Beginning Farmer Asks:
I looked at some property to possibly lease for some apple trees but the lady who owned the land couldn't tell me much. It has a well and I am thinking it may not be up to the challenge of irrigating 2.5 acres of apples. The owner said the said the well flows 25 gph. Do you think this is enough? Also the well and pump are on the property but the pressure tank and all the controls are across the street making it not ideal to get it back across. Any thoughts would be appreciated.
Farmer Mentor Answers:
She probably meant 25 gpm.
That is enough for 2.5 acres of apples. I always figure 10 gpm per acre to be on the safe side. I would recommend having the well tested before you do anything. Typically in a land lease arrangement the person leasing the land is responsible for all costs associated with the well and pump. You really need to know the "draw-down" on the well, the depth of the water, and the depth of the well. 2.5 acres of apples is a huge investment and water is the most important input.
Follow up Question:
Thanks for the input. I am hoping that’s what she meant. With the draw-down, depth of the water, and well are there any numbers I should be aware of? I appreciate the help. Agreed, hopefully it works out!
Answer:
You will have to rely on local knowledge for most of the information related to your well. The company doing the testing will be able to provide you with the basic information related to the overall productivity and reliability of the well and they will be very familiar with the regional water dynamics.
Follow up Question:
This is what she told me. Inspection was October 2011. The well is 202' deep. Water level 36', draw down 44'. Average yield 24 gpm. They test pumped for two hours straight to a final water level of 80 ft. Pump is at 180'. Do you think it is worth getting inspected again? Thanks again, you have been a big help.
Answer:
Sounds to me like you are in a good water area. We have had three dry years since the test but I'm guessing the well is probably O.K. If it was me I would take the test results from 2011 back to the company that did the test and tell them what your estimated usage is and ask their opinion about how the well would handle your system. You should also talk with an irrigation design person in your area just to get some basic irrigation system design ideas. Are you planning on drip, micros or hand moved pipe? Till or no-till? All of these things will have very different design considerations in terms of flow rates and zone design. 25 gpm might be able to handle a 1/2 acre "zone" using drip so, running straight off the pump, you may need to have 5 separate irrigation zones. The higher the delivery rate the more zones you would need. The bottom line is that you could end up spending quite a bit of money on an irrigation system adequate to handle 2.5 acres of apples. You certainly wouldn't want to make the investment in the trees and irrigation system if the well was not up the challenge of continuous flow for up to 20 hours at a time. The other huge consideration is slope. If you have any slope at all then uniform pressure becomes a design issue too.
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