High river levels postpones floodplain reconnection project
Tue, Jun 02 2009 at 4:15 PM
By The Nature Conservancy
Due to high water on the Ouachita River and flooding of the 16,000-acre Mollicy Unit, the East Side of Upper Ouachita National Wildlife Refuge, near Bastrop, Louisiana, is closed to ensure public safety.
The unusually high river level is overtopping the obsolete 30-foot tall levee at the refuge that has been targeted for partial removal.
Overtopping or even catastrophic failure of the levee does not pose any threat to surrounding communities, and has nothing to do with the flood control levee system protecting the area.
Floodwaters are expected to continue to rise through Wednesday. Water will likely continue to spill onto the floodplain at the refuge for several more days until the river’s level drops below the levee.
Floodplain Reconnection Project
This flood will postpone the beginning of work on a $4.5 million project to permanently breach the Mollicy levee, reconnect the Ouachita River to its floodplain, and restore 25 square miles of valuable fish and wildlife habitat. Nearly $2.1 million comes from the Recovery Act stimulus funding.
The U.S. Fish and Wildlife Service and The Nature Conservancy jointly developed the project, which is believed to be the largest floodplain reconnection project in the Mississippi River Basin and possibly the entire United States. “The overtopping of the levee is flooding the Mollicy Unit area now,” said George Chandler, project leader for all national wildlife refuges in North Louisiana. “We hope to start up the restoration project as soon as it is safe.”
“This only underscores the need for carefully engineered breaches in the levee, which for decades has artificially separated the river from its floodplain,” said Keith Ouchley, director of The Nature Conservancy in Louisiana. “Reconnecting the river to its floodplain, as we’ve planned to do in partnership with the U.S. Fish and Wildlife Service, will eliminate the risk of catastrophic levee failure, alleviate flooding downstream, improve water quality and enhance fish and
Harold Leggett, Secretary of the Louisiana Department of Environmental Quality, added that this project also offers a unique opportunity to measure water quality improvement provided by floodplain reconnection.
“This is the epitome of a non-point source pollution reduction project because the partners in this venture are converting cropland into wetlands,” said Leggett.
“This is a very good step toward reducing nonpoint source pollution to area waters and eventually to the Gulf hypoxic zone. It’s also an important and unique project because we can take water quality samples before and after the project begins. This information will play a vital role as we look at ways to improve water quality throughout the state.”
LDEQ is providing project funding for water quality monitoring through the state’s Non-Point Source grant program.
Due to the flooding, high waters may partially fill the floodplain and potentially cause breaches in the dirt levee. Either a planned or unplanned breach of this levee will help reduce peak flood levels downstream.
“The Wildlife Refuge Project is an excellent example of a key environmental operating principle for the Corps,” said Brig. Gen. Michael J. Walsh, Commander of the Mississippi Valley Division. “We always try to seek a balance between human development activities and natural systems by joining economic and environmental solutions that support and reinforce one another.”
The levee last failed in 1991. A 300-foot long hole in the levee allowed water to inundate the refuge’s 25-square mile floodplain, reducing flooding downstream in Monroe.
The east part of the refuge will remain closed until further notice.
Upper Ouachita National Wildlife Refuge’s History and Ecology
In the 1990s, the Conservancy helped acquire much of the refuge’s floodplain. The U.S. Fish and Wildlife Service has planted over three million trees on 10,000 acres of the refuge in order to restore the floodplain forest that existed before the property was converted to farmland. Additional reforestation will follow in future years.
White-tailed deer, bobcats, foxes, rabbits, grey and fox squirrels, wild turkeys, wood ducks, alligators, bald eagles and more than 265 species of migratory birds are commonly seen at the refuge. The site also provides prime wintering habitat for tens of thousands of ducks and geese. The endangered red-cockaded woodpecker and the threatened Louisiana black bear also live on parts of the refuge.
MNN is working with The Nature Conservancy to bring you state-by-state environmental information.