Another big storm is forming and will start taking its toll on the country on Oct 20, following tropical storm Gaemi which is expected to hit Thailand tomorrow, Agriculture and Cooperatives Minister Theera Wongsamut says.
The second storm of this year will be named Phrapiroon, a Thai name, and it is forecast to deluge almost the same areas expected to be battered by Gaemi _ the lower Northeast, East, Central region and upper South, Mr Theera said.
In preparing for the coming storms, the Royal Irrigation Department was speeding up draining about 44 million cubic metres per day of water off the plains by the eastern side the Chao Phraya River, he said.
As for water retention areas on the western side of the river, the total water volume to be drained per day was 33 million cu/m, Mr Theera said.
The Pasak Jolasid dam, expected to receive a surge in runoff caused by the first storm, needs to release about 8.6 million cu/m per day so it can accommodate it all, he said.
The dam is now around 83% full and it can take only about 300 million cu/m of additional water if no drainage is carried out.
The other two major dams, Bhumibol and Sirikit, were both about 60% full and they could accommodate higher volumes of water than the Pasak Jolasid dam, said Suthep Noipairoj, deputy director-general of the department.
Bangkok and its surrounding pro-vinces were also preparing for the arrival of the storms by accelerating drainage of water into the Gulf of Thailand through the Chao Phraya River, said Mr Suthep.
National Disaster Warning Centre director Somsak Khaosuwan, however, said the second storm was expected to weaken into a depression or low pressure area which would result in scattered rain not as heavy as last month's.
Riverside communities in the lower Northeast, Central region and Bangkok are being warned of possible floods as a result of rivers overflowing from today until Monday.
Although high seas are not expected during the storm period, areas in eastern Bangkok including Lat Krabang, Nong Chok and Min Buri, plus some parts of neighbouring Chachoengsao province have shifted into top gear to drain water from their reservoirs, said Mr Somsak.
Eastern Bangkok, in particular, is expected to be hit hard by Gaemi.
As about 80% of the capital would be affected by the storm, City Hall would closely monitor and provide updates on the water situation at half-hourly intervals on http://dds.bangkok.go.th, said Bangkok Governor MR Sukhumbhand Paribatra yesterday.
The governor also expressed particular concerns over the greater flood vulnerability of areas on the eastern side of the Chao Phraya River where a large volume of excess water will be drained.
He said these areas were normally low-lying and surrounded by canals and they used to be drainage zones about two decades ago but had been filled in by residential communities.
Defence Minister Sukumpol Suwanatat said the army is preparing to allow areas of the 2nd Cavalry Division at Sanam Pao to be used as flood retention zones as requested by Deputy Transport Minister Chatchart Sithipan.
The division has been draining water from its swamps and will be ready to receive some of the capital's flood water.