Nakhon Si Thammarat Readies Floodway Ahead of Monsoon Season
Nakhon Si Thammarat is accelerating preparations for its royal‑initiated city bypass floodway to shield the inner city from monsoon floods, even though the project is still unfinished. Officials say the partially completed canal can already divert over 40 % of peak floodwater and could be turned into an emergency floodway if needed. They warn that the upcoming 2026 monsoon may be severe, with heavy rains from the north and central regions moving southward.
Officials in Nakhon Si Thammarat said on 15 October 2026 that the flood mitigation project, or city bypass canal, remains under construction but is ready to handle monsoon floodwaters. The project comprises a newly dug 18.64‑kilometre canal and improvements to two related channels totalling 17.8 kilometres, built with a budget of 9.58 billion baht to divert water from Tha Dee Canal through districts such as Na Sar, Na Phru, Chang Sai, Phra Phrom, Tha Rua and Tha Rai before emptying into the sea at Bang Chak. Although work is incomplete, all contractors along the route have been summoned to prepare for flood influx; last year the scheme successfully diverted large volumes of water before it reached the city centre, and this year’s progress has raised confidence that it can shunt more than 40‑50 % of the peak flow away from the inner urban area. To enhance readiness, contractors have been asked to temporarily remove earthen embankments and construction pits along the canal alignment, allowing the entire waterway to be converted instantly into an emergency floodway if water levels become critical. Authorities warn that the approaching 2026 monsoon season could be severe, as heavy rainfall already affecting the north and central regions is expected to move southward, potentially matching the intensity seen in the central plains and exacerbated by broader climate changes. Nevertheless, all concerned agencies continue to monitor the situation and refine their flood‑response plans.
