Water levels in the reservoirs behind Thailand’s four main dams have dropped substantially, raising concerns of insufficient supply for agriculture and consumption, due to intrusion of sea water further into the Chao Phraya River.

According to the Royal Irrigation Department, the combined water volume in the big and medium-sized reservoirs across the country is estimated at 16.13 billion cubic metres, compared to 18.616 billion cubic metres at this time last year.

The reservoirs behind the four main dams are holding:

• Bhumibol, 7.113 billion cubic metres, 53% of capacity
• Sirikit, 3.943 billion cubic metres, 41% of capacity
• Kwae Noi, 191 million cubic metres, 20% of capacity
• Pasak Jolasid, 142 million cubic metres, 15% of capacity

The Royal Irrigation Department predicts that the drought, induced by El Niño, may last until next year, forcing the department to manage the use of water in reservoirs strictly, to ensure that there is sufficient for agriculture and consumption.

Anusorn Tantiwut, deputy director of the Royal Irrigation Department’s 10th irrigation office, said that the water level in Pasak Jolasid this year is not much different from last year and better compared to the situation three years ago, when only 8-9 million cubic metres of water were left in the reservoir in June.

He added, however, the amount of water being discharged from the dam for consumption has been cut to about one million cubic metres a day, from 3-4 million cubic metres previously, to conserve water for agriculture.

Anusorn added, however, that there will be enough water for the next 3-4 months, after which he expects the reservoir to be replenished from Phetchabun province.

He also said that, during the rainy sea, water will be discharged from the dam mainly for consumption, while farmers will have to rely on rain water, with water being discharged from the reservoir only when necessary, adding that farmers have been advised to delay their rice cultivation until there is a regular rainfall.

Meanwhile, Assistant Professor Dr. Sitang Pilailar, chief of the water resources engineering  department at Kasetsart University, expressed concern that intrusion of sea water into the Chao Phraya River may affect the source of raw water to be processed into tap water, as he forecasts that the El Niño phenomenon may last until March next year.