Collection for reuse
Opportunities to collect water for reuse and at-source surface water reduction should be the first option considered.
Appropriately sized rainwater harvesting systems and associated downstream flow reductions should be accompanied by corresponding calculations.
Systems which reduce the rate at which surface water is conveyed into the drainage system, such as green roofs, rain gardens or rainwater harvesting are preferred by the Lead Local Flood Authority (LLFA) as they can increase the sustainability of a site.