Calling the U.S. Army Corps of Engineers’ arguments “myopic,” a federal district court ruled Thursday that restoring thousands of acres of wetlands damaged by the Mississippi River Gulf Outlet does not require the state to pay almost $1 billion as its share of the cost.

Instead, the court found Congress clearly stated the closure of the navigation channel, and the restoration of damaged wetlands surrounding it, was meant to be 100 percent federally funded, U.S. District Judge Lance Africk ruled.

“Rather than abide by the clear intent of Congress and begin the immediate implementation of a plan to restore that which the Corps helped destroy, defendants arbitrarily and capriciously misconstrued their clear mandate to restore and ecosystem ravaged by MRGO,” Africk wrote.

The Mississippi River Gulf Outlet navigation channel runs from the Gulf of Mexico to the Port of New Orleans and was meant as a short cut for shipping traffic. Completed in the late 1960s, the navigation channel was originally built 36 to 38 feet deep and about 500 feet wide through wetlands that ran along the eastern side of St. Bernard Parish.

Over the years, boat wake and wave erosion increased the width of the channel to almost 2,000 feet in some areas, allowing more salt water to get into and damage the freshwater marsh. Both the erosion and the marsh loss led to the loss of wetlands, which allowed levee systems to be more exposed to tropical storms and hurricanes.

After Hurricane Katrina caused widespread destruction in southeast Louisiana, Congress passed a series of actions to help repair the damage, including the closure of the MRGO channel and restoration of the surrounding wetlands damaged through its use and construction.

Closure of MRGO was completed in 2009, but problems with the restoration portion surfaced in 2012 with a Corps report estimating the ecosystem restoration would cost almost $3 billion. The report indicated the funding would be split between the federal government and the state in a 65-35 percent split. That would have meant an almost $1 billion bill for the state.

The state Coastal Protection and Restoration Authority filed a lawsuit on Oct. 28, 2014, challenging the Corps’ cost-share decision. The state has long maintained the Congressional action authorizing the work was clear that the work be wholly federally funded.

The court agreed.

The Corps is reviewing the decision with the U.S. Department of Justice, said Rene Poche, Corps public affairs specialist. Because there could be an appeal, he said, any additional questions would have to be answered by the U.S. Department of Justice. Emails to DOJ were not immediately answered.

Officials with the state Coastal Protection and Restoration Authority were busy with White House staff tours of coastal restoration efforts Friday and unavailable for comment.

Follow Amy Wold on Twitter @awold10.