This paper outlines an experimental approach aimed at leveraging IoT (Internet of Things) technology to develop a sustainable system for monitoring hot and cold-water usage. By integrating both invasive and non-invasive IoT sensors, the authors propose a more comprehensive design for real-time monitoring system for the hospitality industry. The prototype developed focuses on a more holistic monitoring of hot and cold-water consumption, including temperature, representing a significant advancement in sustainable water management. Indeed, creating an intelligent water flow sensor involves crucial stages such as hardware design and system development. This paper highlights the hardware design which focuses on the selection of materials, sensors, power sources, and communication interfaces for accurate measurement and data transmission. It also details the system development which assembles and integrates components, followed by extensive testing to confirm precision. The paper discusses the need for meticulous calibration and environmental considerations which are crucial for measurement accuracy. Moreover, it covers the sensor selection which should align with specific application requirements, considering precision and infrastructure compatibility. In terms of evaluation, this study documents the accuracy of invasive turbine and non-invasive ultrasonic water flow sensors over a period. The analysis of this sensor data shows consistent measurements with minimal variances. However, in conclusion, the authors show that integrating both invasive and non-invasive IoT sensors offers a more reliable and holistic solution as well as vast potential for enhancing sustainability across diverse industry settings, including tourism.