Roofwater harvesting: a handbook for practitioners

Water professionals are becoming increasingly worried about water scarcity. The UN World Water Development Report of 2003 suggests that population growth, pollution and climate change are likely to produce a drastic decline in the amount of water available per person in many parts of the developing world. Domestic Roofwater Harvesting (DRWH) provides an additional source from which to meet local water needs. In recent years, DRWH systems have become cheaper and more predictable in performance. There is a better understanding of the way to mix DRWH with other water supply options, in which DRWH is usually used to provide full coverage in the wet season and partial coverage during the dry season as well as providing short term security against the failure of other sources. The handbook is primarily focused on low-cost DRWH in the humid tropics. It is deliberately specialised in geographical scope and target group, and more prescriptive than the good review of rainwater harvesting practice contained in John Gould and Erik Nissen-Petersen's 1999 book: Rainwater Catchment Systems .