Hydropower plants are one of the renewable energy sources that have higher efficiency compared to other renewable resources. One of the suitable planning approaches to maximize efficiency in these plants is the application of modern optimization methods such as metaheuristic algorithms. The aim of this study is to simulate and optimize a model based on single-point and two-point risk coverage rules to evaluate the efficiency of these rules and policies in operating the reservoir system and maximizing the total hydropower generation of the Dez Dam during the period 1991–2020 on a monthly scale using the M2O-CSA algorithm for both baseline and future periods. According to the results, the total power generation during the optimization period and in order to find the best solution (maximum generation capacity), the highest total power output can be achieved using 2PHP, with a maximum of 11051.64 MW in April and a minimum of 6029.45 MW in November under the SSP585 scenario. Therefore, based on the given results, 2PHP and 1PHP provide the maximum generation capacity, respectively. Comparing the results shows that 2PHP is more efficient and effective than 1PHP for the hydropower reservoir energy issues of Dez Dam in the future period.