Stormwater Management Reports

A Stormwater Management (SWM) Report explains how a site will collect, control, treat, and safely release stormwater runoff after development.

At Reliance Engineering Canada Limited, we prepare practical SWM reports for residential, commercial, industrial, and institutional projects across Ontario.

We do not just run calculations — we develop stormwater strategies that satisfy municipal criteria and support a buildable site design.

Why Professional Stormwater Management Reports Are Essential

Without proper stormwater management, a site can increase flooding risk, overload municipal systems, impact adjacent properties, or fail municipal and conservation authority review.

What's Included in Our Stormwater Management Reports Services

  • Pre- and post-development drainage analysis
  • Runoff coefficient calculations
  • Peak flow calculations
  • Quantity control storage design
  • Allowable release rate calculations
  • Orifice and outlet control sizing
  • Water quality treatment strategy
  • Low Impact Development review, where required
  • Overland flow assessment
  • SWM summary tables and design recommendations

Our Process

Criteria Review: We review municipal comments, conservation authority requirements, and applicable SWM criteria.
Hydrologic Analysis: We calculate pre- and post-development runoff and establish control targets.
SWM Design: We size storage, controls, quality treatment, and conveyance measures.
Report Submission: We prepare a clear report with calculations, conclusions, and support through review comments.

Who We Design For

  • Commercial Developments
  • Industrial Sites
  • Townhouse Projects
  • Apartment Buildings
  • Parking Lots
  • Institutional Buildings
  • Infill Developments
  • Site Plan Approval Applications
  • Rezoning and Planning Applications

Stormwater, Drainage and Site Considerations

Our SWM reports address quantity control, quality control, water balance, overland flow, downstream capacity, and protection of adjacent properties where required.

Code and Municipal Compliance

  • Municipal SWM Criteria
  • MECP Stormwater Guidelines
  • Conservation Authority Requirements
  • Low Impact Development Guidelines
  • Site Plan Approval Requirements

Why Clients Choose Reliance Engineering

Clear Calculations Straightforward tables and assumptions reviewers can easily follow.
Practical Controls Storage and outlet designs that work with the site layout.
Municipal Experience Reports prepared with local review expectations in mind.
Complete Support Revisions and responses provided throughout the approval process.

Let's Manage the Runoff

A proper SWM report protects the site, the municipality, and neighbouring properties. Contact us today to discuss your stormwater management requirements.

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