As two of my colleagues revealed yesterday, NRDC has just released a new report called Rooftops to Rivers II showing how communities across the country are using green infrastructure techniques to stop water pollution. The report provides case studies for 14 cities that all can be considered green infrastructure leaders, using a six-point “Emerald City Scale” to identify which key strategies each city is using to become cleaner and greener.
It’s only fitting that our nation’s capital, Washington, D.C., is one of the most highly rated cities on the scale. The District is implementing an impressive five of the six strategies we identified, second only to Philadelphia – the only city to adopt all six.
- Green roof at World Wildlife Fund Headquarters, Washington, D.C. -- photo courtesy American Hydrotech, Inc.
Here’s how D.C. scored so highly on the Emerald City Scale:
- Thanks to its new Clean Water Act stormwater permit issued just last month, the District is committed to adopting a requirement for all newly developed and redeveloped properties over 5,000 square feet to retain the first 1.2 inches of stormwater on-site. Thanks to this requirement, properties throughout the city will use green infrastructure to capture and store rainwater.
- The District’s new stormwater permit also commits it to using green infrastructure to reduce runoff from 18 million square feet of existing impervious surfaces.
- The District has a dedicated funding source for green infrastructure in the form of two stormwater fees, paid to the District Department of Environment and D.C. Water, both of which are based on the amount of impervious surface area on each ratepayer’s property.
- D.C. government provides incentives for individuals and businesses to use green infrastructure practices on their own properties. For example, the District is developing a program to give ratepayers a credit off of their stormwater fee if they use green infrastructure controls.
- Last but not least, the District provides training, guidance, and assistance for the use of green infrastructure, reaching out to citizens with a public education campaign and providing subsidies and technical help to those installing green roofs and other practices.
The District is using green infrastructure to address pollution from both its separate and combined sewer systems. While the new stormwater permit described above mandates the use of green roofs and trees in the separate sewer areas of the city, D.C.’s water utility is also using green infrastructure to stop combined sewer overflows, as the Washington Post describes today.
However, the city does fall short in one area: it hasn’t adopted a long-term green infrastructure plan to guide its progress, as other cities (such as Nashville, New York, and Philadelphia) have done.
Still, the steps that D.C. has taken represent a true commitment to green infrastructure for which we commend the city. They’re going to go a long way in cleaning up the District’s historically troubled rivers, saving money on stormwater management costs, and making the city a more beautiful place to live.