Gravity-fed water?

Discussion in 'Homesteading Questions' started by Janis Sauncy, Dec 8, 2006.

  1. Janis Sauncy

    Janis Sauncy Well-Known Member

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    Ok. I just had my second repair in six months on my well's pump. I'm not sure yet what the problem was this time because it was fixed yesterday while I was at work and I got home kinda late and I didn't call the repair guy (plus I'm procrastinating because I'm not sure how I'm going to pay for it).

    So....my question is about gravity-fed water systems. The hillside behind my house is full of springs. Even during the summer months, a couple of the springs continued to flow out of the hillside. Is setting up a gravity system practical and affordable? Is it possible to get water from the system without relying on electricity (I hate not being able to flush the toilet when the power goes out)? And, who would I go to to set up such a system? A well-person?

    A guy at work told me that's not the way to go. Too much possibility of contamination.

    Just wondering......
     
  2. The Paw

    The Paw Well-Known Member

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    Depending on the slope of the hillside, altitude of the springs, and how deep you need to put a water line to avoid frost, a gravity system might be practical. You would need some sort or resevoir or cistern at the spring source, and the altitude and volume of the cistern would determine how much pressure you would have in the line.

    I wouldn't use a surface spring for drinking water though, as there is a higher risk of contaminants. But you could still use it to supply the toilet and for washing.
     

  3. Windy in Kansas

    Windy in Kansas In Remembrance

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    One place to start might be to look at a topographic map to see just how much of a rise there is between the house and the spring/hill. Most of the maps show 20 foot rise increments.

    Pretty doable if you have enough rise. However you won't be getting much pressure at the house in all likelihood unless you have considerable rise.
     
  4. Silvercreek Farmer

    Silvercreek Farmer Living the dream. Supporter

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    Good thought Paw, Just the toilet and and clothes washer would save a lot of wear on your pump...
     
  5. big rockpile

    big rockpile If I need a Shelter

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    I have a friend that gets all their water from two Ponds at the top of their hill.They have plenty of Natural Water pressure.They have a very good Filtration System fixed up.Don't know all the details.Just know it works very good for them.

    big rockpile
     
  6. vicker

    vicker Well-Known Member

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    Our spring is right at 120' above our house. The cistern is another 1o or so below the spring. I have a 1" poly pipe feeding down to the house. I haven't measured exactly, but at the spiget outside I can fill a 5 gal bucket up in less than 15 seconds :D
    I dug the spring out, back filled with limestone in a heap, covered all with 4 mil. plastic and then 2' of earth seeded in grass. It has a cement disk top to access for cleaning. Dang good water.
     
  7. punkrockpilot

    punkrockpilot Well-Known Member

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    We get our water from a spring on the hill behind the house - which is 105' in elevation above house. We have a 165 gallon tank holding tank up there with an overflow to return water to the spring stream. The water comes down 3/4" black tubing that Home Depot sells. I measured our minimum flow at 6 gallons/minute in the summer.

    Here is the formula to see if you have enough pressure
    Pressure = 0.052 * ρ * h

    Our house
    105 feet x 8.33 pounds per gallon x .052 = 45.4818 psi

    I am not sure what someone would consider to be the minimum suitable pressure - maybe 30 psi?

    Easy way to figure the rise is to get a stick 5' long and a laser level = put the stick at the start and put the level on top and mark a spot, move the stick to the spot and just keep going till you get to the top - 5' at a time.

    Only problem is once this summer a critter chewed a little hole in the tube - only took a minute to fix.

    Hope this helps - on the other hand - if I already had a well I would stick with it.
     
  8. MELOC

    MELOC Master Of My Domain

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    what does the constant .052 represent? does the size of the pipe come into play?
     
  9. Windy in Kansas

    Windy in Kansas In Remembrance

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    To determine water pressure---i.e. pounds per square inch at the bottom of a column of water, you multiple the feet of height of the column (head) X 0.434 according to "Pocket Ref" by Thomas J. Glover. It is one of those little reference books you often see awaiting purchase at a checkout stand.

    It doesn't matter if the column of water is 20 feet in diameter or 1 inch in diameter, the pressure at the bottom will be the same if they are of equal height.

    Flow is a different matter much of which is determined by pipe diameter and distance, number of fittings in the line, and pressure which is determined by head which is described above. You can increase the flow of water to compensate for lack of pressure somewhat by sizing the pipe larger to increase the flow that way. A ten inch line will still never deliver the pressure of Flagstaff, Arizona if there simply isn't the head or pressure to go with it.

    Showering in Flagstaff will nearly peel your hide off.

    When you folks talk hills I'm thinking maybe a rise within 100 feet of the house and 30 or so feet tall, for us flatlanders your hills are more like mountains to us. My property is about a ¼ mile from front to back and has about 80 total feet of topographical rise. Not much pressure available even if I lived at the low end and had a spring on the high side.

    A gravity flow system is what we had where I grew up. Our "tower house" had an overhead tank in it that was maybe 20 feet above ground level. Not much head in 20 feet meaning we had low water pressure at the house even if the flow was good.
     
  10. Janis Sauncy

    Janis Sauncy Well-Known Member

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    I'm getting lots of good information here and I really appreciate it.

    I still haven't talked to the repairman yet but, since the old pump is laying on the ground next to the well, I guess it's safe to assume I have a new pump. I'm going to have to grow some b***s and call him tomorrow and find out what my bill is.

    I was under the impression when I bought this place the well was installed maybe around five years ago, if I remember right. I wonder if that means that priot to the placement of the well, a gravity system existed and for some reason didn't work out. I'll have to call the guy I'm buying it from soon and ask.

    If I were to want to go to a gravity system, even for backup, who would I hire to set it up? As smart as I like to think I am, I'm not sure I could tackle a project like this without professional help.

    Anyway, thanks for the information already posted and thanks in advance for anything else anyone can think of.
     
  11. SmartAZ

    SmartAZ Well-Known Member

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    The .052 makes the result come out in pounds per square inch. It's easier to just divide the height in half and guess slightly less than that. So a 100 foot fall will give a little under 50 psi.

    You can also use gravity to lift water. The hydraulic ram is simple and reliable, and suppliers will help you figure lift versus flow for your situation.
     
  12. fantasymaker

    fantasymaker Well-Known Member

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    64.5 devided by 144 give you the weight of water in a colum 1 foot tall
     
  13. Tiffin

    Tiffin Well-Known Member

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    We have gravity fed water. The system was put in by the previous owner. A local excavater person put it in. There is a very deep cistern and then pipe probably 4 or 5 feet deep and about 500 yards from the house. The pressure was okay but we ended up putting in a booster pump in the house. We also had a water filter system put in because of sulfur and iron. The prevous owners didn't care plus didn't have the money. Anyway, now that it is all set up it's great.
     
  14. Windy in Kansas

    Windy in Kansas In Remembrance

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    I believe your formula must have some component missing. How can you determine the weight of water in a column without knowing the diameter of the pipe? Ex: A four foot diameter pipe one foot tall will have much more water (determined by weight) in it than a 6 inch diameter pipe one foot tall will have.

    The aforementioned "Pocket Ref" states: Pounds Water=Pipe Length feet X Pipe diameter inches squared X 0.34

    Along those lines, one gallon of water weighs 8.333 pounds and a cubic foot of water weighs 62.5 pounds and contains 7.5 gallons.

    Janis, I really don't know what tradesman you would contact to have such work done, I'm a do it yourselfer. I suppose I'd start by speaking with a plumber and ask their recommendations.
     
  15. fantasymaker

    fantasymaker Well-Known Member

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    You dont really care about the total weight its pressure that counts so pipe diameter is ilrelavant
    Just figger 1/2 pound pressure per foot of height diference thats in the right neighborhood
    .4479146 pounds of water in a 1 inch square collum 1 foot tall. so 100 feet of height gives you 44.79 PSI
    Humm water must b a little heaver here? :shrug:
     
  16. highlands

    highlands Walter Jeffries Staff Member Supporter

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    The water for our house has come via gravity fed piping, down the hill from springs up on the mountain, for about 200+ years. The old pipes were made of wood. It works wonderfully. We get about 35 psi. We use modern 1" black plastic water pipe but other than that the system hasn't changed much in all that time. It is quieter and more reliable than pumped well water. We have never had a problem with quality or contamination. I don't let the livestock in the area above the springs. Visitors are always commenting on how great the water tastes here.
     
  17. Ole Man Legrand

    Ole Man Legrand Well-Known Member

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    Janis What part of the country are you located? Are there other gravity systems? if you have others you could get some one that put in his own system to work for you. Maybe a hot meal and a case of beer might get the job done . here in N.C. there is a lot of these systems. My friend left the kitchen faucet on all the time to keep the water from freezing & to keep the water fresh.
     
  18. TnAndy

    TnAndy Well-Known Member Supporter

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    We have a gravity system also. Been our only source of water for the 25 years we've lived in the house.

    I built a small 'catch' basin out of brick at the spring, and then brought a pipe down to where I could get a tank in the ground.....we bought a new, 1000gal concrete septic tank from a local tank company, and they cast be a 1" galvanized fitting in the bottom to hook my line to the house. The line is about 1200' to the house, but the vertical drop is about only 70-80', so we get about 30lbs pressure at the house.....not city pressure, but it's enough.

    About 10 years ago, I decided we needed more storage capacity, as our spring gets down to just a trickle in the late summer/early fall, so I built a 10x20 cinderblock building back into the hill just above where the concrete tank was, and put 2 1500gal plastic tanks in the building, and hooked that into the line coming down, cutting out the concrete tank. Also ran a 3/4" overflo from the tank tops down to my pond so I can see that there is water filling the tanks, and more. That little bit of increased height helped the pressure, and I feel good about having 3000 gallons of water all the time.

    I also added an ultraviolet light sterilizer inline in our basement......just in case....though we used the spring for 15 years without one just fine.

    Recommend 1" PVC line MINIMUM, and if I had to do mine again, I'd probably go to 1 1/4" or 1 1/2". You can't go too big, but you can sure go too small. The longer the run to your collection point, the more pressure loss you will have with small lines.

    As to WHO you'd get to do it ? Dunno....I do everything here myself....I guess you'd find an excavation/backhoe sorta guy.

    But I'd take gravity fed ANY DAY over any other way of supplying water. If you have a way to do it and aren't, you're missing the boat.