20 October 2016 Published by Green Communities Canada
Rain gardens blooming across North America
Rain gardens are inexpensive and simple to build. They are an environmentally sound method of managing urban stormwater runoff with the added benefit of beautifying city streets and neighbourhoods. These bowl shaped gardens capture rain onsite and reduce the amount of runoff entering storm sewers. As well, they improve the quality of water entering local waterbodies and reduce flood risk.
With all the benefits this simple green infrastructure provides it is not a surprise a growing number of North American cities are supporting the installation of rain gardens. The City of Calgary has created three large demonstration rain gardens in an area where traditional stormwater management technologies were not feasible. Thunder Bay, in partnership with Green Communities Canada member organisation EcoSuperior, created a Rain Garden Rebate program. Residents can receive up to $500 towards the creation of a rain garden on their property, and the City has also provided free courses on proper construction and maintenance.
The positive impact of rain gardens increases with the installation of multiple gardens. If you live in Maplewood, Minnesota the City offers rain gardens to residents undergoing road reconstruction. The City digs out the site, provides plants, and helps plant the rain garden. Since 1996, Maplewood has installed over 700 boulevard rain gardens maintained by homeowners and 60 rain gardens on city land maintained by city staff.
Rain gardens can also be strategically placed for collective impact. This is the philosophy behind 12,000 Rain Gardens in Puget Sound. Currently, local governments in the watershed provide financial incentives and rebates to support residents who build rain gardens. In places like Seattle, the building of rain gardens in targeted sewer overflow basins is encouraged through rebates to hire a trained rain garden contractor.
While the popularity of rain gardens continues to grow few Canadians know how to properly design and build one. Many ‘engineered’ infiltration solutions minimize the importance of soil, plants and roots to maximize infiltration and reduce flood risk. To help increase the capacity of Canadians to build functioning and beautiful rain gardens Green Communities Canada is hosting a two-day workshop (October 27- 28) on how to design and build rain gardens. Facilitated by one of North America’s leading rain garden experts, Rusty Schmidt, the workshop is geared towards conservation professionals, landscape professionals, gardeners, master gardeners and stormwater engineers. In addition to design and construction tips the workshop will also include information on how plants and roots work to soak up runoff and reduce flood risk. More details and to register.
Soaking up rain in Atlantic Canada.The Atlantic Stormwater Initiative is coordinating three green stormwater infrastructure projects in Moncton (New Brunswick), Charlottetown (Nova Scotia) and Sydney (Nova Scotia). These three demonstration projects will incorporate permeable paving and bioswales that will be monitored overtime for water quality and quantity, as well as maintenance requirements. Ramona Doyle from the City of Charlottetown also hopes the sites will show residents what they can do on their own properties to help manage stormwater.
City of Victoria introduces stormwater utility bill. This month Victoria residents will receive a separate bill for their use of the stormwater system. The charges are based on the area of impermeable surface, property use and the length of street frontage-- and will be billed annually. The city has also developed a Rainwater Rewards Program to encourage property owners to manage rain on their properties.
The ‘unsung’ benefits of green stormwater infrastructure.The focus of green stormwater infrastructure has been to mitigate the impacts of runoff in the urban environment. An article by a Seattle based Landscape Architect highlights a few additional environmental benefits. Capturing water onsite and reusing it also cuts down on the energy requirements of piping water from its source to a treatment plant and then to homes and businesses. Additionally, increased vegetation (especially forests) assists with evapotranspiration- a major function of the water cycle. In a forest, nearly 50% of rainfall is absorbed by evapotranspiration—preventing it from becoming runoff.
Green infrastructure as a mainstream strategy for stormwater management. Using green stormwater infrastructure to manage rain is becoming the norm for utilities across the United States. Adam Krantz, CEO of the National Association of Clean Water Agencies (NACWA) states, “Green infrastructure is still in its infancy, but utilities and regulators are getting more comfortable with the value it brings”. A 2015 report by NACWA states that wastewater utilities are progressing beyond mandated water quality regulations while lowering costs, increasing revenue and helping to boost the local economy.
Cost- benefit analysis of stormwater best management practices. This study examined the performance, and the costs and benefits of eight rain gardens, eight infiltration trenches, an underground stormwater storage and infiltration facility, and a stormwater pond in Saint Paul, Minnesota (a location with a continental climate- characterized by warm/hot summers and cold winters). The analysis took into consideration the annual volume reduction and pollutant removal costs, the annual operation and maintenance costs, and construction costs.
Promoting Green Streets—A Recipe for Integrating Water and Transportation Infrastructure Investment. A document created by the Rivers Network that outlines a simple and logical methodology for promoting street-based stormwater management in mid-sized cities. Based on experiences and analysis from Philadelphia, Boston, Chicago and New York.
How to design and build rain gardens. Workshop. 27-28 October 2016. Peterborough, Ontario. Limited seats available. Register online.
CitiesAlive: Rising to the Stormwater Challenge. 1-4 November 2016. Washington, DC. Register online.
Making it Work: Low Impact Development SWM Construction, Inspection, Maintenance, and Monitoring. Workshop. 14 November 2016. Alliston, Ontario. Register online.
Improving Agency Education and Capacity for Erosion and Sediment Control Review. Workshop. 14 November 2016. Alliston, Ontario. Register online.
Roads and runoff — using green infrastructure to manage stormwater runoff from roads and highways. Webinar. 1-2pm (EDT). 23 November 2016. Presented by Robert Goo, Office of Research and Development, USEPA. Register online.
Want to see more events? Check out the RAIN Events Calendar for other upcoming green infrastructure workshops, training, webinars and conferences.
The Umbrella Stormwater Bulletin is a free, monthly newsletter on green stormwater infrastructure published by the RAIN Community Solutions program of Green Communities Canada. Our audience is made up of municipal stormwater professionals, policymakers, academics, engineers, conservation authorities, nonprofits, and interested community members. We encourage submissions from our readers. Please contact the editor to submit a news item, blog idea, or event. RAIN Community Solutions builds support for and participation in stormwater innovations that reduce runoff by managing rain where it falls.