Before: Environmental Manipulation

Initial analyses characterized the post-Katrina flooding as the result of a levee system overwhelmed by natural forces — a natural disaster. Only later did it become clear that the real cause of the flooding was the inadequacy of the system, which failed due to decades of underfunding, shoddiness, incompetence and/or outdated science. But what allowed the storm surge to get so close to the city in the first place? The answer lies in the relentless human manipulation of the deltaic environment starting in the eighteenth and nineteenth centuries, but mostly occurring during the long twentieth century, from 1890 to 2005.

Modern levee construction and municipal drainage effectively ended the occasional flooding — from river, lake or sky — that frustrated New Orleanians in historical times. [2] These interventions also inadvertently eliminated incoming freshwater and sediment, removed the water component from the soil body, and allowed organic matter to decompose. Fine sand, silt and clay particles settled into the resultant air cavities, compacting the soil and lowering its elevation. The result: soil subsidence.