Canal drainage test forges ahead

The government is determined to press ahead with a plan to test canal network drainage capacity in the east and west of Bangkok next week, despite mounting concerns over possible flooding in the capital.

Published: 31/08/2012 at 12:00 AM
Writer: Post Reporters

The flood preparedness trial must be carried out in September, insisted Science and Technology Minister Plodprasop Suraswadi yesterday.

The Water and Flood Resources Management Committee (WFRMC) has consulted with agencies _ including the Bangkok Metropolitan Administration (BMA) _ about the drainage tests to take place on Wednesday and Friday, said Mr Plodprasop, who serves as committee chairman.

The maximum volume of water that will be discharged into the canals for the drainage test is 20 cubic metres per second. Khlong Mahasawat has the highest rated capacity of 60 cubic metres per second, he said.

Therefore, water will definitely not overflow the banks of the canals and rivers, Mr Plodprasop said.

The water to be used in the test has already been set aside and stored somewhere outside the Chai Nat Dam. It is not the water in the dam now, he said.

To determine the drainage capacity of the canals, two methods will be employed, the minster said, allowing the water to flow freely and accelerating the water flow by pushing it using boat propellers.

Most canals along the drainage route from the North into the sea have been dredged and rubbish and water hyacinth have been removed, Mr Plodprasop said.

Broken sluice gates and water pumps have also been repaired as part of the flood prevention plan, he said.

The water drainage test in western Bangkok is scheduled for Wednesday. The water will be released from a reservoir near the Chai Nat Dam into the Chao Phraya River, before being diverted into Khlong Mahasawat in Bangkok.

From this main canal, the water will eventually empty into Nakhon Chaisi River in Nakhon Pathom and the Chao Phraya River in Bangkok Yai district of the capital via different routes.

The test in the eastern part of the capital will take place on Friday. Water from Chai Nat Dam will be diverted into Khlong Rapeepat in Pathum Thani before eventually being drained into the Gulf of Thailand through Makkasan swamp and through tambon Khlong Dan in Bang Bo district of Samut Prakan.

If there are signs of any problems, the exercise will be called off immediately, Mr Plodprasop said.

Prime Minister Yingluck Shinawatra defended the drainage testing plan, saying the government could assure Bangkok residents that they would not be affected.

Bangkok Governor Sukhumbhand Paribatra said he was not convinced by the government's assurances.

He called on the WFRMC to take responsibility for any possible accidents that might occur if the water drainage test does not go according to plan.

Weather forecasters say that a storm could form in the Philippines between Wednesday and Friday and this might affect Thailand, MR Sukhumbhand said.

He said the BMA now had in place its own measures to deal with possible impacts from the test.

If the test resulted in flooding problems, the BMA would reserve the right to make decisions on its own without consulting the WFRMC.

The governor said that Khlong Song and Khlong Lat Phrao run through densely populated neighbourhoods. The city administration has not yet completed repairs on seven water gates which were damaged during last year's flooding, he said.

Smith Dharmasaroja, former director general of the Meteorological Department and current member of the Strategic Committee for Water Resources Management (SCWRM), also voiced concerns over possible negative impacts of the drainage test.

To drain water from a major dam that was only 40% full now could lead to a more serious water shortage in the coming months, he said.

By December and January there will insufficient fresh water reserves to mitigate the seawater intrusion that usually is common at that time of the year, Mr Smith said.

The Stop Global Warming Association, an environment advocacy group, also called on the government to consider cancelling the drainage test for fear it could affect people living along the canal banks.

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Discussion 1 : 31/08/2012 at 06:41 PM: I think propellers do help, but only if its put all along the rivers. If not the speed in one section will slow down because it loses momentum after traveling a certain distance. Even if it put on the river, there needs to be enough units to make it work, not just 2 or 3 along the river as seen in many sections. It will just propel the top of the water , while the bottom flow has little difference. Having boats all line up on a stretch of the river is the same, the water will loses momentum and slow down unless boats are on the entire river to keep the momentum of water up. A good plan, but not doable in this scale.
Discussion 2 : 31/08/2012 at 12:17 PM: Why in the world are they expanding Don Muang, which was closed down for MONTHS due to the last floods, when there are no defenses in place and it is anybodies guess when it might happen again. Only in Thailand.
Discussion 3 : 31/08/2012 at 12:12 PM: Hopefully this test of Bangkok's drainage system will spur the BMA to speed up the repairs of those parts of the system for which it is responsible.
Discussion 4 : 31/08/2012 at 12:11 PM: dieter D11: if what you say is true, why are Hatari and other companies still making money? If a propeller is in a fixed position, it propelles what is not fixed from one side of itself to the other. As simple as that.
Discussion 5 : 31/08/2012 at 12:03 PM: Stunning, more silliness, graft and boondogle I am shocked. The moment I read anything about "propellers" being used you can discount the remainder as foolishness. Fluid dynamics, just about any entry level engineering program will have it. In a semester you can learn why this propeller goofiness makes this a joke. There are capable hydraulic engineers in Thailand why not use them? There are known flood prevention methods why reinvent the wheel? Where in the world do they test flood? Just a silly excuse to spend money and pretend you did something to get it.
Discussion 6 : 31/08/2012 at 11:52 AM: D10 Ian - Comparing an electric pump connected to a 1/2 inch pipe to some boat propellers on the top of a klong 4 meters wide by 2 meters deep is like comparing apples and moon rocks. They aren't even in the same world. If they want to test different flow rates, then they have to increase / decrease the output at the source. Propellers will only increase the speed of the surface water for the next 30 meters at best.
Discussion 7 : 31/08/2012 at 11:33 AM: #5 mitrapaap. The answer is simple, really. It's all about Bangkok and nothing more. If the areas above Bangkok become flooded again, they'll do what they did last year, big bags and make sure Bangkokians are safe. In case anyone in the Rangsit/Pathumthani hasn't noticed, the klongs are full of debris and weeds and flood walls are being built along Phaonayothin road in Rangsit. In short, Bangkok will be safe at the expense of their upper neighbors...again.
Discussion 8 : 31/08/2012 at 11:32 AM: Testing is an essential part of flood prevention preparations and as long as experienced scientists and engineers are closely involved, the results should be very useful. The current conflict between BMA and the government should guarantee that any negative results will not be hidden (as would otherwise be the case).
Discussion 9 : 31/08/2012 at 11:06 AM: Well progress is evidently being made. How about repairing the damaged Tsunami Warning Tower in Krabi Ao Nang just in case 2004 repeats itself!
Discussion 10 : 31/08/2012 at 11:06 AM: Well progress is evidently being made. How about repairing the damaged Tsunami Warning Tower in Krabi Ao Nang just in case 2004 repeats itself!
Discussion 11 : 31/08/2012 at 11:04 AM: How on earth can you test a system without giving it a trial run. Politics should not obstructive in this circumstances. For the ordinary people, we want a peace of mind to see of all the government planning and efforts in flood mediation stand up to the hype. Sukhumbhand really has little credibility to hold the test to ransom. The only reason he is unconvinced is that he has not supervised and manage all the flood prevention works to completion. He is really letting himself down as the governor election draws near.
Discussion 12 : 31/08/2012 at 10:35 AM: I am certain the amount and complexity of projects required to manage the country’s water recourses are quite extensive. I am also fairly certain the planning phase of these projects cannot happen overnight. We are aware of the bidding process being underway for some of these projects which would indicate that progress is being made. It would certainly be futile for the government to make all these infrastructure upgrade plans without knowing for certain if the financing is available. I believe the government is using a systematic approach to water management development. The fact they are not simply throwing the budget away is showing fiscal responsibility.
Discussion 13 : 31/08/2012 at 10:25 AM: This boat propellar business is a mystery. Has anyone at mechanical engineering Uni's looked and commented on this ? What happened to all those pumps that were purchased and temporarily installed around the place last year ? Couldn't they do a similar job ? Probably disappeared into dai-din around the place and all proceeds gone to fund various personal charity choices.
Discussion 14 : 31/08/2012 at 10:24 AM: Th flood last year came from the dams not being drained .If they have been drained then we dont have anything to worry about unless it rains for 3 days .If that happened we would flood regardless .
Discussion 15 : 31/08/2012 at 10:04 AM: The two sides are at battle and the rainy season is only just upon us. An admission from the governor that there is still work to be completed on some canals. An experiment that at best will prove nothing, except that water always flows down hill. Greenpeace involve as if we have not got enough fingers in the pie. The boats are out so called pushing water.NO thought of the amount of water it displaces!! When is the big bad[bag]wall going up? We are expected to have confidence in a team who got it wrong when deciding where to have its HQ last year. I am glad we got our flood insurance because this is a disaster waiting to happen.
Discussion 16 : 31/08/2012 at 09:23 AM: Using boat propellers to speed up the flow of water is the equivalent of sitting in a sail boat and blowing into the sail. The result is "ZERO".
Discussion 17 : 31/08/2012 at 09:05 AM: A well conducted test of flow rates is an excellent idea, however it seems the BMA intends to assure that they are not well conducted. regarding the comments about ship propellers increasing flow. Most people are familiar with electric jet sprays. I would suggest the following experiment, connect a half inch pipe to a large barrel of water, time how long it takes to empty the barrel. Now refill the barrel and connect the half inch pipe to a jet spray, time how long it now takes to empty the barrel. In the first case gravity is doing the work, in the second case gravity is being supplemented by electrical power.
Discussion 18 : 31/08/2012 at 08:20 AM: The idea of testing in advance is sound and welcome ... but reading through, numerous questions and concerns can be seen. First the water is stored somewhere outside the dam ... how can you test the results of dam discharge (the cause of last year's flood) if you don't open the sluice gates? And how much water can you store without using a dam or reservoir? Second, boat propellers will be used to test faster flow rates, it sounds like they have not consulted with ANY hydrologists if they still feel boats propellers actually speed up overall water flow. Third repairs to all the water gates haven't been finished, shouldn't repairs be finished before testing, what happens if their test re-damages the gates, it is getting a bit late to start repairs again. And before the red brethren jump on the BMA for not finishing the repairs yet ... what happen to the 350 billion baht in flood prevention and restoration projects that the cabinet passed in an urgent emergency decree? Just a small percentage of that money has been "urgently" used and the vast majority of ideas haven't even been made into project specifications yet. At least the BMA projects are underway, not sitting on a planning table covered with dust.
Discussion 19 : 31/08/2012 at 08:05 AM: A massive wall of boat propellers should be installed in every klong to keep the water moving. Might also be a good idea to treat the water with penicilin.
Discussion 20 : 31/08/2012 at 08:02 AM: Good, let them test -- all permutations and combinations. Even let them over-flood a little and see the people's preparedness -- it is better to live with a little artificial flooding than the uncontrollable floods...
Discussion 21 : 31/08/2012 at 07:39 AM: And if you test a system with only a third of it's capacity, what will you see? Everything fine, government has done a good job, we are the best, we have resolved the flooding problem - until nature comes and tests the system at full capacity or a bit more.
Discussion 22 : 31/08/2012 at 07:35 AM: "If there are signs of any problems, the exercise will be called off immediately, Mr Plodprasop said." I wonder how they would do that. Once the water is released it's gone. Other than that, we see the same pattern as last year. Government telling us Bangkok is safe, and the Bangkok administration running its own show.
Discussion 23 : 31/08/2012 at 07:28 AM: Doing a test like this is logical and should be done every year, the water is available , canals are there, great way to test everything is working as it should and if not then it gives a good opportunity to get it rectified. BMA should have tested everything by themselves already, or are they just not ready ?
Discussion 24 : 31/08/2012 at 07:04 AM: There is nothing to fear but fear itself.... Unless there's something to hind the city should not worry about the test and should cooperate fully, because it will not be tested at full capacity.
Discussion 25 : 31/08/2012 at 06:10 AM: Why has the BMA failed to complete the repair of all water gates? Surely this should be a priority!
Discussion 26 : 31/08/2012 at 02:43 AM: Great idea! At least any problems will be found and fixed before the flooding season arrives. However, it will be best not to screw thing up at the dams up north like last year.

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