When an application is made for a permit to develop a property where there is no existing approved lot grading plan, the applicant must provide a proposed lot grading plan for the premises. Lot grading plans must be approved by Drainage Planning and Engineering prior to the construction of any buildings, additions to buildings, or alterations of surface drainage on the premises.
Grading for infill housing must convey surface drainage to a City right-of-way via drainage swales that are constructed entirely within the property. Retaining walls must be constructed to support any elevation difference between a re-developed property and an adjacent private property. Retaining walls must be constructed of concrete or of pressure treated timbers with a minimum dimension of 10 cm x 15 cm (4x6), and must project below the existing ground elevation of an adjacent property. Retaining walls must be self-supporting. Permeable walls require a permanent moisture barrier.
- Confirm the site servicing requirements for roof drainage and subsurface water drainage. Contact Drainage Planning and Engineering’s Water and Sewer Servicing group at 780-496-5444 or email firstname.lastname@example.org or information relative to an existing storm service and for options to dispose of subsurface water from the foundation drainage system.
Create a lot grading plan that defines how your lot will convey surface drainage to a City right-of-way without draining onto adjacent private properties. Internal side-lot swales are usually needed to achieve this requirement. Internal drainage swales must provide a minimum slope of 1.5%, a minimum depth of 10 cm and a minimum width of 15 cm.
Plan the demolition and reconstruction processes to ensure interim control of surface drainage during all phases of the redevelopment project. Directing or allowing surface drainage to flow onto adjacent private property is a bylaw violation.
Common property swales may be utilized if consultation with adjacent property owners results in mutually beneficial surface drainage management design proposals.
The City of Edmonton has developed an Infill Action Conversation Toolkit to facilitate conversations related to infill development which may be useful for initiating discussions with adjacent property owners.
Site inspections and grading approvals can be arranged by submitting a lot grading certificate to the Lot Grading section of Drainage Planning and Engineering.
It is the owner's responsibility to maintain the lot grading and ensure it meets the requirements of the Drainage Bylaw and the lot grading guidelines. For more information, please refer to lot grading inspections pamphlet.