City, National govt must work together on flood prevention

Climate change means 2011 disaster could be repeated, experts warn

There is no guarantee that Bangkok will not experience another flood like the 2011 disaster, given the threat of severe weather caused by climate change. Hence, water experts see the need for further preventive measures from the new Bangkok governor and closer collaboration with the national government to mitigate future negative impacts.

"No more blame game," Professor Dr Thanawat Jarupongsakul, head of Chulalongkorn University's Unit for Disaster and Land Information Studies, said. "The [next] Bangkok governor and the government should work together to solve the problem and cope with flood situations."

In 2011, a giant flood paralysed the capital with water rising as high as 2.5 metres in adjacent provinces. Millions of residents were affected and hundreds died. Many had to leave home for a few months and spent a great deal on renovation. Inner city areas - where the business centre is - were saved thanks to millions of sandbags and thousands of water pumps, but the Bangkok Metropolitan Administration was heavily criticised for not helping drain water from the northern provinces.

Bangkok is located on the tail of the Chao Phraya, the key river that carries water from the North to the Gulf of Thailand.

The risk of a reoccurrence exists because Bangkok is located on flat and low-lying land with an average elevation of just 1.5 metres above sea level. A World Bank report released last November noted that global temperatures could rise as much as 4 degrees Celsius by 2100, from the current global mean temperature of 0.8C above pre-industrial levels. Ice sheets will melt and scientists predict the sea level will rise by more than 3 feet by the end of the century.

"The new Bangkok governor should consider that flooding not only affects Bangkok but other provinces as well," Thanawat said, adding that the city needs a flood prevention plan that can cope with any reoccurrence in the next 100 years.

Suthat Weesakul, director of the Asian Institute of Technology's Water Engineering and Management Program, said the new governor needs a new view on water and flood management. Closer cooperation with nearby provinces was necessary, as well as a long-term flood plan that includes shifting houses from waterways.

The designation of flood-risk zones was a top issue for the new Bangkok governor to prevent damage from floods in the future, although designating flood-risk zones might affect the price of land in each area, he said.

Prasert Povichien, from the Thai Hydra Association, said the new governor must study and grasp flood management and prevention, as well as drainage systems, such as the flood prevention infrastructure in each area.

He agreed with Suthat that the new governor must work with other provincial governors to draw up a flood prevention plan, especially for water diversion.

Revising city planning and flood-risk zones were key matters for the new governor.

"The [next] Bangkok governor cannot work alone to deal with the flood situation," he said.

To prevent floods in the long-term, he suggested that dykes along the Chao Phraya be improved to tackle the rise in water level caused by tidal influences. To date, the height of the flood prevention dyke along Chao Phraya is only 2.5 metres above sea level. The new Bangkok governor must raise the height of dykes.

The governor also needed to build a sluice gate to drain water out into the main nearby rivers, such as Bang Pakong and Ta Chin.

He also called on new governor to improve the capacity of pumps that will be used to drain water. At present, water pumps are able to drain only 3 cubic metres of water a second. Bangkok, like other big cities in the US or The Netherlands, needed pumps that can drain at least 300 cubic metres per second, right up to 600 cubic metres a second.

Chawalit Chantararat, executive director of the water-management experts, TEAM Group, said that cooperation with nearby provinces such as Nonthaburi and Pathum Thani were a key aspect in handling floods. Preventing floodwater from flowing into the capital alone would not resolve the problem. Bangkok needed to drain some amount of water through the capital and let it flow smoothly into the sea.

"[Officials in all provinces] should know what each other is doing to cope with flooding," he said.

The new governor also should pay attention to resolve flood problems in 15 risky areas, such as Sathorn, Phaya Thai, Wattana, Din Daeng, Wangthonglang and Jatuchak.

Improving the canal system and tunnels to drain water was another important issue to focus on, he felt.

For more details, see the flood prevention equipment graphic on www.nationmultimedia.com



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