Well water or water from streams flowing over gypsum, limestone, or dolomite is more likely to be hard. Water is heavier than air. Ocean water is salty. There is much more water than land on the earth's surface. A waterfall is water falling from one level to a lower level.
Water comes to the earth as rain or snow.
Most of it goes back into the air. Fog or mist is a cloud on the ground. Ice is very strong. It holds you up when you skate on it if it is thick enough. Some Eskimos used to build temporary houses from blocks of snow and ice.