A friend sent this good recent paper on dams. The basic message is that they are marginally cost effective, and have severe distributional effects. Please have a look into the document. dams.pdf Avnish KatochAn IT professional for 17 years, based in the US since the last 12 years. Founded NGO My Himachal and then Himachal Media Pvt. Ltd.. A Himachali forever. Always trying to bring together people whose hearts beat for the state.