In Cities in Civilization Peter Hall details Rome’s water system.
Eventually, Rome had a system of fourteen aqueducts, reaching a length of some 508 kilometres … delivered a billion litres of pure spring water … into the city every twenty four hours; there were 247 reservoirs … to regulate the supply … Virtually all authorities agree that the water supply was outstanding both in quantity and quality, even by twentieth-century standards.
Frontinus … proudly compares the system with the useless monuments of the Pyramids
This river fed the great baths and private homes. As important, it flushed the streets clean …
very limited storage capacity … principle of constant off-take. … water would overflow … unless constantly drawn off … the overflow from the fountains would run permanently and clean the streets … the fountains were deliberately designed for overflow
It flushed the sewers too. The
huge volume of water coming from the fountains and the baths diluted the sewage sufficiently.
But such waste …
A roman household used as much water in one day as a modern house does in two months or sixty times’ today’s typical consumption, most of which straight into the drains.
Water gushed elsewhere too. Hence
the raised pavements in Pompeii and Herculanem, sometimes 50-60 centimeters high.