In the end of century XX, the humanity if comes across with an age characterized for crises and new chances, mescladas in global interests: while ideological conflicts of east-west are scrumbled, areas appear of confrontation, related to the access and conservation of natural resources and ambient, pointing out contradictions between economic growth and its systems of ambient support, that threaten the precarious conditions of life of the poor countries in development. In way that the deduction on the studies of Ratter agrees that the roots of the majority of the ambient problems are of nature social politics or and that many problems of this order can be decided, having will politics and certain conditions of cohesion and social solidarity in the society. This application of ' ' gua' ' , they must just fix a price for the water, nominated thanks to a tarifao of the water based on a economic evaluation of the uses and the value of this and to the introduction of programs of obligator measurement of the water consumption. On the other hand, in order to limit the negative effect of the economic development of certain hidrogrficas basins and to promote the use rational of the water, the distribution of the water and the respective financings would have to be more efficient. Thus, emphasis will have to be given to the destined measures to improve the order of the territory, and in special to the integration of the question of the water availability in the exploration of agricultural lands, to the strict application of the directive one on the strategical ambient evaluation (), to the census of the hidrogrficas basins that suffer frequent or permanently of water lack and the adoption of disposals of management adequate to these basins. According to Ayers and Westcot argue the following one: The reduction of the availability of hdricos resources of good quality and the increase of the production of domestic and industrial oustings, have stimulated the water use of inferior quality in the irrigation, whose evaluation if becomes necessary (Ayers & Westcot, 1991, P.