Advanced Technologies to
Upgrade Dams under Operation
Upgrading 60-year-old Katsurazawa DamsGovernment of Japan 1MLIT’s comprehensive water management policies:
Planning Formulate long-term strategies and mid-term plans on
flood risk management and water resource management.
Coordinating Enhance coordination among water-related stakeholders.
Implementing Implement water-related infrastructure construction and
improvement projects including dam upgrading under
operation.
Accumulating Accumulate water-related knowledge in cooperation with
relevant research institutions such as National Institute for
Land and Infrastructure Management (NILIM) and Public
Works Research Institute (PWRI).
Why upgrade dams under operation ?
Social
impact
Comparatively
small impact
Environmental
impact
Less impact on
the ecosystem
Need mitigation
measures for the
impact on
ecosystems
Newly inundated land
Shifted roadsCostSevere impact by
rebuilding the local
community
Upgrading an existing dam
ExistingNewConstructing
a new damLessLessLowSignificant
SignificantHighDam upgrading achieves expected benefits with reducing negative environmental impacts
with lower project cost and with shorter construction period.
Disturbance of the
river habitat Low
Newly inundated land
Shifted roadsCostDam upgrade projects have less impact on the environment and local
community than new dam construction projects.
Interruption of the
river flow
Disturbance of the
river habitat
Interruption of the
river flowNoneSignificant
Significant 21. Technologies to increase the reservoir volume
1-1 Raising the dam body
1-2 Constructing a new dam just downstream from the existing dam without stream diversion
1-3 Constructing structures in deep reservoir
2. Technologies to increase the discharge capacity
2-1 Constructing additional crest gates
2-2 Drilling the existing dam body from downstream
2-3 Constructing new spillways
2-4 Upgrading existing spillways
3. Technologies to improve the structural stability
3-1 Improving the structural stability of the existing dam to resist earthquakes damage
3-2 Controlling the seepage through the dam body and/or its foundation
3-3 Improving the stability of the downstream structures
3-4 Inspecting the structural stability to resist catastrophic earthquakes
4. Technologies to improve the operation
4-1 Maximizing the function through the coordination among multiple dams in a river basin
4-2 Implementing the flexible and timely operation on the flood discharge
4-3 Installing a new system without interrupting the operation
4-4 Installing or upgrading the power generating facility
5. Technologies to control the sediment
5-1 Controlling the sediment by the bypass tunnel
5-2 Excavating and transporting the sediment
5-3 Constructing a check dam to control the sediment
5-4 Combining several sediment removal methods
6. Technologies to improve the environment
6-1 Adopting the selective water intake facility
6-2 Bypassing the fresh water directly from the upstream to the downstream
6-3 Adding aerator
6-4 Adding facilities to conserve the ecosystem such as the fish wayP11P13P9P5P3P7
7. Cooperative operation of multiple dams
7-1 Capacity restructuring between damsP15Technologies to upgrade dams under operation 3New Katsurazawa Dam
Existing
KatsurazawaDamNew Intake Facility
1-1 Raising the dam body
1. Technologies to increase the reservoir volume
Increasing the reservoir volume to improve the ability for the flood
control and/or power generation.
・New Katsurazawa Dam in Hokkaido Pref.(Fig.1-1a)
・Kasabori Dam in Niigata Pref.(Fig.1-1b)
・New Maruyama Dam in Gifu Pref. etc.
Fig.1-1b Kasabori Dam (small-scale project)
Fig.1-1a New Katsurazawa Dam(large-scale project)
After upgrading
Gross storage capacity
147.3 million m3
About
1.6times
Increase of
storage capacity
Before upgrading
Gross storage capacity
92.7 million m3
After upgrading
Gross storage capacity
17.2million m3
Before upgrading
Gross storage capacity
15.4million m3
About
1.1times
Increase of
storage capacity
Raising the dam body (4m)
Raising the dam body (11.9m)
1-2 Constructing a new dam just downstream from the
existing dam without stream diversion41-3 Constructing structures in deep reservoir
Upgrading the dam body without interruption on the operation of the existing dam.
・Tsugaru Dam in Aomori Pref.(Fig.1-2)
・Yubarishuparo Dam in Hokkaido Pref. etc.
Installing deep-water structures for re-arrange the active storage capacities without
the restriction on the operational function of the existing dam.
・Tsuruda Dam in Kagoshima Pref. (Fig.1-3)
・New Katsurazawa Dam in Hokkaido Pref. etc.
Fig.1-3 Tsuruda Dam
Fig.1-2 Tsugaru Dam
Tsugaru Dam
(new dam body) Existing Meya Dam
(in operation)
Two blocks are integrated on the lake
surface and transported by ship
Foundation
Pedestal concrete is
not required
Floating
type
coffering
facility
Reduce divingworkDrill a hole from
the downstream
Floating type coffering facility
Tsugaru dam
View from the top of existing dam (in operation)
Flowing water 52-1 Constructing additional crest gates
2. Technologies to increase the discharge capacity
Installing the additional gate to optimize the operation for flood control.
・Nagayasuguchi Dam in Tokushima Pref.(Fig.2-1)
・Houri Dam in Miyazaki Pref. etc.
2-2 Drilling the existing dam body from downstream
Constructing new discharge tunnel through the dam body to optimize the operation.
・Tsuruda Dam in Kagoshima Pref.(Fig.2-2)
・Tase Dam in Iwate Pref. etc.
Fig.2-2 Tsuruda Dam
Fig.2-1 Nagayasuguchi Dam
Drilling method in the dam body
Construction situation
Facility upgrading work
(under construction)
Temporary platform
at the reservoir
Addition of main control gates
6.5t cable crane
New spillway chute
Upgrading of
energy dissipator
Temporary platform
at dam crest
Longest drilling length in Japan (about 60m)
Temporary coffering facility
SWL EL.160m
Deepest
Installation
in Japan
(about 65m)
EL.95m 62-3 Constructing new spillways
Installing new spillway to optimize the operation without affecting the dam body.
・Kanogawa Dam in Ehime Pref.(Fig.2-3)
・Amagase Dam in Kyoto Pref. etc.
Fig.2-3 Kanogawa Dam
呑口
ゲートMain control
gate chamber
Energy dissipator
Guard gate
Steel penstock pipes of 11.5 m
diameter, as the world’s largest,
were installed.
2-4 Upgrading existing spillways
Upgrading the existing spillway to optimize the operation without affecting the dam
body.
・Fukuji Dam in Okinawa Pref.(Fig.2-4)
・Sabaishigawa Dam in Niigata Pref. etc.
Dam body
Downstream spillway
Fig.2-4 Fukuji Dam
Fukuji Dam
Downstream spillway
Upstream spillway
(1) Upstream spillway
before upgrading
(Emergency use)
(1) Downstream spillway
before upgrading
(Normal and emergency uses)
(2) Downstream spillway
after upgrading
(Drum gates installed)
(Normal and emergency uses)
Tunnel spillway
Inner diameter : 11.5m
Length : 457m
(2) Upstream spillway
after upgrading
(Normal and emergency uses) 73-1 Improving the structural stability of the existing dam
to resist earthquakes damage
3. Technologies to improve the structural stability
Improving the seismic resistance while installing the additional flood control
capacity simultaneously.
・Sayamaike Dam in Osaka Pref.(Fig.3-1)
・Hongochi-Teibu Dam in Nagasaki Pref. etc.
Fig.3-2 Kin Dam
3-2 Controlling the seepage through the dam body
and/or its foundation
Implementing an appropriate combination of the countermeasures for controlling
the seepage with a limited budget.
・Kin Dam in Okinawa Pref.(Fig.3-2)
・Chubetsu Dam in Hokkaido Pref. etc.orFig.3-1 Sayamaike Dam (Oldest dam in Japan, more than 1,300 years old)
Before upgrading After upgrading
Before upgrading
For flood control
Existing capacity Existing capacity
After upgrading
Auxiliary curtain grouting
Curtain grouting
Auxiliary curtain grouting
Curtain grouting 83-3 Improving the stability of the downstream structures
Reinforcing the energy dissipator to improve the structural stability of
the facilities in the downstream.
・Tsuruda Dam in Kagoshima Pref.(Fig.3-3)
・Nagayasuguchi Dam in Tokushima Pref. etc.
3-4 Inspecting the structural stability to resist
catastrophic earthquakes
Ensuring the good seismic performance of a new or the existing dam (Fig.3-4).
Fig.3-4 Seismic Design Standard and Seismic Performance Evaluation Guidelines
Fig.3-3 Tsuruda Dam
Design
(Level1)
Seismic design standard based on the seismic coefficient method to
resist the design seismic force (Level 1)
• Seismic design for seismic force according to the following
-dam type (concrete gravity, concrete arch, rockfill dams)
-area classification with earthquake motion records
Check
(Level2)
Guidelines for Seismic Performance Evaluation of Dams During Large
Earthquakes (Level 2)
Required to satisfy the following two seismic performances despite
damage at the time of Level 2 earthquake motion:
(1) The water storage function must be retained
(2) Damage must remain recoverable
Before upgrading After upgrading
Upgrading existing energy dissipator
Existing energy dissipator 94-1 Maximizing the function through the coordination
among multiple dams in a river basin
4. Technologies to improve the operation
Carrying out the integrated operation for effective water resource management.
・Shorenji, Hinachi and Murou Dams in the Yodo river basin (Fig.4-1)
・Ikari and Kawaji Dams in the Tone river basin. etc.
4-2 Implementing the flexible and timely operation on the
flood discharge
Implementing the real time rainfall forecasting system based on the radar
equipment for improving the efficiency of the flood control operation.
・Sarutani Dam in Nara Pref.(Fig.4-2)
・Miharu Dam in Fukushima Pref. etc.
Fig.4-2 Sarutani Dam
Fig.4-1 The Yodo river basin40°30°20°24°
●くろまる: Center position (recorded) of a typhoon 24 hours
before inflow reaches the flood discharge of 1,000 m3/s
Typhoon location
Forecasted rainfall
Typhoon path
Drawdown criteria
Full water level
Target level
Approx.
9 million m310mIf all criteria are
applicable
HIYOSHI dam
AMAGASE dam
NUNOME dam
YODO river weir
YODO river
Integrated dams
Control Office
YODO river officeLakeBIWA
Radar observatory
Meteorological satellite-Radar observatory
Collection of information
TAKAYAMA dam
HINACHI dam
MUROU dam
SHORENJI dam
Supply of information
HIYOSHI dam
AMAGASE dam
NUNOME dam
YODO river weir
YODO river
Integrated dams
Control Office
YODO river office
KINKI Regional
Development Bureau
Lake BIWA-TAKAYAMA dam
HINACHI dam
MUROU dam
SHORENJI dam
KINKI Regional
Development Bureau 104-3 Installing a new system without interrupting the
operation
Enabling the continuous operation during the dam upgrading project.
・Isawa Dam in Iwate Pref.(Fig.4-3)
・Uchinomi Dam in Kagawa Pref. etc.
Fig.4-4 Murou Dam
Fig.4-3 Isawa Dam
4-4 Installing or upgrading the power generating facility
Installing the power generating facility under high water pressure conditions.
・Murou Dam in Nara Pref.(Fig.4-4)
・Terayama Dam in Tochigi Pref. etc.
Passageway (shaft: spiral staircase)
Water-wheel generator to be installed
Gathering data on a continuously operating dam01020304050
Existing Dam Isawa Dam
Inflow (m3/s)
2012年10月3日 0:00 2012年10月4日 0:00 2012年10月5日 0:00 2012年10月6日 0:00
Existing Dam
Operation center of
existing dam
Isawa Dam
Operation office
of existing dam
Existing Dam
Operation office
of Isawa dam
Intake tower
Shaft (basement)
Installation site 115-1 Controlling the sediment by the bypass tunnel
5. Technologies to control the sediment
Extending the lifetime of the dam by improving the stability of the riverbed.
・Koshibu Dam in Nagano Pref.(Fig.5-1)
・Miwa Dam in Nagano Pref. etc.
Fig.5-1 Koshibu Dam
Fig.5-2 Shichikashuku Dam
5-2 Excavating and transporting the sediment
Reusing the sediment as aggregate after the excavation.
・Shichikashuku Dam in Miyagi Pref.(Fig.5-2)
・Yokoyama Dam in Gifu Pref. etc.
Koshibu Dam
Diversion weir
Check dam
Sediment bypass tunnel
Conceptual diagram
Tunnel inlet
Tunnel outlet
Before construction
After construction
Before construction
After construction
In tunnel
Check dam
Reuse in other construction sites
Shichikashuku Dam
excavating 125-3 Constructing a check dam to control the sediment
Extending the lifetime of the dam by controlling the sediment on the riverbed.
・Yuda Dam in Iwate Pref.(Fig.5-3)
・Miharu Dam in Fukushima Pref. etc.
Fig.5-4 Miwa Dam
Fig.5-3 Yuda Dam
5-4 Combining several sediment removal methods
Implementing an appropriate combination of the countermeasures for controlling
the sediment with a limited budget .
・Miwa Dam in Nagano Pref.(Fig.5-4)
・Sakuma Dam in Shizuoka Pref. etc.
Diversion weir
Check dam
Sediment
Bypass
tunnel
Influent sediment
Check dam
Diversion weir
Sediment accumulation
Sediment bypass tunnel
Tunnel outlet
Dredging
Miwa Dam
Outlet for
sediment flushing
Sediment flushing
DredgingareaCheck Dam
Tunnel inlet 136-1 Adopting the selective water intake facility
6. Technologies to improve the environment
6-2 Bypassing the fresh water directly from the
upstream to the downstream
Maintaining the downstream water environment, even when the reservoir
environment is temporarily degraded.
・Urayama Dam in Saitama Pref.(Fig.6-2)
・Miharu Dam in Fukushima Pref. etc.
Fig.6-1 Yokoyama Dam
Fig.6-2 Urayama Dam
Under construction
Intake structure
Bypass channel (steel pipe)
Outlet
Enable sluicing
of clean water
Reservoir: Turbid water
Reservoir: Turbid water
Multiple cylinder gate
Controlling the water temperature in the downstream to preserve biodiversity and
agricultural effectiveness.
・Yokoyama Dam in Gifu Pref.(Fig.6-1)
・Benoki Dam in Okinawa Pref. etc.
Water intake at the lower part
Water intake at the upper part
Fig.6-4 Pirika Dam
6-3 Adding aerator
Reducing the amount of blue-green algae in the reservoir by the aeration.
・Urayama Dam in Saitama Pref.(Fig.6-3)
・Kamafusa Dam in Miyagi Pref. etc.
6-4 Adding facilities to conserve the ecosystem such as
the fish way
Guiding the fish to pass-by the dam reservoir via the fish way.
・Pirika Dam in Hokkaido Pref. (Fig.6-4)
・Samani Dam in Hokkaido Pref. etc.
Fig.6-3 Urayama Dam14Installation Operation Reservoir before operation
Reservoir after operation
(2) Rest pool for fish
(3) Fish ladder
(4) Observation facilities
(5) Nature-oriented fish way
(6) Intake weir of Chushibetsu River
(1) Entrance of fish wayDam(1)(2)(3)(4)(5)(6)Chushibetsu River
7-1 Capacity restructuring between dams
7. Cooperative operation of multiple dams
Efficient utilization of multiple reservoirs by water transmission.(Fig.7-1)
Fig.7-1 Kawaji and Ikari Dams15Project Flow Chart (Overseas Assistance)
導水トンネル
[Sectional view of collaborating facilities]
Kawaji Dam Ikari Dam
Effect of the project
(Downstream of headworks
at the Kinu River in Sanuki)
[Before project]
[After project]
Headrace
tunnel
Kawaji and Ikari Dams
in a rainy season
Kawaji and Ikari Dams in a
dry season
Upgrading of operating dams
(Ongoing major projects)
Ongoing 21 projects as of April 2018.
Takase Dam – Nanakura Dam
– Omachi Dam (Nagano)
Type C
Type C
Sakuma Dam (Shizuoka・Aichi)
Type C
Type A1
New Katsurazawa Dam (Hokkaido)
Type A2
Uryu No.1 & No.2 Dam(Hokkaido)
Type A2
Nagae Dam (Kagawa)
Type A2
Type A2
Type A2
Urushizawa Dam (Miyagi)
Type B2
Type B2
Type B2
Tainaigawa Dam (Nigata)
Type B1
Sengosawa Dam (Fukushima)
Type B1
Type B1
Hamada Dam (Shimane)
Type B1
Type B2
Type B1
: by raising dam bodies
:Additional outlets by drilling technologies
: by tunnel technologies
:Sediments management facilities
Type A1 :Increasing capacities by constructing new dam body
Type A2
Type C
Type B1
Type B2
Type C
Miwa Dam (Nagano)
Shinbogawa Dam (Nigata)
Type A2
New Maruyama Dam (Gifu)
Type A1
Koyagawa Dam (Yamaguchi)
Kanogawa Dam(Ehime)
Urakami Dam (Nagasaki)
Nagayasuguchi Dam (Tokushima) Amagase Dam (Kyoto)
Sameura Dam(Kochi)
Gomyo Dam (Kagawa)
Yahagi Dam(Aichi・Gifu)
Matsukawa Dam (Nagano)
Contact us:
Japan Commission on Large Dams ( General )
E‐mail : secretariat@jcold.or.jp Tel : +81‐3‐3459‐0946
Japan Dam Foundation ( for technical matters concerning constructing dams )
E‐mail : jdf@jdam.jp Tel : +81‐3‐3545‐8361
Japan Association of Dam & Weir Equipment Engineering ( for mechanical matters
concerning dams and weirs )
E‐mail : dam@river.ocn.ne.jp Tel : +81‐3‐3267‐0371
Water resources Environment Center ( for environmental matters concerning R&D of dams )
E‐mail : wechome@wec.or.jp Tel : +81‐3‐3263‐9923
Japan Water Agency
E‐mail : webmaster@water.go.jp Tel : +81‐48‐600‐6553
Public Works Research Institute
E‐mail : damsuiri@pwri.go.jp Tel : +81‐29‐879‐6783
River Planning Division, Water and Disaster Management Bureau, MLIT, JAPAN
E‐mail : river_kokusai@mlit.go.jp Tel : +81‐3‐5253‐8444
Japan Dam Engineering Center ( for technical matters concerning R&D of dams )
E‐mail : info@jdec.or.jp Tel : +81‐3‐5815‐4161
2018.5