Supplying Water to Edo City

One of the big problems of Edo city was water. Since Edo was close to the sea, getting of good water was difficult. So, people brought water from outside Edo city. In 1653, people made Tamagawa canal. The sluice gate was made in Hamura 43km away from Edo city, and supplied the Tamagawa river's water to Edo city. One of the reason for having installed the sluice gate in the place distant from Edo city is for obtaining a vertical interval. They did not have a pump. The vertical interval of the Hamura and Edo city is about 90m. And for obtaining good water.