November 04, 2011 00:00 By Janjira Pongrai
Close inspection has uncovered that many structures have been built illegally on 26 waterways in eastern Bangkok, leading to estuaries being redirected or blocked altogether - one of the key reasons why it is taking so long to drain the floods, the Natura
According to most uptodate maps, the Chuad Ta Thim canal in Bang Na district seems to have disappeared altogether and has been replaced by a luxury housing complex. In addition, many golf courses and apartments have allegedly been illegally built on canals, not to mention several slums along the riverside, sources involved with the inspection said. Suvarnabhumi Airport and several roads are also allegedly blocking waterways and water catchment areas.
The ministry’s permanent secretary, Suphoj Towichukchaikul, said the inspection had been conducted before floods had arrived at key watergates south of Bangkok, and officials had discovered that stoplogs designed to control the flow of water had been used on several canals and that many were overgrown with weeds.
Obstacles like stoplogs were found in seven locations in the lower Sam Wa canal and have now been dismantled, he said, adding: “But there are several similar obstacles in all canals that contribute to slower drainage and flow. A proper inspection will have to be conducted soon.”
The ministry, along with its Department of Water Resources (DWR), conducted an inspection of 26 canals across Bangkok, including those leading to estuaries in Samut Prakan and Samut Sakhon provinces, from Monday to Wednesday.
He added that a number of sluice gates built and operated by the Bangkok Metropolitan Administration (BMA) were also narrowing canals and should be dismantled.
An inspection team led by deputy DWR directorgeneral Chaiyaphorn Siriphornphaibool demonstrated how canals were surveyed using the Acoustic Doppler Current Profiler (ADCP) – a sonar device that can determine the depth, speed and velocity of the current and obstacles under water. Chaiyaphorn said this device was also used to survey most major rivers in the country and had produced accurate results.
The 26 canals inspected were categorised as Zone 1 comprising 16 canals, 35 per cent of which were covered with weeds and 31 per cent had blockages; Zone 2 consists six canals, 61 per cent of which have been intentionally narrowed; and Zone 3 has four, of which 17 per cent are overgrown. NOT VERY CLEAR, CAN’T CONTACT WRITER.
Natural Resources and Environment Minister Preecha Rengsomboonsuk said directing water through channels partly associated with the Khlong Dan wastewater management project was being considered because this way, as much as 700,000 cubic metres of water could be drained out of Bangkok daily. “But since the project is currently part of a criminal investigation into alleged corruption and has been impounded under court orders, a careful study is needed prior to implementing the idea,” he added.