A study is carried out to determine the crop water requirement of some selected crops for the command area in Kunigal taluk. These crops include rice, pulses, groundnut, sugarcane and millet (ragi). Crop water requirement for each of the crops is determined by using 30-year climatic data in CROPWAT. Reference crop evapotranspiration (ETo) is determined using the FAO Penman Monteith method. For all the crops considered, three decades: decades I, II, and III and seven crop growth stages: nursery, nursery / land preparation, land preparation, initial stage, development stage, mid-season and late season stage are considered. The study shows that for the area under study, reference evapotranspiration (ETo) varied from 3.11 to 5.29 mm/day. Crop evapotranspiration (ETc) and crop water requirement for sugarcane varied from 1.61mm/day to 3.46mm/day and 0.0 mm/dec to 51.9 mm/dec, for ragi (millet) from 1.44 mm/day to 3.46 mm/day and 0.0 mm/dec to 2.6 mm/dec, for groundnut( rabi) from 0.66 mm/day to 4.45 mm/day and 0.0 mm/dec to 43.9 mm/dec, for groundnut (kharif) from 1.78 mm/day to 4.34 mm/day and 0.0 mm/dec to 14.6 mm/dec, for rice from 0.39 mm/day to 4.82 mm/day and 1.5 mm/dec to 184.9 mm/dec, and for pulses from 2.41 mm/day to 4.22 mm/day and 13.2 mm/dec to 38 mm/dec respectively. The gross water requirement is 939.14 mm/year with an application efficiency of 70%. Therefore the entire land area of 6572 ha requires 61.72 MCM. Thus the dam can conveniently supply the water required for irrigation in the area.