A look at the New Orleans area on Google Earth tells the story. One of the busiest ports in the world, New Orleans is not on any ocean but nearly 100 miles from the Gulf of Mexico, and at the tail end of the 2,320-mile-long Mississippi River. To the south of the city, the fibrous ganglia of the bayous reach out toward the Gulf of Mexico. To the north lies massive Lake Pontchartrain, the second-largest inland saltwater estuary in the United States. To the east are the Rigolets, a tidal strait that connects Lake Pontchartrain to Lake St. Catherine and Lake Borgne, a saltwater lagoon in the Gulf of Mexico. Water is the lifeblood of New Orleans, and its geography — low topography, lots of water, a hurricane hot spot — has been its fate.