Water pollution is an increasing problem in Malaysia. Most of the water pollution in Malaysia is caused by wastes from industrial area. Currently, the quality of discharged waste water from industrial sites are monitored manually by Department of Environment Malaysia. This project is a development of a prototype to automate the monitoring system. Temperature and pH of water are constantly measured and if the parameters fall on the unsafe level, a warning is sent to the user via Short Message Service (SMS) and activate the valves by the Arduino UNO. Dissolved oxygen (DO) level is also predicted based on the pH and temperature of water using MATLAB Simulink R2019b. In this thesis, the performance of the prototype is tested and the accuracy of the dissolved oxygen prediction was calculated by comparing the predicted value with the actual value.