Garden irrigation using pop-up sprinklers - is the water pressure sufficient?

Hello,

we have two outdoor water taps and would like to install pop-up sprinklers (activated solely by water pressure) on our 440m2 property. We only need to water a relatively small area.

According to our plumbing company, we have the following values:



"The 1/2" outdoor water tap has a flow rate of 0.3 liters per second = 1.08 m3/h.

The water meter has a flow rate of 1.5 m3/h.

The water pressure is determined by the water association, which is approximately 3 bar."



We now plan to water most of the property with about 6 rotary or spray sprinklers, i.e. we turn on one water tap, to which, for example, the first four sprinklers are connected and they start working. Then we turn on the second outdoor water tap and the other two sprinklers do their work.



Now the question: Are the above-mentioned water pressure data sufficient for our project?

You need to measure yourself which flow rate is possible at a pressure of 3-3.5 bar. Your current data is not sufficient for this because the pressure specification refers to the static pressure without withdrawal and the flow rate to a free flow without pressure. In irrigation, however, the pressure must also be present during withdrawal. That means in the end, the possible withdrawal amount is far(!) below your specification. 3 bar static pressure is very low, by the way, or it refers to the pressure in the house that is set on the pressure reducer.

Here is a comparison for orientation since I am currently implementing the irrigation: We have a household water pressure of 5 bar, a meter with a nominal flow rate of 4m³/h, and a direct connection to the garden with 32mm PE pipe. So everything quite generous. Nevertheless, we can only withdraw around 600-800l/h because otherwise, the pressure drops too much.

We only have to water a relatively small area

to water most of the property with rotary sprinklers or nozzle sprinklers,

Hm, exactly how much? The shape of the lawn area(s) to be watered is also crucial.

This needs to be planned (there are tools for that). Ideally, use sprinklers that operate with the lowest pressure. And forget manual turning on/off, that should be automated.

My neighbor also installed many meters and sprinklers, area 300-400 sqm around the house, and I don’t see or hear those things anymore after the first year. He runs around with a hose and sprinkler head. But usually only waters the brown edges.

„The 1/2" outdoor faucet has a flow rate of 0.3 liters per second = 1.08 m3/h. The water meter has a flow rate of 1.5 m3/h. The water pressure is determined by the water association, which is about 3 bar.“

I claim this will not work. We have 3/4", 4.5 bar and ~3 m3/h, so significantly more than you. Still, I cannot operate circuits with 4 sprinklers; they do not come out of the ground properly. There is not enough pressure and therefore not enough flow to the sprinklers. Can you drill a well? Or install a cistern as a buffer, from which a garden pump then supplies the sprinklers with sufficient pressure?