Using PowerPoint, I will explain that the operation rules changed in 1996 cannot cope with the planned flood and that there are defects in the operation rules. The Nomura Dam is constructed with a plan to set the planned flood to 1300 tons per second, store 300 tons per second in the dam, and release 1000 tons per second. In the diagram of inflow and discharge in the basic plan of the dam, the time from the inflow to 1000 tons per second, then to 1300 tons per second, and then to the decrease to 1000 tons per second is set to 4 hours. 2.16 million tons will be stored in the dam. Next, when calculating how much the dam will be stored before the inflow reaches 1000 tons per second, it takes about 3.5 hours to reach the inflow from 300 tons to 1000 tons per second. It will be over 4.4 million tons. Since the flood control capacity of Nomura Dam is 3.5 million tons, the flood control capacity will be used up by the time the inflow reaches 1000 tons per second. In other words, when the inflow reaches 1000 tons per second, the dam will be full, and the inflow that will increase thereafter cannot be stored in the dam, and all will be discharged, so the planned flood will be 1300 tons per second. On the other hand, you will not be able to do anything. The reason why such a basic plan cannot be realized is that the operation rules changed in 1996 adopt a low-volume, fixed-quantity discharge method. If the constant rate and constant amount method is instructed by the Ministry of Land, Infrastructure, Transport and Tourism, the discharge will increase according to the inflow, so even when the inflow reaches 1000 tons per second, there is free capacity in the dam, so every second. It can store 300 tons and store 1000 tons per second. A planned flood of a dam is a flood of a scale that causes a catastrophic disaster to the residents of the basin, so it means that the dam cannot respond, and if it is left as it is, it will be in an extremely dangerous state. Therefore, it can be said that there was a defect in the operating rules that lead to such a dangerous situation.