ABG, a UK drainage specialist, developed SuDS Blueroof, a system that mimics natural drainage and attenuates stormwater to reduce hydraulic impact and downstream flood risk. It is a temporary void storage system for rainwater above ground level or on a roof or podium, with no underground tanks. The water can be released in a controlled manner to manage timely discharge and avoid overloading the downstream drainage system. ABG designs and retrofits cellular water holders and a special restrictor chamber to regulate this outflow over a designated period, limiting the risk of downstream flooding.