Long ago water flowed here. Today we stand at Koigakubo Mura Bunsuirei. This area in Tokyo was once vital for water distribution.
Koigakubo Mura Bunsuirei is a historic landmark. It dates back to 1657. This was just four years after the completion of the Tamagawa Aqueduct. Imagine Kokubunji village, Koigakubo village and Kabae village joining together. These three villages needed water for their rice fields. They petitioned the Edo shogunate. The request was to share water. This became part of the Kokubunji village water distribution system. It is known as Koigakubo Yosui.
This is the oldest and largest water distribution site in the city. The large bank retains its original form. It is a testament to the past. In 2017, marking 360 years since its creation, the city designated it as an important historical site. In the following year, 2018, Koigakubo Yosui-ro Ryokuchi opened.
The Koigakubo Mura Bunsuirei was essential for irrigating rice paddies. This continued until the 1960s. Much of it was then converted into underground waterways. However, within the Koigakubo Yosui-ro Ryokuchi, it remains preserved. You can still see it in its open channel form.
The scale of this water division is significant. It is impressive even as part of the Tamagawa Aqueduct system. The width of the waterway is about six to nine meters at the top. At the bottom, it narrows to about 50 centimeters. The depth is around five meters. The bottom slopes gently downward from north to south. The slope is about 10.2 per 1,000.
Near the Koigakubo intersection, the waterway splits. It divides into three branches. These serve Kabae village, Kokubunji village and Koigakubo village. Much of the original canal has been modernized. It now runs underground due to urbanization. Yet, this surviving section retains its Edo-era character.
As you explore Koigakubo Mura Bunsuirei notice the western wall in the northern area. Here you may spot some partial collapses. These are due to repeated freezing and thawing. This site merges history and nature. It provides a valuable glimpse into the past. Many people visit to enjoy walking and admire the cherry blossoms. Koigakubo Mura Bunsuirei is a reminder of Tokyo’s vital water management history.