Introducing a compatible pattern for roof catchment system in metropolises. (Case study, a residential building in Karaj)

Metropolises are facing water scarcity، particularly in arid climate. Rainwater harvesting as well as multiple use of water can help to overcome the water shortage problem in those cities. Water harvesting system can be employed for rain collecting. However، this system fails in arid regions during summers due to the lack of precipitation when most crops require more water. To overcome this problem، we suggested an innovative solution by adding a second sink in the kitchen to separate the rinse water from the water polluted with detergent. This improved system has successfully been tested in a four-story building in Karaj where led to a significant reduction of municipal water used for irrigation. The amount of harvested water is increased by an increase in the number of apartments in the building. In addition، this system decreases the rate of wastewater.