A Stormwater Management Report sets out how runoff leaving your site is controlled. It rests on three pillars: quantity, quality, and water balance.
Quantity control holds post-development peak flows to the pre-development rates. Ontario guidance applies this across the design storms, typically the 2-year, 5-year, and 100-year events.
Quality control sets a minimum Total Suspended Solids removal rate. That target depends on how the receiving water body is classified.
Water balance addresses groundwater recharge. It matters most on sites inside identified sensitive recharge areas.
Low impact development (LID) measures are documented where they form part of the strategy. That covers bioretention, permeable paving, infiltration trenches, and enhanced swales.
Reports are prepared against the design criteria applicable to the project municipality, provincial guidance, and the requirements of the responsible conservation authority. Work in or near a regulated area may also require a separate conservation authority permit.
The report is reviewed and sealed by a licensed Ontario Professional Engineer, as applicable. The service covers private development, parks and open space, and municipal infrastructure projects.
Storage sizing and overland flow routing both depend on site levels. The report is prepared alongside your grading plan for the site. Its servicing assumptions carry into the Functional Servicing Report.
For more on stormwater requirements, read When Is On-Site Stormwater Storage Required? .