Storm Nongfa causes widespread flooding in Thailand's major river basins
Tropical Storm Nongfa causes severe flooding in the Pasak, Yom, and Nan river basins, with authorities ramping up flood response efforts across affected areas.
Prasert Jantararuangtong, Deputy Prime Minister and Minister of Digital Economy and Society, as Chairman of the National Water Resources Committee, on Wednesday expressed concerns over the water situation in several areas affected by Tropical Storm Nongfa and the monsoon trough. The storm has brought heavy rainfall to the Pasak, Yom, and Nan river basins, with some areas recording over 200 millimetres of rainfall. Impact on major river basins is as follows:
Pasak River Basin
Phetchabun province has been severely affected by continuous heavy rain, leading to flash floods in residential areas and agricultural land in multiple districts, including Lom Kao, Nam Nao, Lom Sak, Mueang Phetchabun, and Nong Phai. Authorities have already begun evacuating vulnerable residents and relocating their belongings to higher ground. Water levels have started to recede, and the mass of water is flowing into the Pa Sak Jolasid Dam. It is anticipated that within the next 7 days, the water level in the dam will rise from 35% to 45% of its storage capacity, an increase of nearly 100 million cubic metres.
Nan River Basin
Heavy rainfall in the southern areas of Sirikit Dam has caused the Nan River, particularly in Phitsanulok city, to rise rapidly, with water levels now less than one metre from the riverbanks. The Sirikit Dam has reduced water discharge to slow down the flow and mitigate the impact on downstream areas. However, with the dam’s water level reaching 86% of its capacity, controlled releases of up to 40 million cubic metres per day will begin between September 5-7 to ensure the safety of the dam and to manage the water in preparation for future inflows. The dam remains structurally secure.
Yom River Basin
Mae Mok Dam has seen its water level exceed the storage capacity, reaching 104%. The overflow has been managed through the spillway, raising water levels in the basin. However, the Mae Mok River has sufficient capacity to handle the additional volume, and no immediate impact on the surrounding areas has been reported.
Flood management measures and assistance
Prasert has instructed the National Water Resources Office (NWRO) to set up temporary water management centres in flood-prone areas of central Thailand, along with additional centres in the Yom-Nan river basin. These centres will work to manage the water flow efficiently and mitigate the impacts on residents. Immediate assistance and relief efforts are being coordinated to support affected communities. Additionally, Prasert has emphasised that all regional flood response centres should closely monitor the situation and work together to prevent and resolve flood-related issues.
