A water monitoring and control system adapted for residential and commercial use automatically shuts off the water supply after a predetermined period of time, whether the flow is intentional or unintentional, thereby preventing damage from leaks and other malfunctions. The system also gives an indication of all water flow ranging from normal usage to leakage of a few drops and large flow, as would typically occur due to a break in the plumbing system. The system is easily bypassed in the event of power outages. In terms of hardware, the main components of the system include a normally closed water shut-off valve, preferably solenoid-operated. A pressure-responsive switch senses changes in water pressure and sends a signal in the event of a pressure drop, and a timer is provided to start a timing cycle when there is a demand for water, either intentional or unintentional, and shut-off the flow after a predetermined period of time selected by the user. The system also preferably incorporates a water demand indicator used to visually indicate water usage in the system, again, whether it is intentional or unintentional.