The Romans were master builders, and they took waterworks to a whole new level.

Using specialized tools to measure distance and angles, at least 11 aqueducts were built into Rome. They tapped fresh water sources like rivers, lakes and springs from as far as 60 miles away. Extra-hard concrete made with volcanic ash and the use of the arch were techniques the Romans perfected in building their water infrastructure.

A whole cottage industry developed around water. Scouts charged with locating good water supplies looked for villagers with clean skin -- the thinking being that clean skin meant clean water. Laws were written to deal with water disputes -- laws that formed the basis of the modern legal water code.

The Romans were so good at bringing in water that there was enough for each citizen to consume 200 gallons a day -- twice the current consumption of the average American.