A Hand-Cut Irrigation Tunnel of 1857
The Miroku Sekketsu Water Tunnel (弥勒石穴) is a 189-metre tunnel cut through the rock of Mount Mitsuishi as part of a channel feeding Miroku Pond at Tomidanaka, Okawa-machi, Sanuki City, Kagawa Prefecture, completed in 1857, and was registered as a Registered Tangible Cultural Property (structure) on February 15, 2000. It still carries water to the pond (Agency for Cultural Affairs, Ministry of Agriculture, Forestry and Fisheries).
The Agency for Cultural Affairs records it as a tunnel 189 metres long with stone portals; registration number 37-0025, owned by the Tomida Central Water Users' Association.
A Vessel without Water
According to the Ministry of Agriculture, Forestry and Fisheries, Miroku Pond was enlarged in 1835 to relieve water shortages, but for some twenty years it remained a vessel without water to fill it. Concerned, the village headman Nokihara Shozo petitioned the Takamatsu domain in 1855 for a tunnel, was appointed to oversee it, and dug through the rock of Mount Mitsuishi from both ends.
Working day and night with hand chisels alone, the diggers broke through in 1857, three years after starting, and brought water from the Saisekidani valley. For this feat Nokihara was later charged, in 1869, with the outlet tunnel works at Mannoike Pond (Ministry of Agriculture, Forestry and Fisheries). The Agency for Cultural Affairs adds that he designed it with help from the local mathematician Hagiwara Eijiro, and that Tada Shinzo supervised the work.
Why It Was Registered
The Miroku Sekketsu Water Tunnel was registered as a structure that contributes to the historic landscape of the country. Cut by hand at the end of the Edo period, it still carries irrigation water today (Agency for Cultural Affairs, Ministry of Agriculture, Forestry and Fisheries).
What to Look For
The portals of the Miroku Sekketsu Water Tunnel are protected by stonework and stone retaining walls (Agency for Cultural Affairs). The ministry notes that the tunnel runs almost straight and is just large enough for a person to walk through stooping.
Water is drawn from the Saisekidani valley about 500 metres below the Okawa Dam on the Tsuda River system. At the outlet into Miroku Pond, in Miroku Nature Park, there is an information board and a registration plaque (Ministry of Agriculture, Forestry and Fisheries). The pond takes its name from stone Buddhas, including Miroku (Maitreya), once dug up here.
Getting There
The outlet of the Miroku Sekketsu Water Tunnel is in Miroku Nature Park, Tomidanaka, Okawa-machi, Sanuki City (Ministry of Agriculture, Forestry and Fisheries). According to the Kagawa Prefecture Tourism Association, the park is free to enter (some facilities charge) with free parking, about 10 minutes by car from JR Sanuki-Tsuda Station or the Tsuda-higashi interchange.
Q&A
- When was the Miroku Sekketsu Water Tunnel built?
- Work began in 1855 and broke through in 1857 (Ministry of Agriculture, Forestry and Fisheries).
- Why was the Miroku Sekketsu Water Tunnel built?
- To bring water from the Saisekidani valley to Miroku Pond, which lacked water even after enlargement (Ministry of Agriculture, Forestry and Fisheries).
- How was the Miroku Sekketsu Water Tunnel dug?
- From both ends through the rock of Mount Mitsuishi, day and night, with hand chisels (Ministry of Agriculture, Forestry and Fisheries).
- Is the Miroku Sekketsu Water Tunnel still used?
- Yes, it still feeds Miroku Pond (Ministry of Agriculture, Forestry and Fisheries).
- When was the Miroku Sekketsu Water Tunnel registered?
- On February 15, 2000.
Basic Information
| Name | Miroku Sekketsu Water Tunnel (弥勒石穴) |
|---|---|
| Location | Off 3519-1 Tomidanaka, Okawa-machi, Sanuki City, Kagawa Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2000/2/15 (Heisei 12) |
| Quantity | 1 structure |
| Dimensions | Tunnel with stone portals, 189 metres long |
| Owner | Tomida Central Water Users' Association |
| Public Access | Outlet viewable in Miroku Nature Park (free entry) |
References
- Miroku Sekketsu Water Tunnel (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00001536
- Miroku Sekketsu (Ministry of Agriculture, Forestry and Fisheries)
- https://www.maff.go.jp/j/nousin/sekkei/museum/m_bunka/yuukei16/index.html
- Miroku Nature Park (Kagawa Prefecture Tourism Association)
- https://www.my-kagawa.jp/point/211/
Last verified: 2026.10.10