The Ba River basin has abundant water resources for agriculture and power generation. To respond to the socio-economic development of the basin, the water work system has been planning to improve the efficiency of water resource allocation, serving sustainable development. This study was designed to evaluate the effectiveness of water work plans built on the Ba River basin by assessing their ability to supply water for agriculture, domestic, industries and services. Water balance calculations show that water demand in irrigation areas in the Ba River basin increases significantly corresponding to basin development, especially in the Krong Pa and Nam Bac An Khe regions. With the application of irrigation planning, agricultural development plans and changes in land use structure, water resource allocation in the Ba River basin has been improved in the future. The effectiveness of the planning is obviously shown in the Upper Ayun, Ayun Pa, Upper and Lower Dong Cam where water demand increases sharply and water shortages are controlled, ensuring water supply requirements for irrigation and other sectors of over 85% and over 90%, respectively.