All perfect praise be to Allah, The Lord of The Worlds, and may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
Undoubtedly, water is one of the greatest blessings that Allah has bestowed upon planet Earth to give life to all its creatures; therefore, preserving rainwater, on the level of the individual and that of country, is a key reason for securing drinking and irrigation water.
As regards diverting rainwater into the sewerage system, we are afraid that this act is tantamount to wasting the blessing that Allah, The Almighty, has favored his servants with, especially since there is a dire need for water resources at times of drought. It is imperative that rainwater-which is abundant, thanks to Allah-is diverted into a special storage tank, or is left to flow into valleys and accumulate in dams, or is utilized for irrigation purposes and watering cattle. And Allah knows best.