NEW ORLEANS, Sept. 21 (UPI) -- Estimates on the amount of protection New Orleans' levee system provides were "guesswork based on old data, the New Orleans Times Picayune reported Wednesday.
Following the failure of several levees when Category 4 Hurricane Katrina hit the city Aug. 29, the newspaper had Lee Butler, an engineering consultant and former Army Corps of Engineers computer analyst study the system's design.
The corps based its levee design on a fictional, meteorologically inaccurate "standard project hurricane" devised in the 1960s, based on characteristics of past storms that had flooded the city. Then in the 1990s, it used computer models to analyze the system, and claimed the levees could protect the city against a fast-moving Category 3 or weaker storm.
However, the strength categories of the Saffir-Simpson scale used by meteorologists are based on wind speed -- not the storm surge flooding that poses the most serious threat to the region.
Prior to Katrina, the corps said the long-term likelihood of a flood overflowing the levees was estimated at 10 percent in a 30-year period, the current lifespan of the levee project.
