The Impacts of Climate Change and Porous Pavements on Combined Sewer Overflows: A Case Study of the City of Buffalo, New York, USA

Abstract

Combined sewer overflows (CSOs) release pollutants collected in urban runoff into local waterways, impacting both aquatic life and human health. The impact of climate change on precipitation may result in an increase in the frequency and magnitude of heavy precipitation events, with a corresponding increase in CSO discharges. The installation of Green Infrastructure (GI) such as Porous Pavements (PP) is a resilient approach to mitigate CSO events. However, an understanding of the impact of climate change on CSO events and the effectiveness of GI practices is crucial for designing sustainable urban stormwater management systems. Using the Storm Water Management Model (SWMM), the performance of PP as a CSO abatement strategy was studied for the city of Buffalo, New York, USA. This paper used the Intensity-Duration-Frequency (IDF) curves for current (1970–1999) and future (2070–2099) design rainfall scenarios, with four rainfall durations (1, 6, 12, and 24 hours) and four return periods (2, 10, 50, and 100 years). The simulation results show that (1) current 100-year events generate CSO volumes similar to predicted 50-year events; (2) CSO volumes could increase by 11–73% in 2070–2099 compared to 1970–1999 when no GI intervention is performed; and (3) the installation of PP can reduce 2–31% of future CSO volume. This case study demonstrates the regional CSO challenges posed by climate change and supports the use of GI as a mitigation strategy.

A Discussion on the Application of Terminology for Urban Soil Sealing Mitigation Practices

“…SuDS are a complement to conventional sewer system infrastructure to minimize the hydrological impacts of urbanization and increase resilience to climate change in urban areas [ 41 ]. These measures are intended to limit extreme precipitation events [ 40 ] and are known to provide many environmental benefits [ 42 ], including the mitigation of climate change impact [ 43 , 44 , 45 , 46 ], along with ecological and social benefits and other potential long-term economically quantifiable benefits [ 47 , 48 , 49 ]. Types of SuDS include green roofs, permeable surfaces, wetlands, detention and infiltration basins, and filter drains, among others [ 50 ].…”

A stochastic approach for assessing the chronic environmental risk generated by wet-weather events from integrated urban wastewater systems

“…In some areas the increase of high intensity rain events will result in more frequent wet-weather discharges. 10,11 Tavakol-Davani et al 12 estimated an increase in wet-weather discharge frequency (18%), volume (12%), and duration (17%) in Toledo (Ohio, USA). Salerno et al 13 estimated an increase of 40% in phosphorus load in a river in northern Italy.…”

Global Resilience Analysis of Combined Sewer Systems Under Continuous Hydrologic Simulation

“…Managing and reducing these discharges from combined sewer overflows (CSOs) has become a priority of public policies and water utilities worldwide, due to increased attention towards water quality (European Commission, 2000;UK Government, 2021;United Nations, 2018). In the face of emerging pressures such as climate change and urbanisation, the issues associated with CSOs are likely to increase (e.g., water quality and ecological impacts on receiving waters) (Astaraie-Imani et al, 2012;IPCC, 2022;Roseboro et al, 2021). Therefore, there is agreement that CSS need to be redesigned to support resilience (Butler et al, 2017;Marlow et al, 2013;Ofwat, 2015; UNESCO World Water Assessment Programme, 2018;) -i.e., the ability to minimise failure magnitude and duration under exceptional conditions (Butler et al, 2014).…”

“…Among the different interventions in CSS to enhance resilience, decentralised stormwater strategies that mimic natural processes, such as "green infrastructure" (GI) (e.g., green roofs, bioretention cells, permeable pavements) (Browder et al, 2019;Fletcher et al, 2015;Matsler et al, 2021), are gaining popularity. Research has demonstrated the efficacy of GI under various precipitation conditions, with some studies showing significant reductions in CSO volume (24-100% reduction) through the implementation of different GI types under different spatial allocations (Casal-Campos et al, 2015Joshi et al, 2021;Lucas and Sample, 2015;McClymont et al, 2020;Rodriguez et al, 2021;Roseboro et al, 2021). Conflicting findings on the effectiveness of GI in reducing CSOs suggest a need for further exploration of GI's relationship with CSS resilience performance, as current literature lacks clear characterisation in this regard.…”