Miwa Dam

Client Khowa Engineering Company Ltd / MLIT
Location Nagano District, Japan
Scope Of Work Due to two major weakness zones, the sediment load into Miwa is one of the highest in Japan, causing rapid loss off storage volume. MLIT requested a demonstration of technology capable of removing reservoir sediments from the many reservoirs in Japan having sediment problems.
Schedule 2008

Project Detail


Miwa dam is the main test facility for sediment handling in Japan. The 4 km long reservoir has a debris collection dam, sediment check dam and a 4km sediment bypass tunnel. The past years’ various sediment discharging methods have been tested, among them SediCon Sluicer (2008) and SediCon Dredge (2010).

Implementation: SediCon supplied a full scale SediCon Sluicer system capable of discharging sediments using the available head difference. The SediCon Sluicer tested at Miwa was 30 m long 5 m thick sediments deposited above the SediCon Sluicer and were removed during the test.

Results: During the test 1.200 m3 sediments were discharged downstream of the dam by opening the outlet valve. The successful test verifies that the SediCon Sluicer is a suitable system for sediment removal.

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