Estimating Stormwater Runoff for Community Gardens in New York City

Mara Gittleman


Community gardens are built and managed by local residents on vacant land, often as acts of resistance to urban decline and disinvestment. Community gardens have a number of documented benefits, particularly in the social realm: they have been shown to improve community stability, reduce crime, and provide a number of health benefits. While much of the literature also cites community gardens as providing environmental benefits for cities, there is very little research actually quantifying these benefits. Despite the numerous urban ecosystem services these spaces provide, some municipalities, including New York City, do not consider community gardens as part of their plans for open space and green infrastructure. Without an ecosystems services framework, the case for community gardens is often framed around financial trade-offs with other types of urban land-use, such as housing, leading to the loss of green space.

One of the biggest challenges of maintaining a healthy urban ecosystem is stormwater. New York City’s sewer system relies on combined sewer overflows (CSOs), that release raw sewage and stormwater runoff into local waterways during precipitation events. Adding built infrastructure to deal with the runoff would be a costly endeavor that would not benefit the urban ecosystem. To mitigate this issue, New York City released NYC Green Infrastructure Plan: A Sustainable Strategy for Clean Waterways, a formal plan for increasing green infrastructure, which details water where it falls so that it may percolate through the soil or be saved for later use. Community gardens, however, are not included in that plan. The goal of this thesis is therefore to evaluate community gardens as green infrastructure by comparing the stormwater runoff rates of urban vacant lots, community gardens, and residential development in New York City.