Detailed view for Nikaryo Kamikawara

NameNikaryo Kamikawara
Concerned RiverTama
TypeObermeyer, air-filled
Short Description

Nikaryo Kamikawara weir is located on the Tama River, in Japan, and was completed in 2012.

It is an air-filled Obermeyer dam and it is composed of 5 spans of 42.6 meters each.

Main characteristics
Water Head (m)Unknown
Upstream height (m)Unknown
Downstream height (m)Unknown
Discharge (m/s)36.6 (mean), 4500 (max)
Total length (m)231
Number of spans & dimensions

5 spans of 46.2 meters each

Weir height (m)0.86
Progress statusCompleted
Date of completion05/31/2012

Keihin office of Kanto Regional Development Bureau of the ministry (Land, Infrastructure and Transportation Ministry)


Kawasaki city of Kanagawa prefecture

Design group

Marsima Aqua system Corp


Marsima Aqua system Corp

Cost estimationUnknown


PIANC References for this project

In progress


Tama is one of the river flowing to Tokyo Bay and its source is located at Kasatori moutain, which is at an elevation of 1,953 meters. The protection against the flood is very important as Tokyo is one of the most inhabited city.

 The first dam was built in 1611 for irrigation purpose. In the XXth century, industry took also advantage of the water retaining device.

A concrete dam was built in 1941. It was 425 meters wide, 3.6 meters high. A part of the weir was damaged in 1966 by two typhoons. The reconstruction was carried out in 1971 and consisted in 248 meters of fixed weir and 3 flood flow gates.

This dam was then modified to improve the ability to flow down the debris. 1.6 meters of the fixed dam was removed and the actual gates were placed on top of the remain concrete structure.

The weir is automated. In normal operations, the angle of the panels is between 30 and 60 degrees, but the membrane can be completely deflated to lay down the panels and deal with floods.

Documents to download
  • 115- PReview WG166- Nikaryo Kamikawara weir.pdf - 115- PReview WG166- Nikaryo Kamikawara weir.pdf