Putting Green Infrastructure on Private Property in New York City

New York City, like other cities that built combined sewer systems in the early twentieth century, is embarking on the reconfiguration of its approach to stormwater management – one that shifts away from exclusive reliance on “grey infrastructure” (asphalt, pipes, tunnels, sea walls) to greater reliance on “green infrastructure” (green roofs, bioswales, rain gardens, permeable pavements, coastal wetlands). That reconfiguration will entail physical changes as well as changes to the regulation and financing of stormwater management. And, underlying these physical, regulatory, and financial changes is New Yorkers’ role in managing and paying for stormwater runoff – that too must change to make stormwater management greener. Why change from grey to green? The most immediate reason is that existing grey infrastructure is failing to manage stormwater in several important respects, chiefly in relation to maintenance of regional surface water quality, adaptation to a changing climate, and allocation of cost burdens pursuant to the “polluter pays” and “beneficiary pays” principles. There are other reasons as well. As has been noted by the U.S. Environmental Protection Agency (EPA), by New York State’s Department of Environmental Conservation (DEC), by New York City’s Department of Environmental Protection (DEP), and by a long list of commentators and authors, GI is the source of multiple benefits – both direct and ancillary. This paper proceeds in four sections. The first provides an overview of the problems confronting New York City as a result of existing stormwater management infrastructure and regulation, and also summarizes the City’s current green infrastructure (GI) goals. The second section summarizes the benefits and costs that are expected to accompany GI in the New York City context. The third describes the City’s goals for creating GI on public and private property, as well as the timeframes currently envisioned for the task. It also notes the particular importance – and difficulty – of scaling up GI installations on private property. Finally, the fourth section examines the knotty administrative and legal issues involved in using public money to increase the volume of GI on private property