If you are trying to give your property the competitive edge, spend your money where it counts – install a tank.
How much rain can I collect?
Calculating the amount of water you can collect from your roof is easy. Basically one square metre of roof will collect one litre of water for every millimetre of rain. So if your garden shed measures 4m x3m (that’s 12 square metres) and you have 10mm of rain, you could collect 120 litres of water.
Choosing the right tank size
Working out what size tank you need is a tad more complex, but the experts agree that it makes good sense to buy the biggest tank you can either fit or afford, as the more water you have the better off you’ll be. This is sound advice when you think that the average top loading washing machine uses 170 litres of water per load or that an ordinary handheld hose can use up to 20 litres per minute.
Choosing the right tank size
Working out what size tank you need is a tad more complex, but the experts agree that it makes good sense to buy the biggest tank you can either fit or afford, as the more water you have the better off you’ll be. This is sound advice when you think that the average top loading washing machine uses 170 litres of water per load or that an ordinary handheld hose can use up to 20 litres per minute.
Pump it up
Remember you might also have to budget for a pump. Tank water forced out simply by its own weight will not give you anywhere near the water pressure you get from a mains tap, so if you want to run the water up hill or around your block at will you will need a pump.
Tank Styles
Nowadays tanks come in all manner of sizes and shapes. You can still get the iconic round galvanized tanks. They remain one of the cheapest options, though these days they have polymer linings to help prevent corrosion. If you are cleaning an older tank, it is important not to disturb the film which builds up on the walls inside the tank as this helps protect against corrosion.
Concrete tanks are strong and long lasting and can be installed underground (larger tanks are often cast in situ). Concrete can however crack, so don’t make the mistake of planting big trees close by. All concrete tanks need to be flushed to remove the concrete taste from the water.
The biggest advantage of polyethylene tanks is that they don’t corrode and are easy to relocate. Provided they are made of high grade materials and are of the correct thickness, algae growth won’t occur and collected water won’t have a plastic taste or smell.
Clever designers have quickly risen to the challenge of post-construction installation of tanks and there are now modular tanks that can be fitted into wall cavities when renovating, bladder tanks for under-house installation and wall style tanks than can easily be fitted beside the house or as a feature along the fence. Some even have specially designed brackets so that you can attach cosmetic screens.
Planting a screen
Of course, you can grow plants over your tank to help camouflage it. Be careful to choose plants that do not have rapacious root systems and make sure the inlet strainer is kept free of leaf litter and vine tendrils. For an effective screen, you’ll need to plant multiple screening plants close together, so they will need all the water-saving support you can give them. Drip irrigation is the proven method of choice for water use efficiency – and this time their water supply will be right there on tank!
Three climbing plants for fast screening
- Orange trumpet creeper (Pyrostegia venusta). Sheets of deep orange tubular bells in winter.
- Purple wreath (Petrea volubilis). Called sandpaper vine because of its abrasive leaf surfaces. Long lasting purple blooms.
- Yellow allamanda (Allamanda cathartica). Big yellow trumpets are a familiar sight in warm climate gardens.