Irrigation Rough Ins - Product Selection For Future Main Line

[RobK68]

Hi folks. Turning to the experienced and pros here to hopefully give me some direction.

I am doing some extensive work on my rear yard, that includes some trenching for an electrical service to the rear of my property, approximately 90'.
Although not part of the scope of this project, eventually it is planned to have the yard serviced with an irrigation system, fed by an underground rainwater collection system (RCS). These are not planned for the near future, likely 2+ years out, so I don't have a lot of specific details needed to plan out even a preliminary irrigation design. (ie dischange pressure, zone layout etc)

I would like to take this trenching opportunity to perhaps lay a main irrigation line to tap into for a future irrigation feed. The trench essentially runs the same as what the main irrigation line would run, with the laterals feeding the zones running off it. Again, the length of this main would be about 90' at that would be high once the rainwater harvesting vault is installed. The last 20' of the line would see a raise of about 3', about a 15% slope. Pressure to the system is unknown, it will depend on the pump installed for the RCS (open for suggestions as part of this question!!).

So, my question - what size and product would you suggest to install in this trench (~20-24" deep) in anticipation for a future irrigation feed, despite having critical factors such as pressures (source and friction loss etc) unknown. Is there an "average" common for a system of this size (- no detailed irrigation plan, but preliminatry info sees as irrigated lot with approx 3000 sqft of turf, and another 1000 sqft of garden - drip or spray) that would provide a "safe" future? When irrigation design is underway, the main line will be a know factor in determining pump size and zone planning.

 

[Breplum]

The turf irrigation question would be, do you plan on irrigating it all as one zone or multiple zones serving the same lawn.
For my 1,400 sq ft lawn, 1" PVC fed with 50 psi is barely enough for 8 Hunter PGP rotary heads. So maybe 1-1/4" would be safer.

 

[Sponsor]

 

[RobK68]

Hi @Breplum, thanks for your reply. Appreciate it. I don't think I'd be able to get away with a single zone system. I feel that it wouldn't be reasonable to get that much pressure to do that. Certainly the gardens would be on a seperate zone than the turf, and I figure the turf would have at least two, maybe three zones with smaller rotary heads. It appears I only have access to 1" or 1.5" 100 PSI Irrigation Poly Pipe.

This is a good starting point!

 

[Reach4]

You will need to take winterizing into account. You will need to blow the lines free of water.

Expect polyethylene pipe to endure residual water freezing better than PVC. Do not pull your poly pipe tight, but let it snake in the trench. Frost line in Ontario is 3 to 4 ft.

I don't know irrigation design, but I would look to see that these items are considered.

 

[RobK68]

@Reach4, good info in your post. Thank you. I am familiar with irrigation system maintenance, but not design and installation. So although I'm up on blowing out lines each fall, the choice of material (polyethylene vs PVC) and snaking the line in the trench is valuable. I'll have to search around for Polyethelyne. If I can't find it, or it's cost prohibitive, I'll have to ensure proper burial depth and be prepared to put air through the system (which I probably would anyway).

 

[Reach4]

@Reach4, good info in your post. Thank you. I am familiar with irrigation system maintenance, but not design and installation. So although I'm up on blowing out lines each fall, the choice of material (polyethylene vs PVC) and snaking the line in the trench is valuable. I'll have to search around for Polyethelyne. If I can't find it, or it's cost prohibitive, I'll have to ensure proper burial depth and be prepared to put air through the system (which I probably would anyway).

When I search for poly, I tend to use "SIDR" as a search term, but some seem to call that IPS (iron pipe size). There is also a pipe called funny pipe special for irrigation. I am not sure if they are sized the same ID as SIDR. SIDR is for barbed fittings, and usually has a worm gear hose clamp clamping it on.

I don't have irrigation experience.