Gravity irrigation system using recycled material

A vacuum cleaner pipe and a watering rose

We use gravity to irrigate our garden by collecting water from the roof into a series of caged water tanks and wheelie rubbish bins. Our total rain water storage capacity is over 5000 litres. All this cost us less than $100. What a deal! (We can buy a caged 1000 L tank for $25. Contact us if you want to know where to source them.) From these tanks, a swimming pool hose and grey PVC flexi pipe bring water to the garden. At the end of the pipe is a vacuum cleaner pipe with a watering rose. Gravity (about 1-1.5m height difference between water tanks and garden bed) is sufficient to deliver enough water and pressure to hand irrigate the garden with a nice and gentle sprinkle of water from the watering rose. No pump and electricity needed – just the height difference. More importantly it saves us a lot of walking with a watering can.

A caged water tank with a swimming pool hose

We also use a gravity fed drip irrigation system successfully. Brown, irrigation drip tube with dripper nozzles, spaced about 30cm apart, works well on low pressure. A standard garden hose syphons from a rubbish bin to the garden bed and it connects to the drip tube. By varying the depth that the garden hose is placed into the water storage (half way or at the bottom of the container), we  can control how much water will be used (half or all of the water storage). Also, by adding a liquid fertilizer (seaweed, a compost tea bag) into the stored water,  your garden can be fertilized.  The only issue we found was that seedlings need to be planted near the drippers as the plants might struggle for water.

A tip: Water tanks which do not have an outlet at the bottom such as rubbish bins can be connected in series with a piece of hose from one to another over the top. The symphonic effect via pipes full of water  automatically levels water in all tanks.