# Towards Digitalization of Water Supply Systems for Sustainable Smart City Development--Water 4.0
## 6 Summary, Prospects, and Challenges  
In recent years, we have been on the verge of a new industrial revolution in which emerging digital technologies and ICT are utilized in industries to improve operations through seamless control and monitoring of operational stages. Digital technologies have a good prospect to enhance the operation of water supply systems for sustainable development and are currently being applied in the water sector. For instance, in the use of digital technology for monitoring water quality level on a global scale, the water utility monitoring market has a growth of more than 5.11% CAGR during the period of 2018 to 2022 [147]. With the increasing use of ICT, data for the relevant water process becomes increasingly feasible and may be analyzed using big data analysis. Therefore, further analysis could be performed with other data such as weather to generate a water demand forecast for future planning and decision making. The IoT, AI, and other emerging digital technologies have the potential to transform the water sector by improving day-to-day water management and addressing long-term challenges of water leakage [148]. A digital transformation of a water supply system for sustainable development is shown in Figure 11. In this figure, an IoT-based smart water network management (SWNM) application is illustrated to achieve real-time continuous measurement which relates to the state of the network. The data must be continuously acquired, processed, and transmitted via wireless means to a remote center where further analysis takes place for optimal decision making. Most modern smart sensing devices possess in-built data storage and processing capabilities, which makes it possible to pre-process the data within the network [2,3]. The market size of IoT in utilities is estimated at $28.6 billion in 2019 and is expected to reach almost twice that amount (that is, 53.8 billion) by 2024. This corresponds to a compound annual growth rate (CAGR) of 13.5%. It has been proved that utilities with IoT features will be able to eliminate operational inefficiencies, optimize resources utilization, and increase the reach of service to more end users [150]. While the IoT has uplifted the utilities segment of oil and gas and the energy sector, the advent of this technology is now clearly visible in water utilities. Monitoring the complex water supply distribution network in real-time is a challenging task. Nevertheless, Water 4.0 is conceived as a revolutionary methodology for improving operational performance and providing water distribution networks with monitoring capabilities. Thus, the overall picture of such an idea is promising. Information and communication technologies (a feature of the Water 4.0) can play a crucial role in solving the various challenges associated with water distribution network management. ICT-based systems can be used to safeguard water distribution networks, prevent unauthorized physical access to susceptible or vulnerable regions, and provide security surveillance systems. However, the security flaws within wireless systems result in security risks to WSS infrastructure monitoring [151]. In Water 4.0, the CPS and IoT smart sensing devices communicate via wireless communication technologies to enhance the system's flexibility, but due to the broadcast nature of wireless media, they pose more security risks [152] and are susceptible to multiple cyber-physical attacks. A successful attack on WSS could cause various levels of damage such as long operational downtime and economic loss to utilities. This makes security a critical factor to consider before large scale deployment of these digital technologies into water supply systems. Therefore, cyber-security is a serious issue in ICT-based water management systems. One of the most perilous threats in the internet is Denial of Service (DoS) attacks [153; 154; 155] where the resources of a system are exhausted until the system fails to provide its usual services in a timely fashion.