I bought a house which has an 8" well. The well was semi buried in foliage and no pump equipment was attached to give me an idea of what had been running originally. I'm hoping to revive this well and run an irrigation system from it. I'm a novice, so please bear with me.
I ran some numbers. By my calculations, each foot of the well pipe holds 2.6 gallons as the diameter is 8 inches. It is about 9 feet to the water level. The bottom of the well seems to be about 30 feet, and I did pull out a 30 foot flexible pipe with foot valve from it.
To test the well, I borrowed a 2" pump which can pump 160gpm. I connected a 2" hose and dropped it down the well 28 feet. Pretty much to the bottom. It took about 30 seconds to exhaust all of the water from the well until the pump ran dry. I then measured the water depth and timed how long it took to refill. I was unable to see the bottom very well, but could see when it got to around the 22 foot mark. I made multiple sets of measurements, but it averaged at about 1:45 to fill back to 22 feet from 28 feet. As the water level rose higher and higher, the rate at which it did so slowed down.
To fill back from 28 to 22 is 6 feet, or 15.6 gallons. If this took 1:45, then I concluded that I have approximately a 10 GPM refill rate at this depth. Based on this, I would think I should be able to run an irrigation system with a pressure tank as long as I do not set each zone to have too many heads.
Are my assumptions/measurements correct? What am I missing? Is there anything else I should be doing to test this well?
If I do indeed have a 10 GPM refill rate on the well, then how should I take that to size the pump I need? Do i just find a pump that can pump around 10GPM from 25 feet or so (if possible)? Maybe put in a submersible?
Go easy on me!
Thanks in advance.