The basins like units of planning

The  need  to promote  environmental recovery and  maintain  limited  natural resources  such as water,  Made the concept of hydrographic basin to be very known and consolidated it worldwide during the 70’s.

To face problems like  pollution,  shortage and conflicts for  water use, it was necessary to  acknoledge  hydrographic  basins  such as an ecologycal system,  comprising  all  organisms that function in   team work in a certain region. To understand how  natural resources are  interwoven and depend on each other.
That means that when a river course is changed or deviated to carry sewage away from an area, this ends up polluting another region. By the same mechanism, making soil waterproof in a region makes that flow to another one and cause floods. With these examples, it was made clear that the waters have a dynamic and that the geographical limits to work on the ecological balance have to be the ones from the hydrological basin. That is, the territorial space given by the drainage and influence of water, from the hydrological cycle on Earth’s surface and not the ones dictated by political divisions given by society, as municipalities, States and nations, which do not comply with the entire and complex dynamics of nature.

Since  man  started to live in organized societies and has recognized the importance to controll  potable water availability ,  humankind first attempts  to  interfere with  natural environment have started.   Development of activities  such as agriculture and  urbanization have always  been connected with the controll of water. Ancient civilizations like Egypt, China, India and Mesopotamia were called  hydraulic civilizations. The  rise and fall of those people  is deeply connected with  water uses and abuses.
The same happens with our society. All urban and rural areas developments  are defined according  to the availability of sweet waters, it means, their  amount and quality. Therefore, to promote  sustainable development and the  exchange  between regions with common interests, or between  those that fight for the right to use the water for different  purposes, it was necessary to recognize and adopt the hydrographic basin concept in whole world.

In Brazil, this concept has begun  to be developed  in the middle of the  70’s. In the Sao Paulo state, the first experiences  started in 1976, in the metropolitan region, with the creation of the Agreement Committee between the Sao Paulo state and the Mines and Energy  Ministry