Glossary

Coastal Protection and Restoration Authority — The Louisiana legislature created the Coastal Protection and Restoration Authority and placed it under control of the governor and directed this organization to represent Louisiana before congress in all matters concerning hurricane flood protection and coastal restoration.

The Great Mississippi River Flood of 1927 — considered to be the most destructive river flood in U.S. history — began when heavy rains came down on the central basin of the Mississippi in the summer of 1926. By September, the Mississippi’s tributaries in Iowa and Kansas were swollen to capacity. On New Year’s Day 1927, the Cumberland River at Nashville topped levees at 56.2 feet. The Mississippi River broke out of its levee system in 145 places and flooded 27,000 square miles.

Federal Flood Control Act of 1928 — After the great flood, Congress authorized $300 million to begin the Mississippi River and Tributaries project. This was more money than had been spent on levees throughout history. This massive flood control project, which continues today, incorporated not only levees but also dams and spillways to help control the flow of the river. The project also included a diversion of the Mississippi River into the low-lying areas of the Atchafalaya River.

Fill — Soil brought in to raise the level of the ground. Depending on the soil’s placement, fill might also change the flow of water or even increase flood elevations.

Flood — A general and temporary condition of partial or complete inundation of normally dry land from the overflow of tidal or inland waters or the unusual and rapid collection of runoff of surface waters from any source.

Floodplain — Any land area that is prone to being flooded by any source.

Floodwall — Concrete wall constructed next to waterways in order to reduce flooding on the landside of the wall. Floodwalls are normally constructed instead of or in addition to levees where the land required for levee construction is too expensive or not available.

Levee — A man-made structure that is typically an earthen embankment. Levees are designed and constructed according to sound engineering practices to contain, control, or divert the flow of water in order to provide protection from temporary flooding.

Levee Breach — A gap, rupture or break in a levee system which ultimately causes flooding.

Levee Crevasse — A crack or breach in a levee that causes flooding.

Levee Failure Breach — A gap, rupture or break in a levee causing flooding in the adjacent area and for which a cause both known and occurred without overtopping. An investigation is usually required to determine the cause.

Levee-Impacted Area — The floodplain area landward of a levee system.

Levee Overtopping — Floodwater levels that exceed the crest elevation of a levee system and flow into levee-impacted areas.

Levee Overtopping Breach — A gap, rupture, or gap in a levee system that causes flooding in the adjacent area and where the cause is known to be a result of overtopping.

Levee Owner — This could be any of the following: A federal or state agency; flood control or water management district; levee district; local community; a nonpublic organization; or even an individual considered the proprietor of a levee.

Levee System — A flood protection system that consists of a levee, or levees, and associated structures.

Lines of Protection — Locations of levees or walls that prevent floodwaters from entering an area.

Mitigation — A sustained action taken to reduce or eliminate long-term risk to people and property from flood hazards and their effects. Mitigation distinguishes actions that have a long-term impact from those that are more closely associated with preparedness for, immediate response to, and short-term recovery from specific events.

Pumping Stations — Pumps located at or near the line-of-protection to discharge interior flows over or through the levees or floodwalls (or through pressure lines) when free outflow through gravity outlets is prevented by high exterior stages.

Sector Gates — Used in a waterway, these are floodgates that permit continued navigation. Gates remain open until a storm approaches. The purpose of these structures is to continue flood protection over a waterway.

West Bank and Vicinity Hurricane Protection Project — The West Bank and Vicinity Hurricane Protection Project consists of approximately 56 miles of levees, 11 miles of floodwalls and two navigable flood gates, providing flood protection for portions of Jefferson Parish’s West Bank, Algiers (Orleans Parish), Belle Chasse (Plaquemines Parish) and Western St. Charles Parish to the Davis Pond Fresh Water Diversion levees.

Powered and Designed by Planetguide