As well as being masters of water engineering, the Romans also engaged in a long distance trade in water across the Mediterranean - embodied in grain, oil, wine, cloth, metals and other goods. They also discovered the food-water-energy nexus - and not in a good way. We need to heed the warnings from Roman history.
Conflict continues to rage in Iraq over control of the Mosul dam, which impounds 11 cubic kilometres of water and controls water levels and supplies across the country, writes Jonathan Bridge. It's not the first battle fought over control of water - and it's certainly not the last in a drying Middle East with fast-growing populations.