The results of this study demonstrate the potential impacts of climate change on the Cedar River watershed and the importance of proactive management strategies to mitigate these impacts. By using the HEC-RAS model to simulate future climate scenarios under the SSP8.5 and SSP4.5 scenarios from the CMIP6 model, this study has shown that the Cedar River is likely to experience an increase in stream flow and discharge due to the predicted increase in precipitation in the area. The predicted increase in stream flow and discharge has significant implications for the management of the Cedar River watershed, including the potential for increased flooding and erosion. Therefore, it is crucial that management policies and adaptation measures are put in place to mitigate the potential impacts of climate change on the river. This study has also highlighted the importance of incorporating climate models such as the CIMP6 model and the SSP8.5 and SSP4.5 scenarios to provide more accurate predictions of the potential impacts of climate change. Overall, this study emphasizes the need for proactive management strategies and further research to better understand the potential impacts of climate change on river systems and ensure the long-term sustainability of these ecosystems.