From a Census of 680,000 Street Trees to Smart Stormwater Management: A Study of Efficacy and Economics of Street Tree Guards in New York City

Green Infrastructure (GI) is a strategy of incorporating a distributed network of eco-technical systems that retain and detain stormwater to improve the hydrology of developed landscapes. GI is particularly needed in urban environments where roads, buildings, parking areas, and paved public spaces create a hardscape that results in rainfall rapidly running off and subsequently polluting natural waterways. However, the same dense, built-up environment that necessitates GI also creates a barrier to installing the amount of GI needed to meaningfully alter urban hydrologic behavior. Although a wide array of systems have been developed to fit in different urban niches, as exemplified by sedum green roofs, bioswales, rain gardens, rainwater harvesting, and permeable paving, many can be costly and difficult to integrate at scale. Thus, measuring and optimizing the performance of existing urban vegetation represents an important area of focus for stormwater management and offers potential for more economical use of resources allocated for GI. This paper focuses on examining the role of urban street trees in stormwater management