Modeling the Impact of Green Infrastructure on Stormwater Flood Mitigation in Worcester, Massachusetts Using i-Tree Hydro

Keywords: Urban forestry, Urban hydrology, i-Tree Hydro, Stormwater flooding, Urban tree planting
Session Type: Virtual Poster Abstract
Day: Monday
Session Start / End Time: 2/28/2022 11:20 AM (Eastern Time (US & Canada)) - 2/28/2022 12:40 PM (Eastern Time (US & Canada))
Room: Virtual 33

Abstract

Trees in cities are one of the most important forms of green infrastructure as they help regulate stormwater and severe flooding events. These ecosystem services are more important than ever due to the increased risk of flooding from climate change as intense precipitation events become more common. While vegetation has historically been used to mitigate flooding across a variety of developed landscapes, it is unknown how the distribution of tree cover in subdivisions of a large urban watershed impacts stormwater runoff volume. This study investigates the role of tree planting to achieve higher canopy density resulting in the mitigation of flooding in Worcester's Green Island watershed. Using i-Tree Hydro, an urban hydrological modeling tool, alternate tree density scenarios examined the effect of zero green space, increased tree planting on city-owned properties, and an ideal tree planting scenario for the city of Worcester where tree canopy in green space is maximized. Base case and alternate scenarios were examined at the full watershed scale as well as five sub-watershed divisions. Precipitation data were sourced through the National Oceanic and Atmospheric Administration (NOAA) for the year 2018 to examine present hydrology with different tree canopy scenarios. Results show that targeted tree planting in subdivisions with high amounts of green space can substantially reduce stormwater flooding in the watershed. Results indicate that municipalities should take a watershed approach to reduce flooding with tree planting.