Cisterns anyone still build/design homes for them?

[Dimitri]

I was just wondering if anyone still thought a Cistern would be useful in a home, I've talked to people who own homes with old cisterns and they claim they are useful for watering the lawn etc.

So anyone still use them even though they have city water or wells ??

Dimitri

[MountainDon]

I believe that any place could make good use of them for irrigation in particular. You have to calculate the amount of rainfall available vs the cost of the cistern and the costs of pumping well water or buying municipal water to decide if it is a good deal.

Back home where it rained a fair amount we hardly had to irrigate at all. Here in the desert, with little rainfall (maybe 9 inches in a year), it would be nice to have any "free" water, I don't know if I could build a cistern that would pay for itself though?      Depends on what the cost of water goes up to.

[Dimitri]

I guess I'm just picturing this as a installed when the house is built type of deal atleast I never heard or anyone adding a cistern after the house was built. Actually for that matter I don't know of a single house newer then 50 years old with a cistern. I figure the way I've seen them "built in" inside of the basement that they cannot cost all that much more to put in when building the foundation/basement. 

Still thinking about my "prefect" house idea, and although its generally the same requirements, it changes little by little over time.

Dimitri

[glenn kangiser]

Ferrocrete would be the most cost effective I think-- read cheap..

You have to think about keeping critters out of them also. 

[MountainDon]

I don't know of a single house newer then 50 years old with a cistern.

George W Bush's ranch house in Crawford, TX was built 2000-2001. It has a 25,000 gallon rainwater cistern. It is also off grid.

Off-Grid.Net


Practicalenvironmentalist.com


Truthorfiction.com

[Robbo]

Water tanks are a "must" in this environment.  I have a 25000 gal main water tank, as well as two 4000 gallon tanks and this would be regarded as relatively modest by our standards.  It represents in excess of 12 months supply at modest usage rates.  They supply all houshold water except for the flushing toilets - these are fed by pond water pumped uphill to additional storage tanks and reticulated down under gravity to the house.  All greywater and blackwater is treated with a Biolytix aerobic water treatment plant and the output waters gardens and orchards.

For us, smart water management is essential and cisterns/tanks are an important part of that.

Cheers

Robbo

[Willy]

Water tanks are a "must" in this environment.  I have a 25000 gal main water tank, as well as two 4000 gallon tanks and this would be regarded as relatively modest by our standards.  It represents in excess of 12 months supply at modest usage rates.  They supply all houshold water except for the flushing toilets - these are fed by pond water pumped uphill to additional storage tanks and reticulated down under gravity to the house.  All greywater and blackwater is treated with a Biolytix aerobic water treatment plant and the output waters gardens and orchards.

For us, smart water management is essential and cisterns/tanks are an important part of that.

Cheers

Robbo

I have a great well for my water supply and a 15 acre lake also. But I still have a under ground 6,000 gal tank for fire protection set up with 1200 ft of fire hose. The fire hose is set up in 4 different folded hose lays and nozzles on each for quick deploy. All are marked for which building they go to during the confusion of a fire. During the winter the lake freezes over so it is a way to get lots of high gallon per min water since the well only gives 25 GPM. I have 3 roof sprinklers set up to feed off the tank if a fire gets close. They put out 45 GPM each from my gasoline water pump. This can wet the place down real quick! Mark

[Dimitri]

Bush's home is where I've been getting some more recent ideas for a home. 

Still I was referring to not knowing personally any new homes with cisterns. 

Dimitri

[MountainDon]

... knowing personally any new homes with cisterns. 

...me neither   

[John_C]

My house in the FL Key, built in '83  - "84, had a cistern as the sole water supply.  We gathered rain water off the roof and had a 14,000 gal. concrete tank in the back yard. 

Now it all seem so.....  last century

[Dimitri]

John,

I guess it rains enough to keep the supply of water in the cistern high enough all year long since there is no winter there ?? 

I wouldn't depend on a cistern all year here, since half the year its snowing instead of raining, but would be good for summer time watering of the lawn. 

Dimitri

[akemt]

Everything in Ketchikan, AK outside of city limits (the majority of new housing and a great deal of old housing...say, half the population?) have rain water cysterns as the sole water supply.  We had about an 8,000 gal tank.  Maybe a bit more.  My mom's is only about 2,300 gallons.  For her in a rainforest that is dandy, but for us with kids, not so much!  Even up here the cysterns themselves cost maybe a couple thousand.  Our neighbor had their foundation as their water tank.  (All the foundations are crawlspace...no slabs or basements because of the water table, etc)  I assume they used some kind of sealant on it, and it was built with that as the plan.  Then the other neighbor cut a tree that fell into their house and cracked the foundation --lovely, eh!?  They ended up just buying a tank liner for it and they're still going strong.  Cysterns are VERY practical, if you get any rain where you are, with roof catchment for gardening at the least.  I'd definately check into it.  Keeping "critters" out isn't a big deal...you can build a stick-built roof for the thing with a hatch.  And to add it to the property after the fact isn't a big deal either, but you will need to pay for some concrete to set it in.  Ours is about 1/3 under ground and 2/3's above.  Makes it nicer for eye-sore quality. 

Best of luck!

[akemt]

Oh, trade secret (not that I'm in the trade)...to keep pine needles and leaves out that come from the roof, install an ultra-technical nylon stocking to the end of your pipe that empties into the tank.  It'll let the water through, catch the stuff, and expand to keep on going.     You have to change them, and sanitize the water a bit if you're using it for potable water, but keeps your water pump/filter happy and is a cheap alternative to trying those pain-in-the-rear gutter covers, etc. 

[Dimitri]

When you say a nylon stocking your not referring to a womens nylon pantie hose are you ?? 

Dimitri

[akemt]

    Precisely what I was talking about. 

[John_C]

Dimitri,
   I think a cistern would be a viable water supply almost anywhere.  It requires sizing the catchment area and storage capacity to meet your needs.  Even in the FL keys where we got an average of 55 - 60 inches of rain/year we often went 4 months or more without getting a rainfall that would add to the cistern. Usually the first 1/4 inch or more was absorbed by the concrete roof.  But then we would get a tropical storm and get 8 - 20 inches in a day or so.

Jonsey, one of the members here, lives in a part of Australia that gets 8 or 10 inches of rain annually, if I remember correctly. He does just fine on a cistern.  I know of people who have had cisterns in extremely cold climates. There are ways of dealing with the cold. Building the cistern as an underground basement and possibly adding an air bubbler, for example. Probably an area that got even less rainfall than Jonsey would be difficult.

[Robbo]

If you rely entirely on a cistern as we do, you have to do your arithmetic.  Roughly,  1mm of rain falling on 1 square metre of roof theoretically yields 1 litre of water X collection efficiency of about 80%.

I have about 400 square metres of roof and we get about 650 mm of rain per annum yielding 208,000 litres of water.  This means we have to average less than 4000 litres per week - which for us is easy - matter of fact, we use only about 1500 litres.

[MountainDon]

FYI:

650 mm = nearly 26 inches.

1500 litres = 413 gallons (US)
4000 litres = 1101 gallons (US)

400 sq meters = 4305 sq ft

[Dimitri]

Thats quite a large roof. 

Still lots to think about, thanks guys!

Dimitri

[John_C]

I agree with Robbo.  Do the math.  In FL one inch of rain was almost exactly 1000 gal of water in my cistern.  In OZ   house often have disproportionately large roofs in order to gather sufficient water with their meager rainfall.  Collection off of outbuildings is also a possibility.   In place like the Bahamas where most of the rain is seasonal the storage tanks are very large to carry them over.  30,000 gallons was not uncommon.

[Robbo]

Thats quite a large roof. 

Still lots to think about, thanks guys!

Dimitri

I guess it is a lot, but it includes house, sheds, outbuildings etc.  As`I said earlier, for us this is a matter of necessity as I look with envy at the rainfall received by my "in-laws" in SW Pensylvania.

[desdawg]

I have installed many cistern tanks here in the desert. However they are not for catching rainwater, they are filled with hauled water. Drilling a well is cost prohibitive for many people and water is available at community wells for a small fee. I went for many years without a well and my tank is still in place. Now the well fills it automatically and I don't have to haul water anymore. I think drilling a well in this area is running about $30K these days. I spent $12K when mine was done. My well is 586' deep and many in this area are much deeper than that. My  home is built on a slab and my tank is beneath my utility room floor with only the manway access cover protruding.

[glenn kangiser]

We have a similar situation here, desdawg.  Many mountain places here get deliveries from a water truck.

We put in a 2600 gallon plastic storage tank on the mountain and fill it from our 1 gpm well.  Sort of a cistern.

[davidj]

We've currently got a "regular" well setup - 1HP 220V well pump, 85 gallon pressure tank and a 6KW 220V portable generator to run the thing (we're off the grid and sleeping in the 8'x8' shed weekends/vacations).  The downside is that the draw-down on the pressure tank is maybe 20 gallons, so often we need to run the generator multiple times per day, and it's noisy and inconvenient.  And some guests seem a little confused in having to find a gas can and locate the choke just to get a drink of water!

In the medium term (before the cabin is finished) we're likely to get some solar capacity.  Given that, I'm wondering if it's sensible to put in a 1000 gallon tank and a 12V RV-style pressure pump?  Then just run the generator for an hour/week to fill the big tank and run from solar/batteries the rest of the time.  And in the long term, maybe get a solar water pump in the well (skipping the 220V inverter forever).

The tank probably needs to be underground, given that it freezes overnight for 9 months of the year (and using the generator is even harder in winter).  And the land is as flat as a pancake, so a pump is necessary either way, and I've already got one lying around from a previous project.

Is there more to an underground water tank than digging a big hole, dropping in a tank, running a couple of 3/4" PVC pipes and wiring up 2 or 3 float switches?  It looks like this might only be $1000 + pump (already have) + backhoe time?  I guess the 12V pump needs to be low enough that it can self-prime.  Any structural issues with the tanks? Are the right-ways and wrong-ways with float switches?  Or is this just over the top for a few years of quiet and convenience?

Thanks,

David.

[desdawg]

There are two types of float switches, one that shuts off power when it floats up and one that shuts off power when it drops straight down. Use the down switch to prevent your pump from running when you have run out of water and the up switch to shut off power when your tank is full. If you have any question which type you have in your hand you can test it with a meter. Other than that it is pretty straight forward. I was using 1700 gallon polyethelene tanks. They need to be protected from vehicle traffic and have a riser that attaches to allow you to put them in deeper. The tanks designed for underground installation are molded with ribs to add strength. A 1700 gallon tank was costing around $900. Tank manufacturer was Norwesco. The tank hole was 5' wide and 10' in length. Depth with the riser was about 7'. These tanks are small enough to be easy to haul yet large enough to provide sufficient capacity for most applications. The tank that is under my floor is a 2100 gallon fiberglass tank that I got used way back when. It also had ribs and a coating inside to keep the fiberglass intact. Back then I didn't have access to a backhoe and I dug that hole by hand.  I had more time than money.