Subsidence takes many forms around New Orleans. The land beneath our feet is soft to a depth of between 70-200 feet. Deposited here over the past 100,000 years it is settling and compacting into a form that could become bedrock a million years hence. However for now it is unstable.

The river splays back and forth across the land depositing its load of silt and moving on to build higher land elsewhere. Once the river moves on and the annual floods no longer replenish the land, it sinks.

New Orleans is sinking at a rate of 4 tenths of an inch per year. Three feet per century. When it was settled in 1718, the land was all above sea level. Now it is not. People keep building on lower and lower land.

Parts of New Orleans are sinking faster. Other parts are barely changing. The area close to the river is the most stable. The old back swamps in mid-city, Lakeview, Gentilly and Metairie that we pumped dry over the last century are settling faster. New Orleans East is sinking the fastest.

It is happening underground. Nothing we can do will change it. Nothing we have done is causing it. This land is unstable and it is sinking.