Karatooka Shimizu Common Waterworks

Karato-oka no Shimizu Communal Water Station: A Living Spring on Teshima Island

On the tranquil island of Teshima, nestled in the Seto Inland Sea between Kagawa and Okayama Prefectures, a remarkable stone-built communal water station has been serving the local community for nearly a century. The Karato-oka no Shimizu Communal Water Station (唐櫃岡の清水共同用水場) is a registered tangible cultural property that stands as a testament to the island's deep relationship with water, stone, and community life. Built in 1929 using locally quarried granite, this tiered water facility channels natural spring water from Mount Danyama through a series of basins, each designated for a specific purpose — a system that has sustained the Karato-oka village since its earliest days.

The Legend and Origins of Karato Spring

The spring water at Karato-oka is known as "Karato no Shimizu" and carries a legend stretching back over a thousand years. According to local tradition, the revered Buddhist monk Kobo Daishi (Kukai), who traveled extensively across Japan in the early 9th century, stopped at this location and, feeling thirsty, dug into the ground — whereupon fresh water miraculously sprang forth. The spring has also been called "Reisen Kossui" (霊泉越水), meaning "sacred overflowing spring," reflecting the spiritual significance the water holds for the island's inhabitants.

The spring emerges at a geological boundary where the granite bedrock of Mount Danyama meets layers of tuff and conglomerate rock. This natural formation filters rainwater through the mountain's thick forests of evergreen chinquapin (sudajii) and oak trees, producing water that flows at a consistent temperature of 13–14°C year-round. The daily output ranges from 50 to 130 cubic meters — an impressive volume for such a small island — and remarkably, the spring has never been known to dry up, even during severe droughts.

Construction and Design of the Water Station

The communal water station as it exists today was constructed in 1929 (Showa 4) through the generous philanthropy of Kisaburo Nakano, a native of Teshima who had achieved great success in the stone and civil engineering industry in Tokyo. Nakano's company was involved in major national construction projects, including work on the National Diet Building and Nihonbashi Bridge. Wishing to give back to his home island, he donated substantial private funds to build a modern communal water facility using the island's own granite.

The water station occupies an area of approximately 75 square meters, measuring roughly 10 meters in length, 5 meters in width, and 2 meters in height. The structure features a trapezoidal floor plan with walls built using a technique called "nuno-zumi" (布積み), in which granite blocks are stacked in neat horizontal courses to create a tiered, staircase-like arrangement. Spring water is channeled from an upper reservoir into a series of three smaller connected basins and then into a larger lower basin. Each basin was traditionally assigned a specific use: the uppermost for drinking water, the middle basins for washing vegetables, and the lower basins for laundry rinsing. Excess water flows through a side channel into the village's drainage system and ultimately irrigates the surrounding terraced rice paddies.

Why It Was Designated a Registered Tangible Cultural Property

The Karato-oka no Shimizu Communal Water Station was registered as a tangible cultural property (building) by the Agency for Cultural Affairs on October 12, 2001. It was recognized for its significance as a rare surviving example of a communal water infrastructure from the early Showa period that vividly illustrates how stone was central to daily life on the islands of the Seto Inland Sea. The facility demonstrates the high level of granite masonry craftsmanship that developed in the Bisan Islands region, where stone quarrying and construction had been a major industry since the Edo period.

The water station is part of a group of three registered cultural properties at this site. Adjacent to it stand the Shimizu Kannon-do (清水観音堂), a modest temple hall owned by Jurin-ji Temple, and the Shimizu Shrine (清水神社/荒神宮) social hall dating to 1913. Together, these three structures form a unique cultural landscape where water infrastructure, Shinto worship, and Buddhist devotion are intimately intertwined — a powerful expression of how island communities organized their spiritual and practical lives around a shared natural resource.

Furthermore, the communal water station is recognized as a constituent cultural property of the Japan Heritage story "The Stone Islands: Timeless Islands of the Seto Inland Sea That Built Japan's Foundations" (知ってる!? 悠久の時が流れる石の島), which highlights how the granite quarrying traditions of the Bisan Islands shaped Japan's most iconic historical structures, from the stone walls of Osaka Castle to the Bank of Japan headquarters.

Highlights and What to See

Visiting the Karato-oka no Shimizu Communal Water Station offers a rare opportunity to experience an aspect of traditional Japanese island life that has remained essentially unchanged for generations. The terraced granite basins, with clear spring water flowing gently from one level to the next, create a scene of serene beauty — especially striking when viewed against the backdrop of the sacred grove of trees and the shrine and temple structures above.

Near the water station, the outdoor sculpture "Sora no Ryushi / Karato" (空の粒子／唐櫃, "Particles in the Air") by artist Noe Aoki surrounds the water storage area with interconnected circular steel rings that seem to hover in the sky when viewed from the mountainside. This contemporary art installation, created during the Setouchi Triennale, creates a striking dialogue between the ancient spring and modern artistic expression.

The water station is situated at the heart of the Karato-oka village, which developed around this very spring. A walk through the narrow lanes of the settlement reveals traditional stone walls, old farmhouses, and the quiet rhythms of island life. From here, visitors can easily walk to the famous Karato rice terraces, which cascade down the hillside toward the Seto Inland Sea — a landscape that was restored in 2010 in conjunction with the opening of the Teshima Art Museum.

Surrounding Attractions

Teshima Island is renowned as one of the "art islands" of the Seto Inland Sea, and the Karato area in particular offers an extraordinary concentration of world-class contemporary art alongside its cultural heritage sites.