Glossary

America's WETLAND:  Louisiana's coastal wetlands that lie between the Sabine River on the west and the Pearl River on the east.

Appropriation: money used to pay for government-approved (authorized) expenditures.

Authorization: government approval for a plan or procedure. The money needed to execute what has been authorized is granted through a separate procedure (appropriation).

Barrier Island: A long, relatively narrow island running parallel to the mainland, built up by the action of waves and currents and serving to protect the coast from erosion by surf and tidal surges. Barrier islands are Louisiana’s outermost coastal feature and represent the true border between land and the Gulf of Mexico.

Bayou: A relatively small, sluggish waterway through lowlands or swamps, generally with a slow, almost imperceptible current flow. Often also defined simply as slow moving streams crisscrossing Louisiana.

Brackish: Brackish water is water that is saltier than fresh water, but not as salty as sea water. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur naturally, as in brackish fossil aquifers. Technically, brackish water contains between 0.5 and 30 grams of salt per liter—more often expressed as 0.5 to 30 parts per thousand (ppt or ‰). Thus, brackish covers a range of salinity regimes and is not considered a precisely defined condition.

Coast 2050: A plan completed in 1998 and developed by a broad group of government, academic, and community stakeholders that outlines strategies needed to achieve a sustainable coastal environment in Louisiana. Coast 2050 served as the blueprint for what was outlined in more detail in the LCA Program. For more information www.coast2050.gov.

Canal: Canals are man-made waterways, usually connecting existing lakes, rivers, or oceans. They are used for transportation, often by barges or narrow boats on smaller canals, and by ships on ship canals that connect to the ocean.

CWPPRA: Coastal Wetland Planning Protection and Restoration Act, also referred to as the Breaux Act after Louisiana Senator John Breaux. CWPPRA provides dedicated federal money to build coastal restoration projects throughout Louisiana’s coastal region. More than 70 projects, usually ranging in expense from $2 million to $12 million have been built since the program began in 1991. For more information lacoast.gov

Delta: The fan-shaped area at the mouth or lower end of a river, formed by eroded material that has been carried downstream and dropped in quantities larger than can be carried off by tides or currents. South-East Louisiana is the delta of the Mississippi River.

Diversion project: A restoration strategy that involves ‘diverting’ Mississippi River water through a structure that directs the water and sediments to a specific strategic locale. This method, though expensive, is effective as it mimics the flooding that is responsible for the creation and maintenance of coastal Louisiana’s wetlands prior to the construction of flood protection levees. River diversions are a feature of the LCA program.

Dredge: A process of removing or disturbing layers of sediment, primarily to clear channels and ponds of excessive sediments. Dredging is carried out in Louisiana to maintain navigable waterways. The LCA Program proposes the development of a process whereby the millions of tons of sediment dredged annually in Louisiana will be used beneficially in areas where sediments are needed.

LCA: Louisiana Coastal Area Ecosystem Restoration Program. The LCA is the program through which large coastal restoration projects that affect basin wide areas have been planned and will be executed. The LCA is a federal state partnership. For more information lca.gov.

Levee: A levee (from the French for "raised") is a natural or artificial embankment, usually earthen, which parallels the course of a river. Usually the term levee in Louisiana implies a man made feature constructed for the purpose of flood control.

Marsh: A marsh is a type of freshwater, brackish water or saltwater wetland that is found along rivers, pond, lakes and coasts. Marsh plants grow up out of the water. Typically marshes are composed of grass-like herbaceous plant communities.

MRGO: Mississippi River Gulf Outlet (aka MRGO, Mr. GO). The MRGO is a shipping canal that provides an alternate route from the Gulf of Mexico to the Port of New Orleans. It was dredged through Plaquemines and St. Bernard Parishes in the 1960’s. The MRGO is a controversial feature of the Louisiana landscape as it is blamed for much coastal degradation. Supporters of the MRGO point to its economic impact on the transportation industry at the mouth of the Mississippi River.

Multi-agency task force: A coalition of federal and state agencies that work together to oversee a restoration program such as CWPPRA and the LCA. The complexity of technical and management issues faced in coastal restoration calls for a broad range of skills. Therefore, the task force is seen as a superior to a single agency for effective management of this complex issue.

Natural levee: A natural embankment that parallels the course of a river or bayou. A natural levee is built up over time by seasonal flooding of uncontained rivers and bayous. A natural levee is generally shorter and broader than an artificial levee.

Restoration: Any action taken that physically intervenes with the process of coastal erosion. Restoration can involve the direct creation of new land through importing new sand and other sediments, stabilize land through the planting of wetland vegetation, or it can indirectly restore land by working with natural processes such as controlled flooding through river diversions.

Salinity: The amount of dissolved salt in the water. Salinity is important because it controls what type of plants can grow, or what types of animals can exist, in a given area. Salt marsh for example grows in water closest to Gulf waters with a high salinity, brackish marsh in the next landward zone followed by fresh marsh and swamps. If the salinity in an area increases, as has happened throughout coastal Louisiana, vegetation dies and erosion follows.

Swamp: A generally wet, wooded area where standing water occurs for at least part of the year. In Louisiana, swamps are often characterized by the presence of bald cypress and tupelo-gum trees and almost always occur in areas where freshwater is dominant.

Storm surge: An abnormal rise in sea level accompanying a hurricane or other intense storm, and whose height is the difference between the observed level of the sea surface during the storm and normal sea level.

Subsidence: The process of sinking or settling of a land surface because of natural or artificial causes. In Louisiana subsidence is a natural process that occurs after sediments deposited by a flood begin to dry out and settle. Under natural conditions, subsidence is balanced by the deposition of new sediments with each flood event. Because of flood control however, subsidence continues without any sediment re-nourishment. Human activities have therefore greatly accelerated the subsidence of Louisiana’s coast.