Key Principles of Restoration
Reconnecting the river to its delta: The Mississippi River created the delta that makes up most of the Louisiana coast – which in turn supports the local, regional, and national economy. The delta contains industry and infrastructure critical to the nation and is home to productive fisheries and vital habitat for birds and other wildlife. All this contributes to the unique culture of south Louisiana. Reconnecting the river to the surrounding wetlands through large-scale controlled sediment diversions that mimic the river’s natural land-building function will help save the delta from collapse.
Managing and using sediment to build land: For the coast to survive, every bit of sediment must be used effectively. Instead of treating it as a nuisance that hinders navigation, we must value river sediment as a precious and limited resource. Every year, 22 million cubic yards of sand and mud – the life blood of the wetlands – are dredged to make way for shipping and dumped into the deep water off the Gulf of Mexico's continental shelf. Instead, appropriately placed sediment diversions and strategic placement of dredged material can capture this valuable resource to sustain and build coastal land.
Use of Old River Control Structure (ORCS): The Atchafalaya River is the largest distributary of the Mississippi River and feeds the largest river-swamp in the United States. To maintain the Mississippi River for navigation, the Old River Control Complex restricts the Atchafalaya River to 30 percent of the combined flow of the two rivers – an arbitrary number. Instead, the ORCS should manage flows based on an ecologically sound plan for sustaining and restoring the wetlands on both rivers.
Non-structural flood protection: Flood-control projects along the Mississippi River over the last century have created a false sense of security among coastal engineers as well as inhabitants of low-lying coastal communities. Recent flooding from hurricanes has emphasized that levees fail and that communities are ever more vulnerable as coastal land loss and sea level rise continue. Communities are learning to become more resilient by elevating homes, flood-proofing businesses and hardening coastal facilities, reducing flood risks for people and property.
Restoring hydrology: When canals are dredged through the wetlands for oil and gas exploration and for navigation, the dredged soil is frequently piled along the sides of the canals in small levees called spoil banks. These banks disrupt the normal flow of water and nutrients into and across the marsh and allow salt water to flow far inland, thus killing freshwater marshes. Removing the spoil banks and refilling unused canals are simple and quick steps to restore the natural flow of water and nutrients, preventing further salt water intrusion and helping the marshes to thrive.
Protecting shorelines with living reefs: Restoring living oyster reefs in front of beaches and marshes protects the shoreline in many ways. Living reefs absorb wave action and create a buffer against storms, provide high quality habitat for fish and birds, improve water quality and cast off old shells that naturally armor the beach and prevent erosion. While rocks, frequently used to protect shorelines, sink and must eventually be replenished, natural reefs, such as oyster beds, grow and keep up with sea level rise.
Protecting and restoring barrier islands: Barrier islands define the outer limits of the estuary and help maintain the gradient from fresh water to salt water that makes the delta so productive. They are the “first line of defense" against hurricanes and other powerful storms and provide shorebird and waterfowl habitat for hundreds of species. Without barrier islands, coastal and inland areas are infinitely more vulnerable to the forces of nature.