Calls mount for city flood retention areas

Land owners might be offered incentives, and also a flood tax levied

Flooding on Lat Phrao Road on Monday. (Photo: Onnucha Huttasingh)
Flooding on Bekv?m Phrao Road on Monday. (Photo: Onnucha Huttasingh)

Located in a low-lying area on the Chao Phraya River basin, Bangkok covers a place of 1, 569km² but it has little room for green places that can be converted into overflow retention areas.

The number of green areas per person is 6. 99m², which is lower than the entire world Health Organization’s recommendation of 9m² of green space for each individual.

With limited green areas in the funds, the city also has restrictions on its capacity for water retention, that is needed especially when the entire world is facing a worldwide threat of climate change impacts.

“Excessive rainfall water needs to be handled. If there is no place to retain water, it will flood an area. The important thing will be increasing water preservation sites in the wet season, ” said Assoc Prof Sucharit Koontanukulvong, a lecturer at the Department of Water Resources Executive, Chulalongkorn University.

However , he admitted that it is no easy task for a crowded and big city like Bangkok to set aside water retention areas because of the high price of land.

To make it possible, the Bangkok Metropolitan Administration should have lucrative incentives just for land owners to offer their unused property for water preservation, he said.

For example , the government could offer liberties to any real estate company by increasing the height of a developing that is located in a limited high zone when the company agrees to offer water retention in return, he said. The incentives could also be tax exemptions for any organization that could offer drinking water retention sites.

Secondly, empty land owned by state agencies, organisations or individuals ought to be converted to restore drinking water in case of need, saying public parks, for instance , should be used for drinking water retention because a study found that surface soil can keep 20% more water compared with a concrete surface area.

This individual said Chulalongkorn University or college converts green locations into water preservation zone by maintaining water for a while.

The water is going to be let into a drainage system when the water damage situation on the road outside the university subsides, he said.

He also recommended the government collect a “flood tax”, or even “flood bond” to make use of the money for opportunities in flood-prevention infrastructure.

People living in potentially overloaded areas could also be inquired to pay the ton tax, with a lower rate for those who live in areas with high potential for floods, and also a higher rate for all those living in a low-potential flooding area.

He said an engineering system would partly resolve the problem of flooding in the capital, which includes expanding the pipeline water drainage system, or even constructing the drainage tunnel below roads for flooded waters to stream into a river.

But it are unable to truly solve the issue because the world is certainly facing the weather change phenomenon. Japan, for example , has expanded the water drainage system’s capacity twice, however the amount of rainfall could be triple the average, he said.

He added the government should also invest a lot more in an early caution system, which could inform people in advance the right way to prepare when there is an unusual rainfall pattern. The warning can help restrict damages from asset losses in an overflow.

In the mean time, a source from the Meteorological Department (TMD) stated the country could upgrade its weather predicting ability if there is a lot more investment in technologies.

In highly vulnerable places such as economic zones, a Decision Support Program should be put in place providing better forecasts and also a warning system in order to limit damages.

He mentioned the country gains weather forecast data from international platforms, some of which do not match the particular country’s geography. The TMD needs to create its data system for more accuracy, he said.

Amnat: Create ‘smart networks’

Assoc Prof Amnat Chidthaisong, deputy director of Joint Graduate School of Energy plus Environment, King Mongkut’s University of Technology Thonburi, said the government should put more focus on climate modify impacts, especially uncommon patterns of weather including droughts or floods.

The government should also improve weather-related agencies that smart networks for them to work together and provide full support for better results.