There is a source of water that we do not see but it is the primary source of many lakes, ponds etc. What type of water is being referred to?
Ground Water
Groundwater is the only source of water that we cannot see. It is the source for many lakes as well. It is also this groundwater which is drawn by a hand pump or a tube well. The more handpumps or tube wells that are used in an area, the deeper we need to dig to find this groundwater.