Determining rainwater harvesting potentials in municipalities by a semi-analytical method

Due to increasing population, uncontrolled water consumption, and abnormal climatic conditions, the potential of usable water is running out. Water has become one of the most valuable resources for the countries; therefore, rainwater harvesting systems for water recovery gain importance to implement in buildings. Thus, authorities have begun to search for fast and accurate decision tools before taking any action. In the present study, a semi-analytical method for determining the rainwater harvesting potential of the given location is implemented in the Java programming language. Three major districts of Izmir, Turkey are chosen for the study site, namely Cigli, Bayrakli, and Karsiyaka. The result shows that implementing rainwater harvesting systems only in public buildings recovers less than 1% of the population's water needs. On the contrary, encouraging the free zones, which has large rooftop area such as airports and malls, for implementing and using rainwater increases the water recovery to 13% of that district's water needs. It is still a small portion of the public's water needs; therefore, spreading rainwater harvesting in the communities is necessary. It is believed that more accurate and user-friendly rainwater harvesting simulators would encourage the communities to harvest rainwater.