Water quality assessment and prediction for freshwaters are an essential part of integrated water resources management and protection, in terms of a high level of human economic activities. A number of models were developed to predict and assess the water quality of water bodies, which require several database and information that is usually not available. In additional, the water managers demand relatively simple models for use that, in the most case, cannot accurately predict and assess a water quality. For this propose, two new models for prediction and integrated assessment of water quality in freshwater body was developed. The Water Quality Prediction Model combines the hydrochemical and hydrological parameters of water body and calculates their possible variations based on A2 and B1 main climate change scenarios. The Integrated Assessment Model of Water Quality based on the both natural and anthropogenic pressures, as well as self-purification capacity of the water body, which cause the changes of water quality in freshwater. These models have a simple structure, a high level of prediction accuracy, requires the minimum amount of water data, and is user-friendly for stakeholders. In this article, water quality of the Voghji and Hrazdan Rivers were predicted using the models. The prediction results showed that the concentration of NO3-, NH4+, Cu and Zn in the Voghji River will increase by 1.5 times in 2020 against 2012 based on A2 scenario, as well as the concentration of these parameters will reduce by 10.0-25.7 times (38.9 times for NH4+) for the same period based on B1 scenario. The integrated assessment of the Hrazdan River was stated that, due to the high anthropogenic pressure, the self-purification capacity of water in downstream of the river was damaged and water quality corresponds to the Bad (V) Class.