ᐅ Preparing for automatic irrigation systems

Created on: 21 May 2019 12:35
K
Katdreas
K
Katdreas
21 May 2019 12:35
Hello dear forum,

We spoke with the plumbing company about planning an irrigation system for our garden and asked what preparations might be needed. Unfortunately, they are not very familiar with this (understandable, as they are not landscape gardeners). However, they assume that no special planning is required and that the irrigation can later be connected with a T-piece to the regular outdoor water tap (along with a garden water meter). When I asked whether the pressure would be sufficient, they suggested not reducing or reducing less the pressure for this tap... (at least that’s how I understood it).

These statements seem a bit vague to me, so I’d like to ask you: how did you handle this, and can you confirm their advice?

Best regards!
rick201821 May 2019 12:48
If you want to feed directly from the water supply line, it’s important to have as much flow as possible—that means a large pipe diameter and sufficient pressure.
A better option is a cistern (also serving as a buffer and providing free rainwater) with a powerful pump.
If you already know you will install an irrigation system, make sure to install wall penetrations and lay out the pipes at the same time. In addition to the water lines, you will need control cables running to the valves in the distribution boxes.
There was a recent thread where I discussed irrigation in more detail.
Mycraft21 May 2019 13:01
Since most of the work takes place outside, you can only have the plumbing prepared as already discussed.
K
Katdreas
21 May 2019 13:15
That’s clear. I was just thinking that if you already know a watering system will be installed later, it might make sense to design the outdoor water supply with that in mind.

I’m wondering, if the water pressure at the outdoor faucet is increased to meet the requirements of the irrigation system, wouldn’t it be too high on the other side for regular water use (e.g., washing hands)?

I also read somewhere online the exact opposite, that the pressure from a normal faucet might actually be too high.

I have no experience with irrigation systems yet, and it will be a while until one is actually installed underground. I just don’t want to miss anything now that would cause more work later than if it’s done right from the start.
rick201821 May 2019 14:25
As mentioned, a cistern would be practical in many ways. You would then have a supply line for refilling it.

If you are drawing water directly from the mains, try to use the same diameter as the water meter for the outlet pipe. If possible, choose a water meter with a 25mm (1 inch) diameter from the start.

This way, depending on the length of the supply line, you can achieve a flow rate of about 2 m³/hour (70 cubic feet per hour). The water pressure in a typical house is not very high.

You usually don’t need to increase the pressure. For drip irrigation systems, for example for hedges, a pressure reducer is connected in that particular circuit. Standard sprinklers can operate with 6-8 bar (90-115 psi). If you want to do it “properly,” use pressure-compensating sprinkler heads.

Take a look at the following topic:
https://www.hausbau-forum.de/threads/Leerrohre-auf-Grundstück-Ideen-noch-ist-es-nicht-zu-spät.30853/page-3
H
hampshire
21 May 2019 22:40
Cisterns or wells are very good water sources. For garden irrigation, the goal is to distribute water over longer distances to several parallel outlets. It is advisable to use larger pipe diameters and avoid creating any bottlenecks at the connection points. The installer should simply lay a properly sized pipe, as well as a correctly sized outdoor connection and frost protection. You can then do the rest yourself or have a landscaping professional handle it.