Feb 16, 2012

Report Highlights Rainwater Harvesting as Potential Solution for Urban U.S. Cities

NRDC analysis says green infrastructure practice can curb pollution, increase water supply

A recent analysis on rainwater harvesting by the National Resources Defense Council (NRDC) says capturing rainwater from rooftops provides an opportunity for urban areas to increase water supply and improve water quality.

In the report, “Capturing Rainwater from Rooftops,” NRDC demonstrates the benefits and potential of rooftop rainwater capture, considered a green infrastructure practice that can be used to retain storm water runoff onsite, by analyzing ways in which eight U.S. cities could incorporate the practice. By comparing annual rainfall totals to rooftop coverage, NRDC determined that opportunities exist in each city to capture hundreds of millions of gallons of rainfall every year for reuse.

“Our analysis shows that solutions to one of America’s biggest urban challenges are right in front of us – in this case, literally falling from the sky,” said Noah Garrison, lead author of the report and NRDC water policy analyst. “The potential exists for cities throughout the U.S. to capture hundreds of millions or even billions of gallons of rainwater each year from urban rooftops. We encourage policymakers to look closely at the bottom-line benefits of rooftop rainwater harvesting, and consider implementing policies and incentives that generate more momentum for rainwater collection while making the practice more accessible as well.”

The report comes as the U.S. Environmental Protection Agency is in the process of updating its national standards for controlling runoff pollution from new development and existing paved areas. NRDC encourages cities and states to develop policy options and incentives to encourage more rainwater harvesting, including:

• Adopt storm water pollution control standards that require onsite volume retention;
• Adopt standards that require or promote rainwater harvesting and/or water efficiency;
• Review building, health and plumbing codes for barriers to reusing rainwater;
• Provide incentives for decreasing storm water runoff and promoting water conservation; and
• Require use of rainwater harvesting on all public properties.

The complete NRDC report is available at www.nrdc.org/water/rooftoprainwatercapture.asp.