Sueda-Suka Weir, Weir in Iwatsuki-ku, Saitama, Japan

The Sueda-Suka Weir is a movable weir on the Moto-Arakawa River between Sueda and Shingata-Suka in Iwatsuki-ku, Saitama City. From April to September its gates close to form a 3-metre-deep pond, the Sueda-Suka tamei, from which the Sueda and Suka irrigation channels draw water for southern Iwatsuki-ku east of the river.

The first weir at this site was built about 400 years ago. It was rebuilt several times; the current movable weir was completed in 1993, when computer control replaced manual operation of the gates. From April to September the gates are closed to form a 3-metre-deep pond from which the Sueda and Suka irrigation channels draw water.

The weir's name combines Sueda and Suga, the two districts it separates on the Moto-Arakawa. From April to September the gates close and the pooled water, the Sueda-Suga tamei, reaches about 3 metres deep; the Sueda and Suga irrigation channels draw from it to water fields in southern Iwatsuki-ku. Nearby are the Tsukinoki no Hiroba square and Musashi Dairokuten Shrine.

The structure is best viewed from the surrounding pathways that provide access to the river valley. Visitors should be prepared to notice seasonal changes in water levels and vegetation throughout the year.

From April to September the weir is closed to form a 3-metre-deep pond, from which the Sueda and Suka irrigation channels draw their water. The sluice gates were once opened and closed by hand; since 1993 a computer controls them and adjusts the flow.