The Natural Resource Defense Council (NRDC; New York) recently released the report Financing Stormwater Retrofits in Philadelphia and Beyond. The document uses Philadelphia as a case study for a stormwater billing system that promotes green infrastructure. Philadelphia uses a fee structure based on parcel size and impervious surface area, which provides incentives to reduce nonporous surfaces. The city also gives significant credits to nonresidential property owners who retain the first inch of rainfall. The report delves into attracting private investments by using schemes similar to those for energy efficiency retrofits. Following this example, a portion of future stormwater fee savings would be used to repay the lender or project financier for retrofit costs. The report also covers other innovative financing models for green infrastructure capital costs. For more on green infrastructure from NRDC, also check out its recent report, Capturing Rainwater from Rooftops.