本文讨论了纽约市对结构保护的研究，即通过安装节水装置来节约用水。研究了三种模型:自由放任（依赖于正常更换周期和经济动机导致的房屋周转率和固定装置更换）；补贴置换和强制置换。自由放任政策下的水资源保护非常重要，超过了居民用水的1%。据估计，补贴和强制性项目下的用水减少幅度要高得多，为3-10%。节省1百万加仑柴油的计算成本从136万美元的低成本到369万美元的高成本不等。假设新产能的每个住宅单元的成本为3000美元，这三种激励措施都产生了积极的成本效益。一旦开发了固定装置模型，只需添加收入信息，即可分析替代水价结构。 分析的水费结构的重点是确定在给定的收入增加情况下，哪些方法可以最大程度地减少用水。以每增加一美元收入所节省的每日加仑数分析的各种替代方案的结果，对于具有超额使用附加费的季节性产品来说是最高的。生命线率第二，倾斜阻塞率第三。

This paper discusses New York City studies of structural conservation, that is, water conservation by installing water efficient fixtures. Three models were examined: laissez faire (relying on housing turnover and fixture replacement as a result of normal replacement cycles and economic motivations); subsidized replacement, and mandated replacement. Water Conservation under a laissez faire policy was substantial, more than 1 percent of residential water use. Water use reduction under subsidized and mandatory programs was estimated to be much higher, 3-10 percent. The calculated cost to save 1 mgd ranged from a low of $1.36 million to a high cost of $3.69 million. All three incentives produced a positive cost benefit assuming that the cost per dwelling unit of new capacity is $3,000. Once the fixture model was developed, it was only necessary to add income information to permit analysis of alternative water rate structures. The focus of the water rate structures analyzed was to identify those methods that produced the greatest water use reduction for a given revenue increase. The result of the various alternatives that were analyzed in daily gallons saved per dollar of revenue increase is highest for seasonal with excess use surcharge. Lifeline rate was second, and inclining block rate was third.