Water is like blood in a human body - if blood is blocked, then body or body part dies. If water is blocked from free and steady flow, then nature of part of it dies as well. Having the water flow from top of mountains thru all fields, into river and ocean ....
Sun light evaporates water and clouds build up to rain again. Rain can be attracted and influenced - humans can be "rain-makers" if they know how.
Water never can be lost - hence no need to be stingy with water, but need to care for purity of water and keep all nature including all water pure all times.