New Orleans is a city in southern Louisiana, located on the Mississippi River. Most of the city is situated on the east bank, between the river and Lake Pontchartrain to the north. Because it was built on a great turn of the river, it is known as the Crescent City. New Orleans, with a population of 496,938 (1990 census), is the largest city in Louisiana and one of the principal cities of the South. It was established on the high ground nearest the mouth of the Mississippi, which is 177 km (110 mi) downstream. Elevations range from 3.65 m (12 ft) above sea level to 2 m (6.5 ft) below; as a result, an ingenious system of water pumps, drainage canals, and levees has been