Dripline problems

Discussion in 'Homeowner Assistance Forum' started by TractorSteve, Mar 13, 2019.

  1. TractorSteve

    TractorSteve LawnSite Member
    Messages: 2

    I am a custom home remodeler, so this is not really in my wheelhouse but I'm working on my own property. I have 4 similarly sized beds that are each about 75x35 ft on about a 30 degree slope. The soil type is a sandy loam/clay mixture. each bed has 2-3 well established trees and smaller, decorative trees/plants will be added later. We decided to put in a dripline irrigation system. with our soil, we bought 1/2 in. .6 gph dripline with internal emitters and used a spiral pattern starting from the top tree then moving to the lower tree aproximately 3 feet apart. Later a dedicated waterline will be ran, but for now, i have a 3/4 in hose running about 150 feet from the house and connecting in at the upper tree. After getting around 500 ft of dripline installed, we realized our supplier had given us 1.0 gph instead of the .6 they suggested. After turning on the water at 40 psi, the dripline works around the upper tree, but the further down it gets, more and more emitters are not emitting. By the end of the line, 1 in 8 or so are dripping..

    -Would tying the water source in to more spots along the dripline help?
    -Should I pull up the 1.0 line and replace it with the .6?
    -Is a 3/4 in hose with 95 psi at the house sized correct to feed approx 500 ft of 1/2 in dripline?
  2. rlitman

    rlitman LawnSite Silver Member
    Messages: 2,147

    Static pressure at the house doesn't tell me about flow. Figure out the pressure at the hose bib (install a T) when the line is dripping, and then you will know if it's enough.

    Instead of tying into the end of the drip line, can you tie into the middle? 500' is an awful lot of line. Also, you tell us the emitter rate, but not the spacing, so we're still missing some necessary data.

    If it is really too much flow, perhaps splitting it into zones would make more sense than ripping up all the line.
  3. greenmonster304

    greenmonster304 LawnSite Platinum Member
    Messages: 4,076

    He said it was 1.0 gph he requested .6 gph. 500’ of 1.0 gph drip tube with 12” spacing is 8.3 gpm. You might get that out of a garden hose but I wouldn’t use any pressure regulator. Also I agree feeding from the middle and or multiple location will help. Don’t pull the tube if it doesn’t work just make it two zones.
  4. rlitman

    rlitman LawnSite Silver Member
    Messages: 2,147

    When I asked about flow, I was wondering what flow the hose bib can deliver, not the emitter flow rate. The static pressure doesn't tell you much in the way of the flow capacity of the hose.

    I've seen drip line with emitter spacing at 6", 12", 18" and 24". Yes, 500/60=8.3, but that was another assumption I wasn't positive about.

    Yes, feeding from multiple locations could even out the pressure along the length of the drip line, but it sounds like the flow available from the hose just isn't enough to deliver sufficient pressure to the drip line, hence you get the dramatic pressure drop (even when the elevation change is helping) that leaves the farther emitters dry.

    I suspect that splitting this into two zones will be the best short-term answer (to get the best use of the existing 3/4" hose), but we don't know enough yet to know if it can be run on a single zone from a larger supply line.
  5. OP

    TractorSteve LawnSite Member
    Messages: 2

    I appreciate the quick response. The emitters are 12 inches on center. I actually have a pressure gauge tied in right after the house connection to the drip line with a shut off valve there. The pressure where the hose connects to the drip line is 40 psi with the valve open and 95 psi when closed. Although I’m finishing up another project and won’t get back on this until next week, it sounds like my first test will be to add a Y to the hose and tie in to another spot further down the drip line and see if this resolves it. If not, then I will separate the drip line into 2 zones. If that’s what I end up needing to do, do you think that a 5/8 hose will be enough for less than 250 feet of drip line? Eventually, I will be running permanent lines underground with the shutoffs in my mechanical room.

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