Drainage on your property

Maintaining proper drainage can help ensure that water flows safely away from the walls of your home, or other buildings on your property, and into the City’s stormwater system.

Effective drainage can help prevent flooding in your home and basement. Property drainage is the responsibility of the landowner.

Improving drainage

Here are some of the things you can do to improve the drainage on your property:

Watch where water goes

The best time to learn about drainage on your property is when it’s raining. Watch where the water goes and where it collects.

Check lot grading and downspouts

The ground around your house should slope away from the building and other properties.

Roof downspouts should extend two metres away from your foundation and away from your neighbour’s property.

Keep eavestroughs and drains clear

Keep eavestroughs, downspouts and ditches or storm drains on your property clear of leaves and other debris. If these get blocked, water can start to collect instead of draining and may cause property flooding.

Green infrastructure

Green infrastructure is an environmentally-friendly approach to managing stormwater that’s designed to mimic nature. There are lots of different ways you can incorporate green infrastructure on residential or commercial properties.

Rain barrels

You can place a rain barrel at the end of the downspout from your roof to collect stormwater for your lawn, garden, or plants on your property.

You can have a rain barrel next to your foundation, but the overflow hose should be directed at least six feet away from any foundations. In the fall, rain barrels should be disconnected. The water should be diverted to lawns and gardens at least two metres (six feet) away from the foundation.

Soakaway pits and rain gardens

A soakaway pit, also called a dry well, is an underground pit filled with stones and lined and covered with landscaping fabric. This helps stormwater soak into the ground faster.

You can plant grass or even a garden over the soakaway pit.  Position soakaway pits at least three metres away from any foundation wall and be sure that any overflow drains to the City’s stormwater system.

Rain gardens are planted areas that collect stormwater. To make one, choose a relatively flat location away from any buildings or trees and at least 1.25 metres away from neighbouring properties. Rain garden soil is a mixture of topsoil and compost placed over a layer of loose stones.

Native perennial plants that tolerate both wet and dry conditions are best for rain garden plantings. Rain gardens should be large enough to accommodate the water from a downspout and include a safe pathway for overflow to drain to the City’s stormwater system in heavy rain.

Before you start digging a soakaway pit or rain garden on your property, Contact Ontario One Call to check where utility lines are buried. Keep any digging at least three metres (ten feet) away from the foundation of all buildings.

With any rain garden or soakaway pit, be sure that the overflow drains safely away from all properties.

Permeable pavement surfaces

If you’re repaving a driveway or landscaping your yard, the materials you use to pave can impact your property’s drainage.

You can use porous concrete and asphalt or precast paving stones that allow water to drain into the ground.

Flow-through planters

Even large outdoor planters can be supplied with stormwater provided that they properly drain away from your home’s foundation and neighbouring properties. Water from downspouts can be diverted in to outdoor containers, provided that they are located at least two metres (six feet) away from your foundation and have an overflow that drains safely to the City’s stormwater system.

Large scale rainwater harvesting and collection

Rainwater harvesting works like collecting water in a rain barrel, but on a larger scale. Large properties use storage tanks or cisterns to harvest rainwater that runs off the roof or parking areas. These collect, store and filter stormwater runoff, and some systems can hold tens of thousands litres of water.

There are a variety of design and installation options for cisterns. The water can be used for irrigation on your property or even for flushing your toilets. Contact a licensed professional service to install large cisterns. Connections or rainwater to the plumbing system will require City approval.

Bioretention facilities

“Bioretention” is the process of removing contaminants and sediment from stormwater runoff. Bioretention facilities are excavated areas that collect stormwater runoff, slowing the flow of water and allowing some of the water to soak into the soil. These facilities may include native plantings, amended soils or other features that enhance the capture of pollutants and will have an overflow for heavy rains.

Soakaway pits (dry wells), infiltration chambers and trenches

Soakaway pits, infiltration chambers and trenches create space underground where rainwater collects and soaks slowly into the ground. They are not recommended where stormwater runoff quality is polluted.

Infiltration chambers are large, plastic, open-bottomed devices with perforated sides. They’re generally located beneath parking lots or other impervious areas. They temporarily store stormwater runoff and release it slowly into the ground.

Infiltration trenches are long and narrow, and are often installed alongside or beneath walkways, sidewalks and narrow patches of land between buildings where there is no basement area.

Disconnecting your roof downspouts

A downspout is the vertical pipe used for carrying rainwater down from your eavestrough to the ground. Your home may have several of these pipes directing water from your roof. Some older homes may have roof downspouts connected into the sanitary sewer.

You can disconnect downspouts to reduce the risk of basement water infiltration if you have a safe place to discharge this water. Diverting roof downspouts onto your lawn or garden at least two metres (six feet) away from your foundation should allow stormwater to flow away from your foundation onto gardens, landscaped areas and lawns. Be sure to divert roof water away from neighbouring properties, driveways and sidewalks to avoid property flooding and ice buildup.

Safely disconnecting your downspouts can:

  • Reduce the flow of water next to your home’s foundation and reduce the risk of basement water infiltration
  • Provide a free source of water for your lawn and gardens
  • Keep unnecessary water out of the sewer systems

How to disconnect a downspout

Often you can disconnect your downspout yourself. For more complex disconnections, you can contact a licensed contractor.

This video explains how to disconnect your downspout step by step. You can also follow our guide How To Get Disconnected.


For more information, please call 311 (905-615-4311 outside City limits) or email public.info@mississauga.ca.