Irrigation system for a large (still) empty plot

My first idea:

Set everything to the cistern and in case of running empty, fill it with water from the tap?

Refilling the cistern with fresh water. For example, via float switch or sensors. Of course, it can also be done completely manually. When it makes sense to refill depends on the size of the cistern, the extraction amount per hour, etc. So never fill completely with fresh water. You also want to have space left when it rains.

Hello everyone,

I’ll take the liberty to join this thread, as I am currently facing the same problem as the original poster.
An automatic irrigation system using 24V solenoid valves is to be implemented, including the control (either via
KNX or Hunter, as mentioned here.) to be placed in the garden house and possibly additionally in the garage. The garage and garden house are at opposite ends of the property, with only one distributor it would be necessary to run pipes under the house.
The garden house and garage will have their own sub-distributions and (cistern) water anyway.
Now my questions:

[*]If the valves are installed indoors, of course you need breakthroughs in the floor slab (or outside wall?) for all the water pipes, depending on the number of irrigation zones, that will certainly add up. I can’t quite imagine it; I only find reports/instructions for valve boxes buried outside. Is installing inside possibly a bad idea?
[*]Would it be more sensible to bury a valve box in the north and south and lay the control cables there?

What can you advise me? For the garden itself, almost nothing is planned yet, but the floor slabs will be poured in the next few weeks and I don’t want to “block off” any options here.

Best regards,
Hausbaufaehig

Hello everyone,

I’ll take the liberty to join this thread because I am currently facing the same issue as the OP.
An automatic irrigation system using 24V solenoid valves is to be implemented, including control (either via
KNX or Hunter, as mentioned here). These should be placed in the garden house and possibly additionally in the garage. The garage and garden house
are located at opposite ends of the property; with only one distributor, pipes would have to run under the house.
The garden house and garage will have their own sub-distributions and (cistern) water anyway.
Now my questions:

[*]If the valves are installed indoors, of course, there need to be openings in the floor slab (or exterior wall?) for all the water pipes. Depending on the number of irrigation circuits, that will certainly add up. I can’t quite imagine how that would work; I only ever find reports/instructions for valve boxes buried outside. Is installing them indoors possibly a bad idea?
[*]Would it be more sensible to bury one valve box in the north and one in the south and lay the control lines there?

What can you advise me? Almost nothing has been planned for the garden itself yet, but the floor slabs will be poured in the next few weeks and I don’t want to “block” any options here.

Best regards,
Hausbaufaehig

Heavens, how complicated garden irrigation can be. I simply laid the Gardena pipeline starting from the two taps to the corners of the property and ended it in water sockets. From there, it goes via water distributor automatic into the various circuits with drip hoses, sprinkler hoses, drip systems and pop-up sprinklers. Everything is controlled via irrigation timers at the taps; irrigation starts at 6:00 and runs until 8:00 across all circuits. Done! The irrigation was at least sufficient for our eucalyptus to grow to almost 5 meters in 5 years :)

Gardena is not the first choice for a permanently installed automatic irrigation system. Poor price-performance ratio and the durability is also not optimal. The Gardena pipeline is the worst and most expensive option. They simply use PE-HD pipe (drinking water pipe). I have already seen the Gardena pipeline chewed through... Gardena is just well-known and also available in hardware stores.

Where does your water come from? Freshwater, cistern, or well? If it is directly from the water supply line, have a larger water meter installed right away so that you have enough pressure and flow.

Why control via KNX? I have it myself but there is actually only one real reason to use it: You have so much flow and pressure that you can run several circuits in parallel and thus save runtime. In terms of logic and usability, you will probably never get close to, for example, a Hunter Hydrawise.

If I understand correctly, you are getting a cistern. So install a good/strong pump in the cistern and run from there to the sub-distributions. The cistern needs a refill (fresh water supply line).

Sub-distribution should be as close as possible to the circuits. This saves piping. Also, use the largest possible pipes up to the distributors to avoid unnecessarily losing pressure and flow.

Since your outdoor area is not yet planned/finished, you cannot plan in detail yet. You don’t even know how many circuits you will need (of course this also depends on pressure, flow, and sprinklers). Prepare the refill of the cistern as well as power for the cistern pump. How do you plan to monitor the fill level? Automatic refilling? Where should the control be located? You will need power there as well as empty conduits for the control cables. Sub-distribution in the garage or garden house can be done if it is close to the circuits. Otherwise, it is not practical. If a valve were to leak, you would have water in the garage or garden house (do you have floor drains there?)... Better to use the tried and tested valve boxes. That way you do not have to first run from the cistern into the garage/garden house and then back out again. Since you don’t even have a slab yet, I would lay a large Kabuflex with pulling aid underneath for control cables, power (garden sockets and lighting), possibly LAN and one or two PE-HD pipes (DN40). In the slab, make an additional multi-duct for refill, power cables, possibly control cables, possibly LAN...

You have recognized in time that it is still easy to prepare everything now. The detailed planning with the number of valves, which sprinklers, drip tubing, etc., will come later.

Hello rick2018, thank you very much for the detailed answers, they really help me a lot!

Where does your water come from? Fresh water, cistern, or well? If directly from the water pipe, have a larger water meter installed right away so that you have enough pressure and flow. [..]

Sorry for the sparse information, the post was initially meant as a short call for help. We are getting a cistern with a submersible (pressure) pump and automatic refill via solenoid valve/floater. Would a KNX line for the fill level monitoring be useful here, or just a gimmick?

Why control via KNX? I have it myself but there is really only one good reason to rely on it: You have so much flow and pressure that you can run several circuits in parallel and thus save running time. In terms of logic and usability, you probably will never get close to e.g. Hunter Hydrawise.

Yes, I had already thought so, probably a separate control is preferable. Here I still have to read more closely about e.g. the aforementioned Hydrawise, but with the 24V solenoid valves I am on the safe side and could possibly switch to another system quickly, right? Regarding the pressure/flow of the pump, I have to ask the plumber again, it is unfortunately not yet exactly listed in the offer. Can the pump be too strong, or is it better to have a reserve?

Sub-distribution should be as close to the circuits as possible. This saves cables. Also, you use the largest possible cables up to the distributors in order not to lose pressure and flow unnecessarily.

Would you recommend the DN40 mentioned below for the cable size? For example, is 1 inch too small for the lines to the distributors?

Where should the control go? Here you need power as well as empty conduits for the control lines. Sub-distribution in the garage or garden house can be done if it is close to the circuits. Otherwise not useful. If a valve should ever leak, you have the water in the garage or garden house (do you have floor drains there?)...

We are planning a garden/pool house, which will accordingly have an electrical distribution, fresh water, wastewater, KNX. Here I would also have (inside) the solenoid valves as well as the control (Hydrawise/KNX actuators). Thanks for the tip about the floor drain, I will definitely consider that (if the pool builder didn't already insist on it). So far, no water is planned in the garage, so as you said, probably not a good place for the distribution/valves. I have attached a rough site plan of the garden house (GH), technical room, and garage so that it can be better understood. (Top of the plan is almost exactly north) The property is very long and narrow, the house kind of divides the property into two areas. In the north, the garden/pool house would be well positioned to cover the entire garden area there, in the south there is probably less vegetation, but I would still find irrigation useful there. Hence the idea of an additional distribution in the technical room or garage so that water or control lines do not have to be drawn so far. But that also means 2x Hydrawise, right? Urghs...

A floor drain with backflow preventer is already planned in the technical room, as mentioned, not in the garage.

Better take the proven valve boxes. Then you don't have to first go from the cistern to the garage/garden house and back out again.

Maybe not a bad idea.. How is it then with the control lines/ surge protection? Does it help if you bury the box as close as possible to the garden house/technical room?

Since you don't even have a slab yet I would lay a large Kabuflex with pulling aid underneath for control lines, power (garden sockets and lighting), possibly LAN and one or two PE-HD pipes (DN40). In the slab you make an additional multi-duct for refill, power line, possibly control lines, possibly LAN...

Thanks, that sounds good!