Above ground rainwater system in a cold climate

Hey all!

I’m wanting to get a rainwater system going for my recently purchased tiny house ...I live alone and I only need water for washing dishes and taking a shower, not drinking. I have access to electricity for a pump. My tiny house has a tankless propane water heater and there’s just a very simple garden hose inlet coming out of the bottom of the tiny that connects to both the shower and sink ... I would like to buy a 500 gallon above ground rainwater tank, a pump, and then build an insulated wooden shed around them to make it thru winter without my system freezing. I would insulate the garden hose connection as well...my question is would that keep from freezing in the winter? I live in the mountains of West Virginia we have spurts of the low temps being in the teens and sometimes single digits ...I don’t want to do an in ground system in case I move in the future ....thanks in advance!

https://permies.com/t/49985/advice-freezing-rain-barrels

Good info in this thread. Check out the similar threads at the bottom of the page if you don't find anything you are willing to try in that one.

As an Australian who works with water I am always bemused by the issue of frozen tanks and pipes.
I have found through my work via the internet that the larger tanks do not freeze, in many locations.
I read the link provided by Ben and noted one contributor mentioned a similar fact in his experience.
The other issue is the outlet tap and pipe which may freeze anyway, unless well insulated and dry.

By having the tank inside its own 'barn' it's very possible to keep it from freezing. I have had 5000 gal. tanks installed inside barns
and some even kept at about 5 deg C with a small wood stove that have worked well.

I have found the bigger the tank the cleaner the water also, since there is more time for settlement of fines and the water to purify itself.
You need to work out how much water you would need over the coldest periods when it may not be possible to collect water and size the tank accordingly.

The link at the bottom of my signature deals in capturing rainfall for use.

500 gal. should be good for your purpose. I would suggest using 2 inch pipes to again reduce the freeze factor.

I'm of the understanding that grey water should never be stored in a tank.  In answer to your question, no, that won't keep it from freezing if you have any long periods of time below freezing.

I suspect, given your location, you should be ok.  I would put windows with shutters on the south side of the shed. That will allow for some passive solar heat. Of course, close the shutters at night if the temps drop. My height tunnel in zone 6 has produced salad greens all this winter. I have 200 gallons of water in it.

If you are really concerned, and have electricity, buy a stock tank heater if the temps really plunge.

John,

My height tunnel in zone 6

What is a height tunnel please?
Trace, I think he is talking about fresh water for the sink and shower, not grey water.

Hi John,

My high tunnel is 8 ft high, 12 wide, and about 24 ft long.

I think you'd probably be fine with a 500 gallon tank and insulated hoses. We have a couple 275 gallon tanks above ground in Indiana, which experiences similar temps and they have not frozen. Our only insulation at present is bags of leaves stacked like bricks around the tanks. We have had issues with the plumbing freezing, as it isn't insulated yet. Granted, the way our system works, water is almost always cycling through from the slow sand filter overflow, so that probably helps with the tanks not freezing.
Figuring out how much water you use for dishes and showering would help you know if 500 gallons will meet your needs since you can't always count on liquid water in winter, especially. Practicing ways of using less water for those tasks can be helpful in making a smaller tank work, too.

Thanks for the help all!

Just a quick tip...we live in freezing country and have out in a lot of water lines.

EVERYTIME we put in any waterline we put in two.  One hooked up and one tapped off.  The spare.  Many times it has saved us when a line to a barn or house has broken, froze or?  We just disconnect the line and connect the spare.  Voila!

Hi Janet,

Great idea!!  I am running water and electrical lines all over my back yard.  I will copy your idea in, at least, a couple of places.

John C Daley wrote:John,

My height tunnel in zone 6

What is a height tunnel please?
Trace, I think he is talking about fresh water for the sink and shower, not grey water.

You're right.  I misread the original post.  Apologies.

I've considered burying tanks here, but that's because our winter is long and proper cold...

Your tankless water heater could be plumbed to draw water from the tank, heat it, and return it. You could run this loop as needed (which may only be a couple of times a year, if at all) to keep everything from freezing. Keeping the lines from freezing will be the most crucial part. Insulate them well, or bury them, or make sure water flows on a regular enough interval (timer on pump maybe, or just manage it yourself if you can), and if it is going to be a problem it would be wise to have some kind of solution on hand to thaw out any lines that may have frozen -- heat tape, heat gun etc.

You could also look into electric immersion heaters to keep the tank above freezing when needed (such as for livestock water tanks), but this depends on your electric situation and possibly also where your electricity comes from.... coal fired plants down in your part of the world I assume? Not so great...

To add to my above comment - tankless water heaters can be and are used to heat in-floor radiant heating systems, so, that equates pretty much to the kind of heat recirculating idea I am mentioning.

Okay, one more post... lots of good advice from people above.

Passive solar heating, sounds good to me.... in the summer I've used a 250Gal tank, painted black, to heat and store water for an outdoor shower situation.

John F Dean wrote:Hi Janet,

Great idea!!  I am running water and electrical lines all over my back yard.  I will copy your idea in, at least, a couple of places.

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