The Hoover Dam in the US, the Aswan Dam in Egypt and the recently opened, and sumptuously named, Grand Ethiopian Renaissance dam. Since modern times, huge mega dams like these to tame rivers, create water storage and hydropower, have become a symbol of nationhood used to create national pride and bolster political power, from the Cold War to today. Nehru, the first Prime Minister of India, called dams the temples of modern India. But dams have also been highly controversial, displacing rural populations, disrupting local ecology and more recently it’s been shown that dams can increase the amount of greenhouse gases in the earth’s atmosphere. So why are so many countries like China still highly involved in dam building, and will they need to change tack in the future? And, could the humble beaver offer a solution? To discuss the past, present, and future of dam building, Rajan Datar is joined by Nikita Sud, Professor of the Politics of Development at Oxford University; Donald C. Jackson the Cornelia F. Hugel Professor of History at La Fayette University in the US and author of many books on the history of dam building, including Building the Ultimate Dam: John S. Eastwood and the Control of Water in the West; and Dr Majed Akhter, a political geographer who is senior lecturer in Geography at King’s College London. With the contribution of Dr Emily Fairfax, an ecohydrologist with an expertise in beaver activity and beaver dams from California State university Channel Islands in the US. Produced by Anne Khazam for the BBC World Service. (Photo: The Hoover Dam on the Colorado River straddling Nevada and Arizona at dawn. Credit: Sean Pavone via Getty Images)