Abstract: A continuously refreshing in-line water reservoir system for use in the event of a loss of water source due to a natural disaster or otherwise is disclosed. The in-line water reservoir system may comprise a reservoir for holding water, a water inlet line through which water flows into the reservoir, e.g. water flows into the reservoir from a community water supply, and a water outlet line though which water flows out from the reservoir and to a point of use during normal operation. Moreover, the system is configured in-line between a water supply and a point of water extraction. For example, any time water is extracted from a point of use water pressure from the community water supply forces at least some new water into the reservoir thereby at least partially replenishing the reserve of potable water for emergency use.