Grading and drainage are among the most consequential decisions in residential landscape design, and among the most frequently misunderstood by builders, architects, and contractors responsible for implementation. A grading plan that appears straightforward on paper can lead to ponding, foundation moisture intrusion, or neighbour disputes if assumptions about finished grades, flow paths, and outlet conditions are misinterpreted on site.
This session examines how grading and drainage are approached in residential landscape design practice, focusing on the principles, drawing conventions, and coordination requirements that non-landscape professionals need to understand. Topics include how grading plans are developed and interpreted, the drainage systems commonly used in residential applications, the selection and detailing of surface and subsurface drainage strategies, and the coordination of grading decisions across landscape, architectural, and civil drawings. Municipal requirements in British Columbia and Alberta are referenced where they influence standard practice.
Learning Objectives:
- Interpret residential grading plans, including elevations, slopes, and drainage flow paths, to understand design intent and site performance.
- Identify common grading and drainage failures, such as ponding and foundation moisture intrusion, and their root causes in design and construction.
- Evaluate coordination gaps between landscape, architectural, and civil drawings that can lead to conflicts or site drainage issues.
- Apply appropriate surface and subsurface drainage strategies that comply with typical municipal requirements in British Columbia and Alberta.