Water Conservation: refers to reducing use of fresh water, through technological or social methods. The goals of water conservation efforts include:

• Sustainability - To ensure availability for future generations, the withdrawal of fresh water from an ecosystem should not exceed its natural replacement rate.
• Energy conservation - Water pumping, delivery and wastewater treatment facilities consume a significant amount of energy. In some regions of the world (for example, California [1]) over 10% of total electricity consumption is devoted to water management.
• Habitat conservation - Minimizing human water use helps to preserve fresh water habitats for local wildlife and migrating waterfowl, as well as reducing the need to build new dams and other water diversion infrastructure. (Wikipedia)