Several miles from the mouth of the Pearl River, where land begins its transition to sea, Paul Trahan captains a boat into the Honey Island Swamp and worries about this natural treasure.
"You're going to have beautiful areas that we see all around the boat starting to die," said Trahan, a tour boat operator near Slidell.
The environmental group American Rivers share his concern and named the Pearl to its annual list of the country's most endangered rivers.
Topping this year's list is the Colorado River in the Grand Canyon, where the group fears, "a proposed industrial-scale construction project threatens the Grand Canyon's wild nature and unique experience that belongs to every American.
In placing the Pearl at number 10 on the list, American Rivers cites plans by a flood district in Jackson, Mississippi to install a dam and forge a narrow, nine-mile long lake.
American Rivers called the project "disguised economic development," fearing less water moving downstream and a tree-killing invasion of salt.
"This is also one of the least-altered river systems in the United States of America," said local activist Janice O'Berry. "Unfortunately, man is starting to alter it more and more."
For half a century, the giant Ross Barnett Dam and reservoir north of Jackson have been a source of bitterness, with Louisiana interests complaining the structure altered the Pearl River's flows.
Yet, Mississippi faces its own concerns.
In 1979, downtown Jackson went underwater from flooding rains, causing over $1.6 billion in damage in 2015 dollars. Another flood hit in 1983.
The Rankin-Hinds Pearl River Flood and Drainage Control District expects to release an environmental impact study in coming months.
Representatives from the flood district insist they are sensitive to Louisiana's concerns and those of Mississippi residents downstream from Jackson.
Supporters argue if it were built, the proposed dam would function more like a weir, a much smaller structure in scale that would allow water to flow continuously downstream.
"We know that's a very difficult and dynamic system," Blake Mendrop, a consulting engineering for the district told FOX 8 in a 2013 interview.
In reaction to the top 10 designation, the Rankin-Hinds Pearl River Flood and Drainage Control District put out a sharply-worded statement that accuses opponents of "misinformation to promote their own organizations."
The statement said the section of river where the dam would be constructed was straightened and reconfigured when the U.S. Army Corps of Engineers built levees in the early 1960s.
"Most of the project area is not a natural section of the river," the statement said.
The district argues most of the issues on the lower Pearl "stem from local actions or natural events."
Critics of the dam insist the district should focus more on other alternatives, such as levees or buyouts of homes and businesses within the flood plain.
"Jackson does have a problem," said Helen Rose Patterson, Mississippi organizer for the Gulf Restoration Network. "But there are other really good options."
Paul Trahan worries about the long term effects of any more structures altering the river's flow.
"It's not the snap of a finger," Trahan said. "It's our children's children that are going to see the results."