Water flow is a hydrological process that highly intermittent and dependent on nature. Water flow forecasting is an important task for operation and management of water resources for application that includes irrigation, water distribution, hydropower generation and flood prediction. There has been many methods and tools used to forecast and predicts water flow in many hydrological areas. As a result, the water flow modeling has become a key area of study due to the importance of water resource management. Hence, this paper aim to provide a comprehensive that compare methods used for water flow forecasting and summarized their key characteristics.

Hydropower has a well-established position in the energy sector, and it is very important to promote the further growth of this energy resource, especially in developing countries. As a result, the water flow modeling sector becomes a key area of study due to the importance of water resource management. Where, the precise forecasts of hydropower water flow are important for effective management practices. This paper provides a review on hydropower system. An overview on the method and techniques used to simulate water forecasting is made to provide further understanding. An analysis was also made to identify the techniques that provide high accuracy in hydropower flow forecasting.