Rainwater tanks have many practical advantages. Capable of collecting up to 80% of the water that falls on your roof, they are a good investment even in areas of light to moderate rainfall. A tank can collect up to 800 litres of water from as little as 10 mm of rainfall. For an average family, the water used from tanks can cut their yearly water consumption up to 25 to 30 percent. Moreover, rainwater is less salty than tap water and is said to be better for washing clothes and watering the garden.
Rainwater tanks come in all shapes, materials and a wide variety of sizes including:
- Metal tanks are made from Colorbond or Zincalume are durable and often lined with polyethylene for longevity
- Polyethylene or poly tanks are light, easy to install and available in a range of shapes and sizes
- Fibreglass tanks have similar properties to poly tanks, though are more expensive
- Concrete is a popular option for underground tanks when their inherent strength is needed
Aside from traditional round tanks you can also buy slimline tanks that fit neatly against a wall, or tanks and bladders designed to be buried underground.
Ok if this was me I would build a few barrels underground and store water in them or have a valve that can fill it back up when turned on.