Abstract: An apparatus to permit or stop the flow of water through a conduit is described as having a microprocessor which contains a real time clock, day of the week indication, and an elapsed time clock. Data relating to the quantity of water flowing at any given moment is supplied by a flowmeter to the microprocessor. Primary and subsetting information is supplied to the microprocessor to determine the maximum allowable quantity of water that may flow over a specified period of time. The subsetting parameters override the primary information if so enabled and supply replacement information for certain periods of time. The elapsed time clock is reset whenever the flow rate becomes zero (no water flowing) or when the predetermined period of time is exceeded prior to exceeding the predetermined quantity of water that is allowed to flow within that period of time. If the flow of the predetermined quantity of water is exceeded within the predetermined (allowable) time frame, a solenoid is energized.