Kitayama Canal is an irrigation canal that runs along the western foot of Mt. Fuji, Japan's highest peak. Around the end of the 16th century, excavation for irrigation water began from the Kitayama Honmonji Temple to the Shiba River, which flows from the springs in the north of the city. This irrigation water eventually became a huge irrigation system to irrigate nine villages.

According to a picture drawn in the 19th century, there were aqueducts, buried culverts, and open flumes to take in water from the Shiba River and cross the large and small swamps (eroded valleys) of Mt. Fuji. Before the construction, the Kitayama area had only a small amount of spring water, and people relied on rainwater for living and cultivation. Most of the valleys of Mt. Fuji were dried-up streams with no water, but on the other hand, they became dangerous streams where debris flows occurred during floods, which is the biggest obstacle to maintaining irrigation facilities.

The waterway construction project was initiated by Tokugawa Ieyasu, who later became the Shogun of the Edo Shogunate. In 1582, Masatsugu Ide, the local governor, ordered to excavate. In an astonishing period of three and a half months, a canal 8 km long and 5.4 m wide was constructed, enriching the villages. Later, in 1610, the canal was extended by Tadatsugu Ina Bizen no Kami, and today, this 10km main canal irrigates 110ha of paddy fields.

At present, Kitayama Canal have been refurbished with concrete, making use of the abundant water volume and drop to generate small hydroelectric power at four locations. In total, the maximum output is 428kW and the amount of power generated is 2,437MWh, which reduces CO2 emissions by about 1,084t annually, producing clean electricity that does not generate carbon dioxide.

According to a 19th-century drawing, the irrigation canal traverses the numerous eroded valleys at the foot of Mt. Fuji. Three buried culverts, three aqueducts, and one open flume are confirmed. Because the irrigation area is covered with volcanic ejecta with many gaps, water infiltration rate is high and it is not possible to secure a sufficient amount of water. As a result, there were frequent water disputes.

After that, the issue was resolved through negotiation, and in 1889, the first water diversion agreement was concluded. At the same time, at the Kitayama water intake point, foundation stones were laid on the riverbed to ensure the specified amount of water drawn downstream. Furthermore, in order to ensure a constant water level at the intake point, a notched water gauge was installed so that the water level could be checked. Since then, the Fujinomiya City Kitayama Canal Management Cooperation Committee, consisting of representatives from related wards centering on the Kitayama district, has conducted regular surveys of the need for water supply adjustments and repairs, as well as soil cleaning and weeding.

The Kitayama Canal supplied water to villages at the foot of Mt. Fuji that relied on rainwater for farming, and paddy rice that was cultivated in a limited area. This was made possible by the construction of wooden box flumes'umedoi' and hung wooden box flumes 'kakehi' to avoid debris flows and cross the many eroded valleys of Mt. Fuji. “Umehi” is a canal through which water flows by burying a wooden box gutter in the ground, and “Kakehi” is an aqueduct through which water flows through a wooden box gutter. The application of this technology avoids damage from the large-scale debris flows that frequently occur in the eroded valleys of Mt. Fuji. It greatly contributed to the expansion of the village scale and the improvement of the standard of living.

According to a 19th-century drawing, the irrigation canal traverses the numerous eroded valleys at the foot of Mt. Fuji. 3 hung flumes and 1 open flume were installed. The largest underground box flume was 36m long and 1.8m wide and had a sluice gate on the upstream side for discharge. The largest hung flume is a box gutter with a length of 33m, a width of 1.4m, and height of 0.5m. The pillars of this hanging designed to withstand debris flows. The irrigation canal was constructed in preparation for the threat of mudslides from Mt.Fuji.

The establishment of the Kitayama Canal has brought out the potential of various regions, such as transforming villages with poor water supply into villages that can secure domestic water, and transforming low-productivity dry land into paddy rice farming. Kitayama Canal fundamentally changed the area, which had struggled to secure drinking water, and transformed 110 ha of upland field into paddy field. As a result, the region's food production and stability have been greatly improved. In addition, 11 water wheels were installed in the Kitayama Canal, and they were used for rice milling, barley milling, flour milling, etc., and played an important role as a basic power source in the era before the spread of modern power machinery such as steam and electric power. Furthermore, the power of the water wheels that was hung on the Kitayama canal changed in social life and food culture. This greatly contributed to the expansion of the scale of settlements in the Kitayama irrigation basin.

The eroded valleys at the foot of Mt. Fuji are normally waterless, but when flooded, they became channels for debris flows. Also, these valleys were the biggest obstacles to maintaining the irrigation canals. This difficult problem was solved in the 16th century by installing multiple long aqueducts that flowed through buried box flumes suitable for the size and shape of the erosion valley.

Kitayama Canal originates from the springs at the foot of Mt.Fuji. However, since the arable land is covered with volcanic eruptions and has a high water infiltration rate, we had to pay close attention to the allocation of precious water to each area. At the beginning of the construction, each village was responsible for maintenance and its costs, and local farmers were responsible for managing the water. Due to the inability to secure a sufficient amount of water, conflicts over water frequently occurred between the villages for using the Kitayama canal and the villages in the lower Shiba River basin. After that, the dispute was resolved through discussion, and on June 24, 1889, the first water diversion agreement was concluded. At the same time, a base stone was laid and fixed on the riverbed at the water intake point, and a notched water gauge was installed so that the water level could be checked.

The Kitayama Canal uses buried box flumes and hang box flumes to cross eroded valleys where debris flows occur during heavy rains, and the land, which is prone to water infiltration, was gradually transformed from upland fields to paddy fields. In addition, using the abundant water and the head of the waterway, many water wheels generate the power for milling flour, improving the production activities of the region, and furthermore, the food culture is greatly improved.

According to Kitayama Honmonji Engi, it is said that the initial construction work for the main canal was started on August 1st, 1582 and was completed on November 15th. In order to supply water to a wide area, this water is taken from the Shiba River at the altitude of 550m, which has abundant water throughout the year. The irrigation canal, which was repeatedly improved by the end of the Edo period, was equipped with three aqueducts to cross the eroded valley at the foot of Mt. Fuji. The largest aqueducts over Okubo-sawa is a box flume with a length of 33m, a width of 1.4m, and a height of 0.5m, made from a 9m-long tree. Four 9m-long trees and two-5m long trees grown in the forests of Mt. Fuji were used for the supports of this hung flumes. These structures were buried 1.2m deep and were resistant to debris flows. In addition, the underground built in 1862 was 36m long and 1.8m wide and was equipped with a sluice gate to discharge surplus water upstream.

The Kitayama Canal was constructed 440 years ago of supply water to 190ha of cultivated land, and supplied water to the area at the foot of Mt. Fuji at the altitude of 500m to 250m. Today, the beneficiary area is 110ha, and after the war, the waterway changed from earthen waterway to concrete waterway, and the hanging and underground flames changed from wooden to stone and then to concrete. It remains capable and continues to play an important role in local agriculture.

One of the reasons for its success is the selection of appropriate routes at the time of establishment. In the past, many water mills were built on the waterway, but today, using the abundant water volume and head, small hydroelectric power generation is being carried out at four locations. In total, the maximum output is 428kW and the amount of power generated is 2,437MWh, which is expected to reduce CO2 emissions by about 1,084t annually, producing clean electricity that does not generate carbon dioxide.

After the war, the irrigation canals were renovated from earthen canals to concrete canals, and the hanging and buried Flumes were also changed from wood to stone or concrete. This reduced the amount of water leakage and management costs, and increased the satisfaction level of the beneficiaries.

In addition, since water was supplied, it has provided drinking water and domestic water as well as agricultural water to the volcanic ash land zone where it is difficult to secure water. Therefore, since 1971, Fujinomiya City has developed a water supply facility, which diverts 0.208 m3/s from the main water supply and supplies it to each household in the area.

Since its establishment 440 years ago, nine villages in the irrigation area have borne the costs of maintenance and management of water intakes and waterways, and water distribution and facility management have been carried out by appointing water distributors (supervisors). Even now, an organization composed of villages in the irrigation area (Fujinomiya City Kitayama Canal Management Cooperation Committee) operates and manages the canal independently and democratically.

In Fujinomiya City, where the canal is located, a booklet on the Kitayama Canal was created for elementary school students to provide an educational opportunity to learn about its history and importance. In addition, when the water work was completed, a water festival was held to thank the supply of water. Since then, this water festival has been held once every 50 years and continues to this day. Most recently, it was held at Kitayama Honmonji Temple in 2006, with more than 200 participants, including local officials, elementary and junior high school students. Dedicatory drums were performed and an unveiling ceremony for the monument was held. While appreciating the achievements of their predecessors, the local people pledge to pass them on to the future generation.