Development of a low-cost IoT system for monitoring storm drain overflow during urban flooding

Urban flooding, intensified by climate change, presents significant risks to public safety and infrastructure, necessitating effective early warning systems. These events are categorized into fluvial and pluvial flooding, with the latter becoming increasingly challenging to predict due to its localized nature and short lead times.

In this work we develop a novel low-cost device based on Internet of Things (IoT) useful for urban flooding monitoring. The proposed sensor leverages advances in open-source technology, using ESP32 development boards, to create an accessible and cost-effective solution based on ultrasonic and reed-switch mechanisms. The system features innovative design principles, including a 3D-printed structure, low power consumption, and reliable connectivity through LoRaWAN and MQTT protocols used as potential early warning system.

The system’s primary objective is to detect storm drain overflow caused by intense rainfall, triggering timely alerts to mitigate flood impacts. Functional requirements emphasize ease of installation, durability, and cost-effectiveness, enabling widespread adoption in diverse urban contexts. The sensor design incorporates a float mechanism, reed switch, and microcontroller housed in a compact, water-resistant case.

Preliminary testing demonstrated the system's ability to detect water level changes and transmit alerts efficiently. Further work includes refining the design to minimize false positives and enhance system reliability under various environmental conditions. This development represents a significant step toward scalable, low-cost flood monitoring systems, contributing to global efforts in urban flood risk management.