Design of a Microcontroller-Based Water Level Controller for Overhead Tank Management in Residential Estates in Lagos

This project designs and implements a microcontroller-based water level controller system for automated overhead tank management in residential estates in Lagos State, South West Nigeria. Manual monitoring of water tank levels leads to overflow wastage, pump dry-running, and energy waste, all of which are prevalent problems in Lagos residential estates where water supply from public mains is intermittent and residents rely on borehole-fed overhead tanks. The system uses ultrasonic sensors mounted at the overhead tank and the underground storage tank to measure water levels continuously. An Arduino Uno microcontroller interprets the sensor readings and controls the submersible pump through a relay module, activating the pump when the overhead tank falls below 20 percent capacity and deactivating it when the tank reaches 95 percent capacity to prevent overflow. If the underground tank level drops below 15 percent, pumping is inhibited to prevent dry-running damage to the pump motor. A 20x4 LCD panel displays real-time water levels for both tanks. An audible alert warns occupants when the underground supply is critically low. An additional GSM module sends SMS notifications to the estate facilities manager when either tank reaches critical thresholds. The prototype was tested in a four-unit residential block in Ikeja, Lagos, over a three-week period, demonstrating accurate level monitoring within a 2cm measurement error and eliminating all overflow events that had previously occurred weekly. Pump energy consumption was reduced by 23 percent compared to the previous manual operation practice. Keywords: water level controller, pump automation, Arduino, overhead tank, Lagos.