Cidanau watershed area has an important role in fulfilling water needs, especially for industrial, settlements (population), and agricultural needs. However, along with the increasing development of the Cilegon area, the need for clean water also increased. In 1984, the water demand for the Cilegon region for industrial and settlements was only 0.36 m3/second. But, in 1989 it increased to 1102 m3/second and in 2000 it was 2.200 m3/second. One of the ways to optimize the utilization of limited water resources while the community’s need for water is increasing was watershed management using linear programming (LP) method which supports optimal water distribution. Optimization discharge was carried out to determine water requirements. The optimal discharge for domestic needs was 16.50 liters/second to fulfill the water needs of the population of 47,519 people. The optimum discharge for the industrial sector was 27 liters/second with a total industry of 46 (small industries). When it was added with Krakatau Tirta Industri (KTI) discharge, the total industrial discharge became 1,527 liters/second. The optimum agricultural discharge with an area of 4,689.29 ha was 1,219 liters/second.