Retention Credits and a Big Investment Overhauling D.C.'s Stormwater Infrastructure

Julian Spector details the ongoing work in Washington, D.C. to overhaul the city's stormwater and wastewater systems with green infrastructure, such as "rain gardens, green roofs, permeable surfaces, and leafy drainage ditches known as bioswales that filter and store extra rainwater…"

Critical to the effort, and the focus of Spector's coverage, is the funding mechanism created by the District Department of Energy and Environment, namely a retention credit systemthat establishes a market for stormwater retention. The article details the challenges in establishing a market for stormwater retention and some of the solutions both government agencies and the private sector have found for those challenges since 2014, when trading started. Especially important in scaling up the program has been a $1.7 million investment by Prudential that will allow District Stormwater to "install green infrastructure in places deemed most ecologically beneficial, and then sell the credits." Spector adds, "If it succeeds in turning a profit, Prudential will recoup its investment, plus interest, and the approach could be considered for other cities…"