The amount of water hasn't changed since the creation of the Earth, so you cannot destroy water , all you can do is mix it with good or bad chemicals or lose control of it in your transporting it around for utilization. Using water is not like burning hydrocarbons and having to drill more oil wells to replace it. water is constantly in a cycle of condensation from the ocean into clouds that provide rain over the land refilling lakes and rivers and recharging ground water. We are not running out of water.