在世界各地的许多国家，公民现在坚持认为，在当选官员批准新的供水项目之前，供水设施必须证明它们是节水的。今天的挑战是将需求管理纳入长期供水规划，以在扩容和需求管理之间实现适当的平衡。本文通过三个案例研究论证了这一概念:在澳大利亚新南威尔士州下克拉伦斯县，制定了一项需求管理计划，以降低需求并推迟资本设施，同时在一项建造新供水水库的协议中实现节水目标；在泰国曼谷大都会水务管理局，需求管理被证明是一种经济高效的方式，可以满足曼谷地区未来的需求，因为人口在未来20年将增长35%，达到11000000人以上；此外，在华盛顿特区的华盛顿郊区卫生委员会（Washington Suburban Sanitary Commission），建设大量新基础设施以支持经济增长的计划现在在公众中引起了争议，因为需求已经趋于稳定。 已经实施的需求管理计划，包括国家管道标准，显示在30年内将需求减少10%。这些储蓄的现值为1.22亿美元。本文的结论是，经过验证的评估需求管理计划成本效益的方法可以减少需求，并节省电力公司及其客户的大量资金。包括表格、数字。

In numerous countries around the world, citizens now insist that water utilities prove that they are water efficient before elected officials approve new supply projects. The challenge today is to integrate demand management into long-range water supply planning to achieve an appropriate balance between capacity expansion and demand management. This paper demonstrates this concept through three case studies: in Lower Clarence County, New South Wales, Australia, a demand management plan was developed to lower demand and defer capital facilities, while meeting water saving targets in an agreement to construct a new water supply reservoir; at Metropolitan Waterworks Authority, Bangkok Thailand, demand management was shown to be a cost-effective way to meet future needs of the Bangkok area as population expands 35 percent to over 11,000,000 in the next twenty years; and, at the Washington Suburban Sanitary Commission, Washington DC, plans to build considerable new infrastructure to support growth are now controversial with the public because demand has leveled off. Demand management programs already in place, including the national plumbing standards, were shown to reduce demand 10 percent over 30 years. The present value of these savings was $122 million. The conclusion of the paper is that proven methodologies for evaluating the cost-effectiveness of demand management programs can reduce demand and save the utility and its customer's considerable money over time. Includes tables, figures.