Rainwater Harvesting Systems are becoming more frequent considerations for new build developments and refurbishments. A rainwater Harvesting system is a relatively simple system that can have multiple human and environmental benefits including reduction of water shortages, reduced mains water consumption (and subsequent reduced bills) and control of surface water run off (which helps reduce flooding).

Requirements for a rainwater harvesting system:

• Rainwater must be collected from a roof (except green roofs), ground water is too dirty
• Rainwater must be filtered for debris before entering the tank
• Rainwater must be stored at a low, stable temperature to avoid bacterial growth or freezing (underground)
• Rainwater must be kept away from light to avoid algae growth (underground)
• Rainwater must be controlled upon entry to avoid disturbance of sediment within the tank
• The rainwater tank must be smooth internally to avoid the chance of bacterial growth
• The rainwater must be filtered again before being pumped, typically by a 0.5mm filter
• The rainwater is best not being stored in a warmer tank in a loft which can reduce the water quality

• Flushing toilets
• Washing clothes
• Watering the garden
• Washing the car

Using rainwater harvesting for the above activities can reduce your household water consumption by 50%

We use direct pressure systems as they avoid the need for a secondary tank which reduces cost and can also reduce water quality.

A direct pressure system is where water is collected from the roof of a building (or surface water run off in certain circumstances) and then pumped from the main holding tank (above or below ground) directly to a non portable appliance; i.e. when a toilet is flushed or valve has been opened.

For Excavation

The installation depth of our garden systems is only about 98cm with the 1500 & 3000 litre flat tanks and only about 124cm with the 5000 litre flat tank. The advantages in the amount of excavated earth are obvious. For the 5000 litre flat tank only approximately 9.6m3 of excavated earth is removed compared with 40m3 for a 5000 litre cylindrical container.

75% less excavation compared to a cylindrical container.

For Water Optimisation

In the flat tank FT 1500 - 5000 litre, the residual water (water volume) is only 22 litres! The residual water is the water that remains in the tank and cannot be removed by the pump. For all flat tanks without pump basin the residual water (water volume) is much higher, resulting in a much larger volume loss. The remaining water (water volume) also depends on the type of pump and possible setting of potable water. The lower the residual water, the greater the effective volume!

For all flat tanks without pump basin the residual water (water volume) is much higher, resulting in a much larger volume loss.

Example of volume loss in flat tanks without pump basin