What is the purpose of a rainwater harvesting tank?

It performs two functions: storing water in sufficient quantity, while ensuring adequate safety and quality.

There is often a filtering device and also a pumping system to ensure the distribution of this water.

What are the different types of tanks?

• outdoor overhead tank
• internal aerial tank
• buried tank

What are the different tank materials?

There are mainly 3 types of materials for rainwater harvesting tanks: HDPE, concrete and exceptionally steel.

HDPE tanks

The 3 types of tanks mentioned above (outdoor/indoor aerial or underground) are found.

To water a garden, we regularly see these outdoor tanks with capacities between a few hundred litres and up to 1.5 m3.

It is sometimes possible to "assemble" them, i.e. to mount them in series to multiply the storage capacity.

This solution, often used indoors, allows for significant storage without requiring heavy intervention (compared to the buried version).

The last choice, underground HDPE tanks provide superior storage capacities, whether on round or flat tanks.

They are reinforced to withstand vehicle and pedestrian traffic.

Concrete tanks

This type of tank is mostly buried. For larger capacities (+10m3 approx.), they are sometimes manufactured directly on site.

For prefabricated concrete tanks, think carefully about the complete price: tank + delivery + unloading.

In fact, given the weight, the issue of delivery is a major factor in the total cost.

Metal tanks

For tanks larger than 100m3, galvanised steel can be found for these rather specific installations.

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