Thailand Alerts 11 Chao Phraya Basin Provinces to Rising Waters

On September 20, Daet Lekwitchai, Deputy Director of the Irrigation Department acting in place of the Director, issued a second water alert for the Chao Phraya basin to governors of 11 provinces: Uthai Thani, Chai Nat, Sing Buri, Ang Thong, Phra Nakhon Si Ayutthaya, Suphan Buri, Lopburi, Pathum Thani, Nonthaburi, Samut Prakan, and Bangkok.

Heavy rainfall in the northern region has increased water flow in the Chao Phraya River. The Irrigation Department forecasts that by September 27, the Nakhon Sawan monitoring station (C.2) will record water flow of approximately 1,100–1,250 cubic meters per second, with tributary flows of 50–100 cubic meters per second. This will result in water entering the Chao Phraya Dam at 1,150–1,350 cubic meters per second, with irrigation intakes on both sides receiving 400–450 cubic meters per second.

To manage these conditions, the department must release 700–1,000 cubic meters per second through Chao Phraya Dam, raising water levels in low-lying areas outside embankments in Ayutthaya province by approximately 0.60–1.50 meters. These releases should not affect residential communities. If upstream flows exceed thresholds requiring dam releases above 1,000 cubic meters per second, further notices will be issued.

Currently, the Nakhon Sawan station records 1,124 cubic meters per second. At Chao Phraya Dam in Chai Nat, upstream water level stands at 16.60 meters, downstream at 9.67 meters, with a 6.67-meter distance from the bank. The dam is currently releasing 690 cubic meters per second.

The Irrigation Department has alerted all 11 provinces in the Chao Phraya basin, relevant agencies, and residents along both riverbanks and the Chao Phraya and Mae Nam Noi rivers to closely monitor water conditions.