The Pilot Projectof The Horikawa River Clarification
Summary of the result reportby Nagoya City
Sep. 22nd. 2012
Nagoya City Greenification & Public Works Bureau
River Dep. River Planning Div.
1Inuyama■Outline of this Pilot PJ

Kiso River
Shonai River Injection Point
0.3m3/s
Shonai River
Motoiri Sluiceway
Yada River
Injection routeof Pilot
Project
SanageBridge
0.4m3/sJohoku Bridge

PeriodMarch.27th.2007～March.22nd.2012
TRWKR（3years）

Asahi Bridge
NagoyaStation

Nakagawa Canal

PurposeTo confirm the TRWKR clarification
effect by transmitting pure water
stably for long period.
Volume of transmission of raw water
0.4m3/s（upper limit)

Naya Bridge
Sinsuzaki Bridge
Matsushige Bridge

Matsushige Lock Gate
JR・Meitetsu

Oto Bridge

Shin-Horikawa Riversurvey after TRWKR(2years)

Koshio Bridge

Horikawa River

April.27th.2007～March.22nd.2010

March.23rd.2010～March.22nd.2012

Daiko River
Nabeyaueno
trunk line
Meijo
Water Purification
Kitashimizu
Water
Plant
Nagoya Treatment Bridge
CenterCastle

Oseko Bridge

The Tokaido Shinkansen

Nagoya Port(Ise bay)

Kizaemon Bridge
Minatoshin Bridge
Horikawa Tide Gate

2Inuyama■Outline of this survey

Kiso River
Shonai River Injection Point
0.3m3/s
Shonai River
Motoiri Sluiceway
Yada River
Injection routeof Pilot
ProjectSanageBridge
0.4m3/sJohoku Bridge

Spots
10 Spots
Koshio Bridge, Naya Bridge, etc.

Daiko River
Nabeyaueno
trunk line
Meijo
Water Purification
Kitashimizu
WaterPlant
Nagoya Treatment Bridge
CenterCastle

Asahi Bridge

Koshio Bridge
Naya Bridge
Sinsuzaki Bridge
Matsushige Bridge

Matsushige Lock Gate
JR・Meitetsu

Oto Bridge

Shin-Horikawa River

Horikawa River

Nakagawa Canal

PointsTransparency（general index）
ＤＯ（direct effect on living things）
ＢＯＤ（organic pollution）
ＳＳ（Suspended Solids）
Ｔ－Ｎ、Ｔ－Ｐ（eutrophication index）

NagoyaStation

Oseko Bridge

The Tokaido Shinkansen

Nagoya Port(Ise bay)

Kizaemon Bridge
Minatoshin Bridge
Horikawa Tide Gate3

■Result of water quality survey◆Koshio Bridge
BODDO

6.0

5.6
3.2

3.1

Berore During
After
TRWKR TRWKR TRWKR(2006) (2007～ (2010・2009)
2011)

4.0

4.2

Berore During
After
TRWKR TRWKR TRWKR(2006) (2007～ (2010・2009)2011) 4

■Result of water quality survey◆Oto Bridge
BODDO
5.7

4.2

4.2

Berore During
After
TRWKR TRWKR TRWKR(2006) (2007～ (2010・2009)
2011)

3.6

4.1

4.1

Berore During
After
TRWKR TRWKR TRWKR(2006) (2007～ (2010・2009)2011) 5

■Summary of the survey result
・During TRWKR period
The water quality had been better in the area above
midstream of Horikawa (around Naya Bridge).
・After the stop of TRWKR
While the water quality has become a little worse in
the area above midstream of Horikawa (aroundNaya Bridge), it still keeps better condition thanwhen it was before TRKWR.
This result can be considered to be influenced by the new measures of sewage,
such as advanced water treatment in Meijo Water Treatment Center(2010.5～) ,Horikawa Ugan Rain-water Reservior for pollution control (2010.9～), and thegood water quality of Shonai River in 2011.

6■Survey of fish and benthos
Number of kinds identified from Sanage Bridge to the mouth of the river
80

68
51

60
40

3735

28
20206497

H172005

H192007

1914benthos

17
fish

0
H20
2008

H21
2009

H222010

H23
2011

year

TRWKR
During TRWKR period
fish and benthos: Number of kinds and habitat area were expanded.
After the stop of TRWKR
fish: Compared with during TRWKR, number of kinds didn’t fluctuate
remarkably.
benthos: Number of kinds decreased and became almost as many as before
7TRWKR.

■Water quality simulation model
We made the water quality simulation modelwith the data of 3years (2007～2009) TRWKR

Effect of clarification measures was calcurated by
the simulation modeling.

8

■Simulation results of clarification measures
Improvement of BOD by TRWKR
0.60.5mg/L
surface layer
表層0.5

bottom layer
底層

0.4
0.3

0.3
0.2

0.2

0.2

0.2
0.1

0.1
0
小塩橋
KoshioBridge

納屋橋
Naya
Bridge

新洲崎橋
Shinsuzaki
Bridge9■ Simulation of clarification measure
Improvement of BOD by sewage measure
0.6
surface layer
表層0.50.40.4

底層
bottom layer

0.4

0.3
0.2

0.2

0.2
0.1

0.1

0.10Koshio
Bridge
小塩橋

NayaBridge
納屋橋

Shinsuzaki
Bridge
新洲崎橋

sewage measures: advanced water treatment in Meijo Water
Treatment Center and Horikawa Ugan Rain-water Reservoir forpollution control

10

■The effects of clarification measureby the water quality simulation model
Improvement of BOD
by improvement of the water quality of Shonai River
0.6
surface layer
表層底層
bottom layer

0.5
0.4
0.30.40.3
0.2

0.2

0.2
0.1

0.10.10
小塩橋
KoshioBridge

納屋橋
Naya
Bridge

新洲崎橋
Shinsuzaki
Bridge11

■Evaluation of our water quality simulation
model

Analytical value of2010,2011

Comparison between analyzed value by our water quality
simulation model and actual measured value by regularresearch in 2010,2011 to evaluate our simulation model
BOD

Actual measured value of 2010,2011

It is confirmed that our simulation model has high reproducibility

12

■Evaluation of our water quality simulation
model

Analytical value of2010,2011

Comparison between analyzed value by our water quality
simulation model and actual measured value by regularresearch in 2010,2011 to evaluate our simulation model
DOActual measured value of 2010,2011

It is confirmed that our simulation model has high reproducibility

13

Measures to make Horikawa RiverlimpidImplementation by Nagoya city

Sep. 22nd. 2012
Nagoya City Greenification & Public Works Bureau
River Dep. River Planning Div.
14

■Reserve additional water resource◆Use of groundwater
Use of shallow ground water in the upstream
section of Horikawa River

Sanage Bridge

Upstream sectionof Kizune Bridge

Meijo ParkNagoya Castle
Koshio Bridge
Naya Bridge

Upstream sectionof Tsujie bridge

Instances of using
shallow groundwater

Shimizu
The picture when it was surveyed by drilling
WAKUWAKU Water

completion is scheduled for January,201315

■Reserve additional water resource◆Use of reclaimed wastewater
Conducting reclaimed wastewater thatwas membrane filtered in Moriyama
Water Treatment Center into Horikawa
River up to 4000㎥/day

Moriyama Water
Treatment Center

Shonai
Irrigation

Conducting spot intoHorikawa River
Reclaimed wastewater was conducted during
irrigation season(Apr-Oct)

Horikawa River
Kita Ward16

■Improvement of water quality◆making rapid and pool
Improvement of self-clarification
function of river by changing monotone
straight flow to diversionary flow withwood piles and stones and by increasingvegetation.

Wood pile

Straight stream

Wood pile
Wood pile
Obstacle stone
diversionary stream

Obstacle stone
Image figure

Scheduled to be installednear Kurokawa No.2 Bridge
17

■Improvement of water quality◆Removal of sludge

From FY 1994 to 2011
Removed 144,000m318

■Removal and inflow reduction of pollutants,◆Garbage Catcher（near Johoku Bridge）
Install the gate and the garbage collecting basket by remodeling the sewer outlet

Sanage Bridge④pick up and disposecollected garbage regularly
garbage collecting
basketgarbage collecting
basketMeijo Parkdrain the rainwater
when it rains heavily

weir

Nagoya Castle

floating garbage

catching andcollecting fence①catch and collect floating garbage by thefence by the difference of tidal level
between ebb tide and high tide

③catch and collectfloating garbage by
garbage collecting
basketsewersite of facilities

FY 2011 Collected

Inflow gate

upstream

downstream

Inflow gate

Water Treatment Centerdrain therainwater when it
rains heavily

HorikawaRiver③inflow gate automatically moves according
to tidal level and floating garbage flow incross section view

2.3t

19

■Removal and inflow reduction of pollutants◆Horikawa Ugan Rain-water Reservoir ,which
volume is 13000㎥,for pollution control
Rain-water reservoirs for pollution
control are constructed for storing
rainwater temporarily anddecreasing pollution load.

Horikawa Ugan Rain-water Reservoir*Stored rainwater is treated inwater treatment center after
stopping raining.

Completed in 2010
*Horikawa Sagan Rain-water Reservoir , volume is 14000㎥,
is under construction.

20■Removal and inflow reduction of pollutants◆Advanced water treatment
in Meijo Water Treatment Center
Filtering equipment ,DiscFilters, additionally removes
fine pollution contained intreated sewage.
Average before
introduction（2007～2009）

BODAverage(2011)

５．５
３．３

SS

３．３
less than １
21

Monitoring water quality by gate
operation of Shonai Irrigation
Headworks

Sep. 22nd. 2012
Nagoya City Greenification & Public Works Bureau
River Dep. River Planning Div.
22

■Shonai Irrigation Headworks

6 winch gates on the left bank

4 tilting gates on the right bank23

■Outline of monitoring water qualityLignin, peculiarly contained in wastewater ofthe papermaking process, is focused on tomonitor the water quality change caused by
the gate operation of Shonai Irrigation
Headworks.
The following items are monitored except forthe concentration of Lignin.
・air temperature・water temperature
・ｐＨ・transparency
24

■Monitoring point
ふれあい橋
Fureai Bridge
Kurokawa
Sluiceway
黒川樋門

Mizuwake Bridge

Shonai Irrigation Headworks

Horikawa river

1巻上ゲート1
winch gate
Motoiri Sluiceway

巻上ゲート6
転倒ゲート4

6 winch gates
4 tilting gates

Kita Ward

Moriyama Ward
Hatta River

Katsunishi Sewerage outlet
Shonai River25

■Gage number（right bank） 4 tilting gates（left bank） 6 winch gates②③④Winch Gates⑤⑥１２３Tilting Gates

４Right BankLeft Bank

①26

■Result of water quality survey◆the concentration of Lignin（winter）
108
64
2
⑥2/27

①2/16

①2/13

⑥2/09

⑥2/06

①1/30

①1/26

③1/23

⑥1/19

0
⑥1/16

concentrationof Lignin（mg/L）
リグニン濃度mg/l

12Katsunishi Sewerage

勝西下水出口outletMotoiri Sluiceway
黒川樋門

27

■Result of water quality survey◆the concentration of Lignin（summer）
108642Katsunishi Sewerage
勝西下水路出口①9/10⑥9/6⑥8/30①8/27①8/9⑥8/60①8/2

concentrationof Lignin（mg/L）
リグニン濃度mg/l

12Motoiri Sluiceway
元杁樋門outlet

28

■Result of water quality survey◆The relation between the concentration of Lignin andconcentration of Lignin（mg/L）

transparency
Winter
冬季

Summer夏季

121210108866442

2

00050
透視度(cm) (cm)transparency

100050透視度(cm)transparency
(cm)

10029

■Result of water quality survey◆The relation between the concentration of Lignin and watertemperature
concentration of Lignin（mg/L）

Winter
冬季Summer
夏季

1212101088664422000102030
水温(℃)
Water
temperature(℃)

400102030水温(℃)
Water
temperature(℃)

4030

■Result of water quality survey◆Conclusions of the survey
In winter, the concentration of Lignin
decreased on many days when we opened
the winch gate near the left bank.
In summer, the difference of the concentrationof Lignin by the way of the gate opening was
not observed.
The change of the concentration of Lignin had
relation with transparency and water temperature.
31