Proceedings of the 2023 Mississippi Water Resources Conference

Year: 2023 Authors: Holifield M., Wu W.

Frequent flooding is dangerous to both short- and long-term health, and the expenses of constant repair and upkeep wear down both citizens and city government. Moss Point, Mississippi is an underrepresented and marginalized community on the coast, well known for its frequent flooding for the last few decades. As global climate change shifts local weather patterns towards heavier rainfall and more intense tropical storms, stormwater management becomes a pressing issue concerning existing grey infrastructure. Green infrastructure has shown efficacy in mitigating flood risks while providing other co-benefits such as habitats, carbon sequestration and improved air and water quality, and can be affordable in construction and maintenance. Here we evaluated the impact of low-cost rain garden and high-cost permeable pavement on peak runoff and total runoff in three areas that are most vulnerable to flooding using the EPA's Storm Water Management Model (SWMM). The preliminary results show that both rain garden and permeable pavement led to more reduction in peak and total runoff in the more suburban catchment than in the more rural catchment. In the same catchment, permeable pavement showed more reduction of runoff than rain garden. Permeable pavement could reduce total runoff up to 21% in total runoff and 17% in peak runoff, while the percentages of reduction for rain garden were up to 1.3% and 3.8% respectively. Combining these two types of infrastructure showed effect dominated by permeable pavement. However, permeable pavement can be extraordinarily expensive, and its replacement of existing infrastructure is unrealistic. Future analysis will focus on evaluating additional green infrastructure types with different design parameters individually and combined with multiple storm event intensities. The research will facilitate implementation of low-maintenance green infrastructure in the city of Moss Point to mitigate flood risks.