Subsurface irrigation

Old 06-12-15, 11:08 AM
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Subsurface irrigation

We just bought a new home in Northern Colorado, and are looking to install an irrigation system for the backyard. We want to be water-conscious, and are investigating a sub-surface drip system. I've done a lot of online research, nad have found some good videos, but no real how-to's from start to finish. It seems to be pretty rare here in Colorado, so I'm looking for a little more information than I can find online.

For reference:
- approximately 2500 sq ft of turf
- soil is clay-loam (fairly heavily clay - about 25%)
- installation area is mostly level, with a slight slope across the lot, which we cannot change
- I do have experience installing several "Standard" systems

1 - Will subsurface work in my climate?
2 - Should I be concerned about the dripper pipes moving with the freeze/thaw cycle?
2 - If I'm planning to use 1" poly pipe as the feeder lines, do I still need to bury them at least 12" to get below frost line?
3 - How close should the dripper lines be to any hardscape (we have a patio in the backyard as well)?
4 - Will the slope of my lot present a problem for subsurface?

I'm looking forward to being able to save water and better irrigate my lawn. Any advice/tips/resources would be greatly appreciated!! Thanks in advance.
Old 06-12-15, 02:05 PM
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I'm not a pro at this, but have done some in milder climates.

1) Subsurface drip irrigation may not work effectively for the reasons you state. The soil is so compact with little to allow water to move through it.
2) Your pipes will move with freeze thaw cycle, but not because they are pipes. Anything subsurface that is not intended to be there will move.
2a) Your frost line is closer to 3'. Look at your water meter. It is super deep in the ground. I would think your supply lines would need to be that deep. However, if it is a summer only system and you drain it completely, blowing the lines out with compressed air, you should not have a problem with the frost line. My daughter's house in Denver utilizes piping not quite a foot deep for surface irrigation, but they remove the control valve via unions every winter and blow out the lines.
3) Soil conditions will dictate this, as well as slope of land away from such hardscapes.
4) The slope will probably enhance it as you need a low spot to allow drainage.
Old 06-15-15, 07:20 AM
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Thanks Chandler, I appreciate the input.

Where did you install your systems? Just wondering what the experience was like and how it's worked.

My plan was to dig a trench for the feeder pipes, then lay the drippers on top of the soil, top dress with about two inches of soil, then lay sod. That would make the dripper pipes about 4" deep, and the feeder pipes about 16" deep. At our previous home, the feeder lines (black poly pipe) were that deep, and we didn't have any problem with freezing.

I think I'm willing to give it a try, just to see if it will work around here. I know some local farms have installed subsurface system, but that's a different kind of irrigation with a different goal. And I'm not sure how it's worked. If there's some specific reasons why I should try it, please let me know.

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