The quantum of rain water harvesting differs with location. For example, in Caribbean Islands, rain water is the most important water supply resource for catering water requirements of public buildings, homes and resorts. Thus, rain water is collected with the help of technology and then supplied to general public for use after filtration process. The technological process has further aided ease in water supply and improved water quality significantly. The collected rain water passes through several stages of filtration and technological treatment ensures that water is hygienic and safe for drinking purposes as well. The rain water harvesting process has resulted in decline in soil erosion and flooding (Azoulay, 2016). This is because of the fact that water is diverted from building roofs into collection tanks.