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.