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Water supply infrastructure in the Nihonbashi area (Edo period)

In October 2021, we introduced the water supply infrastructure in the Ginza area and conducted a geographical analysis to prove that it is being released naturally. It is well known that Tamagawajosui is drawn to the Ginza district and Kanda Josui is drawn to the Nihonbashi district, but both were supplied with water by natural discharge. This is the water supply situation in the Nihonbashi area.

Securing domestic water (due to tap water or well water or purchased water) seems to have been urgent. Water saving was carried out thoroughly, and not only townspeople but also samurai and all residents did not use tap water for purposes other than beverages. All the miscellaneous water used well water.

There was no sedimentation or filtration equipment like a water purification plant in the Edo water supply, and the drainage pipe was wooden pipes made of cypress and pine. If you calculate the slope of the part where the wooden tub in Nihonbashi was installed, you can see that the slope is 3/1,000 as in Ginza:

Elevation difference between Nishigawa Riverside and Tooricho Street (now Ginza Street) →　3.12m～3.8m=68cm

The distance between Nishibank and Tooricho-dori (now Ginza-dori) → About 200m

Slope = 3.4 / 1,000

 

Water distribution by wooden tubs

Water distribution by wooden tubs Water supply infrastructure in the Nihonbashi area (Edo period)

Let's take a look at the plumbing status of the water supply with a cutout diagram (drain diagram) showing the plumbing status of the water supply. The wooden gutter buried under the road is a pipe network, with a wooden basin on the way, and the water constantly flows through the gutter pipe according to the natural slope. From the basin facing the street, they were used for joint use, and from the water wells that were called in a tub to each house, they were pumped up with a vine for each house.

Even in areas where wooden tubs were drained, heavy rain fell on the upstream water source immediately hit muddy water. On the other hand, during the drought season, the water supply may be cut off or reduced.

The figure shows the distribution status at the tenement house in Kibori-cho.

At that time, there was no such thing as a tap, so what happened to the end of the natural release? In the case of Nihonbashi, the surplus water that was not used was released into the river from the left and right sides of the Zenibashi Bridge in Gofuku Bridge, which is the end of the water distribution system, or from the water outlet at the Ichiishi Bridge.

At this outlet, a water boater who received the shogunate's license purchased this water and incorporated it into a horse-drawn boat and sold it to residents of the headquarters, Fukagawa, who had trouble drinking water, and a boat.

"Thank you very much for picking sweetfish at the well."

(Reference)

Masao Horikoshi, Published in 1993