Bangkok’s Governor, Sukhumbhand Paribatra, announced today that The Bangkok Metropolitan Administration BMA will spend some US$550M on completing a system of four ‘Giant Tunnels’ that will double the city’s current drainage capacity within five years. Included is the Don Mueang tunnel, which at 13.5km long and 6m diameter will be Thailand’s largest and longest drainage tunnel.
The first of the four, the 5km long, 5m diameter Rama IX-Ramkhamhaeng tunnel in Eastern Bangkok, is the only currently under construction having started in 2001 with completion scheduled for January next year. Work on the second, the 6km long, 5m diameter Ratchadaphisek-Suthisarn tunnel, is expected to begin next year with tenders to be called next month. The third tunnel is Thailand’s largest, the Don Mueang tunnel, at 13.5m of 6m diameter bore, whilst the fourth is the Rama IX Park tunnel, which will be 3km long and of a similar diameter.
The ‘Giant Tunnels’ project is a part of the Governor ‘Bangkok Getting Ahead’ programme, and is integral in preventing a repeat of the large scale flood events seen during this year’s rainy season.
“We need to stop wasting money on temporary solutions to flooding, with hundreds of thousands of sandbags and more pumps being purchased every year, and get to long-term fixes. In just the last three years we’ve spent 11bn baht on flood prevention measures, which have still not brought an enduring solution to the city’s flooding problems. This year’s rainy season has made it obvious that we need the tunnels,” Sukhumphand said.
“The Giant Tunnels programme provides a massive amount of additional drainage capacity. The amount of water that can pour through these four tunnels would allow you to drain four average-sized swimming pools in a single second,” said the Governor.
“More importantly, they will be really big tunnels, with a diameter of 5m or more, which is around three times larger than the average diameter of existing tunnels, which are at about 1.8m,” he said.
According to Sukhumbhand, the system of four tunnels will increase the total length of drainage tunnels in Bangkok from 14km to around 50km.
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“These tunnels will be like a drainage expressway,” Sukhumbhand said, and will re-direct floodwaters under the capital into the Chao Phraya River, which emptied into the Gulf of Thailand.
Bangkok has suffered recent flooding from the Chao Phraya River due to its high tides, flood surges from the North, and the ever-present threat of heavy rainstorms. The Department of Disaster Prevention and Mitigation has said flooding has been responsible for the death of 203 people across the Provinces since October 10th.