<P> New Orleans is located in the Mississippi River Delta, south of Lake Pontchartrain, on the banks of the Mississippi River, approximately 105 miles (169 km) upriver from the Gulf of Mexico . According to the U.S. Census Bureau, the city's area is 350 square miles (910 km), of which 169 square miles (440 km) is land and 181 square miles (470 km) (52%) is water . Orleans Parish is the smallest parish by land area in Louisiana . The area along the river is characterized by ridges and hollows . </P> <P> New Orleans was originally settled on the river's natural levees or high ground . After the Flood Control Act of 1965, the US Army Corps of Engineers built floodwalls and man - made levees around a much larger geographic footprint that included previous marshland and swamp . Over time, pumping of water from marshland allowed for development into lower elevation areas . Today, a large portion of the city is at or below local mean sea level . Evidence suggests that portions of the city may be dropping in elevation due to subsidence Being that the motion of the earth's surface is shifting downwards relative to sea level . </P> <P> A 2007 study by Tulane and Xavier University suggested that "51%...of the contiguous urbanized portions of Orleans, Jefferson, and St. Bernard parishes lie at or above sea level," with the more densely populated areas generally on higher ground . The average elevation of the city is currently between 1 foot (0.30 m) and 2 feet (0.61 m) below sea level, with some portions of the city as high as 20 feet (6 m) at the base of the river levee in Uptown and others as low as 7 feet (2 m) below sea level in the farthest reaches of Eastern New Orleans . A study published by the ASCE Journal of Hydrologic Engineering in 2016, however, stated: </P> <Table> <Tr> <Td> "</Td> <Td>... most of New Orleans proper--about 65%--is at or below mean sea level, as defined by the average elevation of Lake Pontchartrain </Td> <Td>" </Td> </Tr> </Table>

How much of new orleans is below sea level
find me the text answering this question