NETDA borders the Yangtze River and has no hidden ditches and pools. The deep-well water is divided into three layers. The first water-holding supporting layer is not deep, being integrated with the surface water. The second layer is about 160 meters under the ground, where water is poor in quality and not ample in quantity. The third is in the range from 220 to 250 meters under the ground, where water is good in quality and sufficient in quantity, being the main layer for extraction.