Muddy Waters in Jackson, Mississippi: How Can Flood Risks Best Be Reduced?

Abstract Submission: The city of Jackson, Mississippi, lies on the Pearl River (mean discharge = 2,781 cfs) downstream from a 33,000-acre water supply and recreation reservoir. Devastating floods have occurred several times, notably in 1979, 1983 and 2020. The latest in a long series of studies and proposed flood risk management projects comprises enlargement of the river channel downstream from the reservoir by excavating the floodplains. Project alternatives include channel enlargement with and without a 12-ft high dam to create a 1,700-acre lake for recreation and residential development. As described in draft environmental statements (DEIS) either alternative would require reinforcement of seven bridges, excavation of up to 20 million cubic yards of material, potential erosion or inundation of hazardous waste sites, destruction of 1,374 acres of wetlands and degradation of habitats for three threatened or endangered species. Notably, the project would not reduce and might exacerbate flooding from tributaries of the Pearl that cross the city, which disproportionately affects low-income neighborhoods. Project plans and preliminary designs have been criticized for postponing engineering and economic analyses of issues that have major economic and environmental relevance, such as hazardous and toxic waste sites, habitat mitigation requirements, erosion and sedimentation, potable water supply and some water quality issues. Instead, the preferred alternative seems to feature real estate and recreation development. While the current DEIS is disappointing, it should be recognized that the planners were constrained by limits on time, budget and geographic scope, illustrating problems with federal water resources project planning and design procedures.

Learning Objectives/Expected Outcome (Optional) : A re-examination of federal water resources project planning and design procedures. Alternative selection should not occur until vital questions are dealt with more fully.