Attenuation Tank

An attenuation tank is a sealed underground structure that temporarily stores excess rainwater or stormwater during heavy rainfall and then releases it slowly into a drain, sewer, or watercourse at a controlled rate. Its main purpose is to prevent flooding and reduce pressure on drainage systems in urban areas where hard surfaces stop water from soaking into the ground. They are a central part of Sustainable Drainage Systems (SuDS) used in modern UK developments to manage runoff and comply with environmental regulations.