I知 currently finishing up my cabin and I want to throw in a couple tanks to collect water from the roof for potable water till I decide if I知 going to pump from a spring at the bottom of the hill or pound a well. Anyone one have suggestions for what size tanks to put in? Would 3000 gallon total be enough for two people. Plastic or cement? I have 2000 sqft of roof to catch water. My idea was to put in a filtering tank before my storage tank(s) and if I pump the spring I壇 run it through it first too.
Water storage for home
- Thread starter NateF350
- Start date
- Views: 1242
otlski
Gold Member
Will it be enough? Let us look at some math. At 8 foot dia the 3000 gallon tank would have a surface area of 50 sq-ft. If you collect 100% of the water off your 2000 sq-ft roof, you would have a fill ratio of 40:1. Meaning that a 1 inch rain storm would fill your tank to 40 inches of depth. Seeing that such 3000 gallon tanks are 110 inch high it would take 3 inches of rain to over top it (some bounce loss).
So will you and second person use 3000 gallons before the next 3 inches falls? In Pennsylvania the average rainfall is 42 inches per year assuming your cabin is located there. I am guessing it is somewhat seasonal too - will it work for you?
So will you and second person use 3000 gallons before the next 3 inches falls? In Pennsylvania the average rainfall is 42 inches per year assuming your cabin is located there. I am guessing it is somewhat seasonal too - will it work for you?
WranglerX
Super Member
IF spring runs year around and clean water, its you most reliable source..... IF spring is above tank lever it will always fill tank so you may get by with smaller tank....
Dale
Dale
oosik
Epic Contributor
One thing we need to know. Is your cabin a weekend retreat or a permanent home? We had a very remote cabin in AK. Collected water off the roof. Into two 55 gallon whiskey barrels. First barrel - bottom half filled with activated charcoal, top half with clean, washed sand. Second barrel was for storage. Even for those times when we stay for a week - we never ran out of water. The water came off the roof - into rain gutters - into and thru barrel #1 - stored for use in barrel #2.
If it will be a permanent home. And this means the cabin is FULLY plumbed - sinks, showers, toilets, septic system, etc. Consider 65 gallons per person per day. That's a tad short of 48,000 gallons per year - for two people. What is the "normal" annual rainfall at your location. What is the catchment volume of your roof?
Seriously - consider roof catchment as a stop gap measure until you are able to develop a system using the spring or a driven well.
If it will be a permanent home. And this means the cabin is FULLY plumbed - sinks, showers, toilets, septic system, etc. Consider 65 gallons per person per day. That's a tad short of 48,000 gallons per year - for two people. What is the "normal" annual rainfall at your location. What is the catchment volume of your roof?
Seriously - consider roof catchment as a stop gap measure until you are able to develop a system using the spring or a driven well.
RalphVa
Super Member
- Joined
- Dec 19, 2003
- Messages
- 7,885
- Location
- Charlottesville, VA, USA
- Tractor
- JD 2025R, previously Gravely 5650 & JD 4010 & JD 1025R
I'll bet the annual rainfall there is about the same 40" we get here. I did the calc once, easy to do. Think you can collect 30 to 40k gallons/yr on 2k sq. ft. Not sure I'd want to drink water caught off the roof though. Did my calcs for collecting garden rain water.
A spring or well would keep the water nearer a low temperature to keep it more pure and would not have the stuff in it caught from a roof.
Could use roof water for everything but dishwashing and drinking and food prep.
Ralph
A spring or well would keep the water nearer a low temperature to keep it more pure and would not have the stuff in it caught from a roof.
Could use roof water for everything but dishwashing and drinking and food prep.
Ralph
TnAndy
Veteran Member
- Joined
- Aug 9, 2013
- Messages
- 1,993
- Location
- East Tennessee
- Tractor
- Yanmar LX410...IHI 35J excavator Woodmizer LT40
I designed and helped a buddy of mine build an off grid cabin right at the top of a dry ridge here in TN where our annual rainfall is about what yours in PA is....40 some inches/yr. No well or spring option in his case, so he put a 2500 gallon single tank is the basement fed off the roof gutters. Cabin was 24x24 with a metal hip roof on 12:12 pitch....I think that figures to less than 1,000 sqft of roof...and he seemed to have plenty of water from it, BUT only used it weekends and as some place to go grow a garden to get out of his in-town condo. He also had a shed that fed another couple of 1500 gallon tanks he used just for garden water.
Some pics of his cabin: (Basement was 14' tall to get the first floor up to grade, so the height of the 2500 gallon tank was easy to handle)
View from the metal catwalk around the outside is pretty nice ! It was a fun project since I got to use his checkbook....ahahaaaaa.
You can see the edge of the water tank next to the power setup I put in to use the roof solar panels. The solar also powered a small pressure pump that took the water out of the tank and supplied the cabin.
I always felt like the amount he had for the cabin use would be kind of 'iffy' IF he intended to use the place year around, because we can get some might dry spells here from time to time, especially late summer, early fall. He had plenty of room in the basement for another tank, and me personally, I'd have put it in to catch winter/spring time run off, which can be when we often get excessive rain. But it worked for him, the way he used it.
But my first choice would be what DL said above, and what I did on my own place....use the spring. Our spring is located high enough on the mountain of our place that it gravity feeds the storage tanks, and then on down to the house. I put in two 1500 gallon plastic tanks in a 10x20 shed I built back into the bank below the spring. Insulated inside with foam board and it has never frozen. Ran a 1" line down from the spring, then 1" on down to the house, plus another 1" overflow line off the top of the tanks that feeds our 2 small, dug fish ponds in which we raise catfish. Way I piped it, water also feeds the chickens and cattle with a near continuous source of fresh water, then the excess from that flows to the ponds.
Shed that holds the tanks. I made the front wall out of 2x4 so if I ever HAD to replace the tanks for some reason, I could remove the wall and change them out. Never been an issue to date.
Couple things about the spring. Right now, enough water comes out I could generate power from a water turbine ! But in the fall, it has never quit, but will get down to maybe a pencil sized dribble of water...less than 1 gpm for sure. But with 3,000 gallon of storage, even that is more water than you need over 24hrs, so we've never run short.
The distance to our house from the tank shed is around 1500'. In retrospect, I WISH I'd used a bigger line (line 1.5-2"), but I did what I could at the time out of lack of knowledge and lack of depth of checkbook
Pressure at the house was only low 20psi range and we did use that for 25 years. Then I ran into a booster pump while at the Mother Earth News fair in Asheville some years back and put one of those it. We had added a UV light years before that in case a deer or something pooped in the watershed around the spring, so now the setup is complete.
Water setup in our basement. The larger pressure tank is for our drilled well, which I added later as a backup in case the spring ever did dry up, but we only use it for garden irrigation...prefer the soft water of the spring to the hard water of the well (well in limestone, spring comes out of sandstone), but I plumbed the system where we can use either by simply open/close valves.
Tall, gray thing is the booster pump.
Since I take it your spring is located below you cabin, you could locate a storage tank(s) below the spring, and use a pump to pressurize water up to your cabin....either grid or solar powered, OR locate the storage above your cabin, use a small pump to feed the tanks, then gravity or pump on demand, the cabin supply. If you choose solar, the storage above option is the best as the solar pump is a simple setup...just panels/pump, no battery/etc.....sun shine, water pumps. Put a float switch on each end so it quits pumping if the tanks are full (unless you want to feed a fish pond or something like ours does) and a float switch on the spring end so the pump doesn't run if the spring output is insufficient.
Anyway, good luck with your project. I love little 'on the homestead' engineering projects.
Some pics of his cabin: (Basement was 14' tall to get the first floor up to grade, so the height of the 2500 gallon tank was easy to handle)
View from the metal catwalk around the outside is pretty nice ! It was a fun project since I got to use his checkbook....ahahaaaaa.
You can see the edge of the water tank next to the power setup I put in to use the roof solar panels. The solar also powered a small pressure pump that took the water out of the tank and supplied the cabin.
I always felt like the amount he had for the cabin use would be kind of 'iffy' IF he intended to use the place year around, because we can get some might dry spells here from time to time, especially late summer, early fall. He had plenty of room in the basement for another tank, and me personally, I'd have put it in to catch winter/spring time run off, which can be when we often get excessive rain. But it worked for him, the way he used it.
But my first choice would be what DL said above, and what I did on my own place....use the spring. Our spring is located high enough on the mountain of our place that it gravity feeds the storage tanks, and then on down to the house. I put in two 1500 gallon plastic tanks in a 10x20 shed I built back into the bank below the spring. Insulated inside with foam board and it has never frozen. Ran a 1" line down from the spring, then 1" on down to the house, plus another 1" overflow line off the top of the tanks that feeds our 2 small, dug fish ponds in which we raise catfish. Way I piped it, water also feeds the chickens and cattle with a near continuous source of fresh water, then the excess from that flows to the ponds.
Shed that holds the tanks. I made the front wall out of 2x4 so if I ever HAD to replace the tanks for some reason, I could remove the wall and change them out. Never been an issue to date.
Couple things about the spring. Right now, enough water comes out I could generate power from a water turbine ! But in the fall, it has never quit, but will get down to maybe a pencil sized dribble of water...less than 1 gpm for sure. But with 3,000 gallon of storage, even that is more water than you need over 24hrs, so we've never run short.
The distance to our house from the tank shed is around 1500'. In retrospect, I WISH I'd used a bigger line (line 1.5-2"), but I did what I could at the time out of lack of knowledge and lack of depth of checkbook
Pressure at the house was only low 20psi range and we did use that for 25 years. Then I ran into a booster pump while at the Mother Earth News fair in Asheville some years back and put one of those it. We had added a UV light years before that in case a deer or something pooped in the watershed around the spring, so now the setup is complete.Water setup in our basement. The larger pressure tank is for our drilled well, which I added later as a backup in case the spring ever did dry up, but we only use it for garden irrigation...prefer the soft water of the spring to the hard water of the well (well in limestone, spring comes out of sandstone), but I plumbed the system where we can use either by simply open/close valves.
Tall, gray thing is the booster pump.
Since I take it your spring is located below you cabin, you could locate a storage tank(s) below the spring, and use a pump to pressurize water up to your cabin....either grid or solar powered, OR locate the storage above your cabin, use a small pump to feed the tanks, then gravity or pump on demand, the cabin supply. If you choose solar, the storage above option is the best as the solar pump is a simple setup...just panels/pump, no battery/etc.....sun shine, water pumps. Put a float switch on each end so it quits pumping if the tanks are full (unless you want to feed a fish pond or something like ours does) and a float switch on the spring end so the pump doesn't run if the spring output is insufficient.
Anyway, good luck with your project. I love little 'on the homestead' engineering projects.
TnAndy
Veteran Member
- Joined
- Aug 9, 2013
- Messages
- 1,993
- Location
- East Tennessee
- Tractor
- Yanmar LX410...IHI 35J excavator Woodmizer LT40
You can run the water thru a 5 micron filter, then a UV light and it will be as pure, if not more so, than anything that comes out of a municipal water line. And depending on the municipality (think Detroit lead, for example), it could be a LOT more pure !
Water calc: 1" rain = 1/12th of a foot = 0.08333. 2,000 sqft of roof x 0.08333 = 166 cuft of water per 1" rain. 40" x 166 = 6,666 cuft of water per year.
One cubic ft of water is right at 7.5 gallon, so 6,666 x 7.5 = 50,000 gallons a year.
Personally I don't know how much water people use....we've basically never had a water meter, but I read it's something on the order of 80-100gal/day per person, so that would be 3,000gal/month per person, or 36,000gal/yr per person. Based on that, doesn't seem like 50k gallons of roof rain would be enough for 2 or more folks....but with some conservation.....and more storage (you ain't gonna get 4,000 gallons a lot of September/October months), it might be enough.
Last edited:
denchen
Gold Member
If the spring is there all year round, I would be looking up installing a `ram pump` and header tank with pre filter, in the roof.
