By Robert C. Brears
Traditionally, cities have relied on gray stormwater infrastructure — conventional piped drainage systems — to move urban stormwater away from the built environment. However, stormwater runoff is a major cause of water pollution in urban areas with runoff containing heavy metals, trash, bacteria, and other pollutants from the urban landscape. High flows can also cause erosion and flooding in urban waterways, damaging habitats, property, and infrastructure.
Green Infrastructure And Its Multiple Benefits
Green infrastructure uses vegetation, soils, and natural process to manage excess water and create healthier environments. In urban areas, green infrastructure ranges in size from permeable pavements, rain gardens, green roofs, and green spaces in neighborhoods, all the way up to constructed wetlands and restored river ways at the city level. When green infrastructure is interconnected, it can enhance the resilience of infrastructure and communities to extreme weather events by reducing localized flooding risks as well as improving water quality. These benefits are complemented by additional environmental, economic, and social benefits including improved air quality, reduced urban temperatures, energy savings, higher property values, increased recreational opportunities, and aesthetic improvements. Furthermore, green infrastructure, unlike gray infrastructure, can appreciate in value over time with the regeneration of nature and its associated ecosystem services.
Green Infrastructure Sprouting Up
Across the U.S., cities are implementing green infrastructure strategies to enhance resilience of infrastructure and communities to extreme weather events as well as capitalize on the numerous benefits it brings. Two such cities are Chicago and Atlanta.
Chicago’s Green Stormwater Infrastructure Strategy
The City of Chicago’s Green Stormwater Infrastructure Strategy commits additional public funding to build green stormwater infrastructure alongside traditional gray infrastructure to achieve four long-term stormwater management goals:
The city will allocate $50 million over the next five years to build green stormwater infrastructure that will provide Chicago with an additional 10 million gallons of stormwater storage that could reduce runoff by 250 million gallons each year. The funding will be allocated to projects that deliver immediate benefits and improve knowledge and understanding of green stormwater infrastructure with priority placed on communities facing high risk of basement flooding. Initiatives include:
City of Atlanta’s Green Infrastructure Strategic Action Plan
The City of Atlanta has launched its Green Infrastructure Action Plan to reduce stormwater runoff by 225 million gallons annually. To action this plan, Atlanta will implement pilot green infrastructure projects to illustrate the value of green infrastructure technologies to the public, showcase their application on various publicly-owned lands, and build institutional capacity. The implementation of pilot projects will enable the city to develop knowledge and best practices on design as well as maintenance of green infrastructure on various types of land uses across the city, ensuring wide-scale design and implementation will be as efficient as possible. Furthermore, public capital projects will be scoped for their potential for incorporating green infrastructure. At the same time, the city will develop standardized design and construction plans for greening streets including right-of-ways as well as other capital improvement projects that are deemed suitable for green infrastructure. To gain acceptance of green infrastructure as a mainstream way of reducing stormwater runoff, the city will develop a framework for public involvement in green infrastructure. Specifically, the city will develop a public outreach plan and presentation materials for neighborhood groups, business leaders, city council, developers, and other stakeholders.
Green infrastructure enhances the resilience of infrastructure and communities to extreme weather events by reducing localized flooding risks as well as improving water quality. At the same time, green infrastructure provides additional environmental, economic, and social benefits. Following the lead of Chicago and Atlanta, cities around the country can capitalize on these multiple benefits by assessing the feasibility of incorporating green infrastructure in new capital projects, developing pilot projects that embrace learning-by-doing, and enhancing public and institutional awareness of the multiple benefits green infrastructure brings.
About the Author
Robert C. Brears is the author of Urban Water Security (Wiley). Urban Water Security argues that, with climate change and rapid urbanization, cities need to transition from supply-side to demand-side management to achieve urban water security.
Image credit: "IMG_0971" Brad Davis, AICP © 2012, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/