Water Scarcity
In a country having 113 river basins, it is quite. natural that a tremendous variations would be encounterted both in the quantity and quality of water. It is important to mention that all the major rivers are also not perennial. Here although average annual rainfall is very high but monsoon is restricted to only three months in most parts of the country. As a result, most of the rain-fed rivers get almost dry during summer and late winters. The Brahmaputra, Ganga, Mahanadi and Brahmani pass through the regions of high rainfall having average annual discharge of a minimum of 0.47 MCM/ square kilometer and they are perennial. Five major rivers; The Krishna, Indus, Tapti, Narmada and Godavari pass through regions of medium rainfall and having annual average minimum discharge of 0.26 MCM/ square kilometer. The remaining four major rivers, i.e. Cauvery, Mahi, Sabarmati and Pennar pass through the areas where rainfall is low and average discharge being in the range of 0,06 to 0.24 MCM.

As a result of technology advancement and population pressure now a days most rivers are not in the natural state. The flow of almost all the major rivers is restricted due to construction of barrages, dams and reservoirs. Even than, many areas face the water crisis.

Pollution
After a barrage or dam construction on a river, downstream area does not get enough water, as a result for the dilution of pollutants from incoming drains, sewage streams and effluents, required Quantity of water is lacking and river stretches gets polluted. Any form of water while flowing, has got some self- purification capacity and that is why polluted river water after some distance becomes pollution free.

The river Gnaga is considered to be most sacred among all the rivers. It is largest river in length and basin area. Its basin occupies 34.39% area among total basin area of al the major basins. With regard to average annual discharge, it is next only to Brahmaputra. The Ganga is most widely used river and many populous cities are situated in its basin. At many stretches, due to lean flow in summer and excess discharge of pollutants, its water is being polluted. The main problems with our rivers is not the industrial effluent because it is only responsible for 20% of pollution in the rivers. Rest 80% of pollution comes from domestic and municipal sources.

The water quality of rivers is deteriorated not only by the increasing wastewaters discharge but also due to excessive abstraction of water from the rivers, mainly for irrigation rendered them dry or with meager flow in non-monsoon periods. Meagre flow followed by increasing wastewater load has left many river stretches in alarming condition. Any action plan to control pollution may not suffice in such situation. Hence the action plan should also include provision for maintenance of sufficient flow in the course of the river.

For effective prevention and protection measures of water resources, both the nature of return wastewater that users shall be permitted to dispose off in natural watercourses and the nature of water source acceptable for beneficial use needs to define qualitatively in quantitative terms.

Siltation
It has been estimated that about 70-80% of total annual discharge of the river flows during monsoon period of about 55 days; as a result floods are very common in our country. Flood brings silt, solid wastes, fertilizers and pesticides as agricultural run-off along with them into the river. They shrink after the monsoon and summer is marked by a vast area of sand with very little or no water in most of the rivers.

In our rivers, siltation rate is among the highest in the world. It has been estimated that about 135 thousand million metric-tonnes (MT) of sediment load and 32 thousand million tonnes of soluble matter enter into ocean through various rivers in our country. This figure constitutes 90% of the total solid waste going into the ocean. The rest 10% which goes into the ocean is constituted by wind, rain and earthquakes. The water flowing through our river is 5% of the water flowing through all the river of the world. But, Indian rivers carry 35% of the sediments that go to all the oceans in the world.