Success story of the Autoridad Administrativa del Agua IX Ucayali (AAA Ucayali), part of the Autoridad Nacional del Agua (ANA) of Peru. AAA Ucayali built a hydrometric station with an Industrial Shields M-Duino 19R with a cellular module. A piezometric sensor (0 to 10 m, RS-485 Modbus RTU) measures the water column of the Ucayali river in Pucallpa. The PLC sends the data over the cellular network, every minute by default. An MQTT broker, a Node.js client and a MySQL database feed a web app with level, flow, weather and battery values. A solar panel powers the station.

The PDF covers the challenge, the three loops (measure and send, level to flow, remote site), the system architecture with the signal list, real photos and app screenshots, and the hardware used. Interactive version: hydrometric station success story online.