Green Infrastructure Manages Stormwater while Providing Additional Benefits

By Deb Martin Downs, Director, Ecology Division, Toronto and Region Conservation Authority

Colleen Cirillo, Coordinator, Green Infrastructure Ontario Research and Development Section, Toronto and Region Conservation

 

Recent monitoring and modelling activities in southern Ontario reveal that urbanization is degrading the environmental health of many watersheds. Policy documents, including Credit Valley Conservation’s (CVC) Credit River Water Management Strategy Update and Toronto and Region Conservation’s (TRCA) watershed plans, conclude that a new approach to stormwater management is essential to watershed health and climate change resiliency.  These and other Conservation Authorities are proposing a shift away from conventional approaches and including green infrastructure in the response to water management in urbanizing areas.

To assist with this shift, CVC and TRCA developed The Low Impact Development Stormwater Management Planning and Design Guide in consultation with government and industry.  This guide details landscape-based stormwater management planning and low impact development stormwater management practices, many of which are green infrastructure types. Examples include green roofs, swales, and permeable pavement. Additional green infrastructure types, including urban forests and community gardens, also collect and purify stormwater and should therefore be considered by ecologists, planners, and developers as they make this essential shift in stormwater management.

Green infrastructure as stormwater management is even more appealing when the additional benefits provided such as sun protection, air purification, and the mitigation of urban heat island effect are considered. Efforts are underway to assign economic values to these and other benefits and services, and a coalition has formed to advocate for green infrastructure across Ontario.

Members of the Green Infrastructure Ontario Coalition share a common vision of a healthy Ontario in which the economic, social, environmental, and health benefits of green infrastructure are fully realized, protected and enhanced. The coalition is led by a seven-member steering committee with representatives from the following organizations:

·        Local Enhancement and Appreciation of Forests (LEAF)

·        Landscape Ontario

·        Ontario Parks Association

·        Toronto and Region Conservation

·        Green Roofs for Healthy Cities – North America Inc.

·        Evergreen

·        Ontario Association of Landscape Architects (OALA)

The coalition defines green infrastructure as natural vegetation and vegetative technologies that collectively provide society with a broad array of services for healthy living. These services include:

·        water and air purification

·        energy savings for buildings

·        a reduction of the urban heat island effect

·        climate change mitigation and improved adaptability

·        reduced health care costs because of active recreation  opportunities, air and water quality improvements, etc.

·        capital and operational cost savings for traditional gray infrastructure

Green infrastructure takes many forms including natural systems, parks, gardens, engineered wetlands, storm water ponds, green roofs and green walls, urban forests, and meadows.  It also includes soil in volumes and qualities adequate to sustain vegetation and absorb water, as well as technologies like porous paving, rain barrels, cisterns, and structural soils.

Since its inception in 2010, the Green Infrastructure Ontario Coalition has steadily grown in size. As of September 2011, 51 organizations, agencies and businesses from across Ontario have joined as official coalition members. This is a diverse group, with some representatives based in small towns and others in big cities. Some study and protect biodiversity while others design gardens, install green roofs, manage stormwater or advocate for healthy communities. What brings members together is a shared awareness of the great potential of green infrastructure to address Ontario’s stormwater predicament while simultaneously benefiting society in numerous and diverse ways. For more information on green infrastructure and the coalition, visit www.greeninfrastructureontario.org.

 Deb Martin Downs is the Director of Ecology at the Toronto and Region Conservation Authority. Colleen Cirillo is also with TRCA and the Green Infrastructure Ontario Coalition GIOC. Colleen is speaking at Latornell on Friday morning in a session entitled “Making the Case for Green Infrastructure”. The Toronto and Region Conservation Authority is one of the founding members of the Coalition.