The Pilot Project
for the Horikawa River Clarification
・Result of the survey by the Nagoya City

River Planning Division
Rivers Department, Greenification & Public Works Bureau
The Nagoya City

The Summary of TRWKR（ April 22nd ,2007 ～March 22nd ,2010)
2007

3
2,181 million m Running Hours
667( million m3/year ) Down Hours

2008

714( million m3/year )Drought

2,700.3 hr

113 days2009

800( million m3/year )Heavy Rain

2,581.6 hr

108 days

Other reasons

2,515.3 hr

105 days

Volume17,774.9 hr

741 days

7,797.2 hr

325 days

69.50%

Running Rate
Monthly Volume (Left Axis)

100

月導水量

90

Sum Total (Right Axis)

2500

2,181 million m3

導水量・累加370

導水量・累加(万m )

2000

60

1500

5040

1000

3020500

10年・月

2.2010H22.2

12.2009
H21.12

10.2009
H21.108.2009H21.8

6.2009H21.6

4.2009H21.4

2.2009H21.2

12.2008
H20.12

10.2008
H20.108.2008H20.8

6.2008H20.6

4.2008H20.4

2.2008
H20.2

12.2007
H19.12

10.2007
H19.108.2007
H19.8

06.2007
H19.6

04.2007H19.4

3

月導水量(万m )80

成戸平均流量

Average flow in Naruto

20081506100
450
2003Volume of transmissionof raw water
導水量(万m/日)(Million m3 / day)

H22.2
2.2010

H21.12
12.2009

H21.1010.2009H21.8
8.2009H21.6
6.2009H21.4
4.2009導水量

H21.2
2.2009Volume of transmission of raw water

H20.12
12.2008

H20.1010.2008H20.8
8.2008H20.6
6.2008H20.4
4.20082.2008
H20.2

H19.12
12.2007

H19.1010.2007H19.8
8.20076.2007
H19.6

H19.4
4.2007

Average flowat Naruto (m3 /s)/ s)
成戸平均流量(mResults of TRWKR

ShonaiHorikawa River Map

River●41Motoiri SlicewaydYaieraR

Sanage Bridge●Kitashimizu Bridge●Bridge●Koshio Bridge

ChHorikawa River

Nagoya Station

19Meijyo Park
Nagoya CastleuoLine22 Habasita

Injection Point of TRWKR

ＪＲInvestigation by
ｔhe Nagoya City

●Nayabashi Bridge
HoridomeMatsushige
Lock Gate
Shinaikaw
HorSumiyoshiBridge

ＪＲShiratori Bridge

23

１●Koshin Bridge

Horikawaguchi Tide Gate Yamazaki River
Nagoya PortOe RiverLine
MainoyaNagetsu

247

Meitine

Kizaemon Bridge●erRivain LoM
kaidTou

Nakagawa Canal

１ＪＲ Tokaido shinkansen

Oto Bridge ●● :The main points forthe investigation by
the Nagoya CityResult of the survey of BOD(Biochemical Oxygen Demand)（Mean value from April to June）
mg/ℓ
1220062008(3rd Stage)
2010(7th Stage)

10

2007(1st Stage)
2009(5th Stage)
2011(9th Stage)

10.1

7.7

8
6.1

6

5.4

4.5

6.5

6.6

5.4

5.5

Naya Bridge Oto Bridge

Kizaemon
Bridge

5.1

5.0

3.8

4

2.9
2.6

2.4

26.6

2.0

1.1

2.6

2.5

2.5 2.7 2.6

1.30
MotoiriSliceway

SanageBridgeKitashimizu
BridgeKoshioBridgeKoshinBridgeInjection point◆Every water survey was conductedat the ebb of the neap tide.

Result of the survey of BOD(Biochemical Oxygen Demand)（Mean value from April to June）
mg/ℓ
12Before TRWKR (2006)
During TRWKR (2007-2009)
After TRWKR(2010-)

108.9

8642

6.5

6.6
5.1 6.0
5.0

5.4

2.8
2.4 2.8

2.6
2.6
2.5
1.8
2.0

5.2

5.2

4.5

4.3
3.5

3.3 3.2
2.7

1.90
MotoiriSliceway

SanageBridgeKitashimizu
BridgeKoshioBridgeNaya Bridge Oto Bridge

Kizaemon
BridgeKoshinBridgeInjection point◆Every water survey was conductedat the ebb of the neap tide.

Result of the survey of DO (Dissolved oxygen）（Mean value from April to June）
mg/ℓ
1210.62006
2008(3rd Stage)
2010(7th Stage)

9.9

10

2007(1st Stage)
2009(5th Stage)
2011(9th Stage)

8.6

8

7.7

9.7
8.2

7.6 7.7

7.4
7.3

6

6.8
5.2

5.5
4.1

4

3.9

6.0 6.6
4.6
4.5 4.0 4.9

6.1
5.7

3.6

20
MotoiriSliceway

SanageBridgeKitashimizu
BridgeKoshioBridgeNaya Bridge Oto Bridge

Kizaemon
BridgeKoshinBridgeInjection point◆Every water survey was conductedat the ebb of the neap tide.

Result of the survey of DO (Dissolved oxygen）（Mean value from April to June）
mg/ℓ
12Before TRWKR (2006)
During TRWKR (2007-2009)
After TRWKR(2010-)

109.1

8

7.77.2

7.7

8.4

9.0

8.2
7.2

7.2
6.6

6

9.8

5.5

5.7
5.2
4.1

4

6.2 6.6

6.2

6.0

4.9
4.5 4.5

4.2

4.2

20
MotoiriSliceway

SanageBridgeKitashimizu
BridgeKoshioBridgeNaya Bridge Oto Bridge

Kizaemon
BridgeKoshinBridgeInjection point◆Every water survey was conductedat the ebb of the neap tide.

Result of the survey of DO (Dissolved oxygen）（Mean value from April to June）
mg/ℓ12※The mean value in this graph do not include the value of June 2010 and May 2011,
because of red tide occurrence caused by abnormal growth of phytoplankton in these months.

1089.1
7.77.2

Before TRWKR (2006)
During TRWKR (2007-2009)
After TRWKR(2010-)

9.2
7.7

8.4

8.2

7.2 7.3
6.6

6

5.5

5.2
4.1

4

4.5

4.54.54.3

4.9

5.9
4.8
4.2

8.2
6.0

4.2

20Motoiri
Sliceway

SanageBridgeKitashimizu
BridgeKoshioBridgeNaya Bridge Oto Bridge

Kizaemon
BridgeKoshinBridgeInjection point◆Every water survey was conductedat the ebb of the neap tide.

Glossary
BOD （Biochemical Oxygen Demand）
BOD describes the amount of oxygen consumed when microbes
degrade organic compounds in water. It is determined by theamount of organic compounds in drainage water flowing in theriver measured by activity of microbes. It is commonly used toshow the level of organic pollution in the river.

DO （Dissolved Oxygen）
DO means dissolved oxygen in water. It is necessary for water
creatures to live and is also necessary for self-purification of theriver and lakes. When drainage water flow in and pollute the water,
DO is consumed to degrade organic compounds and is decreased.
On the other hand, photosynthesis by algae increases DO. If it shows
less than 3mg/L, fishes hardly survive.