Lot Grading FAQs
Lot grading is the contouring of the land to direct surface water away from building foundations and follow a pre-designed drainage pattern. Proper lot grading is necessary to:
- Direct surface water away from building foundations to help prevent basement flooding;
- Provide for controlled surface drainage where adjoining property elevations match at the property line, and
- In older neighbourhoods, minimize infiltration of stormwater entering the sanitary sewer system
Frequently Asked Questions
How is the drainage plan determined for a new subdivision?
When a new residential development is proposed, the land developer will submit an overall grading plan for the City to review. The plan has the direction of drainage established and the proposed elevations identified for all property lines and corners. This is to ensure the entire subdivision will be graded in accordance with the Municipal Engineering Standards. Land surveyors, working for home builders, use this information to determine the correct elevation of all new homes prior to construction.
What is the lot grading approval procedure?
Upon substantial completion of home construction, the home builder will ask a qualified land surveyor to “grade stake” the property to establish the correct elevations along property lines and at property corners. A grading or excavation contractor is typically hired to complete the grading on the clay, in accordance with the information on the stakes provided, and to ensure positive drainage from the foundation walls.
Once the rough grading is complete, the builder must have a land surveyor return to the property to record the “as-built” grades and prepare a Lot Grading Certificate (Certificate of As-built Grades). This certificate is then submitted to the City for approval.
A City of St. Albert representative reviews the “as-built” grades shown on the certificate, conducts a site inspection of the lot grading, and sends an inspection report or approval letter to the home builder.
If errors are found, an inspection report and red lined certificate are forwarded to the builder. Corrections must be completed by the home builder and re-inspected by the City for approval prior to the placement of topsoil or finished landscaping.
Does the City require Final Lot Grade approval?
No, the City of St. Albert does not require final lot grade certificates or conduct final grade inspections. Once the rough grade inspection is approved and the grading on the property is accepted as correct, the owner of the property is to assume responsibility for future maintenance. A maximum 6” of topsoil must be applied uniformly over the entire lot area to maintain approved drainage patterns and property line elevations. The City relies strictly upon the surveyor for the accuracy of elevations and details recorded.
Does the City of St. Albert have a Surface Water Drainage Bylaw?
What are the City's requirements regarding sump pump discharge?
The sump pit and submersible pump are part of the home’s foundation drainage system which discharges stormwater collected by the weeping tile. In many new subdivisions, the sump pump discharge piping is required to be connected to the storm sewer.
As per the City’s Surface Drainage Bylaw 14/2015, sump pump discharge pipes and all other terminations for drainage shall be a minimum setback distance of 15 centimetres from adjacent property lines and at least 2 metres from the back of the public sidewalk.
Splash pads are recommended below the sump pump discharge piping when a storm pipe connection is not present. The purpose of splash pads is to help minimize soil erosion and direct water away from the foundation wall. Splash pads and the landscaping adjacent to the foundation walls should be sloped for positive drainage toward the property line and down to the street. Concrete splash pads can be purchased at your local home building store.
What are drainage swales?
Drainage swales are shallow, sloped channels intended to convey surface water to an approved surface drainage facility, such as a culvert or catch basin. Swales are typically constructed of grass or concrete. Drainage swales may be designed to manage water between two adjacent lots or to convey water across multiple lots.
Shared Swale Between Two Homes
When new homes are graded, they typically share a common, grass swale between adjacent lots and serve both homeowners by directing surface water away from the dwelling foundations and along the side yard property lines to an approved storm collection facility (i.e., catch basin). To maintain proper drainage, it is imperative for homeowners to protect and maintain the original grade of grass swales when making landscaping changes. Homeowners should not block the common swale by placing structures, landscaping borders, and/or debris of any kind that could impact proper drainage.
Neighbourhood Swale Along Multiple Lots
Some subdivisions are designed with a grass or concrete swale that is shared between multiple lots. These types of swales are typically located within a Utility Right-of-Way (URW) along the rear of the property. Homeowners should maintain the grade of original grass swales and be aware of URW agreement restrictions on their title. Homeowners with a concrete swale on their property should be aware that regular maintenance is required to ensure the swale is free of debris or blockages of any kind that may affect surface runoff.
What is the difference between “split drainage” and “back to front drainage”?
“Split drainage” and “back-to-front drainage” patterns refer to the original grading design that was intended for each lot. The original lot design determines the individual elevations, locations of swales, and direction that surface drainage should flow.
A split drainage lot design indicates that the front portion of the lot should drain towards the street, and the rear portion of the lot should drain to the back of lot towards a swale.
The back to front drainage pattern is designed to move all lot drainage away from the dwelling, along the common property line swales, toward the front street for discharge into an approved surface drainage facility.
What happens if my lot grading settles over time?
Homeowners should be aware that backfill material will typically settle for several years after construction is complete. Repairing areas of settlement are considered regular home maintenance. As a homeowner, you must ensure that you protect your property by maintaining positive grading which slopes away from all building foundations conveying surface water in the direction that your lot was designed.
Am I required to obtain a permit to perform grading maintenance on my property?
No, you do not need a permit to make grading adjustments on your property. However, regrading must be consistent with the original lot design elevations or best grading practices where a grading plan for the area does not exist or is not available. Additionally, homeowners should always consult affected neighbours before making grading changes that may impact adjacent properties.
What is “positive” and “negative” drainage?
“Positive drainage” means a condition where the finished grade of a property is sloped away from all structures and directs water to a swale or storm collection system. “Negative drainage” is the opposite condition where the grade slopes toward the dwelling and/or other structures creating the potential for water damage. “Negative drainage” can develop over time due to settlement, heavy rainfall events and/or landscaping changes. As per the City of St. Albert’s Surface Drainage Bylaw 14/2015, homeowners are responsible to maintain proper grading within their lots, ensuring “positive drainage” away from building foundations and exterior elements, to an approved surface drainage facility.
Last edited: October 24, 2019