Following an announcement by the Thai Meteorological Department, Thailand's rainy season this year officially began on 15 May 2026. The Bangkok Metropolitan Administration (BMA) is preparing to tackle flooding and pressing ahead with infrastructure development, incorporating digital technology to improve drainage systems in response to heavy rain and tidal surges. Preparations include readying pumping stations, reinforcing flood barriers along the Chao Phraya River, installing water pumps at more than 560 points, and enhancing drainage capacity on the eastern side of the city — covering short-term measures, long-term plans, and site-specific fixes — all aimed at managing water and reducing the impact on residents.
The BMA is readying all systems for efficient rainy-season management. In terms of the overall water management picture, the BMA has already cleared more than 3,739 kilometres of drainage pipes (out of a total length of 3,815 kilometres), representing approximately 98.1% of the annual plan. The final phase of that plan was required to be completed by last July so that the system would be fully ready to handle rainfall. For canals, which are the primary drainage routes, dredging has been completed on more than 82% of the total (a combined distance of 267 kilometres), and waterway clearance operations have been carried out on more than 99% of the network (1,412 kilometres). Several major canals have been fully cleared, allowing water to flow freely and eliminating repeatedly problematic bottlenecks. In addition, 4 drainage tunnels, 207 pumping stations, 244 floodgates, and 371 pump sumps have been made ready.
Regarding water pumps and water-propulsion machines — which serve as additional capacity in urgent situations — in 2026 the BMA has installed water pumps at 100% of its 560 designated points across the city. Water-propulsion machines have also been installed and water pumps distributed to offices in all 50 districts as of July 2026. At the same time, 12 rapid-response mobile pump units have been deployed to handle emergency situations.
The BMA has also prepared a suite of measurement instruments and water management support systems to monitor, track, and analyse conditions in real time, comprising:
- 2 stations of C-Band weather radar
- 130 stations of rainfall measurement systems
- 248 stations of road-surface flood detection systems
- 310 stations of canal/Chao Phraya River water-level measurement systems
- 55 stations of canal/Chao Phraya River water-flow rate measurement systems
- 270 stations of pump monitoring and control systems
All of these systems are linked to the Bangkok Flood Prevention Centre, enabling efficient 24-hour situation monitoring, trend analysis, and decision support for BMA water management.
Continuous Readiness, Vigilance Across All Rain Scenarios
The BMA has prepared to handle heavy-rain situations through round-the-clock monitoring of rainfall and water levels; pre-emptive drawdown of canal water before rain arrives, turning canals into temporary retention basins to speed water flow, accelerate drainage, and improve rain response; inspection of the readiness of floodgates, pumping stations, and electrical systems; installation of temporary pumps at risk-prone points; removal of blockages from drainage pipes; dredging of ditches and canals; clearance of waterways; and removal of water hyacinth, aquatic weeds, rubbish, and other obstructions. Additional measures include accelerating drainage after rain stops and bringing the Bueng Nong Bon drainage tunnel into full operation in 2026.
Furthermore, the BMA is advancing long-term measures under the "Bueng Nong Bon Drainage Tunnel Extension Project — Khlong Prawet Burirom — Khlong Si", covering 6 districts (152.90 square kilometres) as follows: Lat Krabang District, Nong Chok District, Khlong Sam Wa District (partially), Min Buri District, Saphan Sung District, and Prawet District. The project will retain more than 4 million cubic metres of water through 3 intake structures feeding into the tunnel, with a maximum drainage capacity of 60 cubic metres per second. Construction is expected to begin in late 2026 and be completed in 2031. The project will speed up drainage from low-lying areas, reduce flooding duration, cope with heavy rainfall driven by climate change, reduce impacts on travel and the economy, and improve Bangkok's long-term flood protection system.
Collaboration with Government Agencies, the Private Sector, and Network Partners for Integrated Water Management in Bangkok
The BMA is working with the Royal Irrigation Department to tackle this year's rainy season by deploying joint field teams — for example, at the Khlong Prem Tai pumping station — to achieve more efficient integrated water management in the boundary area between Bangkok and Pathum Thani Province. In addition, the BMA is working closely with the Metropolitan Electricity Authority (MEA) to prepare for rain-related situations, ensuring that electrical power supply to every pumping station is ready to operate seamlessly, in order to enhance drainage efficiency, reduce flooding duration, and give residents confidence in the safety of their lives and property. The BMA has also collaborated with the Mass Rapid Transit Authority of Thailand (MRTA) to resurface roads with asphalt, levelling road surfaces on various streets — such as Phetchaburi Road Soi 7 in sections that dip and frequently suffer from waterlogging — while also facilitating safe and convenient travel for residents.
BMA Partners with JICA to Advance 50-Year Drainage Master Plan, Upgrading the Entire System to Handle Heavy Rain and Urban Flooding
The BMA has entered into an international cooperation agreement with JICA (Japan International Cooperation Agency) to formulate the "Project for Formulating the Urban Drainage Master Plan Bangkok Metropolitan Area", which has a long-term planning horizon of 50 years to accommodate the increasingly heavy and intense rainfall resulting from global warming. The initiative begins with a 5-year technical cooperation project (2026–2031), divided into two phases: Phase 1 (3 years) and Phase 2 (2 years), focusing on three main objectives: formulating an overall master plan, developing a pilot area, and improving the operational efficiency of the existing drainage management system. JICA has confirmed its full commitment to providing knowledge and technology support in order to jointly drive Bangkok towards an efficient and sustainable long-term drainage system.
Flood Reporting Contacts and Channels
If you encounter flooding, drainage blockages, rubbish blockages, or require assistance, you may report them via:
Flood Prevention Control Centre Hotline — Tel: 0 2248 5115 (available 24 hours)
or Traffy Fondue
Read additional articles in the BMA Newsletter eBook at https://links.bookkurry.com/bkk_news_issue_303
