Multiple Rainwater Tanks or Just One Big Tank?

Multiple Poly Tanks (Team Poly)

Interested in buying a rainwater tank? It might be worthwhile purchasing several smaller ones rather than one large tank.

Choosing whether to install multiple tanks or one single tank really depends upon several factors.

  • Storage needs – how much water do you need to store? If you only need small water storage (less than 10,000L), then cost-wise a single tank is likely better. On the other hand, if you need around 35,000L then you could get two 22,500L tanks.
  • Property space – can you fit in a single large tank on your property? If you can, is it in an ideal position? Would two or more multiple smaller tanks fit better on your property?
  • Council requirements – do you need a water retention tank that stores water for fighting bushfires, or are you required to detain water to assist with stormwater drainage in your area? If so, sometimes having a separate tank for these needs is best.
  • Rainwater & Stormwater – many harvest rainwater that falls on rooftop, and it is becoming common to capture stormwater that flows down driveways and pathways into underground stormwater tanks. Rainwater overflowing from your tank, rather than being fed into stormwater drainage, can be fed into your stormwater tank.
  • Preferred Tank Style – certain styles of tank are only available in certain capacities. Slimline tanks, which are great along the side of your house, are only available up to 5,000L capacities. Of perhaps having a tank completely out-of-sight appeals to you, in which case underground tanks or underdeck tanks would be desirable.