AbstractThe model we propose determines water balances for a project area and emphasizes interactions of a surface water‐groundwater system within the economic context of irrigation management. The program selects the tubewell, canal and surface drainage capacities, the project size, and the cropping pattern. Operation of the system is assumed to proceed subject to certain constraints on continuity at the river; capacity of the canals, tubewells, and drainage channels; mining of groundwater; crop water requirements; availability of land of different soil types; and permissible cropping patterns. A detailed irrigation planning example is presented.