Tuesday 15 November 2011

Experts urge 'super waterway' Outline new strategy to drain future runoff

A team of disaster experts from Chulalongkorn University says the construction of an express flood-way is needed if certain areas of the country are to avoid future flood disasters.

The team, led by Thanawat Jarupongsakul, a lecturer at the faculty of science's Unit for Disaster and Land Information Studies has proposed 11 flood preventive measures to permanently deal with flood disasters.

"One of the urgent solutions is a super-express flood-way," he said.

The floodway will link existing natural canals to drain runoff, starting from the 134km Chai Nat-Pasak canal stretching from Manorom district of Chai Nat to Tha Rua district of Ayutthaya, the 32km Rapeepat canal from Ha Rua district of Ayutthaya to Rangsit of Pathum Thani and the 30km Phra Ong Chaiyanuchit canal from Rangsit to the sea in Samut Prakan.

The total length of the super-express flood-way would be about 200km. It would hold about 1.6 billion cubic meters of water and drain runoff at a rate of 6,000 cu/m per second.

Mr Thanawat said there should be 1km of empty land and two motorways (inbound and outbound) 6m above ground level along both sides of the flood-way. He said this would prevent communities or properties next to the flood-way from being inundated.

He said details such as the width and depth of canals needed to be further investigated.

"This idea is much cheaper than digging a new river as a floodway," Mr Thanawat said.

He said in the past, there were several natural swamps, mostly in the west of the Central Plains, which had been turned into industrial estates and communities, so the natural flood-way was blocked, resulting in areas being flooded.

To ease the flood problem, the super-express flood-way should be built to directly drain the runoff into the sea.

This measure had helped to drain the water from upstream at the Chai Nat-Pasak canal.

"Of course, it will also have a bad effect as the areas along the canals have to be expropriated, but appropriate compensation must be provided to the affected residents," he said.

Other measures should include an early disaster warning system, water resource management as a whole, flood tax, use of a flood-risk map for urban development, public participation in disaster management, groundwater use control, farming periods in accordance with climate variability and establishment of a disaster organization.

Mr Thanawat said a direct flood tax must be collected from provinces or areas which are located in flood prevention systems, and an indirect flood tax should be collected from the owners of properties under the protection of flood prevention systems.

The figure will be used to compensate those affected by the deluge and to help preserve natural floodways.

"Now, the government must stop [trying to] solve flood problems with political methods and turn its attention instead to these 11 measures, especially the super-express flood-way," Mr Thanawat said.

"This year's severe flooding was not from an excessive amount of rainfall, but [was due to] mistakes in the government's water management."

He said it should be realized the giant tunnels of the Bangkok Metropolitan Administration can drain floodwater only in the city, not a massive volume of upstream runoff.

"If there is no step forward, foreign investors will eventually disappear from the country and the next generation will be still worried whether flooding will happen or not," he said.

No comments:

Post a Comment