qnli question: Out of the 620.34 square miles, how much of it is water? sentence: According to the United States Census Bureau, the city has a total area of 620.34 square miles (1,606.7 km2), of which, 601.11 square miles (1,556.9 km2) of it is land and 19.23 square miles (49.8 km2) of it is water.