This document describes a rainwater harvesting control system that uses capacitive sensing technology. It uses capacitive level sensors to measure water levels in tanks and detect when the tanks are full or empty. An MSP430 microcontroller processes the sensor signals and controls an automated flap. The objectives are to use the microcontroller to evaluate the capacitance values from the sensors and monitor the sensor responses to control water supply from mains or rainwater tanks. The goals are to provide an augmented water source for non-potable uses and create a low-cost and reliable rainwater harvesting control system.