The changing climate has a significant impact on the quality and quantity of water that is available. There is pressure on water resources within the UK and subsequently there is a need to manage and use Public Water Supplies as efficiently as possible. Rainwater harvesting has potential for reducing mains water use by providing an alternative source of non-potable water. If adopted at scale, rainwater harvesting may have potential to relieve pressure on public water supply and help reduce downpours overwhelming sewerage systems and sewage overflows into rivers.