Asaka Canal

"Asaka Shui" is a major Meiji project that transformed the Asaka Shui field in Koriyama City into fertile ground [Fukushima Prefecture]

There is an agricultural canal running from Lake Inawashiro to Koriyama City. This waterway is a tunnel dug into the mountain between Lake Inawashiro and Koriyama City to supply water to Koriyama City.

"Asaka Sosui" , was built in the Meiji period and still hydrates the Koriyama region and is also used for hydroelectric power generation.

The historical story of "Asaka Shui" has been recognized as a Japanese Heritage by the Agency for Cultural Affairs as "A "One Waterway" that opened up the future - Okubo Toshimichi "The Last Dream" and the Trajectory of Pioneers: Koriyama, Inawashiro." It was also registered as a World Irrigation Facility Heritage by the International Irrigation and Drainage Committee (ICID).


The Asaka Plain cultivation project started in the early Meiji period.

Koriyama has been called Asaka-gun since the Heian period, and was a territory of the Nihonmatsu clan during the Edo period. It was a post town on the Oshu Kaido road, and it seemed to be quite crowded. However, Asaka District, which includes Koriyama-juku, was a very desolate wilderness due to dry winds blowing down from the Oshu Mountains drying out the land and few water sources.

The project to cultivate the Asaka Plains was started by local people in 1873 (Meiji 6). The group of pioneers formed a private land clearing company called Kaiseisha, and used innovative methods to cultivate the land, including planting foreign fruit trees and using Western agricultural tools. Kaiseikan, a development office, was built by local carpenters who imitated Western-style buildings based on colored woodblock prints.

However, there is still not enough water to turn this wilderness into a rich land. There, they drew water from the large Lake Inawashiro on the west side beyond the mountain. This was the fervent wish of the local people, including Kaiseisha.

The Meiji government realized the long-cherished desire to draw water from Lake Inawashiro.

Overview of Asakan Waterfall in the Meiji Period, Koriyama City Library

From the Edo period to the Meiji period, many of the samurai who were employed by feudal clans in various regions lost their jobs. Toshimichi Okubo, the Minister of Home Affairs, was worried about this problem and thought that he could save the unemployed samurai by carrying out a large-scale land improvement project to channel the water from Lake Inawashiro to Asaka. In 1898 (Meiji 11), we were the first in the country to budget for the Asaka Development and Asaka Canal Opening Project.

However, just before the start of the Asaka development project, Toshimichi Okubo, who was at the forefront of the project, was assassinated (May 14, 1878, Kioisaka Incident).

National Diet Library, Okubo Toshimichi, the Home Secretary

“Azaka Development and Asaka Canal Opening Project” inheriting Toshimichi Okubo’s will

Toshimichi Okubo tragically passed away before he could even see the start of the business, but the business itself continued to be carried out.

First, on November 11, 1878 (Meiji 11), the first group was from the former Kurume domain, followed by 2,000 former samurai and their families from nine domains across the country, including the former Okayama domain, the former Tosa domain, the former Tottori domain, and the former Nihonmatsu domain. Too many people have immigrated.

In 1879, the Asaka Development and Asaka Canal Opening Project, a grand project to dig a tunnel through the mountains (Ou Mountains) that rises between Lake Inawashiro and the Asaka Plains and channel water, was launched as a project under the direct control of the national government. It started in October (Meiji 12).


The groundbreaking "Jurokubashi Water Gate" designed by Dutch engineer Van Doorn

The first thing we worked on was the construction of a floodgate to keep the flow rate constant towards Aizu on the west side of Lake Inawashiro.

Jurokubashi Shuzo gate has been renovated but is still in operation today © Ministry of Agriculture, Forestry and Fisheries

By flowing the water from Lake Inawashiro towards Asakaharano, we cannot reduce the flow rate to Aizu, which has previously used lake water. To solve this problem, van Doorn, a Dutch engineer and engineer of the Meiji government, came up with a scientific solution that was not previously found in Japan.

This involves building a dam like a dam in the area where the lake flows out towards Aizu, causing a stable, fixed amount of water to flow out from the floodgates. The huge floodgate, known as the Jurokubashi Shuimon, was completed in 1880 (Meiji 13).

When the building was built, the gate above the Jurokubashi floodgate was a sidewalk © Koriyama City

``Jurokubashi Water Gate'' was made of stone, and an arch-shaped bridge was built over the 16 stone gates. It was later renovated into its current form in 1914 (Taisho 3) for the development of a power source. "Jurokubashi Water Gate" has been certified as a modern industrial heritage.

Jurobashi Shuimon <Information>

  • Name: Jurokubashi Swimmon
  • Address: Ozawa Oaza Senba, Inawashiro-cho, Yama-gun, Fukushima Prefecture and Akaidonoguchi, Minatomachi, Aizuwakamatsu City
  • Phone number: 024-922-4595 (Asunawari Land Improvement District)
  • Official URL: Asaka Kansui

Google Map


The Asaka Canal was completed in three years, including the Numagami Tunnel and waterway that penetrate the Ou Mountains.

Construction of the intake and tunnels for the Azumihara area began around the same time as the construction of the Jurokubashi Shuzo.

The water intake was originally built in Yamagata (Yamagata/Yamagata, Inawashiro-cho). Water from Lake Inawashiro is poured into the valley on the other side by tunnel.

This tunnel, known as the Numakami Tunnel, runs through Numakamiyama (761m above sea level), total length is 585m. Construction began in December 1879 (Meiji 12) and was completed in July 1881 (Meiji 14).

This led to the water from Lake Inawashiro running through the Ou Mountains and flowing out into the Azumi wilderness for the first time. The water intake was later moved to Kamitoshoku Works (Yamagata, Inawashiro-cho), a little north of the Yamagata floodgate, and is still in operation today.

The right side of the Asakan Waterfall, drawn from Lake Inawashiro, flowing like a waterfall, is the Numagami Power Station © Koriyama City

The water from Lake Inawashiro, which passes through the Numagami Tunnel, descends like a waterfall from the exit on the Koriyama side, joins the Gohyakgawa River and flows downstream.

The Asaka Shui that drifted into Asaka Genro was washed away in about 52.1 km of waterways and 78 km of branching channels, and hydrated approximately 3,000 hectares of new farmland. The Asaka Shui was completed using a national budget of 407,000 yen (currently about 40 billion yen) over a three-year construction period, and a total of 850,000 labor force.

The Asaka Canal has since been expanded and renovated, and now supplies water to approximately 10,000 hectares of rice fields.

Asaka Canal is also used for hydroelectric power generation

``Asaka Canal'' flows out like a waterfall into the converging Gohyaku River. A hydroelectric power plant was built using this flow. The first to be completed was the Numagami Power Plant in 1899 (Meiji 32), which uses the drop that flows from the Numagami Tunnel into the Gohyaku River to generate electricity.

Takenouchi Power Plant ©Koriyama City

After that, the ``Takenouchi Power Station'' began operation in 1919 (Taisho 8), and the ``Marumori Power Station'' began operation in 1921 (Taisho 10). "Numakami Power Plant," "Takenouchi Power Plant," and "Marumori Power Plant" have been certified as modern industrial heritage sites.

Modern Industrial Heritage Power Plant <Information>

  • Name: Numagami Power Station
  • Address: Yasukojima, Atami-cho, Koriyama-shi, Fukushima Prefecture
  • Phone number: 0242-22-4611 (Tokyo Electric Power Company Renewable Power Inawashiro Office)

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  • Name: Takenouchi Power Station
  • Address: Takenouchi, Yasumi-cho, Koriyama-shi, Fukushima Prefecture
  • Phone number: 0242-22-4611 (Tokyo Electric Power Company Renewable Power Inawashiro Office)

Google Map


  • Name: Marumori Power Station
  • Address: Atami 5-chome, Koriyama City, Fukushima Prefecture
  • Phone number: 0242-22-4611 (Tokyo Electric Power Company Renewable Power Inawashiro Office)

Google Map


Many historical sites and related facilities of Asaka Canal remain in Koriyama City.

There are many historical sites and related facilities related to "Asaka Shui" in Koriyama City, and you can get a feel for the history of these sites.

"The birthplace of Asaka Development" where Kaiseikan, government housing complexes and settlers' housing gather

Kaiseikan, a local carpenter in the early Meiji period, built in a Western style by imitating Nishiki-e and other works. © Koriyama City

After being used as a development base, Kaiseikan was used as the county office, Kuwano Village (currently Koriyama City) government office, etc., and now serves as a museum that tells the history of Asaka reclamation and Asaka Canal. "Kaiseikan" is an important cultural property of Fukushima Prefecture and a modern industrial heritage recognized by the Ministry of Economy, Trade and Industry.

Azumi Taiga Building, former residence of Tateiwa Ichiro © Koriyama City

On the premises of "Kaiseikan" (a historic site of Koriyama City as the "birthplace of Asaka development"), there is "Azaka Development Official Residence" (former Tateiwa Ichiro residence / restored, designated as an important cultural property by Koriyama City), "Azaka Development Settlers' Residence" ” (former Koyama family/relocated and restored, Koriyama City designated important cultural property) and (former Tsubouchi family/relocated and restored) are open to the public (both temporarily closed in 2022).

The birthplace of Asaka Development <Information>

  • Name: The birthplace of Asaka Development
  • Address: 3-3-7 Kaisei, Koriyama City, Fukushima Prefecture
  • Phone number: 024-923-2157
  • Official URL: Koriyama City Kaiseikan

Google Map


Rokuyama Park was the final exit of Asaka Canal.

A flying waterfall at Mt. Asaka Shuiro, built to commemorate the passage of the water in Asaka Shui Water © Koriyama City

Hayama Koen is a park that was built in 1827 to commemorate the promotion of Koriyama Village to a post town by the Edo Shogunate. In the Meiji period, after the Asaka Canal was completed, the Asaka Canal was built as a memorial, with the canal flowing like a waterfall called the Asaka Canal. “Azaka Canal and the Flying Waterfall of Mt. Fuji” is a registered tangible cultural property of the country.

Fukoyama Park <Information>

  • Name: Fukoyama Park
  • Address: Inside Furoyama 1-chome, Koriyama City, Fukushima Prefecture
  • Phone number: 024-924-2194 (Koriyama City Tourism Exchange Promotion Corporation 21st Century Memorial Park Office)

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"Former Fukushima Prefectural Junior High School Main Building", which was visited by people involved in Asaka Canal

Azumi History Museum, a former Fukushima Prefecture Important Cultural Property, which is often used in film and television location shoots. © Koriyama City

The school building of Fukushima Prefectural Junior High School, which was opened in 1889 (Meiji 22), is now open to the public as the Asaka History Museum. This is the school where many people involved in Asaka Canosui attended. The former Fukushima Prefectural Junior High School Main Building is a nationally important cultural property.

Azumi History Museum <Information>

  • Name: Azumi History Museum (formerly Fukushima Prefecture's Own Junior High School Main Building)
  • Address: 5-25-63 Kaisei, Koriyama City, Fukushima Prefecture
  • Phone number: 024-938-0778
  • Official URL: Azumi History Museum

Google Map


Asaka Canosui Shrine, the guardian deity of Asaka Canals

``Azaka Cansui Shrine'' is a shrine worshiped as the guardian deity of ``Asaka Cansui''. It is said that workers heading for canal construction always visited the shrine before heading to the site.

Asaka Shusui Shrine <Information>

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Okubo Shrine, where Toshimichi Okubo was prayed for

Okubo Shrine with only memorial monuments © Koriyama City

This is a shrine dedicated to Toshimichi Okubo, who worked tirelessly to build the Asaka Canal, but was assassinated before it was completed. It was founded in 1889 (Meiji 22), and there is no shrine building, only a memorial monument.

Okubo Shrine <Information>

  • Name: Okubo Shrine
  • Address: 4-112 Ushiiwa, Asaka-cho, Koriyama City, Fukushima Prefecture (within Asaka Community Center Ushiiwa Branch)

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