There are 2,487 levee systems in the U.S. and for the first time in history, an inventory of these flood-control systems is under way. Louisiana is peppered with levees, providing a control mechanism for the Mississippi River and protection for its residents. Many levees are deemed to be in unacceptable condition in cities such as Washington, D.C., Sacramento and Cleveland. The U.S. Army Corps of Engineers determined 326 levees, covering more than 2,000 miles, were in urgent need of repair. The Associated Press reports the reasons for the weakened levees are due to trees, shrubs, burrowing animal holes and houses built close to these structures, and in some cases on top of the levees. Hurricane Katrina provided greater awareness of deteriorating levees.

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