A study was conducted at Kharian to develop an agroforestry system by using water harvestging system in semiarid zone. Twop slope lengths: 4m and 5 m and three slope gradients: 7%, 10% and 15% of roaded catchments were tested for finding out optimum slope length and gradient for water resource development to increase crop and wood production. Results of the study showed that four meter slope length with 7% gradient are more effective in increasing the runoff and are economical to construct and maintain. It was also observed that water production to cropping area ratio at Kharian should be 1:2. The study indicated that crop production can be enhanced by 40% and tree growth can be increased by three times by using the water harvesting system.