ONWR puts seven provinces on high-tide watch, Feb 28–Mar 5
Thailand’s water agency has warned that high tides from February 28–March 5, 2026 could push river levels up, causing overflow in low-lying areas and saltwater intrusion that may affect tap-water quality.
High tides and weather conditions drive risk
The Office of the National Water Resources (ONWR) has issued a monitoring alert for higher-than-normal sea levels from late February to early March, urging agencies in Bangkok and six neighbouring provinces to prepare for possible riverbank overflow and water-quality impacts.
ONWR said the risk is being driven by high tides combined with southwesterly winds over the Andaman Sea, the South and the Gulf of Thailand, which could bring heavy rain in some areas and accelerate rises in major rivers.
Where and when to watch water levels
ONWR identified the following rivers and timeframes for closer monitoring:
- Chao Phraya River: February 28–March 3, 2026 (communities outside flood barriers and low-lying riverside areas)
- Mae Klong River: February 28–March 2, 2026 (riverside areas in Samut Songkhram)
- Tha Chin River: March 1–5, 2026 (riverside areas in Nakhon Pathom and Samut Sakhon)
Flooding and saltwater intrusion are key concerns
ONWR warned of two main impacts: sudden flooding in communities without permanent flood protection (or relying on temporary embankments), including riverside construction areas, and saltwater intrusion, which can push further upstream during high tides and affect tap-water quality and freshwater-dependent agriculture.
Provinces on alert and advice for the public
Agencies have been asked to prepare response plans in Bangkok, Samut Prakan, Nonthaburi, Pathum Thani, Samut Sakhon, Nakhon Pathom and Samut Songkhram.
ONWR also flagged potential waterlogging on key routes including Sukhumvit Road, Suksawat Road and Rama II Road, advising residents in riverside areas—and motorists using risk routes—to check water levels in advance and closely follow official updates.
