Bangkok may need Thames Barrier-like defence to prevent flooding
Governor Chadchart proposes massive flood prevention structure to protect city from rising sea levels and high tides
A massive defence structure like the Thames Barrier in London may be needed to protect Bangkok from flooding during high tide, Bangkok governor Chadchart Sittipunt said on Tuesday.
The governor explained that Bangkok is a low-lying basin that can be inundated by high tides or rising sea levels. So far, he said, the Phra Khanong watergate plays a key role in preventing flooding from high tides. However, since the sea level has been rising every year and increasing the level of the Chao Phraya River, the Phra Khanong watergate alone may not be enough to keep the capital dry.
“We may need a massive flood defence structure like the Thames Barrier,” Chadchart said.
“However, a project as large as this will need support from the government, because it will affect several provinces along the river, including Chachoengsao, Samut Sakhon, Samut Songkhram and Nonthaburi.”
The Thames Barrier is the second-largest retractable flood defence barrier in the world (the largest is the Oosterscheldekering Barrier in the Netherlands). It spans 520 metres across the River Thames near Woolwich.
The barrier has 10 steel gates that are about as high as a 5-storey building when raised. These 10 gates essentially divide the river into 10 individual flood gates, with each gate weighing approximately 3000 tonnes. It protects 125 square kilometres of central London from floods caused by high tides and storm surges.
Chadchart added that apart from high tide, Bangkok also faces the serious issue of its Bang Khunthian coast along the Gulf of Thailand being eroded by the sea.
He said rising sea levels had eroded about a kilometre of the shore in Bang Khunthien district. The governor said the Bangkok Metropolitan Administration (BMA) has received funding to build a coastal dam to prevent erosion, but the BMA is in the process of seeking Cabinet approval to build a 2km-long dam in the mangrove forest area.
The BMA also plans to increase the height of some roads along the coast as an embankment to prevent flooding during high tide, including the old Sukhumvit Road and the Bang Khunthien road along the shore.
As for concerns about flooding from upstream runoffs, Chadchart said the BMA has strengthened flood levee along the Chao Phraya with sandbags, especially at the risky spots.
He added that the BMA has also prepared some 2 million sandbags to reinforce the ruptured levees and city residents can inform the BMA if they see the levee collapsing in some areas.
