ONWR Issues Flood Alert for Chao Phraya River Basin

The Office of the National Water Resources (ONWR) has issued an urgent advisory for residents and authorities in four provinces—Samut Prakan, Bangkok, Nonthaburi, and Pathum Thani—to monitor water levels closely. According to a report from Khaosod Online, the combination of a strong southwest monsoon and high tides is expected to increase the risk of water overflowing into low-lying areas along the Chao Phraya River.

Between August 25 and 29, 2026, communities located outside permanent flood barriers or in areas lacking formal protection are particularly vulnerable to potential inundation. The ONWR notes that the situation is exacerbated by increased rainfall across the central region, which may cause water levels to exceed initial projections. Additionally, the country is experiencing heavy rain in the northern, upper northeastern, and eastern regions due to the monsoon and the influence of Tropical Storm 'Narra' in the Gulf of Tonkin.

For travelers and residents, this alert suggests potential disruptions to riverside activities and local transport in the affected provinces. While the ONWR has identified these specific dates for heightened vigilance, the exact impact on specific neighborhoods remains to be confirmed based on real-time water flow and tidal fluctuations. Authorities are currently monitoring the situation, and those in low-lying areas are advised to stay updated through official government channels.