Takahashi River Tozai Yosui Intake and Distribution Facilities

What the Takahashi River Tozai Yosui Intake and Distribution Facilities Are

The Takahashi River Tozai Yosui Intake and Distribution Facilities (高梁川東西用水取配水施設, Takahashi-gawa Tōzai Yōsui Shuhaisui Shisetsu) are a Taishō-era agricultural water system in Sakazu, Kurashiki City, Okayama Prefecture, whose 3 sluice gates were completed in 1924 and which were designated an Important Cultural Property of Japan in 2016. The designation covers the Sakazu Intake Sluice Gate, the South Distribution Sluice Gate, the North Distribution Sluice Gate and 1 office building. Locally the complex is simply called Tōzai Yōsui, or the Sakazu sluice gates.

The system works on one idea, carried out at large scale. The intake gate on the left bank of the Takahashi River draws water into a holding basin. Two distribution gates on the basin's south and north sides then release it into separate irrigation canals. The south gate feeds 5 canals, among them the Kurashiki and Bizenhi canals, while the north gate serves the Hakkagō canal.

Flood control, not farming, set the project in motion. In 1907 the national Home Ministry began a major improvement of the Takahashi River, and as a side project the scattered, older intakes along its banks were merged into one. The facilities occupy the bed of the former eastern channel of the river, left dry by the rerouting. The Osaka civil engineering office of the Home Ministry planned and designed the gates. Okayama Prefecture designed the office, finished in 1926.

One point needs flagging. The Agency for Cultural Affairs database lists individual dates for each gate: 1920 for the intake gate, 1922 for the north gate and 1923 for the south gate. The same database's commentary gives 1924 as the completion year for the gates and does not explain the difference.

Why the Takahashi River Tozai Yosui Facilities Became an Important Cultural Property

The designation rests on scale and on material. Among modern irrigation works that consolidated small intakes dating back to the Edo period, the Takahashi River Tozai Yosui Intake and Distribution Facilities are judged the largest of the Taishō era (1912 to 1926).

All 3 gates are built of reinforced concrete, a method spread across Japan's irrigation works during the Taishō years. Few examples from that period survive as a working group, which gives the complex real weight in the history of agricultural engineering. The formal criterion is high historical value.

The gate leaves and the walkways along the tops of the distribution gates have been renewed, but the structures otherwise keep their original form. The land is protected along with the buildings. Two items are listed as Tsuketari, or appended properties: a stone commemorating the completion of the canal works, and a small single-storey reinforced concrete archive built in 1928 southeast of the office to hold records and valuables.

Before the national designation, the Japan Society of Civil Engineers selected the gates as a civil engineering heritage site in 2003, citing them as among the largest sluice gates in Japan still in daily use.

What to Look For at the Takahashi River Tozai Yosui Facilities

The Granite-Clad Sakazu Intake Sluice Gate

The Sakazu Intake Sluice Gate measures 22.1 meters across the front and 17.4 meters across the back, with a water passage 53.0 meters long. Its 7 openings are gate-shaped, and every visible surface of the concrete body is faced with cut granite, laid with great care. The effect is closer to a castle wall than to a piece of irrigation plumbing.

On the river side, look for the low concrete weir in front of the openings. It keeps sand and gravel out of the channel, a reminder that behind the tidy stonework the engineers were dealing with a sediment-heavy river.

The 15-Bay South Gate and 6-Bay North Gate

The South Distribution Sluice Gate is the longest structure at Tōzai Yōsui: 48.3 meters across, with a water passage of 4.2 meters and 15 openings side by side. The North Distribution Sluice Gate is much smaller, 18.1 meters across with a 3.40-meter passage and 6 openings.

Both use granite for the cutwaters and the top corners, and each opening is framed by an arch on the back face. Stand on the basin side to see the arches in a row. Knowing that each opening feeds a different canal makes it easy to picture one river splitting into the waterways of the Kurashiki plain.

The Symmetrical Office

The office is a 2-storey timber building, 18.2 meters by 7.3 meters, with a hipped Yosemune-zukuri roof covered in Sangawara-buki pantiles. A porch projects at the center of the front and a stair tower at the center of the back, and the whole facade is symmetrical. The walls are finished in mortar. A decorative gable rises over the entrance, with sash windows on each side and 2 dormer windows on the front slope of the roof.

Inside, the ground floor has an office and a meeting room on either side of a central entrance hall, and the upper floor is a single meeting room. Its Western-style design contrasts with the plain strength of the gates, and the building still serves as the headquarters of the Takahashi River Tozai Yosui Union.

Visiting the Takahashi River Tozai Yosui Intake and Distribution Facilities

You can view the 3 gates of the Takahashi River Tozai Yosui Intake and Distribution Facilities from Sakazu Park, a large municipal park, and from the embankments around it. The site is outdoors and no fee is charged to look at the structures. The gates are working equipment, so stay outside the fences and away from the control machinery. No specific photography restrictions are posted for outdoor views, but take care not to get in the way of the union's staff.

The office is a working building, so visits are generally limited to the exterior. If you hope to see inside, contact the Takahashi River Tozai Yosui Union in advance.

By public transport, take a local bus from the north exit of JR Kurashiki Station to the Akebono-bashi stop, about 10 minutes, then walk about 10 minutes. By car, the site is about 20 minutes from Kurashiki Interchange on the Sanyō Expressway, and Sakazu Park has parking for about 300 cars. The park holds about 500 cherry trees, and in blossom season the basin edges fill with picnickers, so expect crowded parking then.