Many of the country's problems seem to circle around water. Water resource constitutes one vital natural resource that has not been utilized as efficiently as in some developed countries. There is a lack of awareness in public about optimal use of water as well as less emphasis is being given to hydrology at the time of planning, designing and operation of water resources projects. Hydrology touches every human activity in some manner. Incomplete information and lack of awareness of principles of hydrology often result in mis-management of water and wastage of money. Some of the common examples are: over irrigation of fields by farmers by cutting canals which may result in water logging of the field; in many places taps are left running or there are no taps at all etc. Apart from these, wastage of water by evaporation; erosion of fertile soil; losses due to droughts and floods; degradation of water quality; failure of hydraulic structures etc. are some of the areas which can be tackled effectively if sufficient knowledge about hydrology is available. More and more increasing demands for food grains and water due to increase in population, increase in per capita consumption of water due to rise in living standards, and increase in industrial development provide opportunities and challenges for hydrologists.