Imbe Water Purification Plant Collecting Well

Where the Filtered Water Leaves

Imbe Water Purification Plant Collecting Well (忌部浄水場集合井) is a concrete well built in 1929 at the Imbe water treatment plant in Higashi-Imbe-cho, Matsue City, Shimane Prefecture, and registered as a Registered Tangible Cultural Property of Japan on 18 April 2008. It gathers the water that has passed through the filter beds and sends it on toward the distribution reservoirs, making it the exit point of the plant's water route.

It stands north of filter bed No. 4. The well is round, 1.8 metres across and 4.1 metres deep, with a small housing on top. Its registered area of 14 square metres makes it the smallest of the nine registered structures on the site.

Built Because the Plant Grew

According to the Agency for Cultural Affairs, the Imbe Water Purification Plant Collecting Well was installed to send the larger volume of filtered water produced after the beds were extended smoothly on to the distribution reservoir. The first expansion, approved in November 1927, took the plant from four beds to six. More beds meant more filtered water leaving the regulating wells, and a point was needed where it could all be gathered.

Alongside the two new beds, the expansion enlarged the supply and distribution mains, and the bed work was finished in mid-November 1929. The collecting well handled the outgoing side of that system and dates from the same moment.

The registration criterion is contribution to the historic landscape of the country. Both the intake, the former valve chamber and receiving well, and this exit belong to the first expansion, which shows that the project reworked the flow through the whole plant and not only the number of beds.

An Arched Canopy with a Secession Air

The housing of the Imbe Water Purification Plant Collecting Well is finished in mortar, with round columns at the front carrying a canopy shaped as a segmental arch, a curve shallower than a semicircle. The low arc gives the little building a calm, settled face.

The Japan Society of Civil Engineers, in its heritage notes on the nearby Senbon dam, describes this building as notable for the way it projects into the clear-water reservoir and for its Secession design. The Secession was a movement in art and architecture that began in Vienna at the end of the nineteenth century and shaped Japanese buildings of the 1910s and 1920s.

Where the filter-bed housings each follow a different idea, the collecting well housing holds together with just columns and an arc. It is a small building at the very end of the water's route, and someone took trouble over it.

Visiting

The Imbe Water Purification Plant Collecting Well is inside an operating treatment plant and is not open to the public; the Japan Society of Civil Engineers also notes that general visitors cannot enter the plant. Visits depend on whether the Matsue City Water and Sewerage Bureau is accepting them, so check in advance.

If you get the chance, go round to the north side of bed No. 4 to see the regulating well and the collecting well together. Follow staff instructions on photography.