All the credible scientific data as well as satellite imagery information clearly point out that water reservoirs, glaciers and sub soil water are fast depleting in the south Asian countries including ours. There is, therefore, a grim forecast of droughts, famines and non-availability of even clean drinking water in near future in these countries. We as a nation have to take urgent steps in order to meet this grave challenge. Our inaction in this regard can thrust us in to a bigger pickle than the one we are currently in due to loadshedding, which in turn has resulted from our inability to take timely actions. It would not be out of place to mention here that as a part of the fast ecologic changes taking place around the globe, the Lahore city, and its nearly one crore population, is threatened with an ecologic calamity of gigantic proportions. Till a couple of years ago, the river Ravi used to flow here with its full might and abundant fresh water and used to constantly wash and feed the subsoil water along its water course. But now with the passage of time, Ravi has largely dried up and is, thus, unable to replenish the subsoil water of its surroundings with fresh clean water. What is left of it now is, literally, a narrow sewer drain that not only contains filthy water, litter and dirty refuse of the city but also poisonous industrial effluents. This sad situation can be effectively countered by replenishing the shrivelled Ravi with fresh water from some other stream. This water can be obtained from river Chanab by means of a canal starting from a place near Marala where Ravi meets Chanab. A certain quantity of this water can be thrown into Ravi at a suitable point where it enters the Pakistani territory. -DR MUHAMMAD FAROOQ, Lahore, via e-mail, May 10.