Rainwater Harvesting - Past or Future?

With increasing pressure on the environment particularly on water resources due to outside forces such as climate change and population growth water is nowadays a scarce and a valuable resource. With the need to find new alternatives rainwater harvesting should be seen as an important strategy for better management of water resources once it constitutes a free source of potable water. Rainwater harvesting systems which already have a global implementation are a recognised way for urban buildings to reduce their reliance on the public mains supply. Its applications are predominantly non-potable namely toilet flushing and gardening. The aim of this report is to produce a comprehensive assessment of rainwater harvesting and its potential use all over the world as well as the potential economical and environmental benefits. It is provided a description of all the rainwater harvesting system components as well as water quality requirements according to the water final purpose.