"Rainwater Harvesting Project" at R & D Polytechnic College , Focal Point, Ludhiana. SAHIL ENTERPRISES, Rainwater Harvesting Company. (An ISO 9001:2015 CERTIFIED COMPANY) is one of the best companies dealing with Rainwater Harvesting Systems. Additional Info:Established In: Sahil Enterprises has been in action for a long time but it became an official firm in 2005.