Question

How can we say that rainwater harvesting system is  considered as the most reliable alternative source of water management .

Answer 1

its bcas rwh is the means to collect water from the roof of buildings and connect it to underground.if we follow this we can definitely control water scarcity and we can manage our water needs for r later use

Answer 2

Because it gives naturally purified water, prevent wastage of water, increased water sources. If we adopt this type of method we can recieve high amount of pure water.