Know More about Miyagase Dam

Construction of the Dam

History behind Construction of Miyagase Dam

Work on construction of Miyagase Dam was completed in December 2000 thanks to the cooperation of persons who moved away from the land they had lived on for many years, landowners who had inherited land from their ancestors, the relevant public agencies, and work-related parties. Here, we introduce the history behind construction of Miyagase Dam as recorded through photographs showing each stage from building of the dam works road to filling of the dam reservoir with water.

Record of Miyagase Dam in Photographs

Night view from beneath the dam (1994)
Foundation excavation works on the right bank top part (1990)
Dam body viewed from the quarry (1994)

RCD concrete construction (1993)
Dam downstream diversion works (1988)
Dam upstream secondary coffering works (1988)

Dam when full (1998)
RCD concrete construction utilizing incline (1992)
Construction of works road (1988)

History of the Construction of Miyagase Dam

Various technologies and measures were adopted in the construction of Miyagase Dam. Planned environmental measures minimized the impact of construction work and other development on the surrounding natural environment, while efforts were also made to restore nature that was lost in the construction so as to preserve the rich natural environment and character of the area.
In addition, to conduct this large-scale construction works in an efficient way, the Roller Compacted Dam-Concrete (RCD) Method was adopted in the design and construction, while an inclined railway to carry the dump trucks and other new technologies were utilized to minimize construction costs as well as the construction time.

About the RCD Method

Implementation of RCD Concrete Method (1993)

The Roller Compacted Dam-Concrete (RCD) Method was chosen for the construction of Miyagase Dam to ensure the effective and economic placement of about 2 million m³ of concrete. This method was developed by the then Ministry of Construction (current Ministry of Land, Infrastructure and Transport) to level and compact thick concrete containing a small proportion of cement. Compared to traditional methods, the RCD Method is not only safer, but results in shorter construction times and lower costs.

Flow of RCD Method

History of Miyagase Dam

April 1969	Sagamigawa River was designated as Class A river (public notice)
September	Construction plan was announced by the former Ministry of Construction
April 1971	Miyagase Dam Research Office established
April 1974	Name changed to Miyagase Dam Work Office
August 1976	Land ownership survey initiated (Kiyokawa-mura, Tsukui-machi)
March 1977	Designated as a dam in Special Measures for Water Source Area Law (public notice)
June	Alternate site for Miyanosato area approved
May 1978	Ishigoya chosen as dam site
October	Relocation framework for lake area announced (currently Miyanohira, and Mizunogo)
December	Basic Plan of Miyagase Dam decided (public notice)
May 1979	Planned site of rivers designated (public notice)
December	General indemnity standard presented (Kiyokawa-mura, Tsukui-machi)
March 1980	Water source area designated based on Special Measures for Water Source Area Law (public notice) Improvement plan of water source area completed (implemented as a promotion plan)
July	Land ownership survey started in Ishigoya area, Aikawa-machi
August 1981	General indemnity standard agreed for areas to be submerged (Kiyokawa-mura, Tsukui-machi)
April 1982	General completion of alternate site for Miyanosato area (relocation started in August)
September	General completion of alternate site A (Miyanohira)
December	Indemnity standard agreed for Toriibara area (Tsukui-machi)
January 1983	Indemnity standard agreed for Nirone area (Tsukui-machi)
February	Indemnity standard agreed for the construction road Hibirano Mukaihara Line (Aikawa-machi)
March	Full-scale start of construction of accessory roads General completion of alternate grave site
November	Relocation of tourist agent in Ishigoya area started
March 1984	Work for provisional drain tunnel started
June	General indemnity standard agreed for dam site (Aikawa-machi)
March 1985	General completion of alternate site B (Mizunogo)
March 1986	Conclusion of agreement on research in relation to plans for the Doshi and Tsukui Channels
November	Alteration of Basic Plan of Miyagase Dam decided (public notice)
March 1987	Agreement on indemnity for fisheries in relation to the construction of Miyagase Dam (Sagamigawa River Fisheries Cooperative)
November	Construction of dam body started
February 1988	Transfer to provisional drain tunnel started
October 1989	Excavation works of dam body started
March 1990	Conclusion of agreement in relation to works to build the Doshi and Tsukui Channels (Toriya and Kushikawa areas)
February 1991	Opening of prefectural road Hadano-Kiyokawa Line
March	Conclusion of agreement in relation to works to build Doshi Channel (Aone area)
October	Pouring of concrete for dam body started (foundation ceremony held in November)
February 1993	Construction of Tsukui Channel started
March	Construction of Ishigoya Dam and Doshi Channel started
July 1994	Transfer to provisional drain tunnel started at Ishigoya Dam
November	Opening of prefectural road Isehara-Tsukui Line Placement of concrete for dam body completed
January 1995	Pouring of concrete in Ishigoya Dam started (foundation ceremony was held in March)
October	Filling test started
March 1996	Opening of prefectural road Miyagase-Aikawa Line
April	Placement of concrete in Ishigoya Dam completed
November	Opening of Hayatogawa Forest Road
April 1997	Operation of Aikawa Power Station No.1 and No.2 started
October	Tsukui Channel completed
June 1998	Lake Miyagase reached full capacity (birth of Miyagase Dam)
September	Canoe competition in the 53rd National Athletic Meet held
October	Filling test completed
December	Restart of Doshi Channel construction was approved by local residents
April 1999	Operation of dam body and Tsukui Channel partially started
November 2000	Doshi Channel completed
April 2001	Full-scale operation of Miyagase Dam started"

Other pages of these contents

Top of this page