Too much gravity in gravity spring system?

Hey all,

Posted recently about my problems with the gravity spring at the house we moved into recently. https://permies.com/t/193100/gravity-spring-water-house#1599631

It turned out to be two separate problems - air in the pipes of the house, and air in the pvc pipe running from the spring to the well. Fixed the air in the pipes in the house but I'm still trying to work out the connection between the spring and the well.

The spring is about 150m up from the well, and the pipe runs downhill the whole way to the well. My problem is that the strength of the gravity is so great that when I prime the pipe at the spring (e.g. pump water down it until it is full of water), the gravity alone sucks so much water down that the spring is depleted before it has a chance to fill up. This is a problem because a) I don't need that much water flow and b) when the spring depletes, the pipe sucks air. The pipe is 1 1/4" black PVC pipe. Normally the pipe is submerged at the well but this happens even when it isn't submerged in the well.

There is a metal T-junction about 3/4 of the way down the run, connecting the pvc pipe. Would it be an acceptable solution to fit a ball valve and control the flow using the valve? So it would be maximum pressure all the way to the valve, then I could control how much water to actually release into the well. I can't see any problem with this in the warmer months, but we live in central Sweden so expect cold winters way below freezing, I'm trying to work out if that would be an issue? The pipe would be at quite a high pressure (until the valve) but the water should be constantly moving.

Aside from that, is this a common problem e.g. force of gravity too strong for the water supply? Is there another way to remedy it? I'm not sure how they had it set up when I moved here but it was more of a trickle than I'm able to reproduce, perhaps they introduced some amount of air into the pipe to limit the amount of water coming down?

Thanks

Hi Luca;
I recall you "helping" the pipe at your spring completely fill and then the suction started and your downhill well overfilled.
What would happen if you let the 1.25" black poly pipe just flow with however much water is coming from your spring?
Do not help it, but allow air to be in that line.   The lower line at the well to your house is the important one to not have air.
Your thought of a valve partway down the hill should work but the freeze potential is much higher!
Once a water line freezes mid-winter you are in for tremendous work to attempt to get it thawed.
Sometimes a temporary line is the only viable solution.


I also live with a gravity system.  Artesian water flows up out of the mountain.  My spring box sits 4' downhill.  I have 2200' of 1.5" line with 300' of vertical drop that runs down to the house.   I do not have a midpoint open well as you do. My water flows down to the house, it supplies the house and gardens as well as running my mico hydro 24 -7.  From the hydro, the water is sent down a separate line that supplies water for livestock and then free flows into a created wetland.
This makes for the constant movement of the water flow, no matter how cold it gets ( in Northern Montana) my water never freezes.

I am wondering why your system has the "well" part way down the hill?
Is there a spot where excess water could flow away year-round down at your home?

My guess about your system is that the supply spring up high does not produce enough water to supply the needs at the house.
The well was dug to provide a reservoir to compensate for lower flows from up above.  a partially filled line that is above ground would not freeze as long as it keeps flowing. Your well below would not freeze being in the ground and the buried pipe to your home would also not freeze and be able to be shut off at any temperature.

Hi Thomas,

Thanks for your informative reply.

You're correct, if the house was connected to the spring directly then it wouldn't supply enough water for say a shower, or the washing machine. It might if I did a bit of work on the spring but at the moment it's just completely open (no box) with the pipe submerged about 1" in water (we do metric here but I'll try with imperial as this site seems mostly American). The well acts as the reservoir, storing water for domestic use. It isn't mortared, so its just rocks set in soil, so I think it just naturally overflows into the surrounding area (not ideal but thats how they set it up).

At some point I'd like to get rid of the well and have a food grade bucket (either buried or elevated) slightly further up the hill, which would be cleaner and also introduce a bit more pressure into the pipe running into the house (water pressure in the house isn't great) but that's a job for next year.

At the minute I actually have it set up the way you've proposed, and there is a trickle of water coming out. I'd guess maybe a litre per minute, maybe less, but I haven't measured. When I made the post the other day I thought that wouldn't be enough but I have been monitoring the well and it has been full the last few times I checked, I will continue to keep an eye on it.

In that case, I will avoid a ball valve for sure as the last thing I want is a frozen pipe in the middle of winter.

I guess my concern is the water flow is so little that it might freeze, is that a possibility? Obviously the water comes out of the spring at a certain temperature year round, and will be constantly moving until it reaches the well, I'll try and get a video to show the flow rate.

I'm from the UK and this is only our third winter in Sweden and our first in a house we own (which is a lot more off grid than the last few places we lived), I'm still getting to grips with the long cold winters we have here as in the UK temperatures just don't get that low for this to be a concern (and also spring water systems are very rare!)

I'll post a video tomorrow, hopefully you can let me know what you think

Thanks again!

Hi Luca,
We have a very similar set up to yours, although our system at the moment is set up with 'hill water' (a pipe in a stream) rather than the proper spring that we should be using. Our spring and header tank (your 'well') are almost at the same level, and like you our spring would not have enough flow to supply the house with a bath full of water at a time hence the header tank. The system is set up so that the spring water should fill a  little tank and then overflow via a submerged pipe into the header tank, which then constantly overflows.
The spring water here is about 12 degrees Celsius year round, so has never frozen (our typical minimum winter temperatures are -5 C, but we have had as low as -12 C on occasion. As long as your water is flowing you should be OK. The pipe between the header tank and the house is the one more likely to freeze, since that one isn't constantly flowing, only when meeting the house demand. Ours is buried only about 6 inch to a foot in the ground and so far we have not had any issues with it.
I've attached a schematic of how our system should work. Our spring is only about 10m or so above the house, hence the rather strange header tank arrangement, to get maximum pressure.
Apart from the spring tank itself being leaky so we have no reservoir to take the water from, we get issues at the moment because of algal growth in the pipe which currently we use to take water from the stream to the header tank. Every now and then we check the water level in the header tank and have to give the feeder pipe a rod though to clear the plug of algae. It soon grows back though...one day we'll reinstate the spring and I'll be able to drink the water without boiling it again.

Why not just use a valve and dial the flow to the amount your spring is replenishing itself?

They make flow control Valves just for this but honestly a quarter turn ball valve can be partially turned to restrict the flow

This is a very low cost and easy fix

Luca, sometimes people fiddle with springs and ruin them.
I suggest you concentrate on the tank, rather than a well which will waste spring water with leakage.
Have you been able to talk with the previous owners about the system?

I am guessing you will have trouble with a frozen pipe from the well unless its put underground deep enough.
Is that possible?
Would it be possible to have a tank in the house, connected to the spring and allowed to drain continuously to prevent freezing.
Water could be supplied to the house via a pressure pump within the house from that tank.