Abstract: Fluid flow control systems and methods are disclosed. In one preferred embodiment, the control system comprises a motorized shutoff valve controlled by logic output from a computer processor, where the computer processor compares input from a sensor measuring the current fluid flow rate against a relevant historical average of the fluid flow rate. If the current flow rate exceeds the relevant historical average fluid flow rate by at least a preselected percentage, then the computer processor transmits a logic signal to the motorized shutoff valve to close the fluid flow intake. If the current flow rate does not exceed the relevant historical average flow rate by the preselected percentage, the relevant historical average flow rate is updated by the current sensed flow rate. In different preferred embodiments, the method and systems may be used to control the flow of water, natural gas, propane, or fuel oil among other fluids.