves, the ground is still workable, and snowmelt is only a few months away.
Why downspouts matter so much in London
A typical roof sheds a lot of water in a heavy rain, and every drop funnels through a few downspouts. If those outlets dump water against the foundation, it soaks into the backfill around your basement. That backfill is often looser and more permeable than the surrounding clay. The result is a damp basement, a sump pump that never stops, and in the worst cases a flooded basement.
London's heavy clay soils make this worse. Clay drains slowly, so water that lands next to the house tends to stay there. Getting roof water out and away is one of the cheapest flood-prevention steps you can take.
What London's Drainage By-law says
London's Drainage By-law WM-4 sets the rules for downspouts and foundation drains. The key points for homeowners:
No storm water into the sanitary sewer. Storm water from your property can't be discharged into a sanitary sewer. That includes roof water and sump pump water.
Foundation drain water has to go to an approved outlet, such as a sump pump discharging to the ground surface.
Downspouts can't connect to the storm private drain connection or to foundation drains (weeping tiles).
Downspouts must discharge at least 0.7 m from the building's exterior walls.
No aiming at the neighbours. Downspouts can't be directed toward a side yard in a way that damages the neighbouring property.
The City's stormwater page goes further. It recommends extending downspouts 2 m (6 ft) from the foundation toward a vegetated area. It also says not to discharge downspouts or sump pumps onto sidewalks, stairs, walkways or neighbouring property.
Fall downspout and sump checklist
Work through this list before the ground freezes:
Clean gutters and downspouts once most leaves have dropped. Flush each downspout with a hose to confirm it runs clear.
Check each outlet. Is it at least 0.7 m from the wall, ideally about 2 m? Does the water head toward lawn or garden, not a walkway or the neighbour's yard?
Add extensions or splash pads where outlets are short. Secure them so the lawn mower and snow shovel don't knock them off.
Look at the ground slope. Soil should fall away from the house. If water pools by the foundation, the grading needs work.
Test the sump pump. Pour water into the pit and confirm the pump kicks on and empties it. Check that the discharge line is clear and runs well away from the house.
Plan for winter. Sump discharge lines can freeze at the outlet. Make sure the line drains fully and the outlet isn't buried under a snowbank.
Look for icing risk. Don't let downspouts or sump lines drain across driveways or walkways, where the water will freeze.
When extensions aren't enough
Sometimes the downspout isn't the real issue. Common signs of a bigger drainage problem:
Water pools in the same spots after every rain.
Soil has settled next to the foundation, so the ground now slopes toward the house.
A low area in the yard stays soggy for days.
Your sump pump runs often even in dry weather.
Fixes we use in southwestern Ontario include:
Regrading so the soil slopes away from the house. Our lot grading guide covers this in detail.
Buried downspout lines that carry roof water to a safe outlet in the yard.
Swales and French drains to move surface water around the house.
Dry wells where soil and space allow.
Our post on why your backyard floods covers these options for London's clay soils.
London's Basement Flooding Grant Program
If your home has flooded, or you live in an area prone to flooding, the City of London's Basement Flooding Grant Program pays 90% of eligible costs up to set maximums. Current limits listed by the City include:
Backwater valve: up to $1,800
Sump pit and pump with weeping tile disconnection: up to $4,000
Additional weeping tile disconnection: up to $2,400
Sewage ejector and holding tank: up to $6,000
Storm private drain connection: up to $7,000
Storm building sewer: up to $3,000
Sump pump battery backup: up to $1,400
To qualify, you must own the home, apply before starting work, and have had flooding or live in a flood-prone area. Condos aren't eligible. The City says reviews take up to four weeks, so apply early. Contact sewers@london.ca or 519-661-2489 ext. 5489. Program details can change, so always confirm on the City's page.
Note that the grant covers plumbing-side work, like the sump, backwater valve and drain connections. Outside work like grading and downspout rerouting is usually a separate project. That's where a landscape and excavation contractor comes in.
Who to call for what
Drainage problems often cross trades, so it helps to know who does what:
A plumber handles work inside the house and on the drain connections, such as backwater valves, sump pits and pumps, and weeping tile disconnection. These are the items the City's grant typically covers.
A landscape and excavation contractor handles everything outside: regrading, burying downspout lines, swales, French drains, dry wells, and restoring the lawn afterwards.
Both together is often the best fix. A new sump pump won't help much if the yard still sends water to the foundation.
Outside London
Rules differ in other towns. Cottage owners along Lake Huron in Grand Bend, Bayfield, Goderich and Kincardine face different conditions, with sandy soils, bluffs and shoreline regulations. See our post on Lake Huron drainage or our Lake Huron drainage page. For St. Thomas, Strathroy, Komoka or Ilderton, check your municipality's drainage by-law before rerouting water.
FAQ
How far should downspouts extend from the house in London, Ontario?
London's Drainage By-law WM-4 requires downspouts to discharge at least 0.7 m from the building's exterior walls. The City's stormwater guidance recommends extending them about 2 m (6 ft) from the foundation toward a vegetated area that can absorb the water.
Can my sump pump drain into the sanitary sewer in London?
No. Drainage By-law WM-4 says no one may let storm water from their property discharge into a sanitary sewer. Foundation drain water must go to an approved outlet, such as a sump pump discharging to the ground surface.
Can I point my downspout at my neighbour's yard?
No. The by-law prohibits directing downspouts toward a side yard in a way that damages the neighbour's property. The City also says not to discharge downspouts or sump pumps onto sidewalks, stairs, walkways or neighbours' property.
What does London's Basement Flooding Grant cover?
The program pays 90% of eligible costs up to set limits. Examples include up to $1,800 for a backwater valve, up to $4,000 for a sump pit and pump with weeping tile disconnection, and up to $1,400 for a sump pump battery backup. You must own the home and apply before starting work. Check the City's program page for current details.
When should I fix downspout and drainage problems?
Fall is ideal. Leaves clog gutters, the ground isn't frozen yet, and fixing discharge points before winter keeps meltwater and spring rain away from your foundation.
Talk to SPM Landscape & Excavation
If water is pooling by your foundation or your sump runs constantly, we can redirect downspouts, fix grading and add drainage that works with London's clay. SPM has served London and southwestern Ontario since 2006, is WSIB covered and carries $1M in liability insurance. Call (519) 474-0008, email spmlandscape@gmail.com, or visit us at 791 Manchester Rd, London, ON.
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