With the example of the water supply engineering planning of small towns in southern china, the effects of town water consumption forecast, water resource selection, water site choice, pipe network planning on the present engineering planning of water supply were investigated. The analyses show that the water consumption forecast should adopt many kinds of methods to check each other, and finally determine a proper value. To ensure water yield of source water reliable and water quality to meet the requirements are the first principle of the water resource selection. The location of water plant should be determined according to the characteristics of the water source and the hydrological and hydrogeological conditions, in accordance with the relevant requirements specification. The basic requirements of the pipe network layout are as follows: the security of water quality; the reliability of the water volume and water pressure; the operation reliability and the least investment. As a part of the overall planning, the water supply engineering planning should proceed from reality to deal with the relationship of the recent construction and long-term development in order to push small towns economy to a rapid growth.
