Or take the Aswan High Dam in Egypt, an unmitigated disaster, according to ecologists.

FORBES: The Story Of Eau

They added that since the completion of the Aswan High Dam, Egypt's population had doubled, calorie intake and meat consumption had risen by more than a third, and the use of fertilisers had increased four-fold.

BBC: Egyptian farmers (Getty Images)

Jelal is a Nubian, one of the people who lived in southernmost Egypt and northern Sudan until the 1960s, when the Aswan High Dam flooded their land.

BBC: The perfect trip: Egypt