Attenuation controls the flow of water as it goes back to the water course or drainage system - valuable if tackling flooding downstream or an overwhelmed infrastructure.

Attenuation consists of the temporary storage of surface water in a suitable chamber below ground level. This chamber needs to be of sufficient size to accommodate the calculated run-off during peak periods of rainfall. The stored water is then gradually released in a controlled manner into a surface water or combined drainage system or watercourse, subsequently effectively reducing the risk of flooding.

Increasingly, as existing sewer networks approach their capacity, attenuation systems offer a cost-effective solution for accommodating additional catchments without increasing the size of existing sewers. Additionally, these systems offer all the benefits of using plastic, as opposed to clay or concrete.