We bought an old vineyard that has an existing well & irrigation system. There is a 3" pipe that comes up from the well at an angle. This leads into a vertical pipe which has a screen which then goes down into the ground and tees North and South supplying the entire vineyard. There is no pressure switch, tank, or any control system whatsoever other than a SPDT switch to power the pump. There are valves throughout the property along the mainline which turns off certain sections of the vineyard. The pressure gauge we installed on an existing garden hose valve shows 10PSI when the pump is running, though the irrigation system's drip lines have leaks all over the place. This vineyard is very old.

3" well pipe going from well to irrigation screen

We're wanting to do other types of farming on this land as well as build a house and barn with normal water pressure. We don't like the manual method of turning the pump on and off and would like to have a pressure switch at least with possibly a tank, however most tee setups we see for pressurized systems are not for 3" pipe.

Can we "tap & thread" The components of a pressure system into this 3" pipe (pressure switch, gauge, pressure relief valve, maybe a good-sized pressure tank) to create the same result of the pump switching on when one of the valves get opened? The entire system provides irrigation for over 100 acres, so getting rid of the 3" pipe isn't an option...the high volume is necessary (I think).

There is also a valve coming off the pipe as seen in the photo. Could we maybe put a pressure tee there with the outlet capped? or does it need to feed back into the main pipe?

We thought about putting in a 2500 gallon tank with an auto-fill-shutoff valve and then having a second pump with a pressurization setup to supply pressurized water, but that still means someone has to physically activate the pump to make sure the 2500 gal tank doesn't go dry.

What is the best approach to get pressurized water from this well while still serving the irrigation needs of the farm?

  • What is the geography of the property like? Is gravity-fed possible? – IronEagle Jun 27 '20 at 17:53
  • The well head is at high elevation on the property. The main line for the irrigation system runs North/South with the well head in the center. From the main line the land slopes down. Gravity feeding already plays a role here because of the slope. All the drip lines start at a higher elevation and gradually slope down for about a 750' run. The issue is not gravity, but being able to have a pressure switch on such a high volume system with such large pipes. – swimex Jun 28 '20 at 2:01

Hoo Boy! You've got some work ahead of you. You "could" add a 2,500 gallon storage tank, but why? How much does the well produce? How deep is it? What is the static water level and how much does it drop when pumping?

If you did add a storage tank, the pump could be controlled by float valves or electrodes in the storage tank.

You really have two systems here: One for domestic water and the other for large scale irrigation. The simplest solution for domestic water would be a jet pump and pressure tank if the well is shallow enough or a submersible pump placed in the well if there is room leading to a pressure tank. Both would be controlled with a pressure switch.

I kinda hate to say it, but this is a large question for here and you may need to bring in a pro to evaluate what you have. Most important are water levels (static and when being pumped and at what rate, what the well can produce. This is big for a DIY effort. Just saying.

EDIT: Thinking about this more, you should also get the water tested to be sure it's safe for human consumption.

Also, can you give us more information about the well? Is it a drilled, steel cased well? A cistern? A surface well? If we can help, i'm sure others will chime in.

  • It's a 240' deep 4.5" cased well with water at 100ft. There is plenty of water, our water rights allow for 100+ acre feet per year. I'm mostly wondering if adding pressure to this is safe as a pressurized system so the pump is on a switch instead of controlled manually. And we are in the process of getting it tested. We're getting our drinking water from other sources until figuring this out. – swimex Jun 27 '20 at 21:09
  • I assume by "on a switch" you mean an automatic pressure switch. Not knowing more, I'd be careful. Irrigation pumps aren't designed to turn on and off a lot. They tend to be high volume, lower pressure pumps of high capacity and not designed to be cycled a lot. Also, just because you have the water rights doesn't mean the well can actually produce that much. Again, I think you need to treat this as two separate systems, one for domestic use and the other for large scale irrigation. You have some heavy duty design work to do here. – George Anderson Jun 27 '20 at 21:50
  • We're definitely designing a separate system for pressurized "domestic use" for the barn/house we plan to build with the well keeping a large tank full. We just aren't sure about putting the well on an automatic pressure switch. We may need to get an adjustable one and dial the cut-off pressure down to 30-40 psi. If all the valves are closed on the system, something usually ends up leaking. – swimex Jun 28 '20 at 1:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.