RID raises water discharge following heavy rain in northern Thailand

Its Smart Water Operation Centre (SWOC) reported the situation on the Chao Phraya River at 6am, noting that at station C2, Mueang district, Nakhon Sawan province, the water flow was measured at 1,053 cubic metres per second and was expected to rise, although the water level remained 5.65 metres below the riverbank.

“To ensure water management corresponds with rainfall and runoff, RID deemed it necessary to gradually increase the discharge through the Chao Phraya Dam at station C13, Sapphaya district, Chai Nat province, from the previous rate of 600 cubic metres per second to 700 cubic metres per second, effective from 9am. This rate will be maintained continuously,” the department stated.

RID noted that this adjustment will cause water levels downstream of the dam to rise, particularly in areas outside the flood embankments, including Phong Pheng Canal in Ang Thong province, Bang Ban Canal in Ayutthaya Province, the Mae Nam Noi community in Sena district, and Phak Hai district in Ayutthaya province.

Regarding the four main dams in the Chao Phraya basin — Bhumibol, Sirikit, Kwae Noi Bamrung Dan, and Pasak Jolasid — the total water volume currently stands at 12,789 million cubic metres, or 51 per cent of their total capacity, leaving more than 12,082 million cubic metres available to accommodate further inflow.

RID is prepared to manage water levels in response to the heavy rainfall in the upper regions and will issue warnings to the public if water levels continue to rise. Residents living along both banks of the Chao Phraya and Noi rivers are advised to closely monitor the situation.

Meanwhile, Sonthi Kotchawat, an environmental and health expert from the environmental scholars’ association, warned on his Facebook post on Monday that this year’s heavy rainfall presents factors that may lead to flooding.

He explained that nearly 80% of Thailand’s territory is experiencing heavy rain, particularly in Bangkok and its vicinity, as well as in northern, central, and Andaman coastal regions. The provinces of Pattani, Yala, and Narathiwat are the only areas spared from the extreme weather.

The south-west monsoon is one of the causes of the heavy rain, as it blows from the Indian Ocean, which is warm and highly humid. When the monsoon reaches Thailand, it carries moisture from the sea inland, leading to condensation and rainfall, he explained.

The monsoon trough, currently positioned over the northern region, is responsible for the heavy rains during this period. If tropical storms pass through the South China Sea, this trough acts as a pathway, allowing storms to move into Thailand, resulting in prolonged rainfall from June through mid-October.

Sonthi predicted that Thailand faces the highest risk from tropical storms in October. While storms may enter Thailand as early as May, the likelihood increases from June onwards until October.

He also expects more storms due to extreme heatwaves in parts of South Asia, including India and Pakistan, where temperatures have reached up to 50 degrees Celsius. This intense heat could potentially trigger storm formation over the Bay of Bengal, he said.