A proposed dam and reservoir on the Pearl River in Mississippi will not be able to avoid review by the U.S. Army Corps of Engineers under a bill working its way through Congress, creating a new hurdle for a plan that supporters have hoped to push quickly through regulatory review.

U.S. Rep. Steve Scalise, R-Metairie, this week added language to the America’s Water Infrastructure Act of 2018 that his office said will ensure the controversial One Lake project on the Pearl will be fully vetted by the Corps of Engineers before it receives any federal funding.

Representatives with Scalise’s office said an earlier version of the bill would have made One Lake eligible for engineering and design funding prior to the Corps approving the project. The reworked bill passed the House unanimously on Wednesday. The Senate is expected to vote on it next week.

The One Lake project is a $345 million plan to dam the Pearl River south of Jackson, Mississippi, and create a 1,500-acre reservoir there to alleviate flooding in the Jackson area.

The project has stirred up widespread opposition in southwest Mississippi and southeast Louisiana, including St. Tammany Parish. Opponents fear the dam will potentially restrict water flow downriver in areas like the Honey Island Swamp, disrupt critical habitat and animal species, and exacerbate erosion in the lower Pearl, among other things.

"Before this project is allowed to move forward, we need to know that it will not decrease the water flow downriver, impact our coastal restoration efforts, or result in additional flooding in areas downriver from the proposed project," Scalise said in a press release.

Congress authorized a dam on the Pearl River in 2007, and officials with the Rankin Hinds Pearl River Flood and Drainage Control District who tout the project have held public meetings in Baton Rouge and Slidell, as well as Hancock County and Jackson in Mississippi, to gather public input for the Corps’ review.

A feasibility study/environmental impact statement is believed to be as much as a year away from being presented to the Corps for its first round of approval, but that didn’t stop hundreds of concerned citizens from showing up at public meetings in recent months to voice their concerns.

Last month, several hundred people attended a meeting in Slidell to discuss the project. Some said they feared reduced water flow into the Pearl River basin could change the ecology and allow saltwater to intrude into parts of the estuary.

St. Tammany and Washington parishes, the City of Bogalusa, the Town of Pearl River and the Louisiana Legislature all have passed resolutions opposing the project, as have Lawrence and Hancock counties and the Town of Monticello in Mississippi.