http://www.signonsandiego.com/uniontrib/20040711/news_lz1m11gatekpr.html
here is a picture of the levee near san diego (san ysidro) Calif ...it is a flood control channel in case of excess rains or if the Rodriguez dam in Mexico breaks..it serves as an open sewer channel complete with Tijuana "brown trout" occasionally floating by..
Those (illegal aliens)getting ready to enter the US illegally used to drive their Chevys to the levee and sit and wait (complete with taco vendors)for their chance to run north and grab a piece of the American Pie...most are going east towards Arizona now because of a "triple fence" but some still try their chances here...
The links provided are great!
Still trying to understand levees. Not that I am unfamiliar with water having lived by the Atlantic Ocean and Chesapeake Bay all my life.
But there's no levees anywhere near here. And I always wondered because of that song. Oh, and never been to New Orleans and sigh, I guess I'll never get there now.