Rain Water As Your Only Source

[mccw]

Hi could some one help on this question pls?

Basically the land is on a hill side and a klong runs along one side of it but only during the rainy season. Any how, if i were to only use rain water collected from the roof would it be enough or should i take from klong too? If I were to build a one bathroomed house and suposing i lived in it the whole year, how many of those blue tanks would i need, or what m3 would i need if i were to build my own? What kind of and how expensive might a filter be, just for showering purposes, if i need one at all?

Cheers in advance

[trogers]

Average 0.25 cu.m a person a day, for shower, toilet, laundry and washing and cooking.

That will be 75 m3 a person per year (calculating 10 months without collecting any water). Typical blue tanks 1-2m3 capacity.

Total no. of tanks will probably take up more floor area than your house, if there are 2-3 of you.

[longball53098]

Trogers is pretty accurate here. Wife and I use about 700 liters a day average but we are not conserving and have city water. Consider digging a well as an option.

[Trickcyclist]

water supply is an under rated problem even in the tropics and its been an unusually dry winter here and the rain fall last summer seemed a lot less than in previous years.

It should be mandatory that all non sewage water i.e. from bath, kitchen etc., be diverted into storage tanks for garden/external use and rainwater tanks be installed in every new house to augment government supply. EG Many houses in Belgium have an underground rainwater storage tank.Can you imagine a long period of water shortages here?

[gregb]

Best way to store rainwater is underground cement tanks. This is just like building a swimming pool, so you need to investigate the proper construction methods. I wouldn't just trust any Thai chang to know how much rebar and cement to use.

To be safe, you need to have a minimum of 500 liters per person per day for the length of time that you will be without rain. Most places in Thailand get at least 1 meter of rain per year, and usually more. So if you have a family of 4, your rooftop should be about 730 sq. meters to collect enough rainwater. Couple that with about a 200 cubic meter tank (a good size swimming pool) to last the 3 month dry season, and you are starting to get a feel for the size of the problem using only rain water. 730 sq. meters is almost half a rai of collection area. For 2 people, your requirements drop, but you also limit the number of people who will buy the property from you. Lack of electricity can be overlooked in many instances. Lack of water on a hillside home is a crisis.

Your best bet would be to dig a pond, and channel the seasonal stream into the pond. I know, not easy on a hillside, but it is possible. Keep in mind that pond storage is different from underground storage in that you will lose water to seepage (unless you seal the pond very well with a liner or a fine clay) as well as evaporation. Figure you will lose 2 cubic meter of water per sq. meter of pond surface area annually to evaporation and seepage.

Or, you can do as suggested and dig a well. But that might be even more difficult on a hill. Certainly going to be alot of rock and no telling how far down you'll have to go. BTW, this is why people generally didn't live on hills before the advent of industrialization and fossil fuel enabled municipal water systems. It is a non trivial problem.

I'll be very curious what you finally decide to do. Let us know the whole story when you have come to a conclusion.

[trogers]

 

Your best bet would be to dig a pond, and channel the seasonal stream into the pond. I know, not easy on a hillside, but it is possible. Keep in mind that pond storage is different from underground storage in that you will lose water to seepage (unless you seal the pond very well with a liner or a fine clay) as well as evaporation. Figure you will lose 2 cubic meter of water per sq. meter of pond surface area annually to evaporation and seepage.

HM the Thai King has encouraged his people to build 'Kem Ling' or monkey's cheeks to retain rainwater on hillsides. These are a series of small ponds made by terracing on slopes. More easy to construct and stable on slopes, while reducing chance of flash floods.

[canopy]

The deal breaker for above ground tank storage is the dry season lasts 5 months give or take in areas of Thailand I am familiar with. It just isn't practical to have such a vast array of tanks to hold half a years water supply. A well or aquifer which are already recommended would be more realistic and preferable to pond water.

[bina]

just in the knick of time : since we have had torrential rains here for the past week (unusual here) , and bad flooding, agriculture ruined, etc, and every day pics of water running off in to the desert, my husband (thai) continuously asked why we dont 'catch' the water. we went to see a local resevoir (everyone was out to see it since it filled, for us an unusual site) and again raised the question. a engineer friend tried to explain why for us collecting water in the winter months (provided it rains enough) would be of little use, and proper use of grey water is a better answer. am using the stats posted above to show answers to both.

out of curiosity, how much water is stored in one ong (those big ceramic water holders)? i take it that u arent including irigation or watering of plants /gardens/lawns since for the most part there is rain most of the year in thailand, compared to us (no rain from april to december more or less) as we are semi arid to arid and not tropical.

bina

israel

[canopy]

out of curiosity, how much water is stored in one ong (those big ceramic water holders)?

The jars hold 1.8 cubic meters in my area. And despite being given a coat of paint to look the part, they are most definitelly not ceramic. They are made of cement using a technique called ferrocement. They cost under 1000 baht and are useful not only for a rainwater catchment supplement, but also as a backup water supply as in many areas water is not consistent. For instance in my village there is no water at night and in the day it is off and on. But these tanks have downsides. They usually have slow leakage and are a breeding ground for mosquitos due to improper lid usage.

i take it that u arent including irigation or watering of plants /gardens/lawns

Right. And that would be a good use for greywater.

since for the most part there is rain most of the year in thailand

Not true. Last year I only recall one single rain from november to march. The dry season in Thailand can be bone dry. That said, the last few days we had some wonderful rains here.

[BEENTHEREDONETHAT]

In Australia we had a 10,000 gallon water storage, above ground made from fiberglass about 12mm thick. We collected the rainwater off of the roof, Never ran out and never had to worry about how long the shower you take is. Also had solar hot water which worked very well and provided all the hot water we could use.

That was in the Brisbane area and had less rain than they do here. You do have to clean it every couple of years and filter the water going into the tank to prevent leaves etc from getting in. A good system but probably more water than you would need, with a little conservation a 5,000 gallon tank would have been plenty.

Since a tank like that might be impossible to find you could build one out of concrete, google it and I'm sure you will get a ton of into on building one. Good Luck with it.

[trogers]

There are two issues here: catching and storing.

Just relying on the roof is not enough. Say your roof has a 200 m2 area. A 2-inch rainfall will only give you 10 m3 volume.

This is where the 'kem ling' comes in.

Digging wells on a hillside is a hit and run as you do not know how deep the water table is.

[bina]

i have a feeling that most kibbutzim (apart from thsoe that are identified as eco oriented) and for that matter, most main cities here would have neither the land space to put up a tank like that per family, nor would it be approved asthetically by the home owner/neighborhood committees, not to mention that in some ways we are third world, and water stealing/poisoning for personal vendettas/any other illegal and nasty activity u can think of-- would happen at a high rate.

as of now we dont have wide spread grey water use but many eco concious kibbutzim and city dwellers have gone back to old fashioned catching extra water/washing dishes in plastic tub and using for small garden irrigation. we were able to bring down our use of water on our kibbutz therefore freeing up allotted water rations for agriculture (livihood); but someone recently brought up the idea of water containment... and i brought up the thai version. just cant imagine where we would put huge tanks for four large families in same building (a two story duplex i think its called), on our very small plots of land, and then of course the mossie management program would have to change. i dont mind showering in water that had gambsas (mossie eating fishlets) but most people would have a problem.

as for rain, thailand still gets much more rain then we do although i suppose where i live it is similar in a way to korat plataeu... we are in thejeruslem hills at the desert water line (u can see the line of green vx yellowexcept for this week of green). we had flooding everywhere, but the thais were not impressed. they always have a one -up feeling over us when it comes to water. we of course were all out videoing the rushing waters puddles and mud.

bina

israel

[canopy]

In Australia we had a 10,000 gallon water storage...We collected the rainwater off of the roof, Never ran out and never had to worry about how long the shower you take is.

This one had me thinking. Given the rainwater patterns, that capacity would be practical in Thailand for a household of 2 people and have some water for landscaping. It could be done with a tank footprint of about 3m x 7m. Placed next to a house and screened it might not be of much visual issue. Anyone attempted such a thing, cement I presume, and cost?

[Khonwan]

I had the same issue 13/14 years ago. My solution gives me enough water for all my family’s needs even in the event of a 7-month drought (which we once had). I posted it sometime ago on the Farming forum: http://www.thaivisa.com/forum/index.php?s=...t&p=1870492

Rainwater is still my only source for all my household needs.

[farmerjo]

Priced 10000 litre poly tanks in chumphae the other day = 45000 baht each.

Does anybody know if the corrogated round tanks put together in kit form with plastic liner inside are avalible in thailand.?

[billd766]

When we moved up here to Klong Lan in the central region we were on the village water but it generally ran out from Feb to May.

I have 2 x 3,000 litre stainless steel tanks for rainwater and drinking purposes only.

For other water usage I had a slab built and put 20 ongs up which gave me around 30,000 usable litres of water.

Fine for most of the time but we had 8 adults and 2 children living here and when friends came as well we tended to run low.

Normal village water was about 3 baht cu/m.

I ran some 1 1/2 inch piping down the side of my land, across my neighbours driveway (buried), across the front of his land, under the road through a drainpipe, across somebody elses land to the klong. I connected my chinese "Honda" water pump to that lot and pumped water about 350 metres to the tanks. It used to cost me about 20 baht per cu/m.

A year or so later I bought a 1300 litre plastic tank and I used to go to the klong about 1 day per week taking 8 return trips with my pickup truck per day and that cost about the same per cu/m but was easier plus I could get a shower at the klong every time to cool down.

My neighbour had water trucked in by tanker and was charged 50 baht cu/m but they run a resort.

Now the village water is pretty much full time so life is easier.

My future plan is to put in a permanent 3 inch pipe and an electric pump to the klong, renting the land if possible but letting the owner use it and dig a collecting pond above my fish pond and pump into that and any overflow can run into the fish pond. From there I need to pump another 300 metres to some storage tanks I haven't built yet and then I can irrigate the whole land plus keep the house water topped up.

I also live on a slope going up to the national park but about 1 metre down is rock and nobody on this side of the road has been able to drill a borehole.

[reallyok]

Back home in oz, i dont have town water. So i have 2x5000Gal plastic water tanks, dont see them here, only those stupid little things, one is fed the rain water from my roofing gutters, which i pump through a bank of 3 filters for drinking, and the other tank i replenish from the nearby creek for all houshold uses, like showers and toilet. I have never run out of drinking water with 4 users.