The contracts were awarded to Nawarat Patanakarn Plc, Thai Engineering Consultant Co and Consulting Engineering Co.
Bangkok Governor Sukhumbhand Paribatra, who presided over the signing of the contract on 12 September , said the Ratchada-Bang Sue tunnel would be large and would greatly improve drainage from low-lying areas where there is only limited capacity to release flood water into the Chao Phraya River.
The flood tunnel would be built from Ratchadapisek Road to Lat Phrao canal, run along Bang Sue canal and meet the Chao Phraya River at Wat Kaew Fah in Kiak Kai area of Dusit district.
The 6.4km tunnel would have a width of five metres and be 20m underground. It would drain water from 56 square kilometres in six districts: Huay Khwang, Din Daeng, Chatuchak, PhayaThai, Dusit and Bang Sue.
It would drain major roads including Phahon Yothin between Saphan Khawi to Lat Phrao junction, Vibhavidi Rangsit, Ratchadapisek, Samsen, Lat Phrao and Kamphaengphet.
Of the THB 2.4bn budget, 50 per cent would be supported by the government. There was also another THB 2.4M in consultancy fees.
Construction would take about three years, so the earliest it could be in use would be September 2016.
Sukhumbhand said the BMA had improved the drainage system in several areas, but improvements throughout the capital would be difficult and would take time.
City Hall also planned to construct two other large drainage tunnels – a 9.4km tunnel in Nong Bon Pond for the East of Bangkok and a 13.5km tunnel on Prem Prachakorn canal in the West of Bangkok.
The governor said plans for the Nong Bon Pond tunnel had already been drafted, so it could be proposed for budget approval by the government. However, there was, at this time, no certain timeframe for the project.
