In November 2025, Hat Yai, a vital economic center in southern Thailand, was struck by its most severe flooding in 25 years. A deluge of record-breaking rainfall overwhelmed the city’s water management systems, exposing deep-seated vulnerabilities in its infrastructure and urban planning. This crisis not only caused immense immediate damage but has also sparked urgent calls for a complete overhaul of the region's approach to climate resilience.
How the Flooding Started in Hat Yai
The disaster began on November 19, 2025, as extraordinary rainfall battered the city for days. Between November 19 and 22, Hat Yai received 595 millimeters of rain, far exceeding the amounts from the significant floods of 2000 and 2010. The Royal Irrigation Department classified the 335 millimeters that fell on November 21 alone as a once-in-300-years event. This downpour was intensified by a combination of meteorological factors, including La Niña conditions, creating a perfect storm.
The massive rainfall quickly overwhelmed the U-Taphao River Basin. By November 25, satellite data confirmed that large parts of Hat Yai were submerged under two to three meters of water, with some areas seeing depths of over four meters. The Office of National Water Resources (ONWR) confirmed that water levels had surpassed those of the historic 2010 flood.
Devastating Impacts of Flooding on Hat Yai City
The scale of the disaster was immense. The flooding affected over 1.9 million people across the southern provinces, with Hat Yai being the epicenter. More than 150,000 residents in the city were directly impacted, and at least 25,102 homes suffered significant damage. As of November 27, officials reported 85 fatalities.
Key infrastructure was crippled. Major roads like Phetkasem Road turned into fast-flowing rivers, isolating communities. The city's main water treatment plant was inundated by over three meters of water, forcing the Provincial Waterworks Authority (PWA) to suspend the water supply to Hat Yai and surrounding areas. This left residents without clean tap water at a time of critical need. Power cuts were implemented to prevent electrocutions, further complicating rescue efforts and forcing businesses to close. The crisis also stranded approximately 7,000 international tourists, primarily from Malaysia and Singapore, as all transportation links collapsed.
Flaws in the Foundation
The 2025 Hat Yai flooding event brought the city's long-standing vulnerabilities to the forefront. The primary drainage canal, Khlong Phuminat Damri, was designed to handle 1,200 cubic meters of water per second, a capacity that was no match for the extreme rainfall. Furthermore, the city's main waterway, the U-Tapao canal, has been narrowed by urban encroachment, drastically reducing its capacity.
Hat Yai's location on low-lying terrain makes it a natural channel for water flowing toward Songkhla Lake. Decades of urban sprawl have eliminated natural flood retention areas, worsening runoff. This was compounded by fragmented coordination among Thailand's various water management agencies, which failed to adequately prepare despite advance warnings of La Niña conditions.
Recovery of Hat Yai City
In response to the crisis, authorities issued a red-flag alert on November 22, ordering the evacuation of 103 communities. Evacuation centers were established, and a massive response involving over 80 water pumps and military units was launched.
The economic fallout is projected to be severe. The real estate market, with active projects worth over 41 billion baht, is expected to take three years to recover. The commercial and tourism sectors faced daily losses estimated at 1 to 1.5 billion baht during the flood's peak.
Looking ahead, experts are calling for comprehensive solutions. Recommendations include deepening and widening the main canals, implementing more effective distributed drainage systems, and adopting stricter building codes for future developments. These codes would require raised ground floors and the use of water-resistant materials. The crisis has also highlighted the need for better institutional coordination and consistent government funding to support long-term climate adaptation strategies.
