The use of deep public tubewells on a large scale in areas where the twin menace of waterlogging and salinity emerged as a serious threat to the fertile irrigated lands in the Punjab was the first major effort which the Government undertook in the shape of SCARPS (Salinity Control and Reclamation Projects) in order to effectively combat waterlogging and salinity. SCARP-I, the Pilot Project under this programme was launched in the central Rachna Doab area of the Punjab—the area found to be worst affected by the menace. This project involved installation of more than 2000 tubewells of medium to large size, with pumping capacity varying from two to five cusecs, at a substantial capital and maintenance cost. As the expenditure involved was large it was essential to keep a continuous watch on the performance of tubewells and project their future behaviour in terms of their discharge. The question most relevant to the cost-benefit study of such a project is obviously the estimates of expected length of time for which the tubewells could go on functioning efficiently with routine maintenance.