For centuries, the boastful citizens of Edo lorded it over country bumpkins by saying, "I'm an Edokko [native of Edo] 'cause I was cleaned with pipe water when I was born and I've grown up drinking pipe water ever since."

It seems an odd thing to crow about given the cultural wealth of Edo, at the time the largest city in the world, but this pride in the city's water system wasn't misplaced. Cool, pure water carried by pipes to the city's remotest corners was indeed a byword for the quality of life in Edo -- as well as being the lifeblood of the city's prosperity.

However, coming up with an efficient and reliable water supply was no easy task. Much of Edo was built on land reclaimed from the shallow waters of Edo Bay, which -- in the absence of the technology required to bore deep wells -- only yielded brackish water. Meanwhile, Edo Castle and the samurai residences were mostly situated on uplands on the eastern edge of the Musashino Plateau. There, potable water was equally hard to come by because the friable top soil was not water-retentive. Indeed, the vast grasslands of Musashino had traditionally been ridiculed by Kyoto aristocrats, who lamented in poems that "Musashino has neither trees nor mountains behind which the moon can set."