The first astronauts when seeing the land in the space adenominaram of blue planet, therefore about 2/3 of its surface water of the seas and oceans are cobertospela. The water candy is of basic importance for manutenode all terrestrial ecosystem e, therefore essential for the survival they dohomem. However 2.5% of the total volume of existing water naterra are only of water candy, being that 99% are under the form of ice or snow very deep polar or water-bearing nasregies. Of the remain, 1% are in the animal and vegetal corposdos, 38% in the humidity of the ground, 8% as vapor d’ naatmosfera water, 1% is available in rivers and 52%% in lakes. Thus, less than 1% of the water candy of the land he is disponvelpara human consumption. This natural resources occurs that, until good little inexhaustible time vistocomo its destination, either to consumption or as source degerao of energy comes being wastefulness object being that one of principaisfontes of loss and use if of the one in agriculture..