Floodwall Planned For Chao Phraya River: Thailand

[webfact]

Floodwall planned for Chao Phraya

The Nation

Embankment to run from Uthai Thani to Ayutthaya; 5 roads in capital to be raised

BANGKOK: An embankment will be put up along the length of the Chao Phraya River from Uthai Thani down to Ayutthaya - estimated to be more than 300km - as part of the government's plans to prevent flooding in the Central region.

Agriculture Minister Theera Wongsamut yesterday said construction would soon start on some parts of the planned stretch.

"We have to do it before the rainy season arrives," he said, adding that the embankment would boost water-management efficiency in the Chao Phraya basin, which suffered the brunt of last year's flood crisis.

The embankment will be constructed from scratch in some areas, and raised from the current level in others.

Muang Angthong mayor Chai Suwaphan said the height of the reinforced-concrete embankment in his stretch of the Chao Phraya would be increased from 7.5 metres to 10m above mean sea level.

"Last year, the water level rose to about 10m [above sea level]," he said.

Chai said the heart of Angthong only narrowly escaped the wrath of the floods last year because the authorities had raised the embankment level with wooden boards and concrete blocks in the nick of time. "So, we have to make more preparations and take precautions from now on," he added.

Winai Limsakul, who heads the Public Works Department of the Bangkok Metropolitan Administration (BMA), said the height of four main roads in the capital would also be raised for flood-prevention purposes.

"They are Suwinthawong, Hataimit, Rat-Uthit and Buddha Mondhol III roads," he said, pointing to the fact that these thoroughfares could serve as floodwalls to protect the inner zone of Bangkok.

Winai said a 10-km stretch of Buddha Mondhol III Road, for example, would become 50 centimetres higher. The bidding process for the surface-level heightening will likely start in May.

BMA deputy permanent secretary Jumpol Sampaopon said canals in the capital would be dredged during the next three to four months as a flood-prevention measure.

"But rain may come earlier than usual, due to the La Nina effect," he said, adding that heavy downpours had already started this year.

Seree Supharatid, who sits on the Strategic Committee for Water Resources Management, said a final decision had not yet been taken on which areas would be used as flood areas if the amount of run-off from the upper part of the country proved too huge to cope with.

"The government may not expropriate the areas, but may pay compensation [for rent] to their owners," he said. "The areas may be rented for about three months each year."

Prime Minister Yingluck Shinawatra earlier suggested that her government would find about 2 million rai of land for water-retention purposes so as to minimise flood damage when the massive amount of run-off from the North heads downstream.

"Definitely, community areas won't be used for water retention," Seree confirmed yesterday.

However, he reckoned that the relevant authorities might have to negotiate with the owners of some fields in Ayutthaya's Bang Pahan, Bang Ban and Phak Hai districts so as to access the plots for water retention.

Theera added that in a bid to prevent severe flooding this year, a new sluice gate was now being constructed in Sing Buri's Prom Buri district.

"It will replace the old sluice gate that was severely damaged last year," he said.

Construction, which will cost about Bt145 million, is scheduled for completion by July.

The Interior Ministry has instructed the governors of 24 provinces to quickly develop flood-prevention plans.

"The rainy season will start within three months. So, the provincial governors must clear any clogging of waterways and drainage pipes in their areas before that," said Pracha Terat, deputy permanent secretary of the ministry.

-- The Nation 2012-02-07

[Reasonableman]

Yesterday we were told the rainy season would start in 5-6 months. Which is it? 3 or 5-6? Any consensus among the planners?

[nong38]

The river starts in Nakhon Sawan, Nakhon Sawan flooded badly last season, hope you are not going to forget that! Thai people live there and surprisingly all the way down to Ayutthaya.

[whybother]

The only thing that will happen if they try and keep the water within the banks of the river is that the river will rise and eventually overflow.

[ratcatcher]

More than 300km of flood wall to be built "before the rainy season arrives"............................Right!

[Mugg]

Yesterday we were told the rainy season would start in 5-6 months. Which is it? 3 or 5-6? Any consensus among the planners?

Jun - Sept (creeps into Oct a bit)

[folium]

A levee is built from Uthai Thani to Ayutthaya.

OK, then what? Unless it is continued all the way down to the Gulf of Siam you are just delivering a vast amount of extra discharge straight into Bangkok, which obviously struggled with flooding last time.

Levees are also a double edged sword as by increasing the discharge and raising the water level even further above the flood plain worsens the hit if the levee subsequently fails. See endless examples from the US of poor maintenance or low quality private levees failing and innundating large areas.

Maybe I am being harsh but this seems like a classic case of absent joined-up thinking/planning. Unless these levees are completed in time, and unless they are well built and maintained, all that will be achieved is that the problem becomes either increased or dumped into someone else's lap (ie Bangkok's).

The only long term solution is to either dramatically increase the ability of the flood plain to absorb excess water (as they are intended to, but probably now impossible due to the amount of residential/industrial development over it), or to channel floodwater away from the vulnerable/high value areas using spillways or the Tha Chin.

[Soupdragon]

More than 300km of flood wall to be built "before the rainy season arrives"............................Right!

300 km of flood wall that won't wash away the first time it gets wet, in that time frame. Good luck with that one.

[Reasonableman]

Yesterday we were told the rainy season would start in 5-6 months. Which is it? 3 or 5-6? Any consensus among the planners?

Jun - Sept (creeps into Oct a bit)

So they are wrong about the El Nina effect, or not? We are gradually learning that traditional weather/climate patterns are no longer good predictors of future ones, I'm afraid. call it climate change, call it global warming, call it what you will. It's been raining in Australia since Christmas 2011, Europe is seeing its worst winter in recent memory, etc. I guess some boffins can predict the rainy season in Thailand, but I remain to be convinced, when some say 3 months and others (at the highest level) say 5-6. Who is right? Who should we believe when we are putting up 300k of embankments? We were too late preparing for the last flood, and we could well be too late preparing for the next. Worst case maybe 3, best case, maybe 6? In fact the recent rainfall patters in Thailand/ SE Asia have already been unusual for this time of the year.

Edited February 7, 2012 by Reasonableman

[scorecard]

More than 300km of flood wall to be built "before the rainy season arrives"............................Right!

300 km of flood wall that won't wash away the first time it gets wet, in that time frame. Good luck with that one.

And where's the promised professional and scientific analysis etc., and public discussion of all of this, as promised?

And is there any thought about the possible downsides of this idea?

No doubt this flood wall is not the answer to the whole problem, so does this wall coordinate well with other measures?

Edited February 7, 2012 by scorecard

[WithMarco]

in the meantime, NIKON fired off an official announcement declaring they lost more than 130 million $ because of the flooding in their factory in Ayutthaya !

Extraordinary Losses Due to the Flooding in Thailand

http://www.nikon.com/news/2012/0203_01.htm

... i guess now they will think twice before investing in thailand again.

[Pib]

A levee is built from Uthai Thani to Ayutthaya.

OK, then what? Unless it is continued all the way down to the Gulf of Siam you are just delivering a vast amount of extra discharge straight into Bangkok, which obviously struggled with flooding last time.

Actually the Chao Phrayo did not overflow that much as it went through Bangkok due to the high flood walls already in place...the water level got very close to the top of the banks/walls in many places but didn't overflow that much/only in a few spots....most of the flooding of Bangkok came from overland due to the flooded central area north of Bangkok...and areas upriver where the walls along the Chao Phrayo are not that high or don't exist.

But it would drive the question of, if the flood walls to be built from Uthai Thani to Ayutthaya keep more/a higher water level "within" the Chao Phrayo raised banks that would mean a higher water level in the river when it arrives Bangkok...a higher level that would overflow the river walls in Bangkok since for the most part the Chao Phrayo levels nearly reached the walls tops and briefly overflow in some parts of Bangkok during the floods. Hopefully there are details we don't know about which supports this not happening....or not.

[Reasonableman]

A levee is built from Uthai Thani to Ayutthaya.

OK, then what? Unless it is continued all the way down to the Gulf of Siam you are just delivering a vast amount of extra discharge straight into Bangkok, which obviously struggled with flooding last time.

Actually the Chao Phrayo did not overflow that much as it went through Bangkok due to the high flood walls already in place...the water level got very close to the top of the banks/walls in many places but didn't overflow that much/only in a few spots....most of the flooding of Bangkok came from overland due to the flooded central area north of Bangkok...and areas upriver where the walls along the Chao Phrayo are not that high or don't exist.

But it would drive the question of, if the flood walls to be built from Uthai Thani to Ayutthaya keep more/a higher water level "within" the Chao Phrayo raised banks that would mean a higher water level in the river when it arrives Bangkok...a higher level that would overflow the river walls in Bangkok since for the most part the Chao Phrayo levels nearly reached the walls tops and briefly overflow in some parts of Bangkok during the floods. Hopefully there are details we don't know about which supports this not happening....or not.

A very plausible scenario. Let's hope for further details that help protect the whole country.

[robblok]

A levee is built from Uthai Thani to Ayutthaya.

OK, then what? Unless it is continued all the way down to the Gulf of Siam you are just delivering a vast amount of extra discharge straight into Bangkok, which obviously struggled with flooding last time.

Actually the Chao Phrayo did not overflow that much as it went through Bangkok due to the high flood walls already in place...the water level got very close to the top of the banks/walls in many places but didn't overflow that much/only in a few spots....most of the flooding of Bangkok came from overland due to the flooded central area north of Bangkok...and areas upriver where the walls along the Chao Phrayo are not that high or don't exist.

But it would drive the question of, if the flood walls to be built from Uthai Thani to Ayutthaya keep more/a higher water level "within" the Chao Phrayo raised banks that would mean a higher water level in the river when it arrives Bangkok...a higher level that would overflow the river walls in Bangkok since for the most part the Chao Phrayo levels nearly reached the walls tops and briefly overflow in some parts of Bangkok during the floods. Hopefully there are details we don't know about which supports this not happening....or not.

A very plausible scenario. Let's hope for further details that help protect the whole country.

Actually the scenario is good for those who were hit because of the overland water (me) and possibly bad for those in BKK. I doubt however they would sacrifice BKK to help others.

[ResX]

If they can't see overall objective that really matter let me suggest. If Thailand can ensure Chao Pharaya river will not discharge higher than 3200 cubic meters/sec (my estimate based on the recent floods) measured at the river mouth then I think Bangkok will not be seriously flooded.

If protecting Bangkok from floods is the Ultimate Key Result Area, then any corrective measure taken shall have something to do with the objective to reduce peak discharge of Chao Pharaya river below 3200 cubic meters/sec measured at the river mouth.

Building the flood wall means an attempt to raise the non flood discharge from 3200 cubic meter/sec to something higher. It is an attempt to manipulate flood equation. It is okay with that but it is not the substitution to solving the initial flood equation.

Set your objective straight to provide ultimate and straight solution to your flood problem.

[Thunder26]

Yesterday we were told the rainy season would start in 5-6 months. Which is it? 3 or 5-6? Any consensus among the planners?

It starts in May up to the middle of October, when the predominant winds are from the south-west. It is called south-west monsoon. But thunderstorms can occur like this year any month, usually more frequent in April. These are called summer thunderstorms. Sometimes they are frequent, but sometimes less frequent. And for this year they predict more frequent rain for Summer months.

[exeter]

Yesterday we were told the rainy season would start in 5-6 months. Which is it? 3 or 5-6? Any consensus among the planners?

It starts in May up to the middle of October, when the predominant winds are from the south-west. It is called south-west monsoon. But thunderstorms can occur like this year any month, usually more frequent in April. These are called summer thunderstorms. Sometimes they are frequent, but sometimes less frequent. And for this year they predict more frequent rain for Summer months.

They also said I would meet a tall dark stranger and that I would win the lottery!

[thaicbr]

'"The rainy season will start within three months. So, the provincial governors must clear any clogging of waterways and drainage pipes in their areas before that," said Pracha Terat, deputy permanent secretary of the ministry '

The Nonthaburi Governor has not even got rid of the rubbish from the last flood. It's all along the side of the roads ..AND they expect the clown to clear the drains etc..

[Pib]

Expect most to maybe all of the province governors are awaiting money from the central govt to begin any serious flood prevention measures.

[Reasonableman]

So, what is there to inspect?

Expect most to maybe all of the province governors are awaiting money from the central govt to begin any serious flood prevention measures.

[trainman34014]

Expect most to maybe all of the province governors are awaiting money from the central govt to begin any serious flood prevention measures.

You can be sure the one strategy they have already worked out is what percentage they will be keeping for themselves. 'Serious' flood prevention measure won't come to much, a few more dirt Klongs and the odd shoddily built wall will be the order in a lot of area's, and when it all goes wrong they will all blame each other....as usual.

[nong38]

Expect most to maybe all of the province governors are awaiting money from the central govt to begin any serious flood prevention measures.

You can be sure the one strategy they have already worked out is what percentage they will be keeping for themselves. 'Serious' flood prevention measure won't come to much, a few more dirt Klongs and the odd shoddily built wall will be the order in a lot of area's, and when it all goes wrong they will all blame each other....as usual.

Surely not! No loss of face here................Where did all the f_____________g water come from!!!!!!!!!

[thaibeachlovers]

Embankments are pointless, unless there are areas for the excess water to go.

The only real solution is a diversion channel large enough to take all the excess water, that starts above Ayutthaya and takes water all the way to the sea. I saw plans like that on tv a few times during the floods.

Ideally, it would be combined with a London style barrier to divert the water into the channel.

Also, all the klongs in Thonburi should lead into an overflow channel that also takes water direct to the sea, which would prevent river levels rising too high through Bkk.

However, should they build a barrier through Bkk, I hope they combine it with a highway that will allow traffic from the north to easily pass through Bkk without having to enter the usual jams. The roadway could be in a waterproof tunnel and a pedestrian walkway could be constructed above it- nice for tourism with potential for outdoor restaurants etc.

[folium]

Embankments are pointless, unless there are areas for the excess water to go.

The only real solution is a diversion channel large enough to take all the excess water, that starts above Ayutthaya and takes water all the way to the sea. I saw plans like that on tv a few times during the floods.

Ideally, it would be combined with a London style barrier to divert the water into the channel.

Also, all the klongs in Thonburi should lead into an overflow channel that also takes water direct to the sea, which would prevent river levels rising too high through Bkk.

However, should they build a barrier through Bkk, I hope they combine it with a highway that will allow traffic from the north to easily pass through Bkk without having to enter the usual jams. The roadway could be in a waterproof tunnel and a pedestrian walkway could be constructed above it- nice for tourism with potential for outdoor restaurants etc.

Spot on. Canalize the Tha Chin and buy off the Slippery Eel (aka 21st PM of LOS) to allow this to happen.

[KeyserSoze01]

And just when you thought the circus had left town.

[hellodolly]

I thought Bangkok was sinking.

Has that bee figured into any plans?

[ResX]

Embankments are pointless, unless there are areas for the excess water to go.

The only real solution is a diversion channel large enough to take all the excess water, that starts above Ayutthaya and takes water all the way to the sea. I saw plans like that on tv a few times during the floods.

Ideally, it would be combined with a London style barrier to divert the water into the channel.

Also, all the klongs in Thonburi should lead into an overflow channel that also takes water direct to the sea, which would prevent river levels rising too high through Bkk.

However, should they build a barrier through Bkk, I hope they combine it with a highway that will allow traffic from the north to easily pass through Bkk without having to enter the usual jams. The roadway could be in a waterproof tunnel and a pedestrian walkway could be constructed above it- nice for tourism with potential for outdoor restaurants etc.

If you can keep the flood water without additional cost why you additional diversion tunnel? Chao Pharaya river is the most efficient and "natural diversion tunnel". Here is the overall scenario that I think I get it very close to the reality. All major and medium size dams in Thailand can store up to the maximum of 75billion cubic meters of water. This is about the same size as the average annual rainfall for the entire Chao Pharaya catchment. The flood that hit Thailand last year is estimated to be "17billion cubic meters of water that flew in 7 days" (It was said the flood is the biggest flood in 50 years). It is obvious that the dams in Thailand can store water 4 times higher than the "1 in 50 years flood return".

Thailand needs water management tools more than anything else.....

[thaibeachlovers]

Embankments are pointless, unless there are areas for the excess water to go.

The only real solution is a diversion channel large enough to take all the excess water, that starts above Ayutthaya and takes water all the way to the sea. I saw plans like that on tv a few times during the floods.

Ideally, it would be combined with a London style barrier to divert the water into the channel.

Also, all the klongs in Thonburi should lead into an overflow channel that also takes water direct to the sea, which would prevent river levels rising too high through Bkk.

However, should they build a barrier through Bkk, I hope they combine it with a highway that will allow traffic from the north to easily pass through Bkk without having to enter the usual jams. The roadway could be in a waterproof tunnel and a pedestrian walkway could be constructed above it- nice for tourism with potential for outdoor restaurants etc.

If you can keep the flood water without additional cost why you additional diversion tunnel? Chao Pharaya river is the most efficient and "natural diversion tunnel". Here is the overall scenario that I think I get it very close to the reality. All major and medium size dams in Thailand can store up to the maximum of 75billion cubic meters of water. This is about the same size as the average annual rainfall for the entire Chao Pharaya catchment. The flood that hit Thailand last year is estimated to be "17billion cubic meters of water that flew in 7 days" (It was said the flood is the biggest flood in 50 years). It is obvious that the dams in Thailand can store water 4 times higher than the "1 in 50 years flood return".

Thailand needs water management tools more than anything else.....

Didn't work very well last year! Climate change means that all previous weather patterns are irrelevant. Just because the dams can hold enough water this year doesn't mean they can hold them in the future. Besides, it's irrelevant how much water can be held if it's controlled by politicians, as polies will always stuff things up.

A diversion channel will always save Ayutthaya and downstream communities, and let's not forget Bkk is sinking, so a diversion or higher barriers are going to be necessary anyway.

[ResX]

Embankments are pointless, unless there are areas for the excess water to go.

The only real solution is a diversion channel large enough to take all the excess water, that starts above Ayutthaya and takes water all the way to the sea. I saw plans like that on tv a few times during the floods.

Ideally, it would be combined with a London style barrier to divert the water into the channel.

Also, all the klongs in Thonburi should lead into an overflow channel that also takes water direct to the sea, which would prevent river levels rising too high through Bkk.

However, should they build a barrier through Bkk, I hope they combine it with a highway that will allow traffic from the north to easily pass through Bkk without having to enter the usual jams. The roadway could be in a waterproof tunnel and a pedestrian walkway could be constructed above it- nice for tourism with potential for outdoor restaurants etc.

If you can keep the flood water without additional cost why you additional diversion tunnel? Chao Pharaya river is the most efficient and "natural diversion tunnel". Here is the overall scenario that I think I get it very close to the reality. All major and medium size dams in Thailand can store up to the maximum of 75billion cubic meters of water. This is about the same size as the average annual rainfall for the entire Chao Pharaya catchment. The flood that hit Thailand last year is estimated to be "17billion cubic meters of water that flew in 7 days" (It was said the flood is the biggest flood in 50 years). It is obvious that the dams in Thailand can store water 4 times higher than the "1 in 50 years flood return".

Thailand needs water management tools more than anything else.....

Didn't work very well last year! Climate change means that all previous weather patterns are irrelevant. Just because the dams can hold enough water this year doesn't mean they can hold them in the future. Besides, it's irrelevant how much water can be held if it's controlled by politicians, as polies will always stuff things up.

A diversion channel will always save Ayutthaya and downstream communities, and let's not forget Bkk is sinking, so a diversion or higher barriers are going to be necessary anyway.

Perhaps re look the strategy that had been used. How come the the total 75 billion cubic meters of storage capacity reservoirs could have been beaten so easily by the 17 billion cubic meters of flood water? Some of the reservoirs even contributed to that 17 billion cubic meters of flood water.

Here is the real problem so that you can see how badly Bhumibol dam went wrong. During floods based on my conservative estimate the dam shall hold at least 4 billion cubic meters of flood waters. How Bhumibol had performed? Close to the opposite. It was not holding 4 billion cubic meters. Worse still it discharged about 1 billion cubic meters of water. So flood control effectivenes, if you want to measure is -25%. Sirkit dam didn't impressed either. I didn't think the remaining 200++ medium size dams were better since Bhumibol and Sirkit dams were very good indicative to see how efficient flood control operation was executed.

[whybother]

Last year, the floods covered about 100 km square to a depth of a metre (on average). Now they want to build flood walls along the river to contain the floods.

The flood walls will need to be a hundred metres high.

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