New pumps can’t save Highway 7 from flooding closure

[Rimmer]

New pumps can’t save Highway 7 from flooding closure

PATTAYA:--The Highway Special Maintenance Department installed five pumps on the Bangkok-Chonburi Expressway after a section became impassable during last week’s storms.

The onset of tropical depression Vamco began bringing heavy rain to Pattaya Sept. 14, flooding northbound Highway 7 at kilometer market 116-117 in Pong Sub-district. Water reached 1.3 meters deep and closed about 300 meters of the highway.

Two vehicles sustained serious damage and motorists were detoured to Sukhumvit Road to continue their journeys to Bangkok.

- See more at: http://www.pattayamail.com/news/new-pumps-can-t-save-highway-7-from-flooding-closure-51497#sthash.MoEoYQpm.dpuf

-- Pattaya Mail 2015-09-22

[Kerryd]

Perhaps what is most surprising to me is, this place (Thailand) has been getting torrential rainfalls from monsoons and storms since....forever ! I rode through a section of Pong yesterday and noted quite a few "Thai" style houses (built 3' or so above the ground). Flooding is nothing new here !

With that in mind it should have been obvious from the initial planning stages that flooding could be a concern. You're already building in an area that is close to being at sea level to begin with. Getting massive amounts of water to drain away (hopefully) as fast as it accumulates is not as simple as installing a a small drain pipe and lots of grated drain holes. The water needs to flow somewhere ! Look at Soi Khao Noi after almost every (significant) rainfall. Massive amounts of water flow into the drains in the upper parts of the soi, but long before it gets to the railway drainage canal the drains can't handle the volume. As a result the water starts coming back out of the drains in gushers (garbage plugging the drains doesn't help of course). Eventually it hits the large grates just before the intersection and is diverted to the ditch and pumping station just past the intersection.

If there isn't sufficient elevation to allow natural drainage via gravity, then pumps should have been included in the initial planning. Back when creating retention ponds, pumping stations and alternate drainage systems (i.e. ditches/canals) could have been figured into the design.

Now it's a case of closing the barn doors after the cows have already escaped.

Of course, enterprising businessmen could line up along the highway (above the parts that flood) and offer jet-ski and long-tail boat ferry services every time it rains ! Judging from the last flood they could almost sail their craft from Jomtien all the way to the flooded portion of Highway 7 anyways ! (I really need to get a rubber dinghy and have someone film me paddling the rapids of the Khao Noi river next time !)

[ross163103]

Wonder how the new tunnel on Sukhumvit's going to handle the rain when relatively level areas can't? I know I won't be entering it when it starts to rain!

[petermik]

Wonder how the new tunnel on Sukhumvit's going to handle the rain when relatively level areas can't? I know I won't be entering it when it starts to rain!

No problems with this..........the design team have assured everything will be fine

[impulse]

Now it's a case of closing the barn doors after the cows have already escaped.

I don't know that that's a fair characterization. It may be.

But it may also be an economic reality that you can build a road that will always be open for $100 million, by building it above grade, with catch basins and pump systems.

Or you can build the same road for $50 million, knowing you're going to have to shut it down once or twice a year for a few hours to let your overworked pumps drain it. And it will be open 99.5% of the time for 1/2 the money.

1 inch of rain over 1 square mile is something like 17 million gallons of water. Figure out what kind of pumps you need to keep up with a monsoon rain, then look around for a lower area nearby to pump the water to, and I suspect the planners made a conscious decision that involves "Road Closed" signs occasionally. It could have been a valid economic decision, though it's an inconvenience.

Now if they just had some budget money left over for a few "Road Closed" signs....

Edited September 25, 2015 by impulse

[Kerryd]

Now it's a case of closing the barn doors after the cows have already escaped.

I don't know that that's a fair characterization. It may be.

But it may also be an economic reality that you can build a road that will always be open for $100 million, by building it above grade, with catch basins and pump systems.

Or you can build the same road for $50 million, knowing you're going to have to shut it down once or twice a year for a few hours to let your overworked pumps drain it. And it will be open 99.5% of the time for 1/2 the money.

1 inch of rain over 1 square mile is something like 17 million gallons of water. Figure out what kind of pumps you need to keep up with a monsoon rain, then look around for a lower area nearby to pump the water to, and I suspect the planners made a conscious decision that involves "Road Closed" signs occasionally. It could have been a valid economic decision, though it's an inconvenience.

Now if they just had some budget money left over for a few "Road Closed" signs....

Could very well be. I don't recall much about construction of that highway (didn't really interest me at the time) but it could very well be that the authorities went with a cheaper option and fingers crossed. True enough that the inconvenience is normally infrequent and short lived (thankfully) !

When I was in Kandahar there was a large "wadi" (dry creek bed) outside what was then the perimeter fence near the compound I worked in. The wadi was about 20' wide and 4' deep and (normally) dry as old toast that's been left in the baking sun. During an expansion of the camp a certain contingent from a certain country decided that since it hadn't rained a drop in the 2-3 months they'd been there, the wadi was just an inconvenience, so they filled it in and built over top of it. Great idea ! They did put in some token ditches which were kind of hilarious from an engineering point of view, because they went absolutely nowhere !! They were more like long, skinny, shallow retention ponds than drainage ditches.

Of course a couple months later it did in fact rain and because Afghanistan is what it is, the rain doesn't soak into the ground. The top layer of fine dust hardens (like flour will) and the water just flows over top of it. Without the wadi (that had probably been there for thousands of years), the water had nowhere to go and as soon as the ditches filled up (mere minutes in some cases) the water flowed out onto the roads and into the compounds. Nasty mess. Especially when the outflow creek from the sewage treatment plant overflowed !

(In late 2011 we had one rainfall that only lasted about an hour. The ditches filled and the roads started being flooded and then a retaining wall somewhere north of the camp let go. Again, with no natural drainage the flood of water washed through the camp. We quickly found that the Hesco and cement barriers designed to protect us from rocket attacks also made excellent dams, preventing the water from flowing and resulting in our compound having waist deep water trapped inside of it. I was living in a prefab shelter up on blocks in a gravelled compound and the water ended up over 18 inches deep inside. The worst part though was seeing all the crap floating in the water (actual crap, probably mostly animal dung as well as other things nobody wanted to speculate on). They ended up having to write off and dispose of the prefab shelters because of the contamination and mold growing inside the walls.)

(The point being that without adequate natural drainage and adding man made obstructions to the equation, what should normally be minor problem can quickly escalate. The other worrying thing is, we've seen various roads wash-out and collapse due to heavy rains and flooding, got to hope that the base under the highway is solid or there could be some expensive repairs needed in the future.)

[Don Mega]

Wonder how the new tunnel on Sukhumvit's going to handle the rain when relatively level areas can't? I know I won't be entering it when it starts to rain!

I think you be fine to enter the tunnel when it starts raining. Now if it had been raining for a while then that would be a different scenario... but then suk road would be flooded anyways so you would not actually get to the tunnel..

[NCC1701A]

how about if you hear there is a frickin' tropical storm coming you stay home?

[JMWPACIFIC]

I got caught in this but fortunately it was right at the Rayong turnoff so no problem getting home. Visually this area looks from a distance that it would not flood---what a surprise. The Suk tunnel will be a disaster.

[burgdawg]

...all Tai engineers know that since they were born kon Tai, they can engineer and plan for

water to flow uphill!

Scary and true.

[thaibeachlovers]

Now it's a case of closing the barn doors after the cows have already escaped.

I don't know that that's a fair characterization. It may be.

But it may also be an economic reality that you can build a road that will always be open for $100 million, by building it above grade, with catch basins and pump systems.

Or you can build the same road for $50 million, knowing you're going to have to shut it down once or twice a year for a few hours to let your overworked pumps drain it. And it will be open 99.5% of the time for 1/2 the money.

1 inch of rain over 1 square mile is something like 17 million gallons of water. Figure out what kind of pumps you need to keep up with a monsoon rain, then look around for a lower area nearby to pump the water to, and I suspect the planners made a conscious decision that involves "Road Closed" signs occasionally. It could have been a valid economic decision, though it's an inconvenience.

Now if they just had some budget money left over for a few "Road Closed" signs....

Could very well be. I don't recall much about construction of that highway (didn't really interest me at the time) but it could very well be that the authorities went with a cheaper option and fingers crossed. True enough that the inconvenience is normally infrequent and short lived (thankfully) !

When I was in Kandahar there was a large "wadi" (dry creek bed) outside what was then the perimeter fence near the compound I worked in. The wadi was about 20' wide and 4' deep and (normally) dry as old toast that's been left in the baking sun. During an expansion of the camp a certain contingent from a certain country decided that since it hadn't rained a drop in the 2-3 months they'd been there, the wadi was just an inconvenience, so they filled it in and built over top of it. Great idea ! They did put in some token ditches which were kind of hilarious from an engineering point of view, because they went absolutely nowhere !! They were more like long, skinny, shallow retention ponds than drainage ditches.

Of course a couple months later it did in fact rain and because Afghanistan is what it is, the rain doesn't soak into the ground. The top layer of fine dust hardens (like flour will) and the water just flows over top of it. Without the wadi (that had probably been there for thousands of years), the water had nowhere to go and as soon as the ditches filled up (mere minutes in some cases) the water flowed out onto the roads and into the compounds. Nasty mess. Especially when the outflow creek from the sewage treatment plant overflowed !

(In late 2011 we had one rainfall that only lasted about an hour. The ditches filled and the roads started being flooded and then a retaining wall somewhere north of the camp let go. Again, with no natural drainage the flood of water washed through the camp. We quickly found that the Hesco and cement barriers designed to protect us from rocket attacks also made excellent dams, preventing the water from flowing and resulting in our compound having waist deep water trapped inside of it. I was living in a prefab shelter up on blocks in a gravelled compound and the water ended up over 18 inches deep inside. The worst part though was seeing all the crap floating in the water (actual crap, probably mostly animal dung as well as other things nobody wanted to speculate on). They ended up having to write off and dispose of the prefab shelters because of the contamination and mold growing inside the walls.)

(The point being that without adequate natural drainage and adding man made obstructions to the equation, what should normally be minor problem can quickly escalate. The other worrying thing is, we've seen various roads wash-out and collapse due to heavy rains and flooding, got to hope that the base under the highway is solid or there could be some expensive repairs needed in the future.)

I'm pickin' that it wasn't Aussies that filled in the wadi. Most Aussies know about dry creek beds that fill up in minutes after a rain storm elsewhere. However, the Brits like building on flood plains in Blighty, then being surprised when their houses flood.

The problem with Pattaya is that it is not the culture to design anything for what could happen, or to maintain anything after it is built. They put really big pipes on the third go under Beach Rd long ago, but I'll bet they are blocked by now, causing Beach Rd flooding after a normal downpour.

The Thai way is to put small pipes in now, and if they aren't big enough to dig the road up again and put bigger ones in later.

[thaibeachlovers]

...all Tai engineers know that since they were born kon Tai, they can engineer and plan for

water to flow uphill!

Scary and true.

Problem easily solved, just put a load of speedboats in the flooded part and use their props to move the water.

[petermik]

Wonder how the new tunnel on Sukhumvit's going to handle the rain when relatively level areas can't? I know I won't be entering it when it starts to rain!

I think you be fine to enter the tunnel when it starts raining. Now if it had been raining for a while then that would be a different scenario... but then suk road would be flooded anyways so you would not actually get to the tunnel..

In case the Sukhumvit tunnel DOES flood the authorities are considering a discount ticketing scheme for Pattayas new water park