Assam is endowed with enormous water resources. The large perennial rivers and other water bodies with the rich aquifer speak about vastness of its water resource. Surface water is available in the forms of river, stream, lake, swamps, pond etc. The ground water is available at low to moderate depth almost in entire state. Although there is seasonal and regional variation in the availability of water resources, the annual availability of water resource remain almost same. In the last few decades the use of water has been growing at a fast rate, which is more than twice the rate of the increase of human population. The consumption of water has increased due to the increase of human population as well as the diversification of human activities. With the increase of per capita consumption of water in domestic, agricultural and industrial sectors, cause the reduction of potential per capita availability of water. Moreover, it may cause the deterioration of water quality to a great extent.

Apart from the rain water received, the state is endowed with number of perennial rivers and lake locally known as beel. The state is drained by the dance networks of two river system, viz the Brahmaputra and the Barak. These rivers have large number of tributaries joining them from both the banks. There are about 73 important tributaries of the Brahmaputra river and 11 tributaries of Barak river.