Women row a boat with their dog through floodwaters in a neighbourhood in Ayutthaya on October 4, 2021, after tropical storm Dianmu caused flooding in 31 provinces across the country. Jack TAYLOR / AFP
People living downstream of Pasak Jolasid Dam in Ang Thong, Lop Buri, Saraburi, Suphan Buri, Pathum Thani, Nonthaburi and Ayutthaya have been warned to brace for flooding as an indirect effect of three successive storms affecting Thailand until October 18th, according to Director of the Climate Change and Disaster Centre at Rangsit University Dr. Seree Supharatid.
The first storm, expected to make landfall in northern Vietnam today, is “Lionrock”, after which it will weaken into a tropical depression. This will be followed by tropical storm “Kompasu” which, until Sunday evening, was over the northern Philippine Sea and it is expected to make secondary landfall over Vietnam mid-afternoon on Thursday and, thirdly, a low-pressure cell.
Dr. Seree said the weather systems will bring more rain to Thailand and this will send more water into the Pasak Jolasid Dam, resulting in the need to discharge more water, while assuring that Bangkok will not be affected.
Unlike the big flood in 2011, which was caused by runoffs from northern Thailand, where dams such as Bhumibol and Sirikit had to discharge excess water to ease pressure on their structures, he said that flooding this year, in many central, lower northern, north-eastern and eastern provinces is not caused by discharges from northern dams, where water levels in their reservoirs are far below their capacities.
Flooding this year, he said, is being caused by the blocking of the natural flow of water by the construction of embankments and other structures, offering the metaphor of a glass of water that overflows if ice cubes are added.
When an embankment breaks, such as the one in the Chaiyo district recently, surrounding areas are immediately flooded.
Another reason for flooding, said Dr. Seree, is ineffective water management resulting from conflicts between the state and the people or between two different groups of people about where to allow the water to flow.