Water Resources Research Act Program

Principal Investigators:

Abstract: Efficient stormwater management is imperative to future sustainability of urban environments. Impervious surfaces in urban areas inhibit recharge and infiltration while intensifying runoff. Rust belt cities such as Buffalo, NY have high percentage of older and sometimes vacant industrial property that were not designed to reduce storm runoff. These settings can intensify storm induced runoff and jeopardize aging grey infrastructure. As rainfall intensity is projected to increase in urban Buffalo, this will in turn increase the probability of combined sewer overflow (CSO). As a solution, rain gardens are a common form of green infrastructure (GI) currently implemented around downtown Buffalo to help minimize urban runoff. Collaborators at the Buffalo sewer authority and PUSH Buffalo have installed rain gardens in order to reduce both runoff and combined sewer overflows. However, there has been limited studies quantifying infiltration rates and efficiency of these rain gardens. The objective of this research is to evaluate rain garden efficiency under current and future climates.Seven field sites in the City of Buffalo are proposed to investigate rain garden efficiency and forecast future climate scenarios. Each rain garden site is chosen based soil composition, underlying geology, garden area, and physical location. Performance of seven rain gardens with different constructions and spatial locations will be evaluated using HYDRUS 1D, a variably saturated flow modeling system. Soil moisture, matric potential, soil characterization, and root distribution data will be collected at each site to calibrate and validate each model. Future climate projections will be coupled with each model using data from the North American Regional Climate Change Assessment Program (NARCCAP), looking at future climates from 2041-2070. While most of the literature focuses on GI in arid regions to address water scarcity, this study is unique because Buffalo is a water rich region. The goal of the research is to give the water managers across the Great Lakes, including the Buffalo Sewer Authority, predictive power to right size GI with a focus of reducing runoff and CSO, and to evaluate current efficacy of rain gardens. Rainfall is projected to increase over the next 30 years across the Great Lakes region, which stresses the importance of infiltration and evapotranspiration of stormwater. Improper management will lead to CSO, which can impact water quality, and the integrity of aging grey infrastructure. The proposed work is therefore imperative in addressing the aging infrastructure in Great Lakes cities such as Buffalo, and innovative in the investigation of GI in water rich regions.