This story was updated at 4:33 p.m. EST.
EPA has greenlit a flood project halted by the Bush administration, saying the new version of the Yazoo Backwater Pumps would not be covered by its 2008 veto of the project.
The surprise move has shocked environmental groups, which say it sets up a dangerous precedent and sidesteps the scientific review process.
A decade ago, EPA determined that the pumps project — proposed in 1941 to alleviate flooding along the Yazoo River, a tributary to the Mississippi River — would threaten up to 67,000 acres of wetlands that serve as critical habitat for migratory birds.
An EPA veto is usually seen as a final action, effectively killing a project. The agency has issued 13 vetoes during its history and modified them just four times, usually for small changes.
But in an unprecedented move, EPA is now saying that a new version of the pumps — located just 8 miles upstream of the previous plan that would damage more wetlands — is not covered by its previous decision.
"EPA has determined that the proposed project is not subject to EPA's 2008 Final Determination," Region 4 Administrator Mary Walker wrote in a letter to the Army Corps this week.
Opponents say it could serve as a road map for future project developers that receive an unfavorable determination from EPA.
"It is a dangerous precedent that any new administration could come in and just overturn a decision of a previous administration on a whim, without any of the scientific review that is required to reopen a Clean Water Act veto," said Olivia Dorothy, director of upper Mississippi River Basin for the nonprofit American Rivers.
In October, the Army Corps of Engineers released a draft environmental impact statement for a new pumps plan that argued new research showed flooding plays a smaller role in wetland hydrodynamics in the Yazoo Backwater Area than previously understood. But opponents say the proposal would still result in environmental harms and unacceptable damage to wetlands.
Walker's letter asserts that the 8-mile difference, as well as slight changes in water levels being pumped, is among "a number of key features that distinguish it from the plans prohibited by EPA's 2008 Final Determination."
EPA also noted other differences in the new proposal, including that the planned 14,000-cubic-feet-per-second pump station would run on natural gas as opposed to diesel, and low-flow groundwater wells would be installed adjacent to the Mississippi River levee and upstream of the Yazoo study area. Under the new plan, the Army Corps would also purchase 2,405 acres of frequently flooded agricultural lands for compensatory mitigation and add another 2,700 acres of reforestation easements for nonstructural flood control.
According to the Army Corps' proposal, the footprint of the pump station would directly affect about 84 acres of wetlands, while indirect hydrological changes would affect 38,774 acres.
But EPA's veto of the Yazoo Pumps indicated that the agency was extremely concerned about any project that would "result in a dramatic alteration of the hydrologic regime in the Yazoo Backwater Area, thereby significantly degrading the critical ecological functions provided by at least 28,400 to 67,000 acres of wetlands."
EPA has been under immense political pressure from Mississippi lawmakers to revive the project since spring 2018, when the Mississippi River and its tributaries suffered catastrophic flooding, including in the Yazoo Backwater Area. Administrator Andrew Wheeler has met with the state's governor and congressional delegation multiple times to discuss the project.
The Army Corps in October argued that the plan would provide a "balanced approach to addressing the flood damage reduction and environmental opportunities in the Yazoo Study Area" — something boosters agree with. They note that the Yazoo Backwater Area has flooded in nine of the past 10 years, with historic floods last year covering more than 500,000 acres for more than six months.
Walker appears to agree, saying in her letter, "EPA fully supports the purpose of the project to reduce flood damages in the Yazoo Backwater Area."
Her letter constitutes a major break from the typical Clean Water Act veto review process.
While EPA has never retracted a veto, it has allowed for minor modifications. Each one required the agency to undergo a brand new review of the initial veto, the proposed modifications and how they would harm the environment — a process that can take months. Avoiding that process means the Army Corps now has the time to approve the Yazoo project before President Trump's term ends Jan. 20.
"This whole thing is just designed to jam this thing through while Trump is still in office, and catch us if you can," said Louie Miller, director of the Sierra Club's Mississippi chapter. "This project has been politically motivated from day one, and they saw a window of opportunity here with Trump's EPA."
Most recently, in 2009, EPA allowed changes to be made to its 1985 veto of a flood control project at the Bayou aux Carpes Site in Jefferson Parish, La.
The project originally would have drained 3,000 acres of wetlands and left them enclosed by levees. The agency redid its whole process to allow just 9 acres of wetlands to be filled in as part of a project to upgrade Louisiana's levees following Hurricane Katrina.
"When a project is vetoed by the EPA, there is a lot of work and scientific evidence that goes into it, and for a veto to be overturned, there has to be an equivalent amount of science and review that goes into it," Dorothy said.
She accused EPA of trying to sidestep that typical process by saying the new Yazoo proposal isn't covered by the veto.
"This is just bonkers. This has never happened before, and it sets such a dangerous precedent that any project could move just a few miles upstream and go ahead," she said. "It's still the same project; it's still the same impacts."
Retired Maj. Gen. Michael Walsh, who commanded the Army Corps' Mississippi Valley Division from 2008 to 2011 and was present when EPA issued its veto, said he has never seen EPA sidestep its own decision in such a manner.
But Walsh, now a senior adviser at the consulting firm Dawson & Associates, argued that the new Yazoo plan differs enough from the original to warrant EPA taking a second look at its veto.
"Since this is the first time this is happening, it would be precedent-setting," he said. "But if you change the project's purpose or if you change the science, you should be able to take another look at it."