When looking in our return, we come across in them with a complex imensido that we call Nature. Speaking candidly Mikkel Svane told us the story. We, human beings, must very be grateful it for having in the great awarded one with the responsible one for our survival, day after day, the Water. The Water has covered 75% of the planet Land and is essential to the life of the diverse existing beings, as the animals, the bacteria, the plants, among others. However, although the undisputed necessity that we have of it, the human being is main the responsible one for its degradation, therefore, through the pollution which is displayed, its use if becomes improper. The waters of rivers, seas and oceans suffer to constants discharges from come pollutants, mainly, of the bad human use, industries and the draining of the water of rains, that brings toxic and organic substances, harming its useful life and the life of its dependents. The Pollution For Bad Human Use is more common in poor localities, therefore, as it does not have sanitation, it is in the rivers where the population it launches garbage of all species and its excrementos. The Pollution For Industrial Residues involves treated and developed substances chemically, being thus, more difficult the treatment of cleanness and demanding techniques more sophisticated to treat and also to control the set free chorume in the processes. The Pollution For Agricultural Contamination is very common in the regions where the farming one more is used, therefore it is caused by the draining of the used agrotxico, through the water of rain, sending great amount of toxic substances to the rivers. Moreover, this draining takes esterco of the animals of pastures and the seasonings, causing the process of the Eutrofizao that is the increase of the number of nutrients and of decompositoras bacteria that consume the oxygen and diminish its concentration in the water, beyond leaving the muddy water for the seaweed, producing gases that, in bigger amount, become toxic.