Rural irrigation setup up issue (low water flow)

Hardware
1

Hi guys,
I was wondering if the community had any tips or suggestions on my current (non working) irrigation set up.

Currently I have 2 1000L IBC tanks at the top of our property, and then a 3/4 inch pipe that runs down to one of our garden patches. The distance is approx 100 meters with a drop of 6 meters between the two distances.
Currently we have it connect to a tap but we did want to have a manifold with some solanoid valves to direct water to different garden beds (on of them back up the hill about 10 meters)

Not researching enough, I bought 2 solenoid valves that had a minimum pressure of 70kpa and tried to install them about 5 meters back up the hill. Water just continuted to flow out of them slowly and after research i learnt that it needs pressure to keep them closed as well as open.

I did a “bucket test” on the tap at the bottom of the hill and it only runs at about 13.5LPM which I guess is also still quite low?

I have not done a pressure test yet to test the Kpa, I will buy one of these on the weekend.

My question is, what would be the solution to getting better water pressure / flow that i can distribute out to the different garden beds via automation such as the solenoids and home assistant?

Would a pressure pump help with this? I notice when the tap is turned on full, it starts off fast, then slows down as well as splatters just a little bit, so it is not just pure flow, it is struggling to get to the tap fast enough? (When i turn the tap off for 5-10 seconds and turn it back on, it flows fast again for a little while and then slows again.
If that is the case, would a pump still help or is my issue elsewhere?

Also just to note, between the tank and the tap, there is about 5 elbow connectors… I read that they do reduce flow, but not by a lot. We dont really have any options to remove them as the pipe is all underground.

Would love to hear any suggestions you have… let me know if you guys want any pictures of my setup if it will help.

Thanks in advance

Ryan

2

Pressure pump will help but flow will also be restricted by the size of the pipe. Like electricity the length of run and the size of the pipe/wire need to be taken into the calculation.

You will have roughly 7.7PSI at that drop of pressure. It depends on wether you want to spend initialy or as ongoing costs. I did all my aquaponics via an arduino.

You could use a motor driven actuator to open the valves (needs no water pressure just power) and then use flood irrigation on the beds. Belimo make spring return actuators so if the power fails the valve will close. A pressure pump at the start of the run will give you higher pressure but the amount of flow will be restricted by the size of the pipe but you may get the flow you want. Thats one of the reasons the flow slows after you turn in on for a while I would guess as under gravity its not going to get “pushed” along. Also the closer you beds are to the same height as the origin (you mention there is a bed 10 metres back up the hill) the less pressure ou are going to have assuming you mean 10 metres as in height. In fact that would make it higher than the origin and thus if thats the case yes you will need a pump. You dont say how the water is sourced. if its a stream you can do things like an Archamedes screw.

Hope this helps. And yes I am a gadget man. Love to tinker :slight_smile:

3

Hello,

It depends on how do you want to irrigate, do you want to setup a drop by drop, sprinklers or just put the water on a localized point. For the two first you will need pressure but not for the last one.

4

Thank you for the replies.

So the water is pumped from a dam into the two IBC tanks (1000 litres each)
But we are using the IBC tanks for the flow.

The one garden bed that is 10m back up the hill is distance, not height… its probably less than 1m in height. a fair bit less actually.

We were hoping to have sprinklers for the beds.

I will post a couple of pictures, maybe it will help

This is the tanks that the water is flowing from (3/4 inch pipe)

20190904_140613
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20190904_140623
20190904_1406234032×2268 888 KB

Does it make it a slower run because of the elbows at the start? or not a big difference?
I notice it also runs faster when only 1 tank is turned on instead of two… that makes sense.

This is the run down the hill from the tanks

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And this is one of the garden beds that I want to supply water to

IMG_20190905_123538
IMG_20190905_1235382268×4032 1.89 MB

5

This give you between 0.1 bar to 0.2bar of pressure. Not sufficient for sprinklers.

You should add a pump with or without a pressure tank.

With if you need a constant pressure, without you will need to make a return to the main tank (with a Y valve).
The characteristics of your sprinklers could help you choosing the pump.