As stormwater runs off urban areas, it
can gather pollutants such as oil, pesticides and other contaminants that can have an
adverse effect downstream. The "non-point source"
water pollution in
stormwater runoff is the most common cause of poor water quality in urban lakes and streams.
The objective of traditional drainage planning is to prevent flooding by
draining stormwater as quickly as possible from developed areas. This approach results in
an increase in the volume and flow rate of surface runoff, causing excessive erosion
and habitat degradation in the receiving streams. Urbanization has changed the
natural hydrology of watersheds, resulting in channel instability, low summer flows, and
altered stream morphology. The cumulative effects of these changes impacts the
integrity and diversity of aquatic ecosystems.
Given the impacts of conventional stormwater management
practices, protecting the health of urban watercourses
clearly requires a different approach.
Integrated Stormwater ManagementThe science of stormwater management is evolving and has broadened from the traditional engineering approach to one that integrates hydrologic and environmental concerns. Integrated stormwater management planning is a comprehensive approach to rainwater management that plans for a range of rainfall events, not just large storm events. One of the guiding principles of an integrated strategy is that:
Integrated stormwater management plans can be used to meet the stormwater component of a
Liquid Waste Management Plan. Stormwater management objectives can be
integrated into local government land use planning and decision-making by
incorporating them into the vision and goals of the
Official Community Plan.
Stormwater Management Facilities
Using design techniques that take advantage of ecological and hydrological processes allows communities to meet flood prevention objectives and preserve or enhance the health of aquatic and riparian ecosystems. The Greater Vancouver Regional District has developed Stormwater Source Control Design Guidelines to promote innovative designs that can be incorporated into new or existing developments such as:
Funding for Stormwater ManagementThose local governments considering undertaking integrated stormwater management plans or related feasibility studies are eligible to receive funding up to $10,000 from the Local Government Department's Infrastructure Planning Grant Program. Joint initiatives that encourage innovation and capacity building in local government planning and decision-making may be eligible to receive funding from the Smart Development Partnership Program. The Department's Capital Grant Programs and other grants can assist communities in developing low impact infrastructure.
The Department's grant programs have funded such projects as:
Stormwater Management ResourcesLocal governments can use a range of regulatory tools to support integrated stormwater management practices. The Local Government Act gives municipalities the authority to implement stormwater solutions such as:
Implementation of integrated stormwater management can be accelerated by applying the practices, designs and strategies contained in the following documents: