You drive along the levee and the levee is a wall of earth between the city and the river and the wall of earth is the only thing keeping the city dry. The levee is not glamorous. The levee is not architecture. The levee is a pile of dirt shaped by engineers and the pile of dirt shaped by engineers is the most important structure in any river city because the levee is the line between habitation and flood. On one side of the levee the city lives. On the other side of the levee the river waits. The river is always waiting. The river has been waiting longer than the city and the waiting longer than the city is the river's patience and the river's patience is the threat.

The levees in New Orleans hold back the Mississippi and the holding back the Mississippi is the bargain that New Orleans has made with water since seventeen twenty seven when the first French colonists built the first earthen embankment. The first embankment was three feet tall and three feet tall was enough in seventeen twenty seven and three feet tall was not enough for long because the river rises and the rising requires the levee to rise and the levee rising requires money and the money requires the government to believe that the city is worth protecting and the believing the city is worth protecting is the political question behind every levee in America. The levee is the physical form of a political decision. The levee says we have decided this land is worth defending against water.

The levees broke on August twenty ninth two thousand and five and the breaking killed one thousand three hundred and ninety two people and the killing was not the hurricane. The hurricane passed. The levees failed after the hurricane passed. The killing was the levee. The levees at the Industrial Canal broke. The levees at the London Avenue Canal broke. The levees at the Seventeenth Street Canal broke. The breaking was the engineering failure and the engineering failure was the Army Corps of Engineers and the Army Corps of Engineers had built the levees and the levees the Army Corps had built were not strong enough and the not strong enough killed people in the Lower Ninth Ward and the killing in the Lower Ninth Ward was the flood and the flood was ten feet of water in people's houses and the ten feet of water in people's houses was the levee's failure made lethal. The levee broke and people drowned in their attics and the drowning in attics is what happens when the bargain with water fails.

The Mississippi River levee system runs for thirty five hundred miles from Illinois to the Gulf of Mexico and the thirty five hundred miles is the longest levee system in the world and the longest levee system in the world is the machine that keeps the Mississippi Valley from being a lake. The Old River Control Structure near Simmesport Louisiana is the point where the Army Corps prevents the Mississippi from changing course to the Atchafalaya Basin and the preventing the Mississippi from changing course is the single most arrogant piece of engineering on Earth because the Mississippi wants to change course and the Mississippi will change course eventually because the river does not respect the levee. The river respects nothing. The river goes where gravity takes it and gravity takes it downhill and the shortest path downhill is through the Atchafalaya and the only thing between the Mississippi and the Atchafalaya is a concrete structure and the concrete structure is the levee's last stand.

You stand on top of the levee and on one side is the neighborhood and the neighborhood has houses and schools and grocery stores and the houses and schools and grocery stores exist because the levee exists. On the other side is the river and the river is higher than the neighborhood. The river is higher than the houses. The river is higher than the schools. You can stand on the levee and look down at the rooftops and the looking down at the rooftops from a levee that holds back a river that is higher than the rooftops is the vertigo of civilization. The city is below the water. The city has always been below the water. The levee is the only reason the city is not under the water and the only reason is a wall of dirt and the wall of dirt is the thinnest line between the built world and the drowned world and the thinnest line is the levee. Holding. Every day. Holding.