An IOT-Enabled Water-Level Monitoring and Pump-Control System Using Arduino and Ultrasonic Sensing

Overhead water tanks in homes, hostels and institutions are commonly filled by pumps that are switched by hand, which leads to overflow, wasted electricity and pumps running dry when the sump is empty. This paper presents the design and evaluation methodology of a low-cost, IoT-enabled water-level monitoring and pump-control system built on an Arduino Uno. A waterproof JSN-SR04T ultrasonic sensor measures the distance to the water surface without contact, and a DS18B20 probe measures air temperature so that the speed of sound, and hence the level, is temperature-compensated. The controller converts distance to level and stored volume, switches a single-phase pump through an opto-isolated relay and contactor using hysteresis thresholds, and enforces three safety interlocks: sump dry-run protection, a no-rise timer that detects a pump running without delivering water, and rejection of implausible sensor readings. An ESP8266 module publishes telemetry and alerts over MQTT to a dashboard and accepts remote commands, while all switching decisions remain local so the tank is protected when the network fails. A review of 19 related studies shows that most existing systems provide threshold switching and remote display but rarely address temperature error or pump protection. Analysis shows that an uncompensated sensor calibrated at 20 °C overreads distance by 4.2 cm at 1.0 m when the tank air reaches 45 °C, about 33 litres in a 1000-litre tank. A test protocol with defined metrics for level accuracy, switching accuracy, fault response and telemetry reliability is provided for prototype validation.