By Michael Goldberg

Environmental groups in Mississippi presented findings Wednesday from the U.S. Army Corps of Engineers showing a long-debated flood control project along the Pearl River would be “destructive,” and the groups said alternative projects should be considered instead.

But proponents of the plan say the documents were improperly released, incomplete and contained information that could be misleading.

The dispute is the latest battle over the One Lake project, which was first proposed years ago to mitigate flooding in the capital city of Jackson and surrounding areas. Opponents said the project is motivated by commercial interests and would harm the environment.

“At the core, One Lake is a private real estate development scheme masquerading as flood control for greater Jackson,” said Jill Mastrototaro, the Audubon Delta’s policy director.

Documents obtained through a public records request by the environmental groups show alternative plans that could be smaller and less costly, members of the Audubon Delta and Sierra Club said at a news conference. The conservation groups outlined an internal Army Corps of Engineers presentation from August, which analyzed the financial and environmental impacts of the One Lake plan and potential alternatives.

The One Lake plan involves dredging and excavation of the Pearl River to widen, deepen and straighten portions of the waterway and reinforce the existing levee system. It could cost between $1.4 billion and $2.2 billion, but proponents say those figures might be inflated. Critics and proponents both say this could lead to commercial development by the new lake.

Environmental groups say the plan would destroy 2,000 acres (809.4 hectares) of wetland habitats and raise water levels by as much as 8 feet (2.4 meters) in some areas. That could increase tributary flooding and, according to the Corps’ presentation, “induce flooding on approximately 230 structures” in the area.

An alternative plan outlined in the presentation would not make structural changes and would cost $199 million, according to the environmental groups. It would elevate and floodproof about 600 structures in the Jackson area without dredging parts of the Pearl River and would not induce any flooding.

In a statement responding to the environmental groups, Keith Turner, an attorney representing the Rankin Hinds Pearl River Flood and Drainage Control District, a flood control board that supports the project, said the documents represent an earlier draft of the plan. He said that the proposed alternative could also be damaging and costly.

“This alternative would either remove people’s homes and neighborhoods or require their homes to be raised off the ground,” Turner said. “They also ignore the downtown Jackson flooding that will continue under a nonstructural alternative.”

The Army Corps of Engineers is set to continue reviewing the project’s environmental impacts in 2024.

In 2020 and 2022, the Peal River flooded parts of Jackson.

Environmental groups and cities downstream from Jackson have argued the project would result in unacceptable environmental harm, such as the destruction of wildlife habitat and wetlands, and a decrease in water flow.

Louisiana officials have said they fear a dearth of freshwater would alter the salinity of wetlands, could hurt native species and could affect industrial discharge by providing too little water to dilute chemicals.