We live in a rural area in New Zealand and want to grow our own fruit and vegetables.Problem is that summer in NZ is very dry (although it has had record rain this year!) and we rely on water "harvested" from our roof rain, therefore we don't have that much to use on irrigation

(We basically have 50 tonnes for household use - this includes keeping the swimming pool full and water for the animals )

To increase this capacity I have installed IBC's (International Bulk Containers) around the property that fill from shelter and shed roofs and top up stack troughs, these are approx 1000litres each (250 gallons) and I have about a dozen around the property.

While the ones for the animals are no problem, carrying water to put in the raised beds is a chore, so I have decided to put in an irrigation system.

Supplies

IBC's

Pipe (Alcathene pipework)

Pipe fittings

Garden Hose

A pump

Soaker Hose

Step 1: Siting the IBC's

Initially I set up 2 IBC's to fill from the small shed, later, after building my bigger workshop shed I set up a further 2 IBC's to fill from that roof. I got these locally for $40 each, they had contained a glucose syrup, so harmless to plants and animals

Once all set up I used to fill buckets to transfer the water to the plants, but obviously this wasn't ideal as it was hard work and took ages

Step 2: Setting Up a Pump Mk I

The next step involved using a large pond pump that I had attached to pipework and soaker hose, to pump directly from the IBC's to the raised beds, unfortunately because of the type of punp (centrifugal instead of positive displacement). there wasn't sufficient pressure to adequately water the beds, so a rethink was needed

Step 3: Setting Up a Pump Mk II

I had an old waterblaster that I bought about 25 years ago in UK before we emigrated, the lance was broken and I was unable to get accessories for it in NZ but it still worked otherwise.

I connected the suction side to the IBC outlet using various hose fittings and the discharge side to the supply to the soaker hoses (by the simple means of cutting off the end of the discharge hose, jamming it as far into the supply as I could and then putting a couple of Jubilee Clips (hose clips) on it)

The pump is gravity fed from the tank and there is also a filter in the pump suction to stop debris damaging the pump.

It was then plugged in via a simple clockwork style timer and tested to see if it did the job, it was then set to operate for 15 minutes a day after sunset

This uses about 150 litres a day so with 4 tanks I have about 25 days worth of water available here

Step 4: Cross Connecting the Tanks

I now have 4 x1000 litre tanks (or about 1000 gallons of water available) but my pump is only connected to 1 tank.

I need an easy way to move the water from the 3 spares to the working tank.

The first idea was to use garden hose to siphon water between the tanks, this actually worked fairly well but had a couple of shortfalls

1) When the tanks fell below a certain level (about 100 litres) they lost the siphon effect and I had to resuck water through (which was pretty yuck)

2) Every so often the dogs would get tangled in the siphon hose and pull one end out a tank, draining the whole tank, I then still had to reset the siphon so yuck

It was obvious that I needed a better solution.

Step 5: Permanent Cross Connect

As I still had a fair bit of the Alcathene pipe left I decided that I would properly Cross Connect all the tanks.

This would mean that they would all fill and empty equally (despite various roof areas) and hopefully by having the connections low on the tanks and burying everything I wouldn't have to siphon stuff

I bought the necessary fittings from Mitre10 (these were the most expensive part of the whole build at $85) and fitted a hose connection to each tank, connected together with a couple of t joints and elbows.

The hardest part of this was threading the hose connectors through the drilled holes in the tanks as it was a real stretch inside the tank, I also had to transfer water from full to empty tanks (and back) using a pump as I wanted to minimise how much I wasted.

On completion a shallow trench was dug to bury the pipework so I won't trip over it

Step 6: Drilling Holes in the Tanks

When the tanks were just about empty I drilled a hole to take the connection stub pipe.
As there was a protective plastic corner cover I first carefully cut that with a larger holesaw taking care not to cut into the tank, then drilled a smaller hole for the connection

Step 7: Putting in the Connection

I used a handy pick up/grab stickto feed the connection from inside the tank then did up its nut from the outside using pump pliers.
There is a rubber washer inside and out to effect a good seal.
Rinse and repeat for the other 3 tanks.

Step 8: Fitting the Alcathene Pipe

The pipe is very strong and quite difficult to get onto the push fittings on the tank connections.
So to make it a little easier I used a thermos of boiling water to soften the pipe then pushed them into place.
I then connected the first 2 tanks together using a t-piece (this was easier to connect as it was a screw on fitting)
Repeated for the other 2 tanks

Step 9: Tanks All Connected Together

Using some more Alcathene I connected the 2 pairs of tanks together.

Step 10: Getting Rid of the Trip Hazard

Once I was happy with all the connections I scraped back the white chip, cut the weedmat and dug a shallow trench to bury the pipe. Once done I recovered with weedmat and chip.

Step 11: Finished

Finally I reconnected the water blaster and half-filled the tanks, that should give me about 2 weeks watering if it doesn't rain. The plastic drum over the top of the pump is just for a bit of weather protection.