The Active Attenuation System is a combination of rainwater harvesting and traditional attenuation. 

Active Attenuation uses the on-site attenuation capacity to act as a storage tank for the rainwater harvesting system. 

The Active Attenuation System uses met office weather data to ensure there is enough on-site attenuation capacity available for the site in the event of a storm. 

If an incoming storm is detected, a valve will operate to send any excess rainwater into the external drains before the storm arrives.