The 6.4km Bang Sue drainage tunnel will begin operation on Sept 6, according to Bangkok Metropolitan Administration.
The 5m-wide tunnel, which runs from Klong Lat Phrao on Ratchadaphisek Road and then goes under Khlong Bang Sue to the Chao Phraya River, can accommodate at least 60mm per hour of rain.
It was designed to prevent flooding in six districts, except when rain is more than 100mm per hour in which case water will be drained at least 50% faster than now.
The six districts, covering 56 sq km, are Dusit, Bang Sue, Phaya Thai, Chatuchak, Din Daeng and Huai Khwang.
Bangkok governor Assawin Kwanmuang on Monday afternoon checked the progress of the construction at Kiakkai pumping station on Pracha Rat Sai 1 Road in Dusit district.
Water was discharged into the tunnel on Monday and it will take 2-3 days to fill it. On Wednesday, pumps and the entire system will be tested.
The tunnel system consists of a pumping station with the capacity of 60 cubic metres a second near the Chao Phraya River, mechanical and electrical systems, three water retention structures (on Ratchadaphisek, Vibhavadi and Kamphaeng Phet roads) and an office building.
The tunnel will help prevent floods on key main roads in the capital:
- Phahon Yothin (Saphan Khwai intersection to Lat Phrao junction)
- Vibhavadi Rangsit (Sutthisan intersection to Lat Phrao junction)
- Ratchadaphisek (Ratchayothin intersection to Khlong Bang Sue)
- Lat Phrao (Ratchada-Lat Phrao intersection to Khlong Bang Sue)
- Kamphaeng Phet (below Srirat Expressway to Chatuchak market)
- Sam Sen (Khlong Bang Krabue to Kiakkai intersection)
It will also improve drainage efficiency in the Phahon Yothin-Vibhavadi section of Khlong Bang Sue and accommodates an additional 150,000 cu m/day from the fourth stage of the water treatment project.
