Flood mitigation, anyone with actual experience?

[Crossy]

OK, so the river is getting inexorably closer to the top of our retaining wall

When we designed our home we knew that flooding was likely so we set our floor level 300mm above the highest flood in anyone's memory.

Then came 2011

We had about 400mm of water on the lower level, at the time we were under construction so it was just wet.

Now we are in residence and I need to prepare, it's guaranteed that if we are ready then the water won't come, so our preparation will benefit all of Bangkok

We have four doorways that need protecting. My current thinking is 1" (or whatever I can get) plywood plates overlapping the doors by 2-3" on each side and the bottom. Secured with concrete anchors and sealed with silicon between wall and wood (masking tape on the wall first so we can get it off later). Say 600mm high, that's a good 6" above the 2011 peak.

If the water gets anywhere near 1/2 way up then sandbags behind to support the wood?

Submersible pump to take care of any leaks. Generator upstairs to power the pump if the juice goes off (it didn't in 2011).

Soooo, will it work, is it worth it?

Any and all thoughts welcomed.

[robblok]

You are thinking along the lines of what i was thinking of but i heard water will come up through toilets and such. If i remember correctly there was a story of someone keeping all the water out. Even though it came through walls ect. He just drained it to the lowest point and then used a pump. You need some sort of collecting area to use a pump. Anyway I hope we will not be flooded this time. I got good hopes as besides 2011 it never flooded here.

Also some of the news I been reading suggest the volume of water is much lower.

As of yesterday afternoon, waterflow at the dam had reached 2,195 cm/s, while the waterflow through Nakhon Sawan province was 1,717 cm/s. (Note: On September 19, 2011 the rate at Nakhon Sawan was measured at 3,935 cm/s.)

[Crossy]

Cheers Rob.

Yes the loo is the weak point, if it come to the crunch we will sacrifice the downstairs bathroom. It's completely isolated from the rest of the house, but SWMBO will be needing a new washing machine if it floods

If things look bad I'll silicon a plywood cover over the lav and stick a few sandbags on top

EDIT JAS21 has just suggested (on Skype) that a plastic bag filled with sand in the toilet bowl would be smart, this idea I like

[robblok]

I recall a topic of a poster who was flooded but unlike his neighbours he kept all the water out. It did go through the walls and loo but he swept it to a low part (once every few hours or so) and pumped it out. I am thinking if i flood again of just moving the floor up 25 cm. Sure I will have a lower ceiling but 2011 never came over 20cm here. Ok its a bit too late to do this now but if it happens for the 2nd time its a good option to do.

[nahkbin]

If you have a typical house it will have a floor drain in the bathroom also. That will have to be plugged.

I think that putting masking tape behind your silicone will be ounter productive. The water will seep in behind it. Worry about cleaning the silicone off the wall after the water recedes. I very securely taped over the electrical outlets in our house last year. After the water was out of the house and when I pulled the tape off water poured out of the outlets. I also tripped all of the lower level circuit breakers. We never did lose power.

Two feet of water in our house last year.

[robblok]

If you have a typical house it will have a floor drain in the bathroom also. That will have to be plugged.

I think that putting masking tape behind your silicone will be ounter productive. The water will seep in behind it. Worry about cleaning the silicone off the wall after the water recedes. I very securely taped over the electrical outlets in our house last year. After the water was out of the house and when I pulled the tape off water poured out of the outlets. I also tripped all of the lower level circuit breakers. We never did lose power.

Two feet of water in our house last year.

You cant really keep it out but you can slow it down enough so your pump can keep up with it. I think that is the best plan make sure it comes in slow and drain it to the lowest point of the house where you have a pump.

[xen]

I have never been in a really bad flood but it occurs to me that a long term preparation measure would be , that is if you are in two storey house , to be able to isolate the electrical power in lower floor from the upper floor . Apparently a certain amount of drownings are caused by leaking electrical current paralyzing the person so if you isolate the lower floor there would be less chance of that happening in the immediate area within your house. I guess it is determined how effective and how safe it would be determined by the house design .

[JAS21]

If you have a typical house it will have a floor drain in the bathroom also. That will have to be plugged.

I think that putting masking tape behind your silicone will be ounter productive. The water will seep in behind it. Worry about cleaning the silicone off the wall after the water recedes. I very securely taped over the electrical outlets in our house last year. After the water was out of the house and when I pulled the tape off water poured out of the outlets. I also tripped all of the lower level circuit breakers. We never did lose power.

Two feet of water in our house last year.

I suggest instead of plugging the floor drain attach a riser pipe to it.

Check behing the toilet, (inside around the back and you may find a hole or the hole covered ... either way ensure that the sealing is good. The sealing in our house was poor and every time it rained the toilet smelled ... I sealed it corectly and now no smell.

[Woodsie888]

We managed to keep the water out last time until it rose to about 600mm above floor height, after that it found its way inside at an alarming rate. It finished up at just over a metre inside. Outside it was 1.6 metres.

I thought we had taken plenty of precautions, but those only delayed the inevitable. If it had been only a day or so rather than 7 weeks under water, I think we could have coped.

We lost electric during the early hours of the morning, and although I do have a generator, supplying fuel to it over a continuous period would be difficult if similar circumstances arose again. In my view flash flooding is much easier to keep the water at bay, rather than a few weeks of high water.

My plan is to totally empty the ground floor including plugs, switches and built in furniture if it looks like happening again. That way, I won't have to fight a losing battle with the Insurance Company again. In actual fact, I don't even know why they call themselves Insurance Companies. They are rather happy to take the premiums though.

[Xonax]

Cheers Rob.

Yes the loo is the weak point, if it come to the crunch we will sacrifice the downstairs bathroom. It's completely isolated from the rest of the house, but SWMBO will be needing a new washing machine if it floods

If things look bad I'll silicon a plywood cover over the lav and stick a few sandbags on top

EDIT JAS21 has just suggested (on Skype) that a plastic bag filled with sand in the toilet bowl would be smart, this idea I like

Water in the plastic bag will work even better, and be way more easy to remove again after the flood. In any way just make sure, that you use the strongest type og plastic bag, so it doesn´t break, due to the heavy weight.

In 2011 I used PVC pipes attached with silicone to rise the floor drains, but luckily they didn´t have to stand a test. We still have the gas-stove we bought for cooking in 2011.

Remember, that you will not be able to flush the toilets or shower on the upper floor as well, so also make a plan how to do this during the flood. If you in any way can find the money for it, you should better just move to dry land and let your house flood, after protecting your belongings against flood and burglars. Living in a flooded house without electricity, water and toilets is definitely no fun.

[ignis]

JAS21 has just suggested (on Skype) that a plastic bag filled with sand in the toilet bowl would be smart, this idea I like

2011 floods, I used the large extra strong black bags, 60x40 extra thick and filled with water, also did the same by taking off the manhole covers dropped in bags filled with water, [Put 1 bag inside the other so extra extra strong] so stopping the water coming into house from drains...

Much easier to get rid of than sand = knife and pull out empty bags..

have already bought 6 pks of 5 from Makro 60x40 extra thick bags on Monday.. just in case..

[peter267]

We managed to defend a 7 Rai Factory with a sand bag wall 20,000 bags in 2011 and wait it out for 6 weeks. At maximum height 60cm water level above site.

All toilets and low drains with open level below flood level will flood - like drain in corner of shower rooms - washing machines etc etc. Each one need blocking. with say cloth tight jammed in? just a little flood head this will be ok .

Yes a pump but this ideally needs a sump to collect the water from. Clever idea would be to plumb your shower drain - maybe find pipe if on low floor into a pump suction flange. (Ok we had sand bag wall but installed huge pumping capacity running 24 hours per day) Pumps like water only not mixed with air.

For doorways. A cheap solution just cement a few blocks around a doors or across a patio door - the lightweight ones - maybe 40-50cm high - this creates a positive wall you link it to outside wall of house - no water seepage through door frames. Knock out after flood - we did this not difficult to touch up afterwards. Also many shop fronts did this.

No working toilet. If you had to wait out several days. Not nice. Diet of daily imodium maybe!!! (that was poor humour not advice) Maybe a big dustbin and some creative initative with plastic bags might sustain a sweet environment.

Most 2011 deaths were electrocution I believe - If you can positevley cut out low circuitry then maybe you can keep mains on - If you are very sure all low stuff is isolated. Around us the power companies were hot wiring connections to upper floors - disconnecting from the low mounted electric meters. from a boat from house to house.

I think I recall 2m within a live submerged power source was deadly.

Know if you live inside or outside a monkey cheek!

[HUAHIN62]

Doesn't make sense that if the water is coming through the toilet the water can be drained out through the shower outlet. If the house is build the same way as mine both the shower outlet and the toilet use the same drainage/sewerage system. Thus if the water is flowing back through the toilet the same should happen with the shower outlet and both should be sealed off. The toilet is 300 mm plus higher than the outlet. If the house is higher than street level water should not be able to push back through the toilet until such a point is reach where the water level is equal or higher than the toilet level.

If your house is flood prone I would invest in waterproofing the outer walls to prevent water penetrating them as this will weaken them over time, plus mould build up.

Hope the flood don't come and if it comes your guys are okay. Everything of the best.

[Stan Bailey]

My business is offering flood advice and providing prevention or at least protection against damage to property in addition to saving lives. However, I deal with large projects in the gov't and corporations to offer these services. There are many flood protecion products on the global market and you can do some research on this matter yourself. Here is one website with the solution to the toilets backing up and in some cases exploding as happened during 2011.

http://toiletstopper.com/product_profile.pdf

Here is another on sealing doorways: http://www.shuswaplakewatch.com/tips/tipdoors.html

And this is one of the many products available on the market: http://www.floodpanel.com/residentialcontactform.php

The challenge at this point is to get these products shipped to Thailand in time to help you out. That is why my company always recommends to do these preventative measures a few months prior to flood season and not wait until the waters are flowing your direction. We also offer concrete blocks which can be put up as a flood proof wall around a building, which is a quicker solution since the concrete is made in Thailand and does not need to be imported. Such wall can also be constructed and then disassembled after the floods are finished and stored until next needed. Hope this helps you make some decisions.

[falkan]

next thread should be about building a flood-safe house

[Pib]

I live in western Bangkok. During the 2011 flood our moobaan had flood waters to 1.5 meters in the main roads. The side sois most of the homes are on like mine are a little higher than the main roads and then the homes foundation are again a little higher. Anyway, at the peak of the flooding I got approx. 20cm into one area of my 1st floor which was the entrance area from the carport and the downstairs bathroom which is about 30cm lower than the 1st story main floor. Like most folks in the moobaan we had to evacuate the first few days of the flood...it reached 1 meter in the main roads within about 2 days, got up to 1.5 meters as mentioned, and other than a couple of visits during the 3 plus weeks we had to evacuate we only returned two times via boat and wading through the chest high water to checkout the house.

As mentioned flood waters only got into that one low area of the house. The only visible means where water could have got in was via the door which I had sealed with silicone around the seams and also sealed by a 1/8 inch thick stiff plastic sheet over the lower one-third of the door on the outside... or water may have got in via the downstairs bathroom floor drain which I had sealed with a plug....also had a sandbag in the commode but the commode top was well above the water level that got into the house. I paid extra attention to sealing above mentioned area as I knew it would be the first to receive any flood waters.

Since we didn't stay in the house during the peak of the flooding I can't say for sure where the water got in. I really don't think it was the door or bathroom drain. I think it might have been hairline cracks the floor foundation (no tiles) in a small storage area under the stairs leading to the 2nd story....this storage area under the stairs is at the same level as the area that got flooded. When it comes to leaks even a very small leak can allow a good amount of water in over a day or so....and if you have to leave the home for days/weeks then the water just fills up the place slowly. If we had stayed in the house--which really would have been a miserable 3.5 weeks during the flooding in the moobaan, assuming the power stayed on all the time which it did as far as I know, and assuming I could have used the sump pump along with some mopping I could have possibly kept the waters out of that area.

Hopefully it won't flood your home, but if does hopefully you can maintain power along with sump pump use to pump out the inevitable small leaks that find there way in. Good luck. Flooding ain't fun...been there...done that...got the tee-shirt when we had to evacuate our home for three and half weeks in late 2011.

Edited September 26, 2013 by Pib

[ignis]

We also offer concrete blocks which can be put up as a flood proof wall around a building,

cannot understand this, in my Village in 2011 many built walls across there gates and drives, even a couple of houses built wall across there home doors/patio doors... myself on the house used conti board and wrapped in table covering [10 m rolls at Big C 300 baht.]

few places about were water came only down the road...... my Village as with most the water came from the ground up.. I stood in the road and water was bubbling up through the tarmac, letter just before leaving was coming up in the garden...... No wall is going to stop water coming up...

Some people I talked to flooded more in another Village said that the water came up into there room from the floor

[David48]

Crossy ... you did wire the house so that the upper and lower level power and lighting circuits were split ...

Edited September 27, 2013 by David48

[Crossy]

Crossy ... you did wire the house so that the upper and lower level power and lighting circuits were split ...

Of course, and there is no electrical outlet or switch less than 1.2m from the floor downstairs.

I suppose we are lucky in some ways in that we knew that the land flooded regularly and so designed our home with that in mind.

Genset is located on the upper level although the power did not go off during 2011, I need to keep the pumps running if the wet gets that high.

During the 2011 inundation we had less than 1/2m on the lower level despite being right next to the river, we had 3m+ in the condo where we were living.

[chiangmaibruce]

I agree with the comment by Ignis ... even with a block wall constructed across your driveway the water will quickly come through the earth and bubble up in your yard .. cannot stop this. Even if your yard is paved it will come up between the paving and the wall, etc. The other thing to do is install inline taps on all pipes into or out of the wall of your house (for e.g. the waste pipe from a washing machine), and ensure the best possible seal around where these pipes actually exit the wall.

All such steps though will only delay the inevitable ... but if the inundation only lasts a couple of days then that will still save you some grief.

[Crossy]

Keep the comments coming chaps (yes, even the negative 'it's not worth it' ones)

A few notes on the construction of our home, remember I said it was designed with some flooding in mind, just not of the 2011 magnitude.

The house is on a solid concrete slab, below the slab is a damp-proof membrane (industrial polythene), intended to stop damp rising, it should (big word that) at least reduce the possibility of water rising through the floor. The only penetrations through the slab are in the downstairs loo (lav, shower floor drain and washing machine drain). We do have a large planter in the centre with a tree in it which goes through the slab too, but it's got a 300mm wall around it.

The access doors (4 of them) all look inwards to a downstairs 'entertainment area', we will sandbag the access to that area and install a sump pump in the downstairs shower (the lowest point) to hopefully handle any leakage.

I also intend blocking off (to 600mm) the doors as noted in Post #1 as a second line of defence should the sandbags and pump lose the battle.

The upstairs toilets feed a separate septic from the downstairs, maybe they'll work or maybe not, if not then there's the bucket option or one of the floating toilets that the local government built last time.

The village power never went off in 2011 (everything is overhead in typical Thai style), nevertheless we have a small (6kVA) LPG/petrol generator upstairs (outside of course) which should keep the pumps running, at least while there is fuel readily available. There are no electrical fittings less than 1.2m above the slab level.

We have 5,000 Litres of fresh water storage which should keep us going for a while, particularly if we flush the loos with flood water (may as well use the available resource).

Hopefully all the above will be moot, the river hasn't risen (other than tidal variations) for the last three days, we shall see.

[robblok]

Crossy,

Water will get into the house, but if your lucky it wont be much and you can "move" it to a low point where you can drain it with a pump. It will be a lot of work but if the floods don't last long doable. So far it looks as if the floods are not really comming and this is nust normal year to year flooding. But you never know.

[Crossy]

Indeed Rob, the whole idea is to keep the ingress within the capabilities of our sump pump. We can withstand several inches on the lower level, no wood floors down there, it's all tile.

I do hope you're right about the levels being about 'normal', certainly the villagers are not worrying just yet although the boats are out.

One positive of the high water is that the noodle-lady can get to our garden gate so Wifey doesn't have to walk round to get her fix

[David48]

So ... has the flood risk abated, increased, or a status quo?

[Crossy]

So ... has the flood risk abated, increased, or a status quo?

Slowly creeping up again, restaurant flooded and closed

Probably about 30cm of rise before we start to get water on our garden then 10cm on top of that before it enters the house.

Watching it closely.

We have the kids from the restaurant staying in our place (they ate all my Pringles before I got home yesterday).

[Crossy]

We have just collected our 100 free sandbags (empty), availability at the sub-district office was announced over the village loudspeakers and loudspeaker trucks.

A large pile of sand has been dumped conveniently outside our gate, tomorrow is 'sandbag day'.

How to build a sandbag dyke http://www.ag.ndsu.edu/pubs/ageng/safety/ae626.pdf

[Pib]

We have just collected our 100 free sandbags (empty), availability at the sub-district office was announced over the village loudspeakers and loudspeaker trucks.

A large pile of sand has been dumped conveniently outside our gate, tomorrow is 'sandbag day'.

How to build a sandbag dyke http://www.ag.ndsu.edu/pubs/ageng/safety/ae626.pdf

Thanks....good info...especially the part about Filling Sandbags. Good luck...may the water continue to "pass by you."