History and context

In 1993, the Ontario Ministry of the Environment (OMOE) and Ontario Ministry of Natural Resources (OMNR) released three policy documents focusing on integrating water resources management and urban planning:

• Water Management on a Watershed Basis: Implementing an Ecosystems Approach
• Subwatershed Planning
• Integrating Water Management Objectives into Municipal Planning Documents

These documents heralded a new approach to water management in Ontario. They emphasized the need for an increased focus on protecting the natural environment and the need for stormwater management practices to pay more attention to water quality and environmental concerns, in addition to addressing traditional water quantity concerns.

In 1994, the OMOE released two practitioners guides to stormwater management planning:

• Stormwater Quality Best Management Practices
• Stormwater Management Practices Planning and Design (SMPPD) Manual

The OMOE SMPPD manual was intended to introduce practitioners to a broad range of stormwater management facilities designed to not only offset the effects of hydrologic changes of urban development on streams and rivers, but also address water quality and erosion impacts. The SMPPD manual also provided detailed guidance on how to design and build multi-purpose facilities and included sections on operations and maintenance and environmental monitoring requirements.

In 2003, OMOE released a new Stormwater Management Planning and Design Manual, which significantly updated and expanded on the 1994 version. The 2003 manual:

• provided an overview of the impacts of urbanization on the hydrologic cycle and stream ecosystems
• addressed the evolution of the watershed planning process and its implications for the design process
• incorporated water quantity, erosion control, water quality protection, and water balance principles into the selection and design of stormwater management practices (SWMPs)
• documented the performance of monitored SWMPs
• incorporated design considerations for SWMPs in cold climates
• provided information on new “state of the art” SWMPs
• addressed infill projects
• updated operations and maintenance requirements
• provided design examples for SWMPs
• updated material related to planting strategies and the function of plant materials in SWMP design
• provided examples of retrofitting SWMPs
• outlined integrated planning for stormwater management

In 2010 LID specific design advice was collated by a team from Toronto Region Conservation Authority (TRCA) and Credit Valley Conservation (CVC). Information from both this 2010 guide, and the 2003 MOE manual has been reviewed and assimilated during the production of this website guide.

Refers to the conditions in which an organism lives and survives or the conditions in which an organism resides. These conditions can be described as aspects of a “physical”, “social” or an “economic” environment, depending on the perspective perceived by the observer.

Refers to the conditions in which an organism lives and survives or the conditions in which an organism resides. These conditions can be described as aspects of a “physical”, “social” or an “economic” environment, depending on the perspective perceived by the observer.

State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include Source, Conveyance and End-Of-Pipe Controls.

The changing of land cover and land uses from rural to urban; the growth of urban settlements.

The circulation of water from the atmosphere to the earth and back, through precipitation, runoff, infiltration, groundwater flow and evapotranspiration.

Includes the protection of soil from dislocation by water, wind or other agents.

The accounting of inflow and outflow of water in a system according to the components of the hydrologic cycle.

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Toronto and Region Conservation Authority

Credit Valley Conservation