The EIB offering is similar to other impact bond offerings that run on a pay-for-success model centered on positive societal impact. By structuring these transactions as bonds, investors can now have a stake in the successful outcomes of the municipal projects they help fund. Green infrastructure incorporates the natural environment into engineered systems to capture and absorb stormwater into soil and vegetation. It can be more cost-effective than traditional “grey” infrastructure, and provides environmental, economic, and health benefits to local communities by creating more green space in urban settings. But as a new approach, green infrastructure typically needs to be piloted before being brought to scale, and bears some performance risk.

https://civsourceonline.com/2017/08/16/quantified-ventures-and-neighborly-launch-green-infrastructure-and-resilience-challenge/?