Five reasons for water scarcity in India are :
(i) Seasonal and annual variation in precipitation.
(ii) Unequal access.
(iii) Overexploitation.
(iv) Availability of water varies over space and time.
(v) Excessive use of water resources.
(vi) Many cities have large and growing population resulting in greater demand for water resources. A large population means, not only more water is required for domestic use but also for higher foodgrain productivity. This has led to over-exploitation of water resources to expand irrigated areas especially for dry season agriculture. It has also contributed to falling ground water levels, adversely affecting the water availability and food security of the people.
(vii) Today the multinational companies and other industrial units consume large quantities of hydroelectric power and for processing which put greater pressure on the existing fresh water resources in India. Multiplying urban areas with dense population and modern life styles have created an ever increasing demand for water and energy resources.
(viii) Pollution of water bodies due to discharge of industrial effluents, use of pesticides, insecticides and fertilisers used in agriculture, make the river water hazardous for human consumption.