Low Impact Development Stormwater Management Planning and Design Guide

Version 1.0 2011

The Low Impact Development (LID) Stormwater Management Guide is a joint initiative of the Toronto and Region and Credit Valley Conservation Authorities that has been developed in consultation with representatives from the Ministry of the Environment, Fisheries and Oceans Canada, GTA municipalities and the development industry.

Both TRCA and CVC have been involved in integrated watershed-wide environmental monitoring and modelling activities for several years, and the results of this work have revealed that the environmental health of many watersheds continues to decline with increased urbanization. This deterioration has occured despite widespread adoption of the conventional stormwater management planning and design practices described in provincial and conservation authority policy documents. Documents such as the CVC’s Credit River Water Management Strategy Update and the TRCA’s Watershed Plans for the Rouge (2007), Humber (2008) and Don (2009) Rivers have concluded that a shift away from conventional approaches and towards low impact development is essential to protecting watershed health, and improving watershed resiliency to some of the hydrologic impacts of climate change.

The guide was developed to provide engineers, ecologists and planners with up-to-date information and direction on landscape-based stormwater management planning and low impact development stormwater management practices, and thereby help ensure the continued health of the streams, rivers, lakes, fisheries and terrestrial habitats in the CVC and TRCA watersheds. It is also intended to help streamline and focus the design and review process, as well as ensure that the goals, objectives and targets outlined in watershed and subwatershed studies are being met.


Full Guide without Appendices

Low Impact Development Stormwater Management Planning and Design Guide (without Appendices) (13 MB)


Appendix A: LID Factsheets (16 MB)
Appendix B: Landscape Design Guide for LID (4.81 MB)
Appendix C: Site Evaluation & Soil Testing Protocol (77 KB)
Appendix D: Glossary of Terms (36 KB)

Individual Sections from the Guide

Cover Page, Acknowledgements, TOC, Preface

Chapter 1 – Introduction

Chapter 2 – Integrating Stormwater Management into the Planning Process

Chapter 3 – Low Impact Development Practices

Chapter 4 – Design of Structural Low Impact Development Practices for Stormwater Management – Section Summary

Chapter 4, Section 4.1, Rainwater Harvesting
Chapter 4, Section 4.2, Green Roofs
Chapter 4, Section 4.3, Roof Downspout Disconnection
Chapter 4, Section 4.4, Soakaways, Trenches, Chambers
Chapter 4, Section 4.5, Bioretention
Chapter 4, Section 4.6, Vegetated Filter Strips
Chapter 4, Section 4.7, Permeable Pavement
Chapter 4, Section 4.8, Enhanced Grass Swales
Chapter 4, Section 4.9, Dry Swales
Chapter 4, Section 4.10, Perforated Pipe Systems

Chapter 5 – Monitoring

Chapter 6 – References

Appendix A

Appendix A, Fact Sheet – Site Design Strategies
Appendix A, Fact Sheet – Rainwater Harvesting
Appendix A, Fact Sheet – Green Roofs
Appendix A, Fact Sheet – Downspout Disconnection
Appendix A, Fact Sheet – Soakaways, Infiltration, Trenches, Chambers
Appendix A, Fact Sheet – Bioretention
Appendix A, Fact Sheet – Vegetated Filter Strips
Appendix A, Fact Sheet – Permeable Pavement
Appendix A, Fact Sheet – Enhanced Grass Swales
Appendix A, Fact Sheet – Dry Swales
Appendix A, Fact Sheet – Perforated Pipe Systems

Hard Copies:

To order a hard copy of the Low Impact Development Stormater Management and Planning Design Guide, email us at: jmcmanus@creditvalleyca.ca


$200 CDN + $10 HST (if picked up at CVC office)
$250 CDN + $12.50 HST (if shipped within Canada)


Data and information released from Credit Valley Conservation (CVC) are provided on an 'AS IS' basis, without warranty of any kind, including without limitation the warranties of merchantability, fitness for a particular purpose and non-infringement.

Availability of this data and information does not constitute scientific publication. Data and/or information may contain errors or be incomplete. CVC and its employees make no representation or warranty, express or implied, including without limitation any warranties of merchantability or fitness for a particular purpose or warranties as to the identity or ownership of data or information, the quality, accuracy or completeness of data or information, or that the use of such data or information will not infringe any patent, intellectual property or proprietary rights of any party. CVC shall not be liable for any claim for any loss, harm, illness or other damage or injury arising from access to or use of data or information, including without limitation any direct, indirect, incidental, exemplary, special or consequential damages, even if advised of the possibility of such damages.

In accordance with scientific standards, appropriate acknowledgment of CVC should be made in any publications or other disclosures concerning data or information made available by CVC.