The effect of sand mining on the economic performance of groundwater irrigation has been studied in the Panruti taluk of Cuddalore district in Tamil Nadu. A comparison of water productivity for different farms-size categories has been done in sand mining and non-sand mining blocks. The cropping sequence, cropping intensity, irrigation particulars, investment pattern on tubewells, use of different HP-motors, etc. have been studied in sand mining and non-sand mining blocks.