24th ICOLD Congress2 to 8 June 2012 ～ Kyoto, Japan

Norihisa MatsumotoJapan Commission on Large Dams

【JWA】

The increase of dams higher than 15 m after 1900

0

500

1,000

1,500

2,000

2,500

1900

-1910

-1920

-1930

-1940

-1950

-1960

-1970

-1980

-1990

-2000

-2009

Num

ber o

f dam

s

Municipal water

Flood control

Multipurpose

Hydropower

Irrigation

Excluding 672 dams constructed before 1900, mainly irrigation use.

【JCOLD】

281

985

4352

1043

Earthfill RockfillCoccrete Gravity Concrete ArchOthers

Type of dams in Japan

Sayama-ike Dam 2003

【Osaka Pref.】

2001 Rehabilitation

④-2. 1452

③. 1608

⑥. 731 ⑦. 616⑧-1. 734（Earthquake）

④-1. 1202

⑧-2. 1596（Earthquake）

⑤. 762

①. 1926～19311962～1964

②. 1620～16211693～16941857～1859

History of Modification of Sayamaike Dam

【Osaka Pref.】

0

20

40

60

80

100

120

140

600 800 1000 1200 1400 1600 1800 2000012345678910

Popu

latio

n

Cul

tivat

ed a

rea

Act

ive

stor

age

capa

city

4,000

3,000

2,000

1,000

0

5,000

A.D.

Population

Cultivated area

Active storage capacity

0

≈

(million m3)(million ha)(million)

Water has sustained population

【MAFF】

VITRTUAL WATER80 billion m3 water imported (2005)

Increase Food Self-sufficiency

Efficient Water Management

108m3

Food and water

【 MOE 】

Utilized for - Spinning - Lighting - Textile - Street cars

1st Stage60kW ‐200kW

19 unitsTotal 1760kWCommissioned since 1891 by Kyoto City

Keage Hydroelectric Power Station

1895

The first hydropower station in Japan

An Element of Lake Biwa Canal Project【Kyoto City & KEPCO】

Development of hydropower in Japan

【ANRE】

0

20

40

60

1900 1925 1950 1975 2000Inst

alle

d ca

paci

ty G

W

Pumped storage

Pumped Storage

Total

Conventional

Run-of-riverReservoir hydro

0

200

400

600

800

1000

1200

1400

1950 1960 1970 1980 1990 2000 2010

Hydropower Thermal Nuclear Others Total

Source of electricity energy in Japan

(GWh/y)

【ANRE】

0

50

100

150

200

250

1870 1890 1910 1930 1950 1970 1990 20100

10

20

30

40

50

60

70

80

90

100

Wat

er s

ervi

ce c

over

age(

%)

Infectious disease patients

Waterservicecoverage

A.D.

Infant mortality rate

Infe

ctio

us d

isea

se p

atie

nts(

103 p

erso

n)

Infa

nt m

orta

lity

rate

(%)20

15

10

5

0

25

Public supply water reduced infant mortality rate

Takizawa Dam

Shimokubo Dam

Yagisawa Dam Naramata Dam

Kusaki Dam

Murayama-ShimoReservoir

OzakuOgochi Dam

Sagami River

Tama River

Ara River

Tone River

Urayama Dam

Yanba Dam

Purification plant

Channel

Intake Weir

Dam

Dams support Tokyo's water works

【Tokyo Pref.】

0

100

200

300

400

500

600

700

1900 1920 1940 1960 1980 2000

2

4

6

8

10

12

14

Popu

latio

n

Wat

er re

sour

ces

(104m3/day)

Dams constructed in the Tone river

Aveage discharge of Tama river

Water resources

Population

(million person)Dams constructed in the Tone river

Dams support Tokyo's population

The ruling party was changed in the 2009 general election. The new policy for flood control is that“depends as little as possible on dams”.

The Ministry established “The future flood management advisory board” in December, 2009.

It released the interim report in September, 2010.Evaluate ongoing projects based on “cost, environment, feasibility and others.”

The change of ruling party in 2009

Jurisdiction Total examined continue discontinue

Central government 25 3 1 2

Japan Water Agency 5 0 0 0

Local governments 53 21 16 5

Total 83 24 17 7

As of May 31, 2012

Evaluation of on going dam projects

【MLIT】

Movement of survey points due to faulting

Inspection of dams after the main shock

inspectedsuffered unusualbehavior* ordamage (failure)

Central Gov. 46 11Local Gov. 104 8Central Gov. 51 4Local Gov. 121 23(1**)

391 48(1)69 2

Total

*unusaul behavior: small increase of leakage & uplift, nominal settlement and others** a failured dam was on a non-regulated river

Jurisdiction Owner

Number of dams

Ministry of Land, Infrastructure,Transport and Tourism

Ministry of Agriculture, Forestryand Fisheries

Ministry of Economy, Trade andIndustry Utilities

Breached reservoir photoed 14 March, 2011

Chernobyl Fukushima

• No acute radiation diseases in Fukushima

• Latent health consequences limited due to timely evacuation

• Partial durable land loss in evacuation zones and beyond (partial resettlement possible and planned)

• Contaminated food has to be withdrawn from circulation

Main specifics of severe nuclear accidents

Dose rates 1 month after accident

ENSI, CH

Prof. Prasser,

Chernobyl and Fukushima

In February 2011, 54 units were operating.

In June 2012, 4 units were decommissioned and the rest of all 50 are not operating under inspection

Locations of nuclear power stations in Japan

【FEPC】

0

20

40

60

80

100

Mar-10 Jun-10 Sep-10 Dec-10 Mar-11 Jun-11 Sep-11 Dec-11

Month-Year

GW

h ×1

03

Hydro

Thermal

Nuclear

Wind

Photovoltaic

Geothermal

Total

Tohoku Earthquake

Source of Electricity Generation

【ANRE】

0:0

0

2:0

0

4:0

0

6:0

0

8:0

0

10

:00

12

:00

14

:00

16

:00

18

:00

20

:00

22

:00

0:0

0

2:0

0

4:0

0

6:0

0

8:0

0

10:0

0

12:0

0

14:0

0

16:0

0

18:0

0

20:0

0

22:0

0

Before the earthquake After the earthquake

Pumped storageReservoir hydro

purchased

Thermal

NuclearRun-of-river hydro

Pumped storageReservoir hydro

purchased

Thermal

NuclearRun-of-river hydro

0：00

2：00

4：00

6：00

8：00

10：00

12：00

14：00

16：00

18：00

20：00

22：00

0：00

2：00

4：00

6：00

8：00

10：00

12：00

14：00

16：00

18：00

20：00

22：00

Load curves for one sample day

People have begun to see hydropower in a new light.

It is domestic, renewable, clean and reliable electricity.

Adding new hydropower capability to existing dams, improving efficiencies at generating dams.

Building small scale hydropower.

Government policy and promotional measures play a key role in sustainable hydropower development.

Hydropower after the earthquake

Rainfall (mm) DeathsNumber of

Flooded houses

July Heavy Rain 600 4 1,057

Typhoon No. 12 1,161 78 5,657Typhoon No. 15 1,035 17 1,801

Flood disaster in 2011 in Japan

【MLIT】

Outflow

Inflow

Reservoir　Water　Surface

7/27 7/28 7/307/29

Inflo

w ・

Out

flow

(m3 /s

)

Res

ervo

ir　W

ater

　Su

rface

(m)

rain

(mm

/hr) 0

255075

0

250

500

750

1000

1250

15:0

0

20:0

0

01:0

0

06:0

0

11:0

0

16:0

0

21:0

0

02:0

0

07:0

0

12:0

0

17:0

0

22:0

0

03:0

0

08:0

0

13:0

0

18:0

0

23:0

0

830

840

850

860

470

472

474

476

478

480

482

484

Ele

vatio

n（m

)

ダムがなかった場合の最高水位(推測値)：480.57m

換算水位：474.67mActual water level

Water level without Dam5.9 m

Yagisawa Dam stored flooding water

【MLIT】

• Effective use of existing reservoirs• rehabilitation (aging, earthquake, flood)• water quality• sedimentation• fishway• climate change• flood security

Our challenges

Sediment bypass tunnel

Dredging

Sediment check dam

Diversion weir Afforestation

Sediment supply (augmentation)

Excavating

Trucking

Sediment Routing

Reducing Sediment Inflow

Sediment Removal

Density current venting

Sediment scoring gate

Reservoir sediment management measures in Japan

【Prof. Sumi】

Miwa Dam bypasses wash Load during flood

Outlet

Trap wier

Diversion wier

By pass tunnel

【MLIT】

Placing sediment

Transport

ReservoirDam

Check dam

Excavation ofsediment

Placing sediment

Transport

ReservoirDam

Check dam

Excavation ofsediment

Placing excavated sediments downstream

Tobetsu Dam during the first filling March 2012

【Hokkaido Pref.】

Fｌood seasonSurcharge water

surfaceflood control

capacity

El. 115.6m

Inactive capacity

El. 131.4m

Fｌood seasonSurcharge water

surfaceflood control

capacity

El. 115.6m

Inactive capacity

El. 131.4m

excavation

new conduits

Stilling basin existing stilling basin

new penstock

increase capacity for flood control75×106m3 98×106m3

Increasing flood control capacity at Tsuruta Dam

【 MLIT 】

Flood season

587m

33m

Murayama-Kami Res. Yamaguchi Res.

Murayama-Shimo Res. 12milion m3

The downstream area is densely populated

【Tokyo Pref.】

●Install drainage layers ●Construct a counter-weight fill●Reinforce the steep slope with polymer geogrid ●Cover the crest with a cement-stabilized soil layer

After Reinforcement

ShellShellCore

Cement-stabilized soil

Counter- weight fill

Geogrid

10.0

15.0

drain

Strengthening to resist earthquakes

【Tokyo Pref.】

Upper Pond

Outlet

Pacific Ocean

Sea water Pumped Storage Power Station J-Power

China(11dams)

Republic of Korea(9dams)

Taiwan (3dams) Philippines

(1dam)

Malaysia(17dams)

Lao (4dams)

Colombia (1dam)

Costa Rica (1dam)

Panama (1dam)

Viet Nam (4dams)

Indonesia (18dams)

Thailand(7dams)

Iran (2dams)

India (2dams)

Turkey (4dams)

Sri Lanka (3dams)

Nepal (1dam)

Bangladesh (1dam)

Algeria (2dams)

Madagascar (1dams)

Kenya(2dams) Brunei

Darussalam(1dam)

Canada(1dam)

Oversea projects Japanese engineers participated in

Ecuador

Peru

USA

Myanmar

Decline in population

Self sufficiency of food

Clean domestic energy

Safety

Global climate change

Use dams and reservoirs wisely

Future of dams and water in Japan