Given that we use only 2 per cent of the rain that falls on these islands, one would not think it an insuperable job to secure our water supplies during the longest dry spells. If the Romans could do it with their technology, surely we can with ours.
Since communities in the ancient world could survive only if they had supplies of fresh water available in the first place — rivers, wells and cisterns — aqueducts were not strictly necessary for human survival. Many places never had one (e.g. London). It was the baths, the Romans’ leisure centres, that created the demand. According to a late survey, Rome had 154 public lavatories, 46 brothels, 1,352 water points — and 856 bath buildings. Its 320 miles of aqueducts — the longest stretching for 56 miles — brought some 1.14 million cubic yards of water per day into Rome. Impressive enough, but Byzantium (Constantinople), the only major city to be founded lacking good local supplies, boasted 370 miles of aqueducts, the two longest measuring an incredible 208 and 133 miles.
Most of the water was directed via tunnels and underground channels of masonry or brick, with aqueducts built only where absolutely necessary — over valleys, for example. The channels were big enough for men to enter and clean (the architect Vitruvius gave guidelines: is the water clear? Does it leave a sludge? Do the inhabitants have inflamed eyes?) Gradient of flow was all important, as the water had to be delivered at manageable speed into the distribution tanks from which conduits or lead pipes fed it out across town. There are many examples of superb engineering to control the flow over such long distances. Charges were made for those who wanted to enjoy a private supply, though this seems to have been rare.
The superintendent of Roman aqueducts Frontinus — appointed in 97 ad — left a treatise, fascinating in its technical detail, on the whole subject (rates of flow, theft, leaks and so on). He commented ‘Just compare the vast monuments of this vital aqueduct network with those useless pyramids, or the vapid tourist attractions of the Greeks!’ Or with our supine water companies.