10.5 Stormwater Management

Principle

Manage stormwater effectively to protect residents, infrastructure, and property while minimizing environmental impacts.

Photo: Steve Boer

The effective management of stormwater is critical for the protection of life, property, infrastructure, and the natural environment. Traditional approaches to stormwater management have evolved from essential flood protection to include measures that minimize water runoff and consider water quality. A balanced approach to stormwater management includes reducing runoff, improving water quality, promoting water infiltration, and reducing soil erosion. The following policies manage the impacts of stormwater while encouraging Low Impact Development (LID).

What are “Low Impact Development” features?

Urban development can have a significant impact on the natural environment. By increasing the number of impervious areas within a city (such as those covered with pavement), this development can disrupt and change natural hydrological processes, typically by changing the flow of stormwater and other runoff. This stormwater runoff contains pollutants from the urban environment and can impact the health of streams and lakes within a watershed.

Low Impact Development (LID) is an approach to development and stormwater management that mimics or restores natural processes in order to manage stormwater closer to the source. Some examples include introducing limits to impervious areas, green roofs, permeable pavement, bioswales, and rainwater harvesting.

Policies

10.5.1.

Require the submission of a Stormwater Management Plan, prepared by a qualified professional, for all new and applicable amended statutory plans, as well as for proposed commercial, industrial, institutional, and multi-unit residential development, prepared according to City standards.

10.5.2.

Encourage the use of existing wetlands and topography to help manage stormwater storage and flows while maintaining the integrity and ecology of such features.

10.5.3.

Require stormwater outfall discharge locations, maximum allowable release rates, unit area release rates, runoff volume control targets, and stormwater treatment to be consistent with the City’s stormwater management plans.

10.5.4.

Protect public safety, infrastructure, and property through the appropriate placement and design of stormwater management facilities.

10.5.5.

Require stormwater management facilities to be located on public utility lots, except where an alternative location is found to be satisfactory by the City. Stormwater management facilities identified as public utility lots and lands prone to flooding will not be accepted as municipal reserve dedication.

10.5.6.

Encourage the use of built forms, development standards, landscaping, and green infrastructure tools to limit the impermeable surface area and reduce inputs into the stormwater management system.

10.5.7.

Encourage the design of surface parking lots that incorporate green infrastructure and LID features to reduce stormwater runoff.

10.5.8.

Encourage the naturalization of all new stormwater management facilities, thereby reducing maintenance costs, adverse effects of stormwater runoff, and the spread of invasive species and algal blooms, while improving water quality.