Bangkok: All sectors are working together to manage water in the Bhumibol and Sirikit Dams, which are at 97-98% of their capacity. They are carefully planning water releases from each dam, continually adjusting plans to the situation, and preparing to deal with Tropical Storm Kalmaegi. The Royal Irrigation Department (RID) has clarified that the planned water release from Bhumibol Dam, which is discharging 40 million cubic meters per day, will not increase the maximum water level at the Chao Phraya Dam, which is currently discharging at a rate of 2,700 cms, as these are separate water bodies.
According to Thai News Agency, Energy Minister Atthapol Rerkpiboon stated that he is monitoring the water situation at dams operated by the Electricity Generating Authority of Thailand (EGAT) and preparing for Tropical Storm Kalmaegi, which will bring heavy rainfall to the North, Central, and Northeastern regions between November 7-9. Two northern dams, Bhumibol and Sirikit, are nearing capacity and require careful water discharge management. This is under joint management by the Office of National Water Resources (ONWR), the Royal Irrigation Department, and relevant agencies.
The Bhumibol Dam's water storage capacity is 13,208 million cubic meters, representing 98% of its capacity. The projected inflow of 400 million cubic meters will increase due to the influence of Tropical Storm Kalmaegi. Water discharge will be increased in a stepped manner, starting yesterday (November 6th), at rates of 30, 40, and 45 million cubic meters per day. This will result in the water level downstream of the dam rising by no more than 20 centimeters.
The water situation at Sirikit Dam is 9,260 million cubic meters, representing 97% of the reservoir's capacity. It is estimated that the inflow will increase by 70 million cubic meters due to the influence of Tropical Storm Kalmaegi. The water discharge rate will be maintained at 10 million cubic meters per day to prevent the water mass from joining the increased water discharge from Bhumibol Dam.
Mr. Atthapol also stated that dams under the supervision of the Electricity Generating Authority of Thailand (EGAT) are multi-purpose dams, managing water for irrigation (supporting agriculture), domestic use, power generation, and other purposes. Hydropower plants are renewable energy sources that offer stability and rapid response to electricity demand, taking no more than seven minutes from start-up to supplying electricity to the grid. Furthermore, they have low production costs. The Sirikit Dam Power Plant Unit 4 has been in operation for over 30 years and many parts are deteriorating, requiring renovation to maintain readiness and ensure stable power generation. The renovation budget is approximately 2.088 billion baht and is currently underway for project approval. The renovation is expected to be completed and commercially operational by December 2029.
Mr. Paitoon Kengkarnchang, Deputy Secretary-General of the Office of National Water Resources (ONWR), clarified that the water management plan has been adjusted to increase water discharge from the Bhumibol Dam reservoir. On November 6, 2025, the water discharge will increase to 30 million cubic meters; on November 7, 2025, the water discharge will increase to 40 million cubic meters; and on November 8, 2025, the water discharge will increase to 45 million cubic meters. Large dams located in the Kalmaegi storm zone include the Bhumibol, Sirikit, and Ubolrat Dams. Continuous monitoring of the situation indicates that the Sirikit and Ubolrat Dams are not yet at risk and are capable of handling the additional rainfall. Management plans have been implemented to best manage the storm situation and minimize the impact on the public.
The situation has been monitored and assessed and adjusted as appropriate. Bhumibol Dam's discharge of 40 million cubic meters per day (460 cms) will not increase the peak water level at Chao Phraya Dam, which is discharging at a rate of 2,700 cubic meters per second (CMS), because they are different masses of water (water is like a train, and the railroad tracks are rivers). The distance from the end of Bhumibol Dam to the Chao Phraya Dam takes 8 days. The highest water level has already passed Nakhon Sawan. Please do not panic. The water drainage plan has been planned in advance for the gap between Bhumibol Dam and the incoming water and the outgoing water. The Ping River in Tak can receive 2,600 cms, Kamphaeng Phet 3,000 cms, Bhumibol Dam has discharged 5,300 mcm in advance since January 1, 2025, Sirikit Dam has discharged 7,500 mcm in advance since January 1, 2025, and the rainfall above C2 (in front of Camp Jiraprawat) Muang Nakhon Sawan District) is 27% more than the average, only one year less than in 2011.