Investments in so called “green” infrastructure solutions such as wetland restoration or agricultural best management practices are increasingly recognized as cost effective ways to achieve environmental quality outcomes relative to investments in “gray” infrastructure such as wastewater treatment or water filtration plants. For example, the Center for Neighborhood Technology asserts “[t]he research shows that green infrastructure measures are as effective as conventional approaches in relieving flooding, and can be installed more cheaply and quickly.” Moreover, green infrastructure is considered a lasting source of ecosystem service benefits for communities that appreciates rather than depreciates over time.
CSE and other partners have pioneered an analytical technique for quantifying the economic and financial tradeoffs between green and gray infrastructure in three decision-making contexts: (1) disaster risk reduction; (2) regulatory compliance, and (3) infrastructure investment. This technique – green vs. gray analysis (GGA) – extends conventional public infrastructure analysis models used to evaluate the cost effectiveness of technological solutions like new reservoirs by factoring the unique role wetlands, forests, riparian zones and other green infrastructure elements can play in enhancing water quality and flow or achieving other environmental objectives. GGA is used to determine whether investing in these green infrastructure options is a more cost effective approach.