Water used for irrigation is accounted for 70%–80% of the total water used worldwide. Thus, efficient management of the water resources is the key point to the sustainable water use. The difference between the inflow and water needs is one of the reasons for constructing a reservoir. Many studies were conducted regarding optimizing reservoir operation for irrigation to achieve the desired goals and objectives of the reservoir system. Significant and increasing scientific efforts were conducted to develop and implement the optimization techniques to operate the reservoirs for irrigation. All of the literature aims to minimize the gap between the water release policy and water demands determine release and transfer decisions that maximize water management objectives, and they all confirmed that using mathematical models to optimize and simulate the reservoir operation can enhance the performance of the reservoirs, as well as improve the crop yield. It is expected that this direction continues to evolve, and hopefully, the results of these models would encourage water managers to put them into practice to upgrade the agricultural sector.