Lot grading maintenance
Once your final grade has been approved, it’s up to you, the homeowner, to maintain surface grades around your home and property, in perpetuity, to the standards established at the time that the Final Grade approval was issued. Strathcona County may, at any time, require you to do maintenance to the site grading if settlement or unauthorized alterations are resulting in surface drainage problems to neighbouring lots or County right-of-ways. This requirement is enforceable under the provisions of the County’s Surface Drainage Bylaw #16-2009.
Lot grading plans have been part of the approval process since 2001. If your home was built prior to that, chances are that your area doesn’t have an engineered lot grading plan. Settlement or improper re-grading over a period of years can create problems that become evident during spring snow melt and after heavy rain storms. This can result in flooded basements, property damage, and disputes between neighbours. See the maintenance checklist below for tips on how to avoid this.
- The maintenance inspection should include all aspects of surface drainage and any potential impact on adjacent properties.
- Ensure downspouts discharge to the ground surface past the backfill zone but no closer than 150 mm (6”) to the property line.
- Ensure positive slope exists away from the foundation walls for a distance of at least two metres. 10% is a good target to try to achieve. This means 6” higher at the foundation than a spot 60” away from the foundation (see Diagram D).
- Make sure drainage swales convey water off the lot without impacting adjacent properties. Periodic adjustments may be required as the ground settles over time.
- Ground under steps, decks and build-outs are very susceptible to settling as water doesn’t reach these areas, and the clay naturally dries out quicker. Ensure these areas are checked regularly and properly backfilled as needed.
- Window wells should be kept free of debris to ensure efficient drainage.
- Eavestroughs should be cleaned in the spring and fall to ensure unobstructed water flow off the roof and away from the foundation.
- Seal any cracks or separations between sidewalks and foundation walls with a flexible exterior caulking.