The Cabinet and the National Water Policy Committee are engaged in an urgent meeting in Government House today, to discuss ways to manage the massive amount of water currently upstream of the Chao Phraya Dam, to save Bangkok flooding and to ease the flooding in several central provinces, as the Royal Irrigation Department (RID) plans to increase further the rate of discharge through major dams in the next few days.
The RID plans to increase the water release through the Bhumibol Dam in Tak province, from the current 45 million cubic metres/day to between 48 and 55 million cubic metres/day step-by-step over the next few days, to ease pressure on the dam from water in its reservoir, which is now 99% full.
This process will take seven days, after which the rate of discharge will reduce, according to the National Water Resources Office.
Water released through the Bhumibol Dam into the Ping River will converge with the Wang, Yom and Nan rivers, to become the Chao Phraya River in Nakhon Sawan province.
This means that 3,100m3/s of water will be flowing into the upper reaches of the Chao Phraya River over the next few days. This will, in turn, increase pressure on the Chao Phraya Dam in Chainat province, requiring an increased discharge rate, from the current 2800m3/s to at least 2,900m3/s , but not as high as 3,700m3/s, which contributed to the devastating flooding of 2014 in Bangkok and surrounding provinces.
PM Office Minister Paradorn Prissananantakul said today that the RID may have to reduce its release rate to under 5 million cubic metres/day via the Sirikit dam in Uttaradit province, because its reservoir still has more space to store water than the Bhumibol Dam reservoir.
He also said that the RID has promised to increase the release of water from the swollen Chao Phraya into the catchment areas to the east and west of the river, from the current rate of 500m3/s to 600-650m3/s.
Paradorn said that this means people living to east and west of the river, upstream of the dam, may be affected, but this option avoids the need to dramatically increase the discharge through the dam and, therefore, eases the flood problem in central provinces downstream.
Asked if Bangkok will be spared from flooding, the minister said only if water is diverted into the catchment areas and the rate of discharge through the Chao Phraya Dam is done step by step.
Meanwhile, Dr. Seri Suparatit, a weather expert and director of the Climate Change and Public Disasters Centre at Rangsit University, suggested that the RID accelerate the draining of water into the catchment areas upstream of the Chao Phraya Dam.
He said that many areas downstream of the dam are already inundated, suggesting that water from the main rivers, which converge to form the Chao Phraya River, should be drained into the catchment areas, which is an option to reduce the pressure on the Chao Phraya Dam.
Rainfall is forecast to decrease steadily over next week, due to the arrival of a cold front from China.
