A nifty brief history of New Orleans Canal system

Nola.com: For centuries, canals kept New Orleans dry. Most people never dreamed they would become Mother Nature's instrument of destruction.

In 1871, city surveyor W.H. Bell sounded what is thought to be the first alarm about the dangers posed by the big outfall canals. He told city officials to place pumping stations on the lakeshore, otherwise "heavy storms would result in water backup within the canals, culminating in an overflow into the city."

That warning was ignored, and in 1915 the most powerful hurricane then on record hit the city and proved him right. The storm's surge pumped the lake 6 feet above normal. The outfall canals flowed over their meager levees, and much of the city flooded. New Orleans' brand new drainage system was overwhelmed, even before the storm knocked out the electrical station that ran the pumps. The death toll reached 275.