BANGKOK -- Bangkok and other areas of central Thailand received new warnings of possible major flooding, even as disaster relief authorities said Wednesday the threat had eased in 13 of 30 provinces elsewhere that were lashed by seasonal monsoon rains.
Seven people have died and two are missing since the weekend from flooding triggered by Tropical Storm Dianmu, the Department of Disaster Prevention and Mitigations said. It announced Wednesday that 197,795 households in 30 provinces, mostly in the north, northeast and central regions had been affected, a 56% increase over the 126,781 reported a day earlier.
Bangkok has had no major flooding yet, but many rural areas have been severely affected. Thai television has shown villagers in several areas walking through chest-high water or being evacuated from their homes on small boats.
However, conditions have improved in 13 provinces around the country, including Chiang Mai, the disaster prevention agency said.
Heavy rains are still forecast for many areas, but the immediate threat triggering warnings to Bangkok and the provinces of Lopburi, Saraburi, Ayutthaya, Pathum Thani and Nonthaburi comes from water that has flowed down the Chao Phraya River from the north in such quantities that it overwhelmed the capacity of dams and reservoirs to retain it.
The dilemma facing planners is that the dams and reservoirs are used to store as much water as possible to help with irrigation during perennial droughts, but have to be able to cope with the unpredictable overflow during rainy season.
Bangkok Governor Aswin Kwanmuang acknowledged Wednesday on his Facebook page that because the capital is on low-lying ground, it is vulnerable to flooding from the Chao Phraya, and cannot be drained quickly. Parts of the city were inundated in a major 2011 flood, fed primarily by water released from reservoirs in the north.
The governor listed measures the city is taking to cope with flooding, including preparing water pumps that connect to a large drainage tunnel.
While large dams and reservoirs in the north have so far been able to cope with this year’s rainfall, others closer to Bangkok have approached or exceeded their capacity this month and have had to discharge water.
The most recent flood warnings follow decisions to increase the discharge of water from the Chao Phraya Dam, 190 kilometers (120 miles) north of Bangkok, and the Pasak Jolasid Dam, about 100 kilometers (60 miles) north of the capital.
Another crisis point is in the northeast, where thousands of people have been displaced by floodwaters.
Prime Minister Prayuth Chan-ocha on Wednesday visited Chaiyaphum, another hard-hit northeastern province, where he offered aid packets.