As my colleague David Beckman wrote today, NRDC released a new report called Rooftops to Rivers II. Our study presents the pollution problems caused by stormwater – particularly contaminated runoff and sewage overflows – and discusses in depth how communities use green infrastructure techniques to clean up their waterways and to bring multiple valuable benefits to city residents. We felt it important to produce this analysis now, because this winter the Environmental Protection Agency will propose an update its national standards for controlling runoff pollution from new development and existing paved areas, and cities’ successes can help EPA develop robust requirements for communities across the nation.
In particular, Rooftops to Rivers II details common water pollution problems and provides case studies for 14 geographically diverse cities that all can be considered leaders in employing green infrastructure solutions to address their pollution problems. These cities have improved their ability to manage stormwater and reduce runoff pollution, saved money and beautified cityscapes by capturing rain where it falls.
To assess the breadth of each of these leaders’ green infrastructure activities, we created a metric we’re calling the “Emerald City Scale.” The six-point scale identifies six core criteria every city can undertake to maximize their green infrastructure investment, including: a long term green infrastructure plan for the city, a requirement to retain a defined amount of runoff from development projects, a requirement to reduce existing impervious surfaces using green infrastructure, incentives for private-party installation of green infrastructure, guidance or other assistance in deploying green infrastructure, and a dedicated funding source to help ensure that green infrastructure projects keep going.
Cities were awarded one point for each of the criteria that have been met. Each city in our report received at least one point but only one received a perfect score of six – and that was Philadelphia, which has emerged as the national leader when it comes to green infrastructure.
- Milwaukee, WI (5)
- New York, NY (5)
- Portland, OR (5)
- Syracuse, NY (5)
- Washington, D.C. (5)
- Aurora, IL (4)
- Toronto, Ontario, Canada (4)
- Chicago, IL (3)
- Kansas City, MO (3)
- Nashville, TN (3)
- Seattle, WA (3)
- Pittsburgh, PA (1)
- Detroit Metro Area & the Rouge River Watershed, MI (1)
(Photo: Seattle's High Point Neighborhood -- Street-sidâes being supplanted with additional plants. Notice trees and shrubs. Photo by Nancy Arazan)
Below is a chart depicting how the communities earned their distinctions as Emerald Cities.
It’s important to note that while some of the cities received higher scores than others, each is meeting at least one of the core NRDC criteria. The ranking is not meant to highlight areas in which some cities are lacking compared to others, because every city that is meeting one or more of our criteria are performing in ways that deserve to be emulated. In fact, because each of these diverse cities has implemented at least one aspect of NRDC’s Emerald City plan, we know it’s doable.
Each of these cities is proof that green infrastructure works. Their success should encourage both the EPA and policymakers on the local and state levels to adopt policies that will drive similar approaches and outcomes nationwide.
For cities not included in the report, but which are pursuing green infrastructure programs that meet NRDC’s six criteria, we want to know about it. NRDC has developed a function on our website that allows municipalities to submit information about local green initiatives. We welcome other communities to add their names to the growing list of cities using green infrastructure. Doing so will further demonstrate to the EPA and other policymakers that green infrastructure is effective, affordable and should be implemented across the country.