Hat yai: After the floodwaters receded in many areas in the South, the crisis is still not over. When the floods were already severe, recovery and relief efforts were more difficult. How can a major cleanup be initiated quickly and carried out so that disaster victims can move forward? At a time when it seems like they have to start over, starting from scratch.
According to Thai News Agency, Dr. Chawalit Chanrat, a water expert and CEO of TEAM Consulting Engineering and Management Public Company Limited (TEAMG), analyzed the massive flooding in Hat Yai and proposed both immediate and long-term solutions to cope with rising water levels amid global warming. He explained that many sources cited the unprecedented rainfall on November 21st, the heaviest day on record, as 335 millimeters, the highest in 300 years, which rendered existing water management systems incapable of coping.
Dr. Chawalit pointed out that while the rain was indeed very heavy, 300 millimeters of rain had also occurred in Hat Yai 15, 25, and 50 years ago. What made this situation more severe was that the rainfall exceeded 200 millimeters for five consecutive days. Factors influencing the continuous rain from November 21 to 25 included the influence of high pressure from China, the La Nina phenomenon that continuously replenished water from the Gulf of Thailand, and the slowly moving low pressure area (Senja) over Malaysia.
The original designed and constructed structures, including Khlong Rama I, Khlong Rama III, and the expansion of Khlong U-Tapao to drain water into Songkhla Lake, are no longer sufficient. Urgent management guidelines have been suggested to address the immediate needs within two weeks, such as dredging the city’s sewers and canals to facilitate drainage.
For medium and long-term solutions, Dr. Chavalit suggested infrastructure improvements like expanding drainage channels under existing structures. This includes widening drainage pipes and expanding railway bridges to prevent water flow obstruction. There is also a need to increase drainage capacity by installing a larger pumping station and building a new drainage canal, Khlong Rama 7, to redirect water away from the city.
The construction of drainage tunnels, such as the proposed Khao Kho Hong Tunnel, is considered critical to manage water flow more effectively. This tunnel would expedite the flow of water into Songkhla Lake, minimizing the risk of city flooding. Dr. Chavalit highlighted the irreversible nature of global warming, emphasizing the urgency of implementing comprehensive water management solutions to prevent future disasters.
Dr. Chawalit also warned of the upcoming rainy season in the South, predicting heavy rains in various regions, which necessitates immediate action to mitigate potential flooding impacts. The dredging of sediment at the mouth of Songkhla Lake is crucial for maintaining natural drainage.