Due to shift in the average patterns of weather, climate change became one of the significant development challenges. Hydropower is currently being utilized in more than 150 countries, including 11,000 stations with 27,000 generating units. Increasing attention has been paid to hydropower generation in recent years, because it is renewable energy. Temperature and precipitation effects from global climate change could alter future hydrologic conditions in Iraq and, as a result, future hydropower generation. This is also valid for the Middle East and Iraq. The aim of this study (part1) is to evaluate potential climate change impacts on hydropower in Dokan region, and to recommend various options to maintain optimum required water level to ensure full capacity of electricity generation throughout the year. A simple approach assumes that hydropower systems will reduce generation if water supply reduces, and vice versa. The analysis of the approach was carried out to convert changes in water resource availability to changes in electric hydropower generation. By the year 2050 and based on 12GCMs, electric power generation in Dokan power plant will decrease by 20-40 MW. The other factors such as the site head, the turbine generating capacity and efficiency which were neglected, will be measured, calculated and discussed in part2 of the study.