Iwaki-Yumoto (Former Joban Coalfield) about 60 years ago and today

History of Iwaki-Yumoto (Former Joban Coalfield)

Whichever way you walk from the front of Yumoto Station, east or west, the road soon starts to climb. The town fits into the floor of a valley long and narrow from north to south, and hills rise up from both sides. In this valley, two things have long been taken from underground. Coal that is dug out, and hot water that springs up without digging. If you advance through the aerial photographs from the oldest era, long, narrow buildings lined up neatly in rows on the slopes of the valley catch the eye. They are the homes of the people who dug coal and their families, and the photographs show as it is how far those rows spread and how they eventually changed form.

A valley where hot water and coal overlap

The measurement points that fall on the valley floor all stay within the 10 m range. The center is 11.3 m, the north and east are both 11.4 m, and the south is 10.5 m. The difference is at most 1 m. However, one point toward the west alone shows 28.8 m, more than 17 m above the valley floor values. It is land where the valley floor is flat, and a slope begins one step outside it. The south is slightly lower because the valley descends toward the south, and the tracks and roads follow that direction obediently. Flat surfaces where people can live were scarce from the start. Because the limited width of the valley floor is used up first by the tracks, the station and the rows of shops, that the homes added later climbed onto the slopes is closer to a demand of the terrain than the result of a choice.

The place name Yumoto comes from hot water springing there. This valley surrounded by hills was known as a place for hot spring cures long before the railway passed through. Coal was layered on top of that. The Joban Coalfield was mined in earnest from the Meiji era as the coal-producing area closest to the capital, and a railway was laid to carry the coal out. Here the hot water and the coal shared the same groundwater, so as the mine shafts went deeper, the hot water springing up got in the way of mining. Facilities were needed to treat the pumped-up hot water, and that water came to be distributed to the hot spring town. It is land where the work of digging and the work of bathing were tied together over a single body of groundwater.

Rows of nagaya row houses filling the slopes

In the 1961-69 aerial photograph, a narrow valley runs through the center of the frame from north to south, and the urban area and the tracks pass along its floor. Near the center, the tracks split wide and parallel, and the extent of a yard handling rolling stock can be read. The slopes on both sides of the valley catch the eye. At the upper right, middle right, middle left and lower left, groups of long, narrow buildings lined up regularly are scattered in many places. The orientation and spacing of their roofs are uniform, clearly different from the irregular arrangement of the surrounding settlements. Dots of bare ground showing white lie on top of the hills, and they can be read as surfaces where excavated material was piled, or as land preparation in progress. At the southern end, paddies and fields divided into steps cling to the slope, and small ponds appear black in the middle left and center right. Small buildings are packed densely around the station, and their arrangement shows that places of trade gathered on the valley floor. Buildings with white roofs one size larger than their surroundings stand above and below the center, showing that uses able to take up width on the valley floor were placed there. The roads crossing the valley can be counted on one hand, and one running from the lower right to the upper left stands out.

In the 1974-78 color photograph, the urban area on the valley floor has grown continuous and thick, and the bundle of lines in the station yard is also clear. On the slopes from the lower left to the middle left, the orderly groups of buildings have spread beyond the black-and-white era. Meanwhile, part of the white bare ground on the hills has returned to green, and new surfaces of land preparation have appeared elsewhere. At the upper right a large white building has been built, with a wide paved surface in front of it. The pond at the center right remains as black water, and in the southern part paddies and fields with clear lots continue. The green of the hills is dense everywhere, and within it only the slopes used for homes look gray. The difference in the depth of green also tells apart the slopes that were worked on and the slopes left alone. This is the land on the mountain side changing how it is used, caught partway through.

A valley that switched to hot water

As the shift from coal to oil advanced, the mines of the Joban Coalfield finished their roles one after another, and the main mines closed by the mid-1970s. It was an event in which the town lost its workers all at once, but this valley had a resource left in hand. The hot water that had been pumped up from inside the mines. In 1966 a large tourist facility using the hot water was opened, and the axis shifted from a town that digs coal to a town that draws people with hot water. That facility is in a place away to the west of the valley and does not appear in this view. In the photographs you can follow how the town, having lost the destination for what it sent out, rearranged its homes and roads.

If you switch to today's photograph, the urban area on the valley floor has become continuous around the station, and the tracks descend south as a single thin band. The groups of long, narrow buildings that were scattered on the slopes have changed into residential areas with uniform lots in several places, and the hills in the left half have filled with rows of houses alike even in the color of their roofs. Much of the once-white bare ground has returned to green, and a facility with a domed building and a bright green sports ground side by side spreads at the upper right. From the bottom center to the southeast, a wide road passes through the valley. A corner where rows of long, narrow buildings and large buildings with white roofs line up together lies along that road and toward the southeast. The pond in the middle left keeps a black water surface in the same position as in the old eras, and part of the upper right still shows a surface of brown bare ground. The official land price (Chika Koji) per square meter was 59,500 yen in 1995. It fell to 36,300 yen in 2012, and is 45,100 yen in the 2026 publication. The difference between the starting point and the bottom is a little over 23,000 yen, and the recovery from the bottom is about 9,000 yen. The observation point is residential land in Joban-Yumotomachi Kamiasagai, about 540 m from this location.

Traces remain on the slopes. Thin roads winding sideways along the contour lines, flat surfaces appearing abruptly on top of the hills, and roads that climb a short way from the valley floor onto the slope and dead-end. All are lines drawn to have people live on the slopes, and even when the homes are rebuilt, the shapes of the lines tend to remain. The gradient of the tracks descending south from the station also mirrors the tilt of the valley itself as it is. The condition of the land, that only the valley floor is flat and leaving it always means climbing, has not changed across the two eras and today's photograph. The change is in what stands in rows on those slopes.