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Is it possible to elevate a catchment tank so that it gravity feeds the home? If so how high off the ground per 1000 gallons would it need to be. Would it be permissible and safe? Just curious if anyone has done this.
I've also considered having a small tank run off the garage or an out building to use for a drip system for gardens.
Mahalo,
mella l
mella l
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bytheSEA
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I've seen a design that calls for a smaller passive pump that uses a small (75-100 gal) tank that is elevated. The pump, pumps up to the small tank from the larger collection tank then gravity does the rest. I bet it would be pretty weak though.
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Also gutter intake needs to be higher than gutter outlet in catchment tank.
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Mella,
I did some research on the internet for this topic. I have also thought about using gravity to supply pressure.
Someone at WikiAnswers said you get about .4 lb of pressure for each foot of height, so 10' would produce 4 lb pressure. Most houses run on 20 lb up to 100, so it would take quite a water tower to provide a good shower. But drip irrigation should not demand much pressure.
I'm glad to know a little more on the topic.
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mella, bud had part of his house gravity fed off his catchment tank, it was on a small hill about 8 or 10 feet higher than the house, it fed a couple of hoses, a sink in the laundry room and a toilet.
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Generally you can use the numbers of:
1. one half pound of water pressure per foot of elevation (one PSI per two feet of elevation)
2. about eight and a half pounds per gallon for the weight of water.
A water tank forty feet high would get some reasonable water pressure but thirty feet would also work. 1000 gallons would weigh four and a half tons so you'd need an engineered scaffold to support the water. You'd probably want less than 1,000 gallons up in the air so you wouldn't have to build such a heavy duty tower. Some farms used to use windmills to operate pumps to fill water tanks.
"I like yard sales," he said. "All true survivalists like yard sales."
Kurt Wilson
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Thank you all for your input. Our lot is pretty level in the grand scheme of lots so guess this is out except for perhaps a small tank to drip a few areas of garden.
Had no idea the elevation required for a PSI pressure. Thanks again.
mella l
mella l
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Here is a great site for sustainable living including all kinds of non-motor water pump.
canhle
canh Le
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Here is a great site for sustainable living including all kinds of non-motor water pump:
http://journeytoforever.org/at_waterpump.html
canhle
canh Le
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Mella, catchment systems are usually set up to have gravity fed (electricity-free) supply to the holding tank. Hence, as Kapohocat noted, the gutters, which collect the water running off your roof, need to be higher than your holding tank. If you are trying to use gravity feed to supply your house, your holding tank would have to be higher than your home, which happens to be where the gutters are attached. Do you get the picture?
You could plan on having a catchment area (typically your roof, but in this case not so) that is higher than your tank so your tank could be higher for gravity feed. But this might look kinda weird on a flat lot. This would effectively be two roofs, one for your house and one to catch rain. You can see why catchment systems are the way they are. We already have the roof on our home with rainwater running off, so, we gather that water.
Having said all that, I think you can run a hose or pipes from the line between your tank and your pressure pump that would certainly supply a drip water system without the use of the electrical pump. This line is often at ground level and there should be enough pressure from the higher level of the water surface/volume in the tank to push out a weak flow. If you are going to be in an area with lower rainfall, you may want to have an effective way to monitor your tank's water level if this valve will be opened a lot so that you don't put out too much water in your garden in times of drought. A second smaller tank might be a good idea in this case. You would also be able to more easily elevate it if you needed more pressure.
Edited by - Les C on 11/28/2007 10:04:09
