A smart valve for controlling a plumbing fixture includes a control valve, a hydroelectric generator, and one or more sensors. The hydroelectric generator produces electrical power for the smart valve. The smart valve monitors sensor data from the sensors, evaluates the sensor data, and performs control actions in response to evaluating the sensor data. Control actions include restricting or shutting off water flow using the control valve. Control actions also include transmitting control messages to remote computing devices, for example to activate appliances or other home automation devices. The sensors may include a temperature sensor, a flow sensor, a proximity sensor, and/or a humidity sensor. The smart valve may shut off the water flow when a measured sensor value exceeds a predefined threshold value. The smart valve may be coupled inline between a plumbing system and a plumbing fixture. Other embodiments are described and claimed.