Sprinkler system pipe choice

I’m tired of moving hoses for our lake place to mow. I had installed a 1" in-ground system in the main area years ago and have been using it without issues. But I still run 5 other hose lines and want to bury the system. I currently run a 2 hp pump that is rated at 83 gal/min with 2" outflow and can run all that at once. As an experiment, I built a 1 1/2 inch PVC line with 10 rotary heads. I like the rotary heads, pretty sweet and do better against the wind. With the main line and 4 hose lines running, the end head of the rotary line runs around 20 psi. It’s sitting on the surface, I’ll ditch witch and drop it when I get everything planned out.

I need to make another 3 or 4 lines. I’ve gone through several website planners and tried to calculate pipe size, number of heads, etc. and have only created mass confusion for myself. I am mainly debating what size pipe to use. I did the 1 1/2 inch only cause it’s the farthest line from the pump and was going off one youtube video that discussed less pressures using a smaller line. Not sure it was necessary. Thinking of just using 1" for the rest of the system. Again, have tried to use the tables and formulas to calculate, but not confident that I have any answer that is real. Any tricks or thoughts from you experienced sprinkler folks?

Also, ideally , I’d prefer to run them all at one time, but if pressures do not allow, am trying to develop a plan to run parts at different times. Understand, most of this is distant control. Use a Vera Z-wave system to control a Z-wave switch to start and stop the pump. Since I’m looking at 1 to 1 1/2 inch pipes, can’t just slap a hose timer on different lines. Wondering if any one has used a Z wave relay to control a solenoid valve? Can easily get the right size valve and relays, even found one with Z wave, but they wanted almost $500 so forget that. Thinking of trying to build a controller, any experience with such?

Any thoughts or directions to good websites for info appreciated.


If you’re going to drop the pipes into the ground, why not just drop a control line in along beside? It’s cheap and practically bulletproof. I’d use at least a 7 or 8 wire line, on the off chance that one breaks, you have multiple others to just hookup. Then you can just get a traditional zone controller, easily available at a home center on online.

We draw lake water, and I don’t know what the throughput of the pump is, but we get about 7-8 sprinkler heads on a circuit before pressure drops too far to add more. Most of the system is 1”, but the upper zones are 3/4”. The side yard is about 20-30’ higher vertically than the lake, so the pump really has to give to get pressure to the two zones up there. I noticed that it was a little soft, and the irrigation guy came and changed the nozzles to slightly smaller diameter ones, and it all works great now. (I do not know what the GPH before and after was, only that he “increased” pressure by installing smaller nozzles. To compensate I run those zones about 20% longer.)

History: I added one zone two houses ago, the entire system (12 zones including gardens), and none here - although I have paid someone else to take us from the original 3 when we moved in to 8. Because I did not plan for a side garden (which we now have) I have added mini-sprayers onto a lawn circuit which takes care of the garden, but without individual control; that zone runs both lawn & minisprayers for the same amount of time, and it seems to work fine.) I have always run tons of drip systems and mini-sprayers. That stuff is easy. I’m past the point of trying to run a ditch witch by myself.

One more thing: I had them add a vertical standpipe to the upper zones along a tree line which I have used for other water chores, and should we ever decide to garden, etc. up in that field it’ll be sort-of pre-plumbed.


Appreciate the insight and your experience Goofy.

My pump is not submersible, so the outflow manifold is basically above ground and simple. In essence, that is what I am thinking of but needing larger solenoid valves than usual. The hiccup is that it seems like the controllers to coordinate and run the valves that I have found have all been WiFi connected. I run control “programs” referred to as Scenes by Vera and would really like to have it all together so if a program fails, it all fails. Don’t really want the pump to work against closed valves (although could default one line open). Vera handles WiFi and Z-wave and both can be used in the same scene program, but WiFi at the lake is a bit more variable. But I may go that route and plan more lines with fewer nozzles.

And yes, I am dropping a 1 1/2 line separate, but in the trench to bring lake water out to my garden edge. But I sincerely appreciate any and all thoughts/ideas/comments. Trying to think and plan rather than have to fix/redo/wish I had down the road.


I would go with poly pipe. This is a video of a machine to put it in with but the one I used you could actually ride on. I rented it for a day and the machine dug the trench and put the pipe in the trench as I went along. It was really sweet because i first started doing it by hand and this made that so much easier.

Poly pipe doesn’t break during freezes but you still want to blow it out because any connectors in the line will bust if frozen. The poly pipe tends to be able to expand and contract… The fixtures are connected by putting a connector into the tube and crimping a metal band around the connector to hold the pipe. You want to have a torch or something to be able to make the poly pipe pliable before putting the connectors on. You can use any sprinkler head because the extension coming from out of the ground will fit the connector in the poly pipe.



looked more like this but could ride on it.


A late reply, but you might want to send the specifics to Rainbird. They offer a planning service (or at least they did when I was installing). You send them yard dimensions, GPM of your water source, and they figure out how many zones you need. They’ll make specific equipment recommendations, but the key in your situation is zones. I doubt you can run everything all at once. You can use any equipment you like. I didn’t use Rainbird valves, for example. But I did use their heads.

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Our system is run off of municipal reclaimed water.

Mains are 2" and feed 11 zones. Zones are 1/2" pvc to a flex line lateral at the head. No more than 7 heads are in any zone. We have 40 points of irrigation in the system and the mains are in a U shape with each valve at a Tee to the main line.

As long as the zones do not have leaking/broken heads, the system works very well.

Thanks for the thoughts!!

I finished the system. Put in over 400 feet of PVC. Two of the seven lines at 1 1/2" and the rest at 1inch. The 1 1/2 lines were major areas. I have over 45 heads of rotary sprinklers. Two of the lines go to a hose bid which connects to tripod sprinklers (2 each). I did make a manifold with valves, but I leave them all open manually and can run it all at one time with good pressure and coverage. I will still wire the valves next year as I anticipate some variable area needs and that provides me control.

The issue for me was the areas to put in pipe. I had areas where despite my pulling about 12 old stumps and roots with my tractor/backhoe, there were residual roots that were problematic. Despite using a trencher, those areas required me to literally breakout my sawzall and axe to cut through roots. The polypropylene (flex) trencher/layer would never have worked.

Appreciate all the input and thoughts. Love the rotary sprinkler heads.



Heh. I had to do that a couple months ago. I had two problems. First, I had a leak underground, and second, water was not flowing in one area. The leak turned out to be another rupture of the poly pipe. I replaced that all with PVC. But to do that I had to dig out a root, and then use my reciprocating saw to remove it. When I did that I found the source of my second problem. The root had compressed the poly pipe closed. It was probably a 5" diameter root.

I’m actually wondering if I should do more to make sure that root doesn’t regrow. I cut about a 6" length of it so I could lay the PVC. I’m assuming the end piece that was disconnected from the tree will die, but the part that is still attached to the tree…will it grow more? Or will the tree abandon it?

Probably depends on the type of tree
I’ve done this to a Japanese Maple and a cedar in the last couple of years. I’ll tell you about the regrowing in 10 or 15 years if I notice anything.


The tree-attached part will grow, probably willowing (sending out multiple small shoots from the sides).

But that was the amazing thing to me, the decapitated roots didn’t show signs of growth but most were very solid. It was like they were preserved in the soil. Immediately superficial ones had more decay and rot. Suspect the deeper ones simply were a bit out of reach to bugs and stuff that accelerates decay. Anaerobes are weaker than aerobic ants/termites? Whatever it is, despite being from a tree that was dropped 15-20 years ago and having the stump ground, there was persistence. No evidence of growth, just surprisingly little to no significant decay.