Lakes are formed usually as a result of tectonic or glacial activity in a region. It can also be formed by a meandering river or even artificially by human activity.
Lakes are important for various reasons, like regulating the flow of river water, storage of water during the dry seasons, to maintaining the eco-system, and also the generation of hydroelectric power. The different types of lakes in India are freshwater lakes and salt water lakes. The Wular Lake in Jammu and Kashmir is the largest freshwater lake in India.
Other freshwater lakes include the Dal in Jammu and Kashmir, the Bhimatal Lake and the Nainital Lake in Uttarakhand, and lake Kolleru in Andhra Pradesh. Lake Kolleru is officially classified as a wildlife sanctuary.
The largest salt water lake in India is the Sambhar Lake in Rajasthan. The salt produced from this lake has made Rajasthan the third largest salt producer in the country. Brackish water is a mixture of salt water and fresh water. It is not as salty as sea water and brackish water lakes are generally situated in coastal areas. The Chilika Lake in Orissa is the largest brackish water lake in India.
Rivers are considered the most basic natural resources required for human settlement. The primary reason is that we depend on rivers for fresh drinking water and water for irrigation. River water is also used for generating hydroelectric power.
The growing demand for water in agriculture, industry and domestic use is affecting the quality of water. There has been some government action to counter this by launching activities such as the National River Conservation Plan (NRCP) and the Ganga Action Plan (GAP) introduced in 1985.