Stormwater Management Plan
What is it?
A Stormwater Management Plan provides direction to a municipality to control runoff of rain water and melted snow to reduce the risk of flood and impact to water quality. In developed areas, impervious surfaces such as pavement and rooftops prevent water from naturally seeping into the ground. Instead, stormwater rapidly flows off of impervious surfaces, collecting urban pollutants, such as oil, pet waste, and fertilizer, along the way. Stormwater Management systems direct stormwater into a drainage system, and out into rivers and streams.
A Stormwater Management Plan provides the direction needed for a successful stormwater management system, and includes tools such as permeable pavements, wetlands, and other low impact development techniques to better prevent flooding, and reduce impact to water quality.
How can municipalities use it?
The primary purpose of a stormwater management system is to detain water and remove pollutants. Municipalities can establish a Stormwater Management Plan to integrate and coordinate other plans and policies that relate directly and indirectly to stormwater, such as local area plans, development permit approvals, park management plans, and source water protection plans. A Stormwater Protection Plan highlights targets, and provides strategies that inform implementation action including land use bylaws. Stormwater management design and best practice manuals further help to guide implementation and adherence to policies. As stormwater management has implications for the entire watershed, Stormwater Management Plans must align with regional strategies.
What are the advantages?
The advantages of a Stormwater Management Plan include:
Integrating the use of natural infrastructure and engineered (grey) infrastructure
Help identifying and mapping natural infrastructure assets in the community
Facilitatation of municipal funding for maintenance of natural infrastructure
When low impact development techniques are incorporated, can minimize impacts of stormwater-borne pollutants on natural infrastructure
Stormwater Management plans, bylaws, and design manuals clearly communicate requirements to municipal staff and developers
What should you watch out for?
No tool is a silver bullet. There are issues for municipalities to watch out for with Stormwater Management Plans, including:
Must align with other local and regional plans and policies
In absence of measures to reduce pollution, the Stormwater Management infrastructure will not protect water quality in natural assets
May focus only on engineered (grey) infrastructure
May view natural infrastructure as non-traditional, and struggle to incorporate it
How can it help maintain natural infrastructure?
When a municipality implements strategies to capture and treat stormwater, it can reduce risk of flood, and reduce the negative impacts the built environment has on water quality. This protects the degradation of natural infrastructure assets, improving functions and benefits.
Town of Okotoks – The Town of Okotoks developed a Stormwater Management Master Plan and Flood Mitigation Plan to define the existing stormwater drainage system capacity along with the required upgrades, and to define the future drainage planning goals of the undeveloped areas.
City of Edmonton River for Life – The City of Edmonton developed the River for Life Strategic Framework Framework, a 30-year strategic plan to reduce pollutant discharge into the watershed.
Protecting Riparian Areas: Creative Approaches to Subdivision Development in the Bow River Basin. A Guide for Municipalities, Developers and Landowners – Designed to assist municipalities and those thinking of developing rural land in the Bow River Basin, this Guide includes a section on stormwater management planning.
Regenerative Stormwater Conveyance System (RSC) – This document provides detailed information on Regenerative Stormwater Conveyance Systems (RSC). RSC is an innovative approach to providing stormwater treatment, infiltration, and conveyance within one system. It has been used as an ecosystem restoration practice for eroded or degraded outfalls and drainage channels.
Town of Cochrane Integrated Stormwater Management Plan (ISMP) – Cochrane's ISMP is intended to assist Town staff, developers and landowners with implementation of sustainable approaches to stormwater runoff management that can better balance community development and environmental protection within the current regulatory landscape.
Green Bylaws Toolkit: for conserving sensitive ecosystems and green infrastructure – This document describes stormwater management - referred to as ‘rainwater management’ - and provides case studies of how this tool is used.
Municipal Natural Assets Initiative: Town of Oakville – This document explains a Municipal Natural Asset Initiative pilot project conducted in Oakville, Ontario, and how these natural assets compare to grey stormwater infrastructure.
City of Vancouver Administrative Report: Rainwater Management Plan and Green Infrastructure Strategy – This report presents Vancouver’s City-wide Integrated Rainwater Management Plan.
Did we miss something?
If you know of a resource that should be on this list - or your municipality has a sample or case that should be here, please let us know!