Basic Planning Principles of Roof Precipitation Harvesting Systems

Water has been one of the main factors determining the fate of civilizations for centuries. Today and in the future, water scarcity is one of the biggest problems for mankind. Precipitation water harvesting can be defined as the collection and accumulation of rainwater and runoff water, the supply of water required for plant and animal production, and the supply of water required for domestic consumption. The fact that the water obtained is free of charge, protecting natural water resources can be easily integrated into the existing water network system. In addition, low operating and maintenance costs make precipitation harvesting extremely attractive for the management of water, which is a scarce resource. With the collection of precipitation water, purposes such as preventing soil erosion and floods, providing quality irrigation water, feeding groundwater, and saving network water can be achieved. Precipitation water harvesting is a water supply method that has provided drinking water to many historical cities since ancient times. Archaeological findings show that rainwater harvesting dates back to 6000 BC. Precipitation water harvesting has been practiced since humans began to live and grow crops in arid areas. While in many arid countries a large part of rainwater is lost through evaporation or turning into wastewater, worldwide awareness and importance of rainwater harvesting are increasing. This chapter describes the elements of roof precipitation water collection systems and includes the basic principles that should be considered when planning.