2 - Environmental characteristics
2.5 – Water resources
The Federal District is situated on high land, which serves as a watershed for water to flow to three important hydrographic basins in Brazil: the Paraná Basin, the São Francisco Basin and the Tocantins Basin. Being that the Federal District is an important region of fountainheads with a perennial flow of water, its hydrography is a gigantic lacy from which almost ten billion cubic meters of water flow annually.
In the last decades, due to heavy demographic growth and the increase of economic activities, increased pressure has been placed on water resources, placing its maintenance and sustainability at risk. The Federal District is composed of seven hydrographic basins:
- Descoberto River Basin: formed by the Descoberto River, which flows through the Federal District at the extreme west of the territory and separates it from the state of Goiás. Descoberto Lake, formed by damming the Descoberto River, is responsible for supplying water to 60% of the Federal District population. This basin is one of the most populated, taking in the urban areas of Taguatinga, Ceilândia, Brazlândia and Samambaia.
- São Bartolomeu River Basin: is that which occupies the largest area in the Federal District, extending from north to south. Within this basin are situated parts of Planaltina, Paranoá, São Sebastião and Santa Maria.
- Paranoá Lake Basin: is situated in the central area and is the only basin completely located within the Federal District. It has a large population contingency composed of several urban areas, such as the Plano Piloto, Guará, Lago Sul and Lago Norte. The Brasilia National Park, located within this basin, is an important conservation unit which contains the Santa Maria Lake, which is important to Federal District water supply.
- Maranhão Basin: is located in the northern part of the Federal District, where a part of Brazlândia, Planaltina and Sobradinho are located. This basin possesses the roughest terrain in the Federal District and is noteworthy for its touristic potential since it contains more than 90 waterfalls, canyons and areas of preserved native vegetation.
- Preto River Basin: can be found in the eastern portion of the Federal District. It is formed by the Preto River, which separates the Federal District from the states of Goiás and Minas Gerais. This basin stands out for its irrigated agriculture, with the presence of central pivots and a large production of grains, vegetables and fruit.
- São Marcos River Basin: is the basin that occupies the smallest area in the Federal District and is located to the southeast. There are no urban settlements in this area.
- Corumbá River Basin: is located in the southwest portion of the Federal District, where the administrative regions of Samambaia, Recanto das Emas, Gama and Santa Maria are located. It is characterized by high declivity and soils that are susceptible to erosion processes.
Figure 8 – Federal District Water Resources