This review paper explores the current state of IoT-based smart water technologies, applications, and future directions. Water is essential for sustainable development and economic competitiveness, but global demand has increased due to population growth, climate change, and economic development. Smart cities use IoT and ICT to improve urban infrastructure efficiency, including water management. Smart water systems leverage IoT to monitor and manage water resources effectively. The study reviews existing research on smart water applications, highlighting technologies like microcontrollers, sensors, communication modules, and protocols used in smart water systems. It also discusses the integration of 3D printing and solar energy into smart water applications, which can enhance sustainability. However, none of the reviewed studies used 5G mobile networks as a communication module. The study also notes the geographical distribution of research, with most studies conducted in India. The paper recommends future research to explore the potential of 5G in smart water applications, as well as the integration of machine learning and LPWAN technologies for improved water management. The findings emphasize the importance of IoT in smart water systems for efficient water conservation and management.This review paper explores the current state of IoT-based smart water technologies, applications, and future directions. Water is essential for sustainable development and economic competitiveness, but global demand has increased due to population growth, climate change, and economic development. Smart cities use IoT and ICT to improve urban infrastructure efficiency, including water management. Smart water systems leverage IoT to monitor and manage water resources effectively. The study reviews existing research on smart water applications, highlighting technologies like microcontrollers, sensors, communication modules, and protocols used in smart water systems. It also discusses the integration of 3D printing and solar energy into smart water applications, which can enhance sustainability. However, none of the reviewed studies used 5G mobile networks as a communication module. The study also notes the geographical distribution of research, with most studies conducted in India. The paper recommends future research to explore the potential of 5G in smart water applications, as well as the integration of machine learning and LPWAN technologies for improved water management. The findings emphasize the importance of IoT in smart water systems for efficient water conservation and management.