Dead Water:Dead water is water that is stored in a reservoir but cannot be used because it is not connected to an outlet. This water is often referred to as “dead water” because it has no practical purpose. Dead water can be created by drought, by dam construction, or by any other process that reduces the flow of water into a reservoir. When water levels in a reservoir decline, the portion of the reservoir that is below the outlet becomes dead storage. The amount of dead storage varies from reservoir to reservoir, and it can range from a few million gallons to billions of gallons.