节约用水有着很大的经济效益、环境效益和社会效益。城市水源开发的趋势是新的水源距城市越来越远,输水工程费用越来越高,水源水质由于工业和生活污染而不断恶化,处理工艺越来越复杂,单位水量的投资和成本越来越高。而节约用水所需的投资一般都比新建水源水厂的投资要小得多,尤其在开展节水工作的开始阶段,约为新建供水工程投资的1/5～ Water conservation has great economic benefits, environmental benefits and social benefits. The trend of urban water source development is that the new water source is farther and farther away from the city, the cost of water delivery project is higher and higher, the quality of water source is deteriorating continuously due to industrial and domestic pollution, and the treatment process is more and more complicated. The investment and cost per unit of water The higher The investment required for water conservation is generally much smaller than the investment for newly built water sources. In particular, the investment in new water supply projects is about 1/5 ~