i2o Water employs IoT technology and Apache Cassandra to mitigate the global water crisis by reducing leakages and energy waste, saving over 235 million liters of water daily. The presentation highlights the inadequacy of relational databases for handling massive volumes of time-series data and demonstrates how Cassandra provides better performance, scalability, and real-time analytics for IoT applications. Key results include over 15,000 devices connected across 70 water utilities globally with a significant uptime and robust security measures.