What an intake tower is
An intake tower stands in a dam or reservoir to draw water off. It rises free of the water surface and is usually linked to the bank by a service bridge.
The intake tower at the Aoshita first dam in Miyagi Prefecture, built in 1933, is described as a free-standing reinforced concrete tower on the upstream left bank, 2.4 metres in internal diameter and 16.97 metres high, connected at its head to a service bridge, drawing water through intakes at three levels and conducting it to a gauging basin downstream on the same bank.
The three levels are the point of the design. Water level and water quality change through the year, so intakes at different heights let the operator choose.
Tunnels belong to the same system. The Aoshita tunnel entrance, built in the same year, is described as the upper mouth of a 696-metre conduit running from the gauging basin to the treatment works, its Tunnel portal a carefully built stone portal finished with pilasters flanking the opening and machicolation ornament along the cornice.
Engineering given an architectural face
Modern waterworks are often finished with more care than function required. The former Nishioka reservoir intake tower in Hokkaido, built in 1909, is described as a water supply structure built on the upper Tsukisamu river for an army regiment, with a hexagonal timber body, weatherboarded and pierced by tall windows, and a hexagonal pyramidal roof, standing on a cylindrical brick base 1.5 metres in internal diameter and 6.6 metres high, designed by a named engineer and long familiar as a landmark in the park.
A hexagonal timber body on a brick base is not what function alone would produce, and the fact that the designer's name is recorded shows the structure was treated as architecture.
The former Sumiyoshi waterworks inlet well in Shizuoka Prefecture, built in 1931, is described as an octagon 9.2 metres across with a circular cornice projecting at the top and an interior 6.8 metres deep, its corners articulated with pilasters carrying pedestals below and Mochiokuri above, their shafts fluted, in a waterworks structure with a worked exterior.
An inlet well receives conducted water and serves a different purpose from an intake tower. Drawing, conducting, receiving, treating and distributing each have their own structures, so a description should establish which stage is meant.
References
- Agency for Cultural Affairs: Registered tangible cultural properties (structures)
- https://www.bunka.go.jp/seisaku/bunkazai/shokai/yukei_kenzobutsu/toroku_yukei.html
- National Cultural Properties Database: Aoshita first dam intake tower, a free-standing concrete tower drawing water at three levels
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00001087
- National Cultural Properties Database: former Nishioka reservoir intake tower, a hexagonal timber body on a cylindrical brick base
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00002188
- National Cultural Properties Database: former Sumiyoshi waterworks inlet well, an octagon 9.2 metres across with worked exterior detailing
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009172
- National Cultural Properties Database: former Sumiyoshi waterworks inlet well, brackets modelled at the top of its pilasters
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009172
Last verified: 2026.09.11