Sizing of new well casing, pump, CSV for irrigation and household

Discussion in 'Pumps and Tanks Well Forum & Blog. Water is life.' started by TJanak, Jun 29, 2018.

  1. TJanak

    TJanak Member

    Joined:
    Sep 9, 2009
    Location:
    South TX
    Doing some thinking and preliminary planning here. Would like to drill a well in the next couple of years that could be used for both irrigation and household use. Household use would be your typical 4 person family in a 3/2 house. Irrigation could be up to several hundred trees on micro sprinklers, but would also like the option of something like a lateral move system for grass that could use up to 200 gal/min (rough guess).

    Would like a submersible pump with a CSV but don't know how high of a GPM I can shoot for and still have a setup that will work for small household usage. Typical pump setting is 100' here (not sure on static or pumping level). Have been told better quality water is available deeper but I don't know how much deeper (this would be a major consideration since the shallower water has higher SAR and TDS/conductivity). Also not sure what size casing would possibly be needed, and I guess that would depend on depth of sand and pump size.

    Thoughts welcome!

    Travis
     
  2. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    200 GPM is a lot! I have done golf courses and tree farms with much less. That would run about 100 sprinklers all at one time. We can do it if you want and can get the water. But most house systems use less than 25 GPM, which can still run 10 sprinklers at a time. The house will only use about 5 GPM, so you size the pump to the irrigation and let the CSV take care of the small uses for the house.

    Casing size also depends on the size of pump. 25 GPM will need at least 4", and 5" or 6" would be better. But 200 GPM will need at least 8" casing, and 10" or 12" would be better.
     
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  4. TJanak

    TJanak Member

    Joined:
    Sep 9, 2009
    Location:
    South TX
    200 GPM is being optimistic, realistically I could get by with much less. But I'd like the option of a small pivot or lateral hose drag system for watering pasture. Yes I know guys with 150 GPM in a 1/4 mile pivot in your neck of the woods but then again they are just big humidifiers really! But I'm talking less than 1/4 mile for sure.

    What is the largest practical single phase submersible that you would use? Electrical service is another consideration. 3 ph is half mile away on the highway.

    But basically you're telling me that we could practically use a setup as large as this for household use as well via the CSV? Would the electrical costs be out of line?
     
  5. Boycedrilling

    Boycedrilling In the Trades

    Joined:
    Sep 30, 2013
    Location:
    Royal City, WA
    In single phase submersible Pump motors 5 hp is the largest 4” motor. 15 hp is the largest 6” motor. With 3 Phase 460 volt power, you can get a 15 hp 4” motor. 60 hp in 6”.

    Years ago, I worked for an irrigation company that installed center pivots. When we used impacts, on top of the span, we designed for 10 gpm per acre irrigated. When we went to drops and rotators, we could drop that to 8 1/2 gpm per acre. 15% water savings from wind drift and evaporation. Can go as low as 6 1/2 gpm per acre. So you want 60-100 gpm to irrigate 10 acres. These numbers are for your irrigation system being your primary source of water, rather than supplementing rain. Where I live we get about 12” of precipitation a year, mostly in the winter. Or when you cut hay. Or when the cherries are just about ripe.
     
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  6. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    Drill and test the well to see how much it will make. You may have to adapt your irrigation to match the well, instead of being able to make the well match the irrigation you would like. But you can make it work either way. Just like the 150 GPM pivots in my area, they are better than humidifiers and will get the ground wet, they just have to start early and stay late. If you have all the water you want, you can irrigate the whole place in a few hours and turn the pump off. But if you don't have a lot of water, you just have to keep it running 24/7.

    We make CSV's for pumps up to 5000 GPM, and you can still use them with only an 86 gallon size tank. I set up a golf course in Nebraska with a 6" CSV for their 75HP, 1000 GPM submersible using only an 86 gallon pressure tank. The CSV can supply the sprinklers on the golf course with up to 1000 GPM when needed, and will also supply the superintendents house with as little as 5 GPM. Oh yeah, still running since 1994.

    But you really do not want any larger pump for the house than necessary, as it cost more to run and repair when needed. If you have large enough casing, you can set a 10-15 HP in the well for irrigation, and set a 2HP just above it for the house.
     
  7. TJanak

    TJanak Member

    Joined:
    Sep 9, 2009
    Location:
    South TX
    Thanks for the replies, you've given me some good info to go on. I know I'll have to match any demand to what a well will produce, I guess I just needed some guidance on what to ask for when talking to a driller. Maybe a 6" casing will be the minimum to get me into the pump size I think I'll need without getting the price prohibitively high. I think my next step it talk to the few well drillers in the area and see who seems knowledgeable and helpful for what I'd like to do.

    Maybe I'll ask each one their opinion on variable speed drives!
     
  8. valveman

    valveman Cary Austin Staff Member

    Joined:
    Mar 15, 2006
    Occupation:
    Pump Controls Technician
    Location:
    Lubbock, Texas
    Lol! They will say they love them. Gotta make enough money to put the kids through college somehow.
     
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