Rain Water and Tanks

pollyanna

pollyanna

Member
Is there any reason, other than apathy or inexperience, that rain water tanks are not more commonly used in Bali? We checked with Ace Hardware and they didn't have the large tanks nor know anyone who does.
We used to live on a small island and were responsible for obtaining and discarding (sewerage) all our water. We did have electricity. We collected rain water in two large tanks, pumped the water uphill to a smaller tank and our house water was gravity fed. Keeping it safe and clean was not an onerous responsibility. And the water was the best we've had any where in the world.
We are thinking that is what we will do in Bali, along with drilling a well or bore for times when the rainwater runs dry.
I would love to hear any comments from people who have some experience with collecting rainwater, especially if this isn't a good idea.
 
Boring a well (with a 5 inch pipe) will cost you on the Island of the Gods - 30 million Rupiah. That will go down to a depth of 50 meters - max! After that it costs more.

Digging a well by hand will cost you 250,000 per meter down to a max of 15 meters

You will hit water (within most areas not mountains) at around the 2 meter level - don't drink it!

The thing is nobody in his right mind would drink anything that comes out of the pipes here. So since we are only going to use the stuff for showering, flushing the toilet, watering, etc. why go any deeper than 15 meters?

Rainwater catchment is something else - it doesn't really rain that much since I've been here (18 months on and off) except in the mountains - on the sea side - dry as a bone.
 
The reason rain water harvesting is not so common in Bali is because, for most places, other options exist. RWH is often considered a last resource option despite the fact that it's totally appropriate especially if you're complementing it with a well or borehole. The question is, if you can get a well in, will you still want to bother at all with RWH?
As Markit mentioned, the water table is fairly high in most coastal area and hilly/mountainous zone take advantage of the many springs that exist. A lot of people will therefore have a well within their compound or use piped water supplied by government water agencies with the reliability that you might expect from such entities..
It is not easy to find a large tank (>5m3) -PE or metal- so either you get it from Java or you build a ferro cement tank which is probably the most cost effective way of building a large size tank (up to 40m3). You could also harvest your rain water in a pond and later filter it for domestic use.
FYI, the average annual rainfall on the island is around 1500mm but varies of course depending on your location. Also, my 20m borehole, 2 yrs ago, cost me around 20 Million so it's worth shopping around for a quote.
Have fun with your project.
 
O said:
The reason rain water harvesting is not so common in Bali is because, for most places, other options exist. RWH is often considered a last resource option despite the fact that it's totally appropriate especially if you're complementing it with a well or borehole. The question is, if you can get a well in, will you still want to bother at all with RWH?
FYI, the average annual rainfall on the island is around 1500mm but varies of course depending on your location. Also, my 20m borehole, 2 yrs ago, cost me around 20 Million so it's worth shopping around for a quote.
Have fun with your project.
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This information is really helpful and I appreciate you taking the time to explain it to me.
We have two reasons in mind for wanting a rain water system with a supplementary bore for when the rainwater is used up. One, we are reading reports about the water table dropping although I'm guessing it is a greater problem in the southern part of the island and two, the warnings about the water, either town water or well/bore water, not being potable. Rainwater is clean, soft, great to drink, divine for shampooing, and feels good on the body when showering. And there are no worries about it being undrinkable.
 
Rainwater sometimes cause colds when drank.
Also I really don't like using rainwater for shower as it's quite slimy to skin.
I rather treat underground water than use rainwater.
 
warm water

On a related subject, does anyone think a black tank placed on a tower would be sufficient to heat water for warm showers. I have seen some plans for make shift solar heaters cut it seems alot simpler to do it this way. The place I would have it has consistent sunshine. I realize it probable wouldn't produce in the am hours. Tom
 
Dropping water tables are happening all over the world thanks to the loosing combination of over extraction (check out how much the water park and other golf courses in Bali are using per day) and global warming (more intense rains over shorter period of time=less time for the water to percolate and replenish the water table) , Oz being on top of the list, you probably know all this. In Bali, there is only anecdotal evidence -as far as I know there hasn't been a wide range study done to analyze this- but all the reports seem to point to dropping water tables with the usual effect of salt intrusion among other issue. Hopefully you're not in one of these zones but you'll still want to drill your well at the very end of the rainy season, if you hit water then, you can be pretty sure to have water all year round.

While rain water is usually fairly safe to drink as you say Toucan (I would classify getting a cold as deep deep bush legend) , assuming your installation is well done -first flush diverter among other thing-, it does not contain any minerals and it is therefore not recommended as a primary source of drinking water.
A black tank would certainly help you a bit..... if you can find one of that color that is . Anyway, I personally think there's nothing quiet as good a a cold water shower to wake you up. Happy shower and shampooing to all !
P
 
O said:
Hopefully you're not in one of these zones but you'll still want to drill your well at the very end of the rainy season, if you hit water then, you can be pretty sure to have water all year round.
P
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I am listening and learning from everyone's advice and I have another question. Did you mean to dig the bore/well at the very end of the rainy season to ensure a constant supply?
 
Tom

If your tank is exposed to the sun it will (depending on the size) get the water warm enough for a shower without any problems but you will have to shower in the evening as by the morning it will get cold again. There is one snag however that is when I turn my tap on within a few minutes the pump comes on and cold water is pumped to the tank :icon_rolleyes:
 
Jimbo said:
Tom

If your tank is exposed to the sun it will (depending on the size) get the water warm enough for a shower without any problems but you will have to shower in the evening as by the morning it will get cold again. There is one snag however that is when I turn my tap on within a few minutes the pump comes on and cold water is pumped to the tank :icon_rolleyes:
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That's the inconvenience of having a warm water in the middle of a hot day for your bath whenever you have a tank on top of your house.
Also, the pressure would be a bit useless if the height of the tank is only from about 3rd storey.
 
Most important thing when choosing a site for your well is to remember where your septic tank is :icon_lol:
 
The water storage vessel you choose forms a central part of your Rainwater Harvesting system, however ensuring you get good quality water with minimal maintenance is not a simple as just putting in a tank.


 
May have something of interest on this subject. Early next year (with the involvement of a lot of people) we may be shipping in box shaped poly water tanks instead of the round type (easier to fit into a container). These can fit in a lot more places on a small block and can be linked together.At this point we are still sorting through the paperwork (to find out who's palm needs greasing at customs) but when and if it does happen I will let you know.
 
Water tanks and irrigation pipe

Thanks for that TJ, look forward to the positive result.

Does anyone know if irrigation pipe is available here. The bendy one with holes!! preferably with the "sock" covering. I contacted Mr Fixit, to be told to use straight pipe, and have my workers drill the holes into it!! good idea, but I want the pipe to bend around corners. Any suggestions would be very valuable.
:icon_e_confused:
 
scout said:
Thanks for that TJ, look forward to the positive result.

Does anyone know if irrigation pipe is available here. The bendy one with holes!! preferably with the "sock" covering. I contacted Mr Fixit, to be told to use straight pipe, and have my workers drill the holes into it!! good idea, but I want the pipe to bend around corners. Any suggestions would be very valuable.
:icon_e_confused:
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Hello Scout,
I checked with our builder today to see what we did. Ours is just as Mr Fixit described, straight pipe with holes drilled into it. First we put down a layer of rock, then a layer of sand, then the holey pipe, and then black hairy palm over that, then more rock, and then backfilled.
We had the same problem you're having with trying to find the irrigation pipe and couldn't find it anywhere.
 
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