Enhancing water utility bulk meter reading through lot retrofit : a reliable and energy efficient wireless solution : the Rand Water case study in South Africa

Abstract

Water is a scarce resource and appropriate smart bulk water metering and leakage detection are crucial. Current smart bulk water metering methods at Rand Water in South Africa are moving from being essentially manual to being automated. However, the currently used methods remain operationally costly, energy inefficient and not so reliable in terms of their employed communication approaches. This often leads to suboptimal resource allocation. Additionally, most of these bulk water meters are enclosed within concrete chambers and are at mostly at low elevation or even underground. This poses a problem in terms of identifying an efficient wireless solution for remote reading and site security. This study investigates and evaluates the performance of an appropriate Internet of Things (IoT) solution capable of reliably and in an energy efficient manner sending bulk water meter readings to a remote server for processing. The proposed solution can overcome the identified low elevation and penetration issues. It also detects possible water leakages, water chamber overflow, burst detection and any kind of site tampering in the form of alarms to ensure timely response and reduced operational cost. This study employs a simulation-based methodology using MATLAB to develop and evaluate deployment-aware models for both LoRaWAN and NB-IoT protocols, specifically incorporating the effects of reinforced concrete attenuation, low antenna elevation, and join/rejoin dynamics. This approach consists of a wireless communication feasibility study of the existing water utility infrastructure, followed by the implementation of identified low-power wide area network (LPWAN) IoT protocols suited for the application and the performance evaluation and comparison of the identified LPWAN IoT technologies in terms of energy efficiency and communication reliability. The results obtained from the proposed approach demonstrate that NB-IoT achieves superior reliability, maintaining packet delivery ratios above 0.96 even under severe concrete penetration losses up to 30 dB, while LoRaWAN exhibits a sharp degradation in reliability below 0.85 beyond 20 dB attenuation. Conversely, LoRaWAN offers better energy efficiency and extended battery lifetime under moderate conditions, whereas NB-IoT trades higher energy consumption for predictable and robust packet delivery. These findings support a deployment-aware, hybrid technology selection strategy for large-scale underground bulk water metering applications.