May I know what means Rain Water Harvesting?

Collect rainwater from the gutters in your house inside a tank. Then use a pump to circulate water for gardening/toilet/cleaning.

Simple schematic attached:





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Wow! Like this need use 2 tank right?

Yup in my housing area they provided a tank outside the house with a pump. I just gave the pump to my dad to build pressure in his house, threw away the RWH tank and joined the pipe work to my main tank in ceiling. So now my garden using tank water.

So normally use for gardening only?

Gardening, washing car/proch, in some cases toilet flush also can use

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This post has been edited by H2D: Sep 4 2013, 05:06 PM

Gardening & toilet use maybe ok but if wash car will affect paint?

While rainwater harvesting is a good idea, the cost is a big barrier. Instead, we can re-use water.

eg, the last rinse from the washing machine. The water clean enough to mop floors, flush toilets, wash cars, etc.

Have the washing machine on the first floor channel the rinse water to large container in the bathroom.
http://renovationmalaysiahq.com/water-problem-in-malaysia/

something to ponder ... american actually have law regulating rain water harvesting.

I think it is a good idea to harvest rain water, but like what everybody has mentioned, the intended usage is quite crucial.

For example, my brother in law built a koi pond in his house. His roof has no gutter and he did not realise that most of the water from his roof flows down to where his koi pond is. He built it during the dry season and when the first bout of heavy rain came, almost all the fish died within half a day. He then monitored during the next heavy rain and realised a lot of rain water from the roof ended up in the pond due to the shape of the roof. After the rain, he measured the pond water with a PH tester and the acidity was off the charts for any koi to survive.

my experience with fishpond usually fengshui got blame ... fish die to counter sha !! lolz ...

btw the USA reason for having law on water harvesting is that water are public property and by harvesting you are hogging public property. its like trying to dig petroleum at your house ...

I guess if they live within the water basin which their treatment plant water is sourced from, there is some logic to such laws.

If not mistaken, Malaysia also have now.

we have rain to HARVEST mehhhh ... if the dam cant harvest water ... you little citizen cannot sucessful in harvesting tooooo ... our government logic ... if we cant have it, you cannot have it tooo ...

Haha, that is another matter la.

Well there are a few points worth mentioning

1. Rain fall at wrong location i.e. in towns etc but not in catchment area. So we have flash floods but not water woh. Harvesting some rain water will help. Act of God, urban migration or over development? You decide.

2. Non revenue water lost at 33% means water lost from treatment plant bcos pipe bocor. Water players did not replace pipes cos high investment blah blah,
http://www.yeobeeyin.com/2014/03/current-w...-of-god-by.html

3. We use too much water per person on "average". If you are water thrifty, congrats, not talking about you. So on average everyone also need to reduce use or reuse water. Those industry that use a lot of water, maybe charge them more?

4. Pollution dump into river so treatment plant cannot handle. Shut down. Responsibility of DOE? http://www.thestar.com.my/News/Nation/2014...reatment-plant/

5. RM4 billion or is it 10 billion now, water pipe from pahang to selangor. Don't know which figure is correct
If give the money to each household to collect rainwater, is this big pipe needed?
http://www.thestar.com.my/story.aspx/?file...1155&sec=nation
http://nakedeyeview.com.my/water/Getwaters...ritiesright.htm

Greater Klang Valley population is 7.2 mil. Say 3 person 1 house there's 2.4 mil homes. Give RM3k subsidy to build rainwater harvesting system in each house 2,400,000 x 3,000 = RM7.2 billion
Not sure calc boleh pakai or not :-) Anyone with better figure, pls correct.

This post has been edited by trinity3: Apr 15 2014, 12:20 PM

Rain harvest is a good concept, but then the cost of having it are not cheap if want to use that water as raw water.

Simple rain water harvesting not difficult. Cut the gutter pipe. Install some elbow joint. Buy some barrels. Put a simple filter system.

I did mine for a few hundred ringgit. Bought 8 x 160l second hand barrel to store the rain water.

The issue is the economic cost of the water collected is less than RM3.

Of course in a time of water rationing, i fill it up with tap water n consider it as my reserve !

You need to invest more, a 400 gallon tank that put on top of roof, a water pump, a level switch and a carbon filter.