Surface drainage

Ground level, commonly referred to as grade, should slope away from the foundation wall towards the edges of the property. Swales are shallow broad channels that convey water directing it away from your property. This helps prevent basement flooding.

Proper grading

Proper grading is critical in preventing water from getting into your home. Grading starts at the exterior foundation or basement wall and moves water away from your home towards the street. Topsoil or sod should slope down at a continuous angle for at least 1.5 to 2 meters (5’) from the wall giving a decline of approx. 15 cm (approx. 6” decline over 5’). If you have decorative rock next to your foundation, take measurements from where the dirt begins.

Water pooling in your yard

Check your grading annually and correct as necessary to ensure proper slope, the ground settles over time, particularly near your foundation or basement wall
Check under the stairs, steps and decks for voids and backfill as necessary
Check the driveway, sidewalk and patio for any cracks or spaces that are next to the foundation wall, caulk or waterproof as necessary
Inside your house, check for moisture around the foundation walls and the floor, fill and seal any visible cracks

For more information about lot grading requirements, visit the City of Edmonton's website.

Did you know?

Good eavestroughs, downspouts, and extensions help improve your outdoor drainage.

Swales

Common swale

Common swales are an effective way to direct surface water away from your foundation wall and channel it off the property. They must be constructed properly to be effective. Common swales are used to allow neighbouring properties to share the same swale and provides a clear path to direct surface runoff to the street or lane. Ensure there are no barriers (fence boards, plastic edging, plantings, etc.) that would restrict flow. Discussion with neighbours prior to commencing work is recommended.

Internal swale

In some cases a common swale is not possible. A retaining wall may need to be constructed to direct surface drainage towards alley or street. This can be done in front of an existing fence or other feature you don’t want disturbed. Ensure the retaining wall has a continuous waterproof barrier that does not allow surface water to enter or drain onto neighbouring properties.

Surface drainage problems

Building a drainage system that guarantees protection against flooding is impossible. Many homes and commercial areas were built prior to the development of city-wide surface drainage plans and procedures in 1993.

Surface drainage problems that developed slowly over a period of years, such as settlement at the foundation walls, can become evident after rainstorms or during snow melt. Also, re-grading or re-development (e.g. in-fill housing) can create drainage problems or highlight existing problems, and result in basement flooding or property damage.

Keep your catch basins clear

Help prevent surface drainage problems from snow melt with these maintenance tips.

To help property owners examine their own property, EPCOR provides a complimentary Flood Prevention Home Check-up service that focuses on flood control and maintenance strategies to protect your property. Call 780-944-7777 or email floodprevention@epcor.com to book a visit by a Flood Prevention Advisor (our email and phones are monitored Monday to Friday from 9:00 am to 5:00 pm).

Lot grading

Property owners are responsible for their own lot grading and need to take the necessary steps to prevent flooding and property damage.

For information and questions about lot grading, visit the City of Edmonton's website.