What to prepare for automatic irrigation

Hello dear forum,

we spoke with the plumbing company about planning an irrigation system for the garden and asked what we might need to prepare for it. Unfortunately, they are not really familiar with it (okay - they are not garden landscapers either). However, they assume that we do not need to plan anything further and that the irrigation can later be connected to the regular outdoor water tap with a T-piece (together with a garden water meter). When I asked whether the pressure would be sufficient, they suggested not or less restricting the pressure for this tap ... (at least that's how I understood it).

These statements seem a bit vague to me, so I ask you: how did you do it and can you confirm this statement?

Best regards!

If you want to feed directly from the water pipe, it is important to have as much flow as possible. That means a large pipe diameter and good pressure. A cistern (also as a buffer and free water from rain) with a powerful pump is better. If you already know that you are installing an irrigation system, do the wall penetrations and lay the pipes right away. In addition to the water, you need control lines to the valves in the distribution boxes. Recently there was a thread where I went into more detail about irrigation.

Since most of it happens outside, you can't have the plumber prepare anything further than what has already been mentioned.

that is clear. I just thought that if you already know that an irrigation system will be installed later, it might make sense to design the water supply for the outside accordingly. I’m just wondering, if the pressure at the outdoor tap is increased to be sufficient for the irrigation system, wouldn’t it be too high on the other side for normal water use (e.g., hand washing)? I had also read somewhere online the exact opposite, namely that the pressure of a normal tap can be too high. I have absolutely no idea about irrigation systems yet, it will take a while until one is actually buried. I just don’t want to miss something now that would involve more effort later than if you do it right away.

As mentioned, a cistern would be practical in many ways. Then a supply line for refilling it. If you only feed directly from the water line, try to run it outside with the cross-section of the water meter. If possible, use a 25mm water meter right away. This way, depending on the length of the line, you achieve about 2 m³/hour flow. The pressure of a house is not too high. You usually do not need to increase the pressure. For drip irrigation, e.g., for hedges, a pressure reducer is connected in the respective circuit. You can operate the normal sprinklers at 6-8 bar. If you do it "right," use pressure-compensating housings. Take a look at the topic: https://www.hausbau-forum.de/threads/Leerrohre-auf-Grundstück-Ideen-noch-ist-es-nicht-zu-spät.30853/page-3

Cistern or well are very good water sources. When it comes to garden irrigation, the goal is to transport water over longer distances to multiple parallel outlets. It is advisable to use larger pipe diameters and not create a bottleneck at the connection. The plumber should simply install a well-dimensioned pipe, an equally well-dimensioned outdoor connection, and frost protection. The rest is then done by you yourself or a landscaper.