The demand of water is increasing day by day because: (i) Irrigation is needed because of spatio-temporal variability in rainfall in the country. The large tracts of the country are deficient in rainfall and are drought prone. (ii) Winter and Summer seasons are more or less dry in most part of the country. It is difficult to practise agriculture without assured irrigation during dry seasons. (iii) Breaks in monsoon or its failure creates dry spells detrimental for agriculture, water need of certain crops makes irrigation necessary. Irrigation makes multiple cropping possible.