Water is currently regarded as one of the planet's most limited natural resources. Plants, animals, and 
humans all value it. The need for researchers to investigate the detrimental effects of environmental 
degradation, particularly on water sources, which is increased by the expanding environmental 
degradation that has been caused in recent years by development, population growth, and climate change. 
More sophisticated techniques in environmental monitoring systems, particularly in the area of water 
quality monitoring, are required due to the global increase in water pollution in lakes, rivers, and oceans. 
Therefore, Wireless Sensor Network (WSN) for monitoring physical and chemical water parameters along 
with machine learning and the Internet of Things (IoT) are promising alternative technologies that could 
be utilized as an alternative to address the abovementioned water quality issues. Furthermore, several
sensors were developed for deployment in different regions connected directly to lab to view the current 
situation in every region. This review sheds light on several attempts for low-cost in-situ water sensors 
which gives full long-term information on the situation in areas under study which would be further a 
good idea to implement them and distribute to have continuous data.