近年來台灣水資源因地形與使用習慣之故日漸短絀，有效的解決之道除『開源』之外更應注重在『節流』，政府自1994年以來，積極地推動省水器材、雨水貯蓄設施、中水道二元供水系統及提升工業用水回收率等節約用水措施，希望藉由上述措施之推動，以減少民生、工業及農業各標的之用水量，同時加強推動中水及雨水等水再生利用相關工作，期能經由「節流」以減緩新水源開發之壓力，並確保國家整體水資源供給不虞匱乏(1,2)。本篇論文是透過民生大用水戶實施節約用水的案例研究，在現場調查蒐集資料後，根據用水型態與經驗式來估算各用水點的用水量，再透過省水器材更換、用水觀念的改善與中水回收再利用，減少各案例的原本用水量，而透過用節水前後水平衡圖的比較與效益評估，可以發現，節約用水除了降低用水量之外更可替用水戶省下可觀的水費。 The number of water resources in Taiwan was decreased seriously in recent years, because of its topography and use habit of people. The effective solutions addressed on not only “water resource discovery”, but also “water consumption decrease”. Since 1994, the government began to promote saving water apparatus, rainwater storage facilities and gray and black water reuse system, and improve the efficiency of industrial water recovery. Therefore, through the executing and promoting the above projects, the government wishes to achieve the goal of reducing the water use in recreation, industrial, and agriculture areas. Simultaneously, strengthening and promoting relevant projects for rainwater and gray water regeneration combines two objects, included “water resource discovery” and “water consumption decrease”, to achieve the goal of sustainable use of water resource and complete the water conservation projects in Taiwan.This research implemented the water-saving project by studying three big civil water consumers. After investigating on-site information and collecting data analysis, the analytic results were compared by difference user types of water consumers. The evaluation methods were selected and executed, such as changing saving water apparatus, educating concept of water use habit and recycling waste water. Thus, this project indicated that changing saving water apparatus and educating concept of water use habit helped to improve the efficiency of water consumption and reach the final goal of water conservation.