Restoration Center News

		Aerial view of a crevasse dredged off a channel in the Mississippi River delta. Water and sediments are flowing from left to right into an open water area where marsh will naturally build. (Delta Wide Crevasses project)     More pictures

Construction has begun on two coastal Louisiana wetland restoration projects -- the Delta Wide Crevasses project located in Plaquemines Parish southeast of New Orleans, and the “The Jaws” project, located in St. Mary Parish. Both projects were funded by the NOAA Restoration Center through the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA, better known as the Breaux Act).

The Delta Wide Crevasses project will re-establish 5 old crevasses and create two new ones by dredging over 310,000 cubic yards of sediment. Crevasses are breaks in the levees that allow the river to deposit sediments into adjacent shallow bays and create new wetlands. The Mississippi River Delta is one of the hallmark symbols of Louisiana’s rich natural heritage. Unfortunately, natural and man-made alterations to the Mississippi River have changed the hydrology of the river and impeded the natural wetland building processes in the delta. The construction of levees to protect commercial shipping lanes has reduced natural sedimentation and freshwater flow, causing deterioration of wetlands and saltwater intrusion. By dredging new crevasses through the levees and allowing nature to takes its course, this restoration project mimics the natural process of crevasse formation that was responsible for building much of the Mississippi River Delta. Expected benefits after 20 years are 2,400 acres of new wetlands. Construction will be completed by November 2004.

The sediment trapping at “The Jaws” project is designed to reduce wave-induced shoreline erosion and promote sediment deposition by creating vegetated wetland terraces and reducing wave fetch, or the distance waves can travel unimpeded. Distributary channels will be dredged to deliver water and sediment to the project area. Dredging 610,000 cubic yards of sediment will construct 40,100 linear feet of terraces initially creating 82 acres of new wetlands. Terraces will be planted with 19,500 giant cut grass plants and 22,000 California bullrush plants to kick-start vegetative growth. Over 20 years of sediment accretion is expected to yield 2,000 acres of new wetlands. Construction will be completed by November 2004. (Erik Zobrist, 301-713-0174)