On-site water quality monitoring using multi-sensor IoT platforms represents an innovative solution for continuous, real-time monitoring of water resources. These systems embed multiple sensors capable of measuring essential parameters such as pH, temperature, turbidity, dissolved oxygen, conductivity and sometimes the presence of heavy metals or chemical contaminants. The data collected is transmitted via wireless networks (Wi-Fi, LoRa, GSM, etc.) to a cloud platform for processing, visualization and storage. On-board intelligence can integrate anomaly detection or prediction algorithms. Powered by renewable energy sources, these platforms are autonomous and suitable for isolated or hard-to-reach environments. They enable rapid detection of pollution or abnormal variations, facilitating decision-making. Compared with conventional laboratory sampling and analysis methods, they reduce time, costs and human intervention. These technologies have applications in agriculture, the environment, water treatment plants and distribution networks. By combining IoT and data intelligence, they pave the way for intelligent, sustainable water management.