Horikawa Sen-nin Chosatai 2010th
Summary meeting for the 13 stage
The secretariat of Horikawa Sen-nin Chosatai
Sep. 29th 2013

Photos : Goyosui-ato-gaien-aigokai Survey Group
Kojo・Horikawa-to-Seikatsu^wo-kangerukai
Survey Group
Kawasemi Survey Group１

Horikawa Sen-nin Chosatai(HSC)2010～Transmission of Raw Water from the Kiso
River(TRWKR)～
1.Purpose
To verify the clarification effects of TRWKR withcitizens(1)Develop to new clarifying measures(2)Asses the influence on an ecosystem(3)Sustain and enhance citizens’ activities.
(4)Develop citizens’ awareness in the entire Horikawa
river basin

2.Water source and Volume of transmissionof raw water■ Increase of Transmisson Volume
from the Shonai River(additional pilot
project）(1)Water Source

Shonai River(2)Transmission Usual 0.3m3/sec(maxium 0.7m3/sec)(3)Experiment Period ：1st Oct-31St 2010(4)Period of Increased Transmision
Volume :Oct .5th-Nov.2nd 2010

(1)Water source : Kiso River(2)Volume of transmisission of raw water: Maximum
0.4 m3/s

3.Pilot project period(1)Evaluation and Survey term:About 5 years（from Apr.2007 to Mar.2012）(Including the term of follow-up survey and evaluation
after the stop of TRWKR)(2)TRWKR period:about 3years(from Apr.22nd 2007 to
Mar.22nd 2010)

２-1

Horikawa Sen-nin Chosatai(HSC)2010☆ The formation of HSC (April 22nd 2007)
With a viewpoint and a sence of citizens, the survey ofthe clarification effect of TRWKR started☆ The survey with a view point and a sence of citizens＊Clearness ＊Transparency ＊Color ＊Smell＊Garbage ＊ Living things ,etc

The first Nagoya City Environmental practice Prize February.2012
Branch of contribution for Regional Environment Development
Award for excellence
２-2

Horikawa River Pilot ProjectTransmission of Raw Water from the Kiso River (TRWKR)
Surveyｓ during TRWKR period :Apr.2007～March 2010
Surveys after the stop of TRWKR :Apr.2010～Mar. 2010

～ HSC(Apr.22nd 2007) ～1)Fixed Point Observation Groups2)Free Survey Groups3)Horikawa Cheering Groups
The survey with a view point
and a sense of citizens

To verify the clarification effects of TRWKR■ It was confirmed that the water quality tended to improved during TRWKR between
Sanage Bridge and Matsushige Brdge.
■Network of citizens who make a wish for clarification and restoration of the Horikawa
River was grown.
■Citzens’awareness of cleaning of the river was developed３

Method of fixed-point observation
Transparency
Meter
100 cmMeasurement oftransparency

Photo : Shinko Survey GroupHow is ―Measurement of COD
Chemical Oxygen Demand. This is anindex of water contamination used
for sea, lakes and marshes. It is anoxygen consumption required foroxidation of organic mattersdissolved in ample water. The higher
COD, the more it is contaminated.

COD pack test

impression of cleanness?
Transparent?
Color?
Bubbles?
Smell?
Garbage?
Living things?

Yuri-no-kai Survey Group
photo:Goyosui-ato-gaien-aigokai
Survey Group

photo:Goyosui-ato-gaien-aigokai
Survey Group

４-1

Horikawa River Pilot ProjectTransmission of Raw Water from the Kiso River (TRWKR)
Surveyｓ during TRWKR period :Apr.2007～Mar.2010
Surveys after the stop of TRWKR :Apr.2010～Mar. 2010
■ Conclusions of Surmmary Meeting for the 10th Stage① More surveys shoud be implemented.

・Continuity of investigation,Clarification of the situation of the river,indentifiaction of
cause of pollution in the river,are needed.
・We will make a improvement plan and take action to the pollution.
・After that,citizens and public administraion will do what is possible to cleans theriver.
②There are many things that citizens can.

・We will expanded the circle of partners who love the Horikawa River and hope
the TRWKR.
・We will deepen exchanges with people living in the basin of the Kiso ,Nagara,and
Ibi River.
・We will check the effect of pollution removal from domestic wastewater andimplement it in each house.

４-2

Network of citizens who make a wish for clarification andrestoration of the Horikawa River has grown

Number of Participants ofHorikawa Sen-nin Chosatai(Horikawa Sen-nin Chosatai started accepting
participation on March 26th. 2007)

Start

Now

April 22nd. 2007

September 29th. 2013

Fixed Point
Observation groups

55 groups
497 persons

93 groups
971 persons

Free Survey Groups

22 groups
234 persons

40 groups
650 persons

Horikawa CheeringGroups

88 groups
1,531 persons

2,498 groups
48,966 persons

Total

165 groups
2,262 persons

2,631 groups
50,587 persons
５Number of Participants ofHorikawa Sen-nin Chosatai
Change in Participants
Fixed Points
Observation
GroupsTotal 50,587 persons

Free Survey Groups

Horikawa
Cheering Groups

Total

Fixed Points Observation Groups : 971 persons
Horikawa Cheering Groups : 48,966 persons
1st stage

3rd stage

2nd stage

5th stage

4th stage

7th stage

6th stage

11th stage

9th stage

8th stage

10th stage

13th stage

12th stageApr.2007
Jun.2007
Aug.2007
Oct.2007
Dec.2007
Feb.2008
Apr.2008
Jun.2008
Aug.2008
Oct.2008
Dec.2008
Feb.2009
Apr.2009
Jun.2009
Aug.2009
Oct.2009
Dec.2009
Feb.2010
Apr.2010
Jun.2010
Aug.2010
Oct.2010
Dec.2010
Feb.2011
Apr.2011
Jun.2011
Aug.2011
Oct.2011
Dec.2011
Feb.2012
Apr.2012
Jun.2012
Aug.2012
Oct.2012
Dec.2012
Feb.2013
Apr.2013
Jun.2013
Aug.2013
Oct.2013
Dec.2013
Feb.2014

Number of Participants

Free Survey Groups : 650 persons

Month and Year
September 29th, 2013６

Survey Period andNumber of Reports of Survey Results
Number ofReports
Spring - Early Summer/ Apr. 22nd - Jun. 30th. 2007 258
Jul. 1st - Sep. 7th. 2007
134
Autumn - Early Winter/ Sep. 8th - Dec. 16th. 2007
383
Dec. 17 - Mar. 31th. 2007
103
Spring - Early Summer/ Apr. 1st - Jun. 30th. 2008
245
Jul. 1st - Sep. 27th. 2008
64
Autumn - Early Winter/ Sep. 28 - Dec. 16th. 2008
152
Dec. 17th - Mar. 31th. 2009100
Spring - Early Summer/ Apr.1st - Jun. 30th. 2009
145
Jul. 1st - Sep. 26th. 200954
Autumn - Early Winter/ Sep. 27th - Dec. 16th. 2009120
Sep.17th.2009 - Mar. 31th. 201081
Spring - Early Summer/ Apr. 1th - Jun. 30th. 2010
111
Jul.1st - Sep.11th. 201044
Autumn - Early Winter/ Sep. 12th - Dec.17th. 2010
104
Sep.18th. 2010 - Mar. 31th. 201172
Spring - Early Summer/ Apr.1st - Jun. 30th. 2011112
Jul.1st - Sep.10th. 201142
Autumn - Early Winter/ Sep.11th - Sep.16th. 2011133
Dec.17th. 2011 - Mar. 31th. 201277
Spring - Early Summer/ Apr. 1st - Jun.30th. 2012148
Jul.1st - Sep. 21th. 201259
Autumn - Early Winter/ Sep.22th - Dec.16th. 2011135
Dec.17th. 2012 - Mar.31th. 201378
Spring - Early Summer/ Apr.1st - Jun.30th. 2013
129
3,083

Survey Period

With TRWKR

Introduction of advanced water
treatment at the Meijo Water
Treatment Center
In-service of Horikawa
Ugan Rain-water Reservior
for pollution controll
Utilization of reclaimed
wastewater from Moriyama
Water Treatment Center
From Apr. to Oct.

total

1st stageinterval
2nd stageinterval
3rd stageinterval
4th stageinterval
5th stageinterval
6th stageinterval
7th stageinterval
8th stageinterval
9th stageinterval
10th stage
interval
11th stage
interval
12th stage
interval
13th stage

７

Investigation spots
Shonai River

NagoyaCastleShin-Horikawa
River
JR Chuo Line

TokaidoShinkansen８Column “To clarify and restore the Horikawa River”
Horikawa Sen-nin Chosatai 2010, which is composed of Fixed Point Observation Groups, Free Survey
Groups and Horikawa Cheering Groups, made a start as a place for citizens’ activities to clarify andrestore Horikawa River on April 22nd, 2007.
Fixed Point Observation Groups survey clarification effect of Horikawa by Transmission of Raw Waterfrom the Kiso River (TRWKR) with a view point and sense of citizens. Free Survey Groups research
Horikawa by free theme. Horikawa Cheering Groups support clarification and restoration of Horikawa.
These three kinds of groups cooperate each other in the big network for clarification and restoration ofHorikawa.
There are 93 Fixed Point Observation Groups, 40 Free Survey Groups and 2,498 Horikawa CheeringGroups, the total is 2,631 groups and 50,587 persons as of Sep 29, 2013. Compared with thenumber of groups and participants, 165 groups and 2,262 persons, at the start, network of people whowish clarification and restoration of Horikawa has developed.
Fixed Point Observation Groups have made surveys at 3,083 times from 1st stage to 13th stage. Theirsurveys show that the situation in the area of the downstream from Sanage Bridge variously changes as
the tide rises and falls from hour to hour in Horikawa basin. We learned that various surveys at various
time, place and tidal situation enable us to understand average and change of water quality in Horikawa.
And it was confirmed that water quality was improved roughly between Sanage Bridge and Matsushige
Bridge for five years of pilot project. It was also confirmed that artificial garbage was reduced during
this period. So it is supposed that citizens’ awareness has changed for example cleaning activities areheld a lot.
～Pilot project for clarification of Horikawa“Clarification effect by TRWKR from April 2007 to March 2012 was confirmed”～【Summary】■Clarification effect by TRWKR was confirmed between Sanage Bridge and Matsushige Bridge■Network of citizens who make a wish for clarification and restoration of Horikawa has grown■Awareness of clarification of Horikawa advanced９After the stop of TRWKR in March 2010, advanced water treatment was introduced at Meijo Water Treatment Center in May
2010 and Horikawa Ugan Rain-water Reservoir for pollution control was launched in September 2010. In August 2011,
reclaimed wastewater, which is treated by membrane filtration at Moriyama Water Treatment Center, started to be transmitted
into Horikawa. The reclaimed wastewater is transmitted into Horikawa from April to October and also transmitted into Shonai
Irrigation from November to March (non-irrigation season) at a volume of a maximum of 4,000ｍ3/day, 0.046ｍ3/sec.
The water quality of Horikawa was deteriorated at 7th stage (from April to June 2010, just after the stop of TRWKR). But
after 7th stage, the water quality has been tend to be improved at a certain area. It is supposed that the water quality isimproved by the new measures for water quality improvement.
Because the number of fixed point observations amounted to more than 3,000 in this stage, we can try to analyze data inthe past and to research yearly change (monthly month). It is confirmed again that impression of clearness, transparency andvalue of COD are bad from Spring to Autumn when people especially gather and play at the waterside.
Also, we tried to research change in impression of clearness compared at spring tide and at neap tide because the water
quality of Horikawa is supposed to be influenced by the tide. The research showed that impression of clearness is evaluatedby “color”, ”smell” and “garbage” between Asahi Bridge and Kameya Bridge especially when it is spring tide from Spring toearly Summer (1st, 3rd, 5th,7th,9th and 11th stage). Among of all kinds of “smell”, “smell of sludge” increases in thedownstream from Asahi Bridge.
These researches showed clearly that impression of clearness is bad between Johoku Bridge and Matsushige Bridge, many
bubbles occur from the bottom Horikawa and smell is deteriorated between Asahi Bridge and Matsushige Bridge in paticular.
It is supposed that the section between Asahi Bridge and Matsushige Bridge is easy to be influenced by deterioration ofcolor, transparency and smell because sludge is exposed and raised and because red tide and blue tide go against thestream by high tide from downstream in the section.

We put data in order on survey activities and survey results on Shin- Horikawa. We don’t haveenough data now, but we found a few features in the upstream and downstream area of Shin-Horikawa.

～Cooperation with community development of Horikawa basin～“Horikawa Machizukuri no Kai” started and “1st Horikawa Round Table” was held on July 30th.
Each group and organization will work respectively and also hold “Round Table” about twice a year to share the informationand make their connection closer.
Two proposal were made by “Horikawa Machizukuri no Kai” secretariat and both are consented unanimously.
■Secretariat proposed below
1 clarification measures and investigation for bustling
２ pilot project of “Horikawa Navi” in “Horikawa Machizukuri Plan”

１０

Horikawa City Planning Party has started to “ Horikawa Machizukuri Plan ”“ 1st Horikawa round table ” meeting was held . July 30th, 2013
Research for water quality improvement measuresand to bring prosperity to the river area

6 Proposed and offered info.
by HSC secretariat

For the purpose of improving attractiveness of Horikawa River between the area of Naya Bridge and Nagoya
Castle, we will research the heap of sludge in it, and investigate effective water quality improvement measures toprogress purifications.
In addition to the water quality improvement of this area, we will also consider using the river space withhistorical properties around Horikawa River to make this area prosperous.
● Investigation to prepare public lots aroundResearch for water quality
improvement measures
・Research of sludge conditions
・Research of non-repaired banks
・Hearing from specialists, and investigations
for water quality improvement measures

the Shikemichi area for a water-friendly space

Shonai River
Yada River

Johoku Brdg.
Suzikai Brdg.

Sanage Brdg.

Nagoya Castle
An average level of high tide

Gojyo Brdg.
Naya Brdg.(Hirokoji Ave.)

An average level of ebb tide

JR LineMeitetsu Line

Shin-Horikawa River

Matsushige
Lock Gate

Horikawa River

Tennozaki Brdg.

An image of the area around Gojo River● Investigation for facility Improvementin the waterside area around Naya Bridge.

Tokaido Shinkansen
Horikawa Tide Gate
Nagoya Port(Ise Bay)
Sludge at the edge of banks which appear at the ebb tide
Setting up of guide boards (maps, name boards)

１１

Main Measures for Water Quality Improvement (1)2007

Mesasures

━ 1st

2008

━ 3rd
━ 2nd

2009

━ 5th
━ 4th

2010

━ 7th
━ 6th

2011

━ 9th
━ 8th

2012

━ 11th━ 10th2013━ 13th━ 12thWith TRWKR(0.4m3/s)

Increase of raw watertransmission from the
Shonai River (＋0.4m3/s)

Introduction of Advanced
water treatment at the
Meijo Water Treatment
CenterIn-service of the Horikawa
Ugan Rain-water Reservoir
for pollution control
Utilization of reclaimed
wastewater from theMoriyama Water
Treatment Center(0.046m3/s)

12-1

Main Measures for Water Quality Improvement (2)Newly launched facilities after the stop of TRWKR○Advanced water treatment at the Meijo Water Treatment Center
Solution : conventional activated sludge process and rapid filtration
Launch : May. 2010
■For improvement of quality oftreated water
Additional filtration of treated waterat the Meijo Water Treatment Center
can improve quality of water
discharging into Horikawa River

⑤

⑥

④

③

②
①

○The Horikawa Ugan Rain-water Reservoir
Volume : 13,000m3
Coverage area : 633ha
Launch : Sep. 2010
■For improvement of combined
sewer system
By storing first flush with highpollution load to restrain outflows
temporarily, the frequency of overflow
from the sewer outlet can be reduced.

凡例
Legend
対策済み区域
constructed
建設中の区域
underconstruction

Improvement of combined sewer system
Construction of water storage facility

12-2

Main Measures for Water Quality Improvement(3)Newly launched facilities after the stop of TRWKR■Securement of Additional Water Resource
Utilization of Reclaimed WastewaterMoriyama Water
Treatment Center

Conducting reclaimed wastewater treated bymembrane filtration at the Moriyama Water
Treatment Center up to 4000m3/day is discharged
into Horikawa River.

Newly installed
pipeline

Start to conduct in Aug. 2011

Shonai
Irrigation

Conducting point into
Horikawa River
Reclaimed wastewater was conductedduring irrigation season (Apr - Oct)

Horikawa
River
Kita Ward
Reference ： 10th Horikawa Sennin Chosatai conference13Data: The Meteorological Agency _ Climate Statistics
http://www.jma.go.jp/jma/menu/report.html

Whether Condition

About whether condition in April to June of the 13thstage, it was higher-temperature, less precipitation, andlong hours of sunshine than normal. The temperature in
May and June was especially high, and the precipitationin May was very little.
■TemperatureThe
monthly climate normal
名古屋地方気象台
平年値(月ごとの値)

1971
～2000

30
14.1
18.5
22.3
18.3
23.4
17.6
11.9
6.7
14.9

30
19.5
23.7
26.7
23.3
28.0
22.4
16.7
11.4
19.6

30
9.2
14.0
18.7
14.0
20.0
13.5
7.6
2.6
10.9

30
188.4
199.6
145.2
177.7
141.9
165.6
159.7
169.7
159.2

■Precipitation
Little as about 70 percent of normal.
Especially in May, there was very little precipitation as 40 percent of normal.

■Hours of sunshine
Longer than normal.
The hours of sunshine in April and May are longer than normal, and in June isshorter than normal.

40
35

2007

35

2008

28.1

30

2009

23.6

25

Change in Mean temperature Spring - Early Summer(Apr. - Jun.)

2010

19.4

2011

20

2012

13.8

2013

Apr. – Jun. (1971 - 2000)
Average of normal temperature 18.3℃

The temperature of the
13th stage was slightly
higher than normal.

30
25
20

18.7℃

19.1℃

19.5℃

18.6℃

18.7℃

18.6℃

18.9℃

13th stage

40

15
10
5

10
5 1,3,5,7,9,11,13st.

0

2,4,6,8,10,12st.
Mar

Feb

Jan

Dec

Nov

Oct

Sep

Aug

Jul

Jun

May

0
Apr

Mean temperature (℃)

the temperature in May and June is higher than normal about 1℃.

The temperature in April ofthe 13th stage was slightly
lower than normal, and in
May and June was higher
than normal about 1℃.

Temperature

15

Slightly higher than normal.
The temperature in April was slightly lower than normal, and11th stage

30
143.3
155.7
201.5
166.8
249.8
116.9
79.5
36.8
120.8

9th stage

Average
平均

1971
～2000

7th stage

Sep.
9月
Oct.
10月
Nov.
11月
Dec.
12月

1971
～2000

Mean temperature(℃)

Average
平均

Minimum
最低

1971
～2000

(℃)

5th stageYearsof data
資料年数

Maximum最高

3rd stage

1971
Statistics
統計期間
data period
～2000

Mean
平均

日照時間
Sunshine(Hour)
(時間)
Total
合計

1st stage

区分

4月
Apr.
May.
5月
Jun.
6月

Temperature
気温

降水量
Precipitation( mm )
(mm)
Total
合計

１４

Whether Condition

Reference: Japan Meteorological Agency
http://www.jma.go.jp/jma/menu/report.html

Temperature

Comparison between 11th stage and 13th stage

11th stage 2012

13th stage 201340

Temperature（℃）

Temperature
11th stage < 13th stage
30

20

10

0
4/1

5/1

6/1

１５

2007

2009

2010

1,3,5,7,9,11,13st.

2011

2012

214.1

Precipitation

203.3

200
129.1

100
0

185mm

203mm 204mm

133mm

123mm

114mm

100
50

1,3,5,7,9,11,13st.

2012

2013

2,4,6,8,10,12st.

Hours of sunshine

186.5
148.5
63.5

13th stage

11th stage

9th stage

5th stage

3rd stage

7th stage

208h

207h
187h

175h

173h

173h

150
100
50

13th stage

7th stage

5th stage

3rd stage

Mar

Feb

Jan

Dec

Nov

Oct

Sep

Aug

Jul

Jun

May

209h

200

0

0

Apr

250

1st stage

130.5

100

2011

11th stage

2010

The hours ofsunshine of the
Change in hours of sunshine Spring - Eary 13th
Summerstage are(Apr. - Jun.)longer thannormal.
Apr. – Jun. Normal(1971 - 2000)
Average 177.7 h

9th stage

2009

300

Hours of sunshine(h/ month)

2008

1st stage

Mar

Feb

Jan

Dec

Nov

Oct

Sep

Aug

Jul

Jun

May

The hours of sunshine in April
and May are longer than normal,
and in June is shorter thannormal on the 13th stage.

300
200

213mm

200

0

2007

400

Apr. – Jun. Normal(1971 - 2000)
Average 166.8mm

250

150

Very little precipitation in
the 13th stage as 70
percent of normal.

Change in average precipitation Spring - Eary Summer(Apr. - Jun.)

300

2013

2,4,6,8,10,12st.

282.2

300

500

precipitation(mm/ month)

2008

precipitation(mm/ month)

500
400

Reference: Japan Meteorological Agency
http://www.jma.go.jp/jma/menu/report.html

Very little precipitation in May of the
13th stage as 40 percent of normal.

Apr

Hours of sunrise(h/ month)

Whether Condition

１６

The 1st 3rd 5th stage
・With TRWKR
・No rain on the day and the previous day

Impression of Water Cleanness
The ratio of “clean”, “slightly clean” and “ordinary”. *60

Shin-Horikawa River80

Nagoya Port

Impression of water cleanness (%)

100

50 5050
40

40

34

The ratio of “clean”, “slightly clean” and “ordinary”
between Matsushige Bridge and Johoku Bridge was low.
61
56 56

50 50
39

27
16

12
No data

54

45

18

20

57

37

23 2125

222020

28

12

6

#N/A
#N/A
#N/A
#N/A
#N/A
0 #N/A

28
23

21

11

42

3836

5

20

25
21

12

8
0

Matsushige Bridge~Asahi Bridge

Asahi Bridge ~Johoku
Bridge

93
87 87

73
62
57

58

53

43
36

4039

29

14 16

0

100100100100100 100

23
20

75

Injection Point of TRWKR

100

2nd stage Sep. 8~Dec.16 2007
4th stage Sep.28~Dec.16 2008
6th stage Sep.27~Dec.16 2009
8th stage Sep.11~Dec.17 2010
10th stage Sep.11~Dec.16 2011
12th stage Sep.22~Dec.16 2012

Meijo Water Treatment Center

1st stage Apr.22~Jun.30 2007
3rd stage Apr. 1~Jun.30 2008
5th stage Apr. 1~Jun.30 2009
7th stage Apr. 1~Jun.30 2010
9th stage Apr. 1~Jun.30 2011
11th stage Apr. 1~Jun.30 2012
13th stage Apr. 1~Jun.30 2013

Transmission of raw water from the Shonai

The 7th,9th,11th stage
・No TRWKR
・No rain on the day and the previous day

60
50

39

0
Minatoshin Bridge~Oseko Bridge

Number ofData

3 2 5 2 2 1 0 0 0 0 2 00

Not enough data

Oseko Bridge~Matsushige Bridge

15 35 33 9 29 25 30 21 25 35 27 26 35 46 103 82 28 37 16 25 25 22 43 43 40 35 12 21 14 2 13 4 6 5 9 12 14 12 7

Johoku Bridge~Sanage Bridge
37 47 42 11 30 17 24 16 20 23 27 20 14

Sanage Bridge~Sakae Bridge
31 41 15 2 8 3 5 8 5 9 9 8 8

Not enough data

■ How did the impression of water cleanness change?
・The ratio of “clean”, “slightly clean” and “ordinary” between Johoku Bridge and Matsushige Bridge was low.
・The impression of water cleanness between Johoku Bridge and Matsushige Bridge was worse than other area.
* “clean”, “slightly clean” and “ordinary” are categorized as the acceptable range for citizens.

Not enough data

１８

Impression of Water Cleanness
from Spring to Early Summer
The percentage of people who answered between “clean” and “ordinary”

Impression of water cleanness(%)

100

The 1st,3rd,5th stage
・With TRWKR
・No rain on the day and the previous day
The 7th,9th,11th stage
・No TRWKR
・No rain on the day and the previous day

Oseko Bridge~Matsushige Bridge

Matsushige Bridge~Asahi Bridge

Asahi Bridge~Johoku Bridge

Johoku Bridge~Sanage Bridge

With TRWKR

Introduction of advanced water treatment at the Meijo Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservior for pollution control
Utilization of reclaimed wastewater

80

Rising trend after carrying out new water quality improvement programs
60

58
53

Rising trend during
the transmission

Declining trend after
stopping the transmission

43

40

36

40

29

27

23
16

20
11

8

18

28

21 23

22
16

12
6

21 23

20
12 14

12
5

0 0
0

2007.4.22~6.30

2008.4.1~6.30

009.4.1~6.30

2010.4.1~6.30

2011.4.1~6.30

2012.4.1~6.30

2013.4.1~6.30

1st stage

3rd stage

5th stage

7th stage

9th stage

11th stage

13th stage

Note: Data we got from Minatoshin Bridge to Oseko Bridge and from Sanage Bridge to Sakae Bridge are not counted
because we got few data there.
■ How did the impression of water cleanness change (spring ~ early summer) ?

→In 7th stage after the stop of TRWKR, transparency was deteriorated. But afterward we have seen thetransparency of improvement. This is considered to be an effect of the new water quality improvement measures,
especialy between Sanage Bridge and Johoku Bridge.

１９

1st stage: No data
2nd to 6th : With TRWKRNo rain of the day and previous day 7th to
12th: No TRWKRNo rain of the day and previous day

Change of Evaluation of Impression on Water
Dirtiness

0%

1st

20%

40%

27
5th
7th
Utilization of
Reclaimed Wastewater

3

40

100%

59
52
60

13th
②Smell③Clarity

19
17
25

18

44
8

22
29
14

0
13
7

50
43

11th

①Coloring

80%

34
3

58
0
54
60
53

3rd

9th

60%

No data in the 1st stage

39
In-service of Horikawa Ugan Rainwater Reservoir for Pollution Control

Introduction of Advanced Sewerage Treatment at the Meijyo
Water Treatment CenterWith TRWKR

Sanage Bridge - Minato-shin Bridge.

40
9

24

4

37
0

22
23

6
7
④Garbage⑤Bubbles18

401
301 193022 17315
10 52
11 0 11014
4 20 63
13 0 84
16
01 67
13 03 75
18
01 112
19
0 113
97
14 10

⑥Living things

90⑦Others

The ratio of “color” was incleasing.
■How did the impression of water dirtiness change ?
→Main evaluation of impression on water dirtiness were “color”, “transparetion” and “garbage”.

After 9th stage, the ratio of “color” was incleasing. This is considered to be an effect of new water quality
improvement measures.

２０

2.Transparency
Measuring transparency

Photo: Survey Group of Team NTT Smile Nagoya

Photo: Shinko Survey Group

Relationship between the impression of clearness
and the average of transparency(translucency)
2nd-9th stage , No rain , Including out-of-period data
Impression of clearness : Evaluated by translucency
All sections (including the upper reaches)

Transparency(cm) , evaluated by translucency

Ralationship between the impression of clearness and transparency(translucency)“Clear”-”Ordinary” are acceptable range for citizens

Over 70cm transparency

Clear

Slightly
clear

Ordinary Slightly
dirty

Dirty

Impression of water clearness , evaluated by translucency

Transparency over 70cm can be an indicator
to improve impression of water clearness.
Note )The values over 100cm are treated as 100cm.

Reference: The reports for the HSC 10th stage meeting

Photo: HSC secretariat

２１

1st - 6th stage： With TRWKR

Change of Transparency

No rain on the day and the previous day

7th–13th stage： No TRWKRNo rain on the day and the previous day

89

87

83

83

90 92

87
81

79 77 7840

Shin-Horikawa River confluence

59

60
Nagoya Port

Transparency(cm)

80
68

50

53

20

56

54

87

84

58

56 57
48

74
65
61

65

61 60
53

80

60

57 59

52

52
45

Meijo Water Treatment Center

95

93

3rd stage Apr. 1-Jun.30,2008
6th stage Sep.27-Dec.16,2009
9th stage Apr. 1-Jun.30,2011
12th stage Sep.22-Dec.16,2012

75

58

86

80

67
64 63 67

71 68

57 57
58
54
51
50
50

43

79 77

88

57

63
59

67
64
62
55 55

42

Transmission of Raw Water from Shonai River

7th stage Apr. 1-Jun.30,2010
10th stage Sep.11-Dec.16,2011
13th stage Apr. 1-Jun.30,2013

100 100

100

2nd stage Sep. 8-Dec.16,2007
5th stage Apr. 1-Jun.30,2009
8th stage Sep.11-Dec.17,2010
11th stage Apr. 1-Jun.30,2012

Transmission of Raw Water from Kiso River

The transparency in “spring-early summer” 1st stage Apr.22-Jun.30,2007
4th stage Sep.28-Dec.16,2008
is lower than “autumn-early winter”

71

0Minatoshin Brdg.
-Oseko Brdg.
3 2 5 2 2 1 0 0 0 0 2 0 0

Oseko Brdg.
-Matsushige Brdg.

Matsushige Brdg.
-Asahi Brdg.

11 30 33 9 29 25 30 21 24 33 26 25 34

22 74 55 18 29 16 22 22 20 40 41 30 33

Not enough data
No data for 7th-10th・12th-13th stages for not enough data

Asahi Brdg.
-Johoku Brdg.
9 16 9 1 11 3 6 5 8 12 14 11 7

Johoku Brdg.
-Sanage Brdg.
13 35 32 8 26 17 20 16 20 23 26 18 14

Not enough data

Sanage Brdg.
-Sakae Brdg
3 41 13 2 8 3 5 8 5 9 9 7 8

Not enough data

■ How did the transparency change？
→ The transparency in “spring-early summer(1st,3rd,5th,7th,9th,11th,13th stage)” was lower than in “autumnearly winter(2nd,4th,6th,8th,10th,12th stage)”, and almost transparency in “spring-early summer” is under 70cm
which is the acceptable range of citizens.
Note )The values over 70cm are treated as 100cm.
The answers between “clear” and “ordinary” are categorized as the acceptable range for citizens.(=over 70cm transparency)

２２

1st・3rd・5th stage ：With TRWKR

Change of Transparency・・・Spring-Early Summer

No rain on the day and the previous day

7th 9th 11th 13th stage：No TRWKR

Note) Except the data of “Minatoshin Brdg.-Oseko Brdg.” and “Sanage Brdg.-Sakae Brdg.” for not enough data.

Oseko Brdg.-Matsushige Brdg.
Asahi Brdg.-Johoku Brdg.
TRWKR

No rain on the day and the previous day

Matsushige Brdg.-Asahi Brdg.
Johoku Brdg.-Sanage Brdg.

Introduction of an advanced water treatment at Meijo Water Treatment Center100

In-service of Horikawa Ugan Rain-water Reservoir for pollution control

Transparency(cm)80

Utilization of reclaimed wastewater at Moriyama Water Treatment Center

During TRWKR
Improved in Sanage Brdg.-Matsushige Brdg.

After the stop of TRWKR A trend of improvement could be seen in Sanage Brdg.-Johoku Brdg.
（An effect of the new water quality improvement measure)
68 Got worse
67

71

65

60

59

59 58
53

61

60 61

56
52

54

58

56
52

64

63

60

57
51

54
48

58 57
50

43
40

20

0

Apr.22-Jun.30
2007

Apr.1-Jun.30
2008

Apr.1-Jun.30
2009

Apr.1-Jun.30
2010

Apr.1-Jun.30
2011

Apr.1-Jun.30
2012

Apr.1-Jun.30
2013

1st stage

3rd stage

5th stage

7th stage

9th stage

11th stage

13th stage■ How did the impression of clearness(spring-early summer) change after TRWKR stopped？
→The transparency got worse in 7th stage just after the stop of TRWKR.
However, the transparency after that is improving between Sanage Brdg. and Johoku Brdg..
We suppose that it is an effect of the new water quality improvement measure.
Note )The values over 70cm are treated as 100cm.

The answers between “clear” and “ordinary” are categorized as the acceptable range for citizens.(=over 70cm transparency)

２３

3.COD
Chemical Oxygen Demand. It shows the organic pollution level
mainly at the sea area and lakes. It means the amount of oxygen
which react(oxidize) with organic substance underwater. The
higher the value of COD, the higher the pollution level.
The COD measurement test

Photos: Goyousui-ato-gaien-aigokai Survey Group２４

Change in COD

1st -6th stage： With TRWKRNo rain on the day and the previous day

7th – 13th stage： No TRWKRNo rain on the day and the previous day

COD in Matsushige Bridge-Minatoshin Bridge islower than in Sanage Bridge-Matsushige Bridge

No data

Number of data 3 2 5 2

2 1 0 0 0 0 2 0 0

Not enough data

COD in “spring-early summer” is mostly
higher than in “autumn-early winter”.

14 34 32 9 28 22 30 17 24 35 26 25 34

27 63 55 19 28 16 22 25 22 43 42 31 35

12 17 14 2 12 4 6 5 9 12 14 11 7

Not enough data

■ How did the COD change？
→ COD in “spring-early summer(1st,3rd,5th,7th,9th,11th,13th stage)” is mostly
higher than in “autumn-early winter(2nd,4th,6th,8th,10th,12th stage)”.
COD between Sanage Brdg. and Matsushige Brdg. was lower than between
Matsushige Brdg. and Minatoshin Brdg..
Note) The values over 20mg/L are treated as 20mg/L.

31 37 41 10 30 17 20 16 20 23 23 18 14

4 9 13 2 8 3 5 8 5 9 9 7 8

Not enough data

２５

4.Bubbles
Examples of the mechanism of the occurrenceof bubbles at the river bed
Bubbles from the river bed

Smell like rotten eggs
At low water level and waterpressure, bubbles insidesludge get released easily

Water
Hydrogensulfate ionizedwater （ＳＯ42-）

Bubbles

SludgeAround Nishiki Bridge:
A lot of bubbles floated to the surface fromthe river bed

Sulfide（Ｈ２Ｓ，ＨＳ－,etc.）

Photos:by secretariat

Bubbles

Bubbles increase
At high temperatures,
bacterium are activatedSulfate reducing bacterium（mainly inside bottom mud）
＊anoxia-loving bacterium
Sulfate reducing bacterium producehydrogen sulfide （H2Ｓ） etc. ,withorganic substance decomposed andsulfate ion （ＳＯ42-） reduced.

Around Nishiki Bridge:
Sludge floated to the surface with bubbles
from the river bed

No smellＳＯ42-（sulfate ion）＋Organic substance→Ｓ2-＋Ｈ2Ｏ＋ＣＯ2
2+
Ｓ ＋Ｈ →ＨＳ （hydrogen sulfate ion）
ＨＳ- ＋Ｈ+→Ｈ2Ｓ（hydrogen sulfide）

Methanemethanogenic bacterium（mainly inside bottom mud）
＊anoxia-loving bacterium
Methanogenic bacterium produce
methane with CO2, H20, etc.
４Ｈ２＋ＣＯ２→ＣＨ４（methane）＋２Ｈ２Ｏ

・Methanic bacterium seem not somuch in salt water・Methanogenic bacterium
predominate in waters with little
ＳＯ42-（sulfate ion）
・Energy source of methanogenic
bacterium is hydrogen produced
through the decomposition oforganic substance by anoxia
bacterium.

２６

Occurrence of Bubbles
With TRWKR

Introduction of advanced water treatment at Meijo Water Treatment CenterIn service of Horikawa Ugan Rain-water Reservoir for pollution control

1st-6th stage ： With TRWKRNo rain on the day andthe previous day
7th-13th stage： No TRWKRNo rain on the day andthe previous day

Utilization of reclaimed wastewater

Occurrence of bubbles_component ratio (%)

Sakae Bridge - Sanage Bridge

With TRWKR

Bubbles rising from the bottom of the river

Bubbles flowed from upstream

Bubbles flowed from downstream

Bubbles were not seen

100%

90%
80%

70%

47
67

73

60%

Not enough data

50
67

74

50%

100

8

50

20%
10%
0%

33

24

25
1st Stage

13

2nd Stage

3rd Stage

4th Stage

5th Stage

6th Stage

7th Stage

8th Stage

9th Stage

38

15

2

8

3

5

8

5

Occurrence of bubbles_component ratio (%)

More frequent in “Spring～Earlysummer”than“Autumn～Early winter”

90%
80%
55

60%

13

14

80

12

9

94 Increasing after89

33

10%

1st Stage
Number of data108

31

14
2nd Stage
208

3rd Stage
172

4th Stage
49

7

17

Increase(worse)
12th,13th

5th Stage
99

5

26
2

2
2

6th Stage
60

8
7th Stage
81

64

80

89

5
5

1

7

Bubbles flowed from upstream
Bubbles were not seen

the stop of TRWKR

1

2
2
16

7

68

75

30%
2
4

9

Tendency of decreasing by the new measures
63
64 for water quality improvement

59
80

50%

0%

86

10th Stage 11th Stage 12th Stage 13th Stage

9

Bubbles rising from the bottom of the river
Bubbles flowed from downstream

With TRWKR

100%

20%

87

100

33

Sanage Bridge -Minatoshin Bridge

40%

100

13

3

Number of data 24

70%

100

20

40%
30%

100

3

8th Stage
63

26

3

20

9
6

12

22

24

8
9th Stage
70

10th Stage 11th Stage 12th Stage 13th Stage
93
108
85
102

Sludge at the river
bed was not at goodcondition because ofhigh temperature.

２７

（Reference） Weather Condition Autumn～Early WinterComparison between 10th and 12th stages

Temperature

Why did bubbles increase in the 12th stage?
⇒ It is considered that it was because sludge
was easily produced at the river bed in hightemperature in Sep. and Oct. 2012.

Temperature
10th<12th
Temperature10th>12th

RainfallHours of Sunshine

Ref.：The Report of the 11th stage of HSC meeting

２８

（Reference） Weather Condition Spring～Early Summer
Comparison between 11th and 13th stages

Temperature

Temperature is high11th < 13th

RainfallHours ofSunshine

Ref.：The Report of the 11th stage of HSC meeting

２９

1st ～ 6th stage : With TRWKRNo rain on the day and the previous day
7th ～ 12th stage : NO TRWKRNo rain on the day and the previous day

Occurrence of Bubbles
Bubbles flowed from upstream

Bubbles flowed from downstream

Bubbles were not seen

100%

49

57

60%

Not enough data

85

40%

74

89

30

1st Stage
33

9
6

19

2nd Stage
47

11

11

3rd Stage

4th Stage

42

9

5th Stage
27

Johoku Bridge～Asahi Bridge
100%

56
74

75

13

5

13

20

6
6
6

32

6th Stage

7th Stage

8th Stage

17

24

16

95

100

9
13

36

25

7
29

Bubbles flowed from upstream
Bubbles were not seen

70

100

100

79

66

100

100

40%
50

20%
0%

8
8

5

20

21

10

1st Stage

2nd Stage

3rd Stage

4th Stage

5th Stage

6th Stage

7th Stage

8th Stage

12

21

14

2

12

3

5

5

Numberof data

17

20
8

Bubbles flowed from upstream

Bubbles flowed from downstream

Bubbles were not seen17

9th Stage 10th Stage 11th Stage 12th Stage 13th Stage8

Bubbles rising from the bottom of the river
Bubbles flowed from downstream

12

14

12

With TRWKR
80%

Not enough data

60%

86

84

94

7

75

89

100

100

76

83

92

94

100

95

40%
20%
0%

11
7
7
1st Stage

Number 15
of data

3
3

13

4
7

3

4

14

3rd Stage

4th Stage

5th Stage

6th Stage

7th Stage

8th Stage

34

30

9

9

24

28

19

17

3
3

13

2nd Stage

Oseko Bridge～Minatoshin Bridge
100%

Not enough data
80

92

64

9th Stage 10th Stage 11th Stage 12th Stage 13th Stage
14
20
22
20
23

50
84

64

5

With TRWKR

80%
60%

78

25

Bubbles rising from the bottom of the river
Bubbles flowed from downstream

Asahi Bridge～Matsushige Bridge
100%
Occurrence of bubbles_component ratio (%)

45

12
15

21

Bubbles rising from the bottom of the river

100%

82

24

20%

Numberof dataMatsushige Bridge～Oseko Bridge

With TRWKR

80%

0%

Occurrence of bubbles_component ratio (%)

Bubbles rising from the bottom of the river

Occurrence of bubbles_component ratio (%)

Sanage Bridge～Johoku Bridge

Occurrence of bubbles_component ratio (%)

Occurrence of bubbles_component ratio (%)(Sanage Bridge - Minatoshin Bridge, each section)

5

8

23

31

22

25

Bubbles rising from the bottom of the river

Bubbles flowed from upstream

Bubbles flowed from downstream

Bubbles were not seen

40

42
69

60%

1
1

2

70

With TRWKR

Not enough data

67

60%

100

100

100

100

100

100

40%
20%
0%

No data33
1st Stage

2nd Stage

3rd Stage

4th Stage

5th Stage

6th Stage

7th Stage

8th Stage

3

2

5

2

2

1

0

0

Numberof data

9th Stage 10th Stage 11th Stage 12th Stage 13th Stag
0

0

2

0

Bubbles flowed from upstream
Bubbles were not seen

58
3

40%
4
4

58
20%
1st Stage

Numberof data 45

30

88

81

49

8
5

11

35

40

82

4

42

38
13

2nd Stage 3rd Stage
104

87

100

52

58

56

23
0%

42

55

4th Stage

5th Stage

6th Stage

27

31

15

7th Stage

8th Stage

24

23

12

18

9th Stage 10th Stage 11th Stage 12th Stage 13th Stage
19

42

39

39

■ In which section are there many bubbles
rising from the bottom of the river?
Ratio of “the bubbles rising from the bottomof the river” between Asahi Bridge andMatsushige Bridge is higher than othersections.

35

There are many bubbles rising from the bottom or the river
between Asahi Bridge and Matsushige Bridge

29

80%

With TRWKR
80%

7

9th Stage 10th Stage 11th Stage 12th Stage 13th Stag

３０0

Difference of “bubbles flowed from the bottom of the river”
from upstream to downstream・・・Spring～Early Summer
1st, 3rd, 5th, 7th, 9th, 11th, 13th stages : No rain
Asahi Bridge

90
80

Nishiki Bridge
Habashita Bridge

7060

Kitashimizu Waterfront Park

50
40
30

Naya Bridge

20

10
0
Minatoshin*
Kiraku*Kizaemon*
Oseko
Goryo
Atsuta Memorial
HatayaKameya*Sumiyoshi
Oto
Furuwatari*
Sanno*
Matsushige*
Hioki*
Iwai*
Suzaki*
Shinsuzaki*
Tennozaki
Naya
NishikiTemma*
Sakura*Naka*
Gojo*
Keiun*
KoshioHabashita
Asahi*
Taiko*
Takajo*Sujikai
Horibata*
Nakatsuchido
JohokuKinjo*
Tabata*Kitashimizu
Kurokawa*
Shiga
Sanage*Chigonomiya
KizuneRuriko*Tsujie*Kurokawa No.1*
Meoto
Asahi*
Sakae*

Occurrence of bubbles_component ratio (%)

100＊：10 or less times of investigation

Occurrence of bubbles_component ratio (%)＝Days when bubbles flow from the bottom of the river／All investigation Days×100
There were many “bubbles flowed from the bottom of theriver” near Kitashimizu Bridge, Habashita Bridge, Nishiki
Bridge, and Naya Bridge in “Spring ～ Early Summer” season.

３１

5.SmellOccurrence of Smell

Reclaimed wastewater

1st～6th stage ：TRWKRNo rain on the day and the previous day
7th～13th stage：No TRWKRNo rain on the day and the previous day

Horikawa-Ugan Rainwater Reservoir
TRWKR

Advanced treatment at Meijo Wastewater Treatment Center

Sanage Bridge - Sakae Bridge

Terrible smell

Bad smell

Smell

Slight smell

No smell100%
Ratio of Occurrence of smell and component

90%
80%

60%

Not enough data

50

70%
78

80
94

50%

■ Change of Smell

60
74

75
100

78

78

100

87
100

40%
30%
20%
10%
0%

50
13

13

40

13

25

13
3
7
3
1st Stage 2nd Stage 3rd Stage 4th Stage 5th Stage 6th Stage 7th Stage 8th Stage 9th Stage

22

22

10th
Stage

11th stage

13

9

Number of data 23

40

15

2

8

3
Terrible smell

Sanage Bridge - Minato shin Bridge

5

8

Bad smell

5
Smell

9

Slight smell

9

12th
Stage

8

13th
Stage

8

In the 12th and 13th stages theaverage temperature was high and it
made sludge worse and Horikawa
River smell bad.

No smellRatio of Occurrence of smell and component

100%
90%
80%

24
39

48

37

42

70%

61

50%

20%
10%

32

（see 12th report）

34
32

28

36

30

40%
30%

improved by the new measures
44
50
conducted
by the57city government
56
60

68

60%

→“Autumn – Winter” is better than“Spring - Summer”
It got better during TRWKR. Althoughsmell worsened in the 7th stage, justafter the termination of TRWKR, it ischanging better after that. We thinkthat measures conducted by the city
government worked.

28

37
15
12
6

20
10

8
25

31

11

11

24

7
9

5

31

212

176

52

111

63

11
11

84

27

15

6
9
4
8
7
4
3
3
0%
1st Stage 2nd Stage 3rd Stage 4th Stage 5th Stage 6th Stage 7th Stage 8th Stage 9th Stage
Number of data

109

20
27

67

75

8
4
4
10th
Stage

113

15
15
11

7
4
2
11th stage

110

12
3
12th
Stage

98

10
13th
Stage

91

３２

1st～6th stage ：TRWKRNo rain on the day and the previous day
7th～13th stage：No TRWKRNo rain on the day and the previous day

Occurrence of Smell
Ratio of Occurrence of smell and component (%)
TRWKR

TRWKR
Matsushige Bridge - Ooseko Bridge
100%

Bad smell

31

80%

43

52

59
60%

Terrible smell

No smell

17
15

29
20%

13
7

3
9

7

15

11

9

11

32

13

21

4

10

17
23

9
21

24
3

65

29

23

5

10

9

9
17

29

39
62

23

18

0%

Slight smell

33
61

64
78

80

40%

Numberof data

Smell

Not enough data

19

17

31

11

Number1st Stage 2nd Stage3rd Stage 4th Stage 5th Stage 6th Stage 7th Stage 8th Stage 9th Stage 10th2935
915 35 3325
30 21 24 Stageof data

20

4
11th

26
stage

19

17

12th
Stage

35
Stage

26

13th

Not enough data

Not enough data
Not enough data

No data
Numberof data

Numberof data■ Places where smell often→The ratio of “smell” – “terribly smell” ishigher between Asahi Bridge to Ooseko
Bridge.

Numberof data３３

Relation between Bubbles and Smell

13th stage

No rain on the day
and the previous day

Both bubbles and smell are related to sludge,
water level, speed of flow, and weather like
temperature, direction of wind.

Horikawa River smells
more frequently whenbubbles are seen.

■ Relation between Bubbles and Smell
When bubbles appere Horikawa River smells
1.5 times more often than when not.
Bubbles are coming up from the bottom
when water level is low.
Lowering water level and increasing the
speed of flow disturbs sludge, whichmakes bubbles coming up from the bottom.
In the previous reports, we found out that bubbles from the riverbed are also
influenced by the tide which changes water level and the speed of flow.
near Naya Bridge 23th July 2013

● Lowering water level decreases water pressure.
● Increasing the speed of flow disturbs sludge.

３４

Change of the smell along the river・・・Spring - Summer Ratio of the smell ; bad-terrible（％）＝ number of days reported bad-terrible／number of all days reported ×100

Ratio of the smell ; bad-terrible
1st・３rd・５th・７th・９th・１１th・１３th stages

No rain both TRWKR and no TRWKR＊：under 10 reports

Hataya Bridge

Nishiki Bridge

Kameya Bridge

Naya Bridge

Habashita Bridge

In the middle stream
The places reported smelly arealmost the same places reported
bubbles from the bottom.

Kitashimizu
Shinsui Hiroba■ Report by the group of Nagoya Institute ofTechnology 【May 26th 2009】

Kameya Bridge
when it smelled like rotten eggs

Naka Bridge
sludgeRiver water was transparent when waterlevel was high.
But water turned black
suddenly and SS rose up quickly when waterlevel started to get down.
Black water cameup from the sludge and the smell changed
terrible.

３５

Kind of Smell

1st～6th stage ：TRWKRNo rain on the day and the previous day
7th～13th stage：No TRWKRNo rain on the day and the previous day

Reclaimed wastewater
Horikawa-Ugan Rainwater Reservoir

TRWKR

Advanced treatment at Meijo Wastewater Treatment Center

Smell of

Sanage Bridge - Sakae Bridge

Ditch

SludgeRotten Egg

Pulp

Sea

othersRatio of kind of Smell and component

100%
90%

20

Not enough data

33

80%

50

70%

50

50

20

60%

50%

100

20

100

100

■ Occurrence ofSmell wastewater
Reclaimed

100

40%
50

20%
10%

→ Smell of “ditch” and “sludge”
is 80% of all reports.

67

30%

50

50

40

■ Change of the kind of Smell

No data0%
1st Stage 2nd Stage 3rd Stage 4th Stage 5th Stage 6th Stage 7th Stage 8th Stage 9th Stage 10th Stage11th stage12th Stage13th Stage
2
2
3
1
2
1
5
1
2
0
0
0
Number of data

Smell of

Sanage Bridge - Minato shin Bridge

Ratio of kind of Smell and component

100%

5

14

90%

3
2

80%
16

70%

3
32

3
3

15
5
5
5

4
4
9

Ditch
1

5

30

27

9
7
4

1

Rotten Egg
10
7

6
4

Pulp
2

13

Sea
16

4

37

others
8
4

2

8
6

2

8

Smell of ditch and sludge is 80%

15

60%

Sludge→After TRWKR, smell of “ditch”
decreased and smell of sludge
increased.
But this turned opposite in the
12th and 13th stage.

40

52

42

24
35

34

50%
40%
65

30%

54

55
42

20%
10%

smell of ditch decreased andsmell of sludge increased.

65
55

43

36

41

42

62
49

No data0%
1st Stage 2nd Stage 3rd Stage 4th Stage 5th Stage 6th Stage 7th Stage 8th Stage 9th Stage 10th Stage 11th stage12th Stage13th Stage
111
75
20
29
44
52
49
50
111
20
66
63
Number of data・ not showing data of 0 %３６

6.Colors
Photos taken at Nishiki Bridge⑤green⑦yellow gray⑧light grayyellow green⑨gray yellow
green⑩gray green⑪dark grayMay 11, 2013 red tide

３７

Component ratio of colors
Sanage Bridge～Minatoshin Bridge

2nd ～6th stage：With TRWKRNo rain on the day and the previous day
7th ～13th stage：With TRWKRNo rain on the day and the previous day

The “colors” has been on the survey list since the 2nd stage

High frequency：⑧light gray yellow green, ⑨gray yellow green and ⑩gray green①colorless⑥gray⑪dark gray②milk white⑦yellow gray⑫light yellow
gray③yellow⑧light grayyellow green⑬yellow brown④yellowgreen⑨gray yellow
green⑭brown⑤green⑩gray green⑮green brown

Number of data
213
176
52
111
63
85
67
76
113
113
98
91

In the 13th stage, darker
colors such as ⑪dark
gray and ⑮green brownincreased.

■What colors were seen frequently?
→From the 1st stage to the 13th stage, ⑧light gray yellow green, ⑨gray yellow green and ⑩gray
green appeared frequently.
In the13th stage, frequency of darker colors such as ⑪dark gray and ⑮green brown increased.

３８Colors mainly seen when impression of Water clearness
2 ～6 stage：With TRWKR
was “slightly dirty” or “dirty”
No rain on the dayndComponent ratio of colors

Sanage Bridge～Minatoshin Bridgethand the previous day
7th～13th stage：With TRWKRNo rain on the day
and the previous day

With TRWKR■ What colors were seen when
the impression about clearness
was “slightly dirty” or “dirty”?
→ Colors seen frequently were
⑤green, ⑦yellow gray, ⑧lightgray yellow green, ⑨grayyellow green, ⑩gray green and⑪dark gray.
When the color was ⑧lightgray yellow green, sometimes it
smelled like a rotten egg. It
may occur with blue tide.
⑪dark gray appeared whensludge raised up.
This color was seen in thestages from spring to earlysummer. In the 13th stage, ⑪dark gray appeared frequently.
The existence of sludge might
affect the impression of“slightly dirty” or “dirty”.

Colors that appeared frequently were ⑤green, ⑦yellow
gray, ⑧light gray yellow green, ⑨gray yellow green, ⑩gray green and ⑪dark gray.

⑪dark gray increased.
It is considered that existence of sludge affected
the impression of “slightly dirty” or “dirty”.

３９

What colors were mainly seen
when impression of cleanness was “slightly dirty” or “dirty” ?

No rain on the day andthe previous day

Component ratio of colors(Sanage Bridge - Minatoshin Bridge)
Comparison among 9th Stage, 11th Stage and 13th StageOn the 13th stage, darker colors like ⑪Dark
gray and ⑮Green ash were increased.
■ What colors were mainly seen when impression of cleanness was “slightly dirty” or “dirty” ?
(Comparison among 9th stage, 11th stage and 13th stage）→ They were ⑦Yellowish gray, ⑧Pale yellow-green ash, ⑨Yellow-green ash, ⑩Greenish ash,
⑪Dark gray and ⑮Green ash.
On the 13th stage, darker colors like ⑪Dark gray and ⑮Green ash were increased.

４０

（Reference) Source：The report of Horikawa Sen-nin Chosatai 12th conference

Fresh

Fresh

Case of 13th StageIn the 13th stage, high temperatures, little rain and the longhours of sunshine caused red tide (at Nagoya port). Red tide
could appear greenish ash color in certain place.

It looks

It looks

Greenish ash.

dark gray.

Fresh water
Salt water

Red tide

Sludge was raised up
The ebb tide period(around noon) in thespring tide, the sludge gets raised up andHorikawa may be colored dark gray.

４１

From 2nd to 6th stage :With TRWKRNo rain on the day and the previous day
From 2nd to 6th stage :With TRWKRNo rain on the day and the previous day

7.Litters
Frequency of finding Litters(From 2nd～13th stage, all section)■Litters component
Plastic wastes(PE shopping bag, PP bag, foam bowl, foam tray, PET bottle, etc.), can, glass
bottle, cigarette(wrapping, butt)“PE shopping bag 1.8” means that PE
shopping bag was found 1.8 times in 10
investigations. （or 18 times in 100
investigations)

Litters ：in decreasing trend
Frequency of finding litters ( / 10 surveys )= number of surveys in which litters was found/number of surveys ×10＊Frequency of finding litters is not same as the number of litters.
If litter is found one or more times in each survey, it counts just one.

Total of 18 itemsof litters in eachstage.

■What trend frequency of finding litters was?
Freqency of finding litters was in decreasing trend. Change of social environment, such as more active
cleaning, charging of shopping bag fee and etc. may influence.
The most frequent littered item was cigarette butt.

４２

Litters on Riverside Ways
（2nd～13th stage，each section）

From 2nd to 6th stage :With TRWKRNo rain on the day and the previous day
From 7th to 13th stage :No TRWKRNo rain on the day and the previous day■Litters component
Plastic wastes(PE shoppingbag, PP bag, foam bowl, foam
tray, PET bottle, etc.), can,glass bottle,
cigarette(wrapping, butt)

With TRWKR

Rate of plastics and cigarette are highRate of plastics is decreasing
Component ratio (%)＝the number of sighting each kind of litter／ the number of sighting all kind of litter ×１００
Litter does not include leaves, branches and grass.
The number of sighting is not the number of litters. We count one, even if one litter is sighted in the investigation.
■What kind of litters on the riverside ways was sighted frequently？
→The rate of plastics and cigarette are high.
The rate of plastics is decreasing.

４３

From 1st to 6th stage :With TRWKRNo rain on the day and the previous day

Number of litters per one survey

Change in Floating Litters■Litters component
Plastic wastes(PE shopping bag, PP bag, foam bowl, foam tray,
PET bottle, etc.), can, glass bottle, cigarette(wrapping, butt)

The sum of eachstage, the number oflitters per one survey

5[data number of investigation]
1st stage ：145
2nd stage：255
3rd stage：191
4th stage：54
5th stage：119
6th stage：66
7th stage：90
8th stage：75
9th stage：81
10th stage：122
11th stage：122
12th stage：106
13th stage：99

Total of All section
4

Rate of plastics
Is high

3.0

3From 7th to 13th stage :No TRWKRNo rain on the day and the previous day

2.3
2.2

2
1.4

1st stage
3rd stage
5th stage
7th stage
9th stage
11th stage
13th stage

2nd stage
4th stage
6th stage
8th stage
10th stage
12th stage

Cleanup
VesselFloating litters are not decreasing.

1
0.4

0.2

0.1

total

plastic

can

0

0

0
bottle

0.5

0.2

0.3

paper

cigarette

Kind of litters
Note: the number of litters per one survey= the number of each litters found in all surveys/
the number of surveys*the number of litters is the number of litters found through all surveys“if some kind of litters was found “countless(=***)”in some survey, it counts”10”, themaximum number in one survey substituted for the number of “countless”■What trend the floating litters goes?
→ The litters on the riverside ways are decreasing. But the floating litters are not decreasing.
Cleanup Vessel run regularly, but the floating litters might come and go with the high and low tide inHorikawa liver for many hours. The rate of plastics is high.

４４Kind of floating Litters

With TRWKR■Litters component
Plastic wastes(PE shopping bag, PP bag, foam bowl, foam tray, PET bottle, etc.),can, glass bottle, cigarette(wrapping, butt)

From 1st to 6th stage :With TRWKRNo rain on the day and the previous day
From 7th to 13th stage :No TRWKRNo rain on the day and the previous day

Rate of plastics
is high50~80%( ) the numberof the data

Rate of litters (%)＝the number of each kind of litters／ the number of all kind of litters ×１００
the number does not include leaves, branches and grass*the number of litters is the number of litters found through all surveys“if some kind of litters were found “countless(=***)”in some survey,
it counts”10”, the maximum number in one survey substituted for the number of “countless”■What kind of floating litters were found flequently？
→ The rate of plastics is high, 50~80%

４５8. About winds

Direction of windWind for upstream
For upstream

For upstream 17%

100

100

80

60

60

60

40

40

40

20

None wind

56%

Wind for side

8%

From side

80

50%

For
downstream

Koshio Bridge
100

36%

1st～13st stage
the number of the data 68

Fordownstream

Winds for upstream and downstream
are more frequent than for side

12%

13% For downstream

For upstream
100
80
60
40
20
0

20

35%

1st～13st stage
the number of the data 140

Oto Bridge

40

19%

26%

32%

For upstream

10%

None wind

None wind0

Nishiki Bridge

600From side

1st～13st stage
the number of the data 60

Fordownstream

From side

100

33%

10%

80
60

40
20

None wind

12%

11%

44%

29%

20

None wind010%

1st～13st stage
the number of the data 53

For upstream

From side

100

80

0

19%

For upstream

28%

80

20

From side

Johoku Bridge

Kitashimizu Bridge

Meoto Bridge

From side

None wind

0

30%

4%

1st～13st stage
the number of the data 217

Fordownstream

1st～13st stage
the number of the data 120

56%

For
downstream

Wind for downstream■Direction of wind
We organized the data through all
surveys(1st stage ~13th stage).
The winds for upstream anddownstream are more frequent than
the winds for side.
The rate of winds for upstream anddownstream is 80% at Nishiki Bridge.

４６9.Change of Horikawa River
Impression of the Water Quality(annual change)

From April 2007 to March 2013
No rain on the day and the previous day

The percentage of “clean” “a little clean” and “ordinary”■ How did the impression of the Water
Quality change throughout the year?

Quality

The upstream
from Sanage Bridge

Over 50% through the year

In the upstream section from Sanage
Bridge, the percentage of people who
answered between “clean” and “ordinary”
was over 50% through the year.
In the downstream from Sanage Bridge, thepercentage of “clean” “a little clean”and“ordinary” was over 50% in November.
Impression of the Water Quality was bad
especially during early summer and early
autumn. (the percentage of people who
answered between “clean” and “ordinary”
was under 20%)

Quality

The downstream
from Sanage Bridge

Impression of the Water Pollution
is bad especiallyduring early summer and early autumn.

Over 50% in November.

＊”clean”, “a little clean” and ”ordinary” arecategorized as the acceptable range forcitizens.
and we categorized the evaluation of lessthan 50% as bad, and categorized theevaluation of less than 20% as especially
bad.

４７

Impression of the Water Quality(annual change)
Between Asahi Bridge and Kameya Bridge

From April 2007 to March 2013
No rain on the day and the previous day

The percentage of “clean” “a little clean” and “ordinary”

Quality■ How did the impression of the Water
Quality change throughout the year?
Impression of the Water Quality is bad through the year.
Less than 50%.

Quality

Impression is bad especiallyat the beginning of springand during spring and early autumn.

The percentage of people who answered
between “clean” and “ordinary” between
Asahi Bridge and Matsushige Bridge wasunder 50%.
Impression of the Water Pollution was bad
through the year. It was bad especiallyduring early spring and early autumn. (thepercentage of “clean” “a little clean” and“ordinary” was under 20%)
The percentage of people who answered
between “clean” and “ordinary” between
Matsushige Bridge and Kameya Bridge wasover 50% between December and February.
Impression of the Water Quality was bad
especially during early spring and summer.

Over 50%
between December and February.
Impression is bad
during spring and summer.
＊”clean”, “a little clean” and ”ordinary” arecategorized as the acceptable range forcitizens.
and we categorized the evaluation of lessthan 50% as bad, and categorized theevaluation of less than 20% as especially
bad.

４８

Evaluation of impression of the Water Quality(annual change)
The upstream
from Sanage Bridge

Not enough data

From April 2007 to March 2013
No rain on the day and the previous day

litter■ How did the impression of the Water
Quality change throughout the year?

The downstream section
from Sanage Bridge

There was more "smell"from April to October.

There were the most evaluations of"color" through the year in thedownstream from Sanage Bridge,
it was between 50% and 60% from April
to December, it was between 70% and
80% from January to March.
The evaluation of litter increased from
April to December.
The evaluation of smell exceeded 5%
from March to October, and it increases
to 10%-20% from July to August.
It is thought that weather condition , tidelevel fluctuation and sludge at the riverbottom are related to it.
litterThere was more “litter“
from April to December.

４９

Evaluation of impression of the Water Quality(annual change)
Between Asahi Bridge and Kameya Bridge
From April 2007 to March 2013
No rain on the day and the previous day

litter■ How did the impression of the Water
Quality change throughout the year?

There was more “litter“
from April to December.

There was more "smell"from April to October.

“There was more "color" throughout the year.

There were the most evaluations of"color" through the year between Asahi
Bridge and Matsushige Bridge, it was
between 50% and 60% from April to
December, it was between 70% and
80% from January to March.
The evaluation of “litter” decreasedslightly from April to December.
The evaluation of “smell” increased
over 10% from April to May and from
July to August.
It is thought that weather condition ,tide level fluctuation and sludge at theriver bottom are related to it.

litterThere was more "smell"from June to August.

“There was more "color" throughout the year.

５０10.Change of Horikawa by tidal cycle
Comparison of spring tide with neap tide
Section from Sanage Bridge to the mouth
is influenced by the tide

Tide level on the winter solstice Dec. 2012spring tide
neap tide

neap tideebb tide
the
月
moon

the
地球

high
tide
gravitation

high
tide

earth

Dec. 2012

the winter solstice

Tide level on the summer solstice Jun. 2013
waning moon

ebb tide

spring tide

spring tide
middle tide
26
27
28

new moon

29
30

the
sun
太陽

1
spring tide 2
3

gravitation

25

24 23 22 21

neap tide

17 spring tide

the
地球
earth

4
neap tide
middle tide 5 6
10
7 8 9

spring equinox

the earthsummer solstice

the sunneap tide

20 middle tide
19
18
16
15
14

full moon

13
12
11 middle tide

Jun. 2013

the summer solsticeSource：statistical information of meteorology by the Meteorological Agency

Change of impression of clearness relates to water quality of Horikawa. We
haveorganized it by comparing of spring tide with neap tide.
waxing moonConsequently, it turned out that impression of clearness was especiallyestimated by color, smell and garbage from Asahi Bridge to Kameya Bridge at
winter solsticespring tide in spring or early summer(1st,3rd,5th,7th,9th,11th stage).
Particularly, it turned out that smell of sludge was greater at downstream from
Asahi Bridge. From the result, it is supposed that impression of clearness in thisarea is infulenced by sludge heaping on the riverbed.

autumn equinox

５１

Impression of clearness Spring tide/Neap tide by month
Percentage of “Dirty” and “Slight dirty”

Apr. 2007（Start of 1st Stage）- Mar. 2013
No rain on the day and theprevious day

At spring tideandImpression of clearness from spring to early autumn is especially bad

we extracted andorganized data at springtide and neap tide, fromthe data of between
April 2007 and March2013.
How is impression ofclearness at springtide and neap tide?

data

At neap tide

There is little difference in the change of impression ofclearness between spring tide and neap tide.

andImpression of clearness from spring to early autumn is especially bad

It is especially badfrom spring to early
autumn at both springtide and neap tide.
There is little
difference betweenchange of impressionof clearness at springtide and neap tide.

data

５２

Impression of clearness from spring to early summer Spring tide/Neap tide
Percentage of “Dirty” and “Slight dirty”
1st,3rd,5th,7th,9th,11th Stage
Apr. – Jun.

1st,3rd,5th Stage： With TRWKR
7th,9th,11th Stage： Without TRWKRNo rain on the day and the previous day

Impression from Matsushige Bridge to Kameya Bridgeis the worst
andHow is impression of clearness at
spring tide and neap tide fromspring to early summer?

data
1st,3rd,5th,7th,9th,11th Stage
Apr. – Jun.

andImpression from Sanage Bridge to Kameya Bridge is bad

data

Impression of clearness at springtide becomes worse fromupstream of Sanage Bridge todownstream of Kameya Bridge.
Especially, impression from
Matsushige Bridge to Kameya
Bridge is the worst, percentage
of “Dirty” and “Slight dirty” is up
to 96％.
Impression of clearness at neap
tide from Sanage Bridge toKameya Bridge is bad,percentage of “Dirty” and “Slightdirty” is around 80％.

５３

Impression of clearness from autumn to early winter Spring tide/Neap tide
Percentage of “Dirty” and “Slight dirty”
2nd,4th,6th,8th,10th Stage
Sep. – Dec.

Percentage of “Dirty” and “Slight dirty” is lessthan that of period from spring to early summer

2nd,4th,6th Stage： With TRWKR
8th,10th,12th Stage： Without TRWKRNo rain on the day and the previous day

How is impression of clearness at
spring tide and neap tide fromautumn to early winter?
About impression of clearness at
spring tide, percentage of “Dirty”
and “Slight dirty” is around 40%60% as little as that from spring toearly summer.
Impression from Matsushige Bridgeto Kameya Bridge is 66% the worst.

data
2nd,4th,6th,8th,10th Stage
Sep. – Dec.

Percentage of “Dirty” and “Slight dirty” is lessthan that of period from spring to early summer

data

Became worse

About impression of clearness atneap tide, that from Johoku Bridge
to Asahi Bridge is bad, percentage
of “Dirty” and “Slight dirty” isaround 80％. Percentage of “Dirty”
and “Slight dirty” is around 30%60% in the other area. It is lessthan that from spring to earlysummer.

５４

composition ratio of the assessment of the impression（％）

Evaluation of the impression of water quality
from spring to early summer in spring and neap tide
The 1st・3rd・5th・7th・9th・11th stage
from April to June

Spring tide from spring to early summer①color②smell

100%
90%
80%
70%
60%

③clearness④garbagelitter4%⑥the look of creatures

4%
2% Increase
18%
Increase
9%

19%
28%
13%
6%

⑤bubbles4%
12%

The １st,３rd,５th stage ： With TRWKR
the ７th,９th,11th stage： No TRWKRNo rain on the day and the previous day■ How is the impression of thewater quality from spring to earlysummer in spring and neap tide?

⑦others

3%
12%

14%
7%

18%

→Composition ratio of theimpression is different from the
upstream and downstream part ofAsahi Bridge in both spring andneap tide.

6%

16%

50%
40%
30%
20%
10%
0%

decrease

62%

61%

51%

Composition ratio of the impression is different in
upstream and downstream part of Asahi Bridge.

Oseko Bridge～
theKameya Bridge
number of16
data
samplescompisiton ratio of the assessment of the impression
（％）

52%

79%

Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge
J
25

55

14

Neap tide from spring to early summer①color②smell③clearness④garbagelitter⑤bubbles34
The 1st・3rd・5th・7th・9th・11th stage
from April to June

⑥the look of creatures

100%
90%

25%

80%

18%
6%

8%

70%

2%

40%
20%
10%

18%
decrease

100%
67%

30%

18%

⑦others5%

decrease

60%
50%

Zyohoku
Bridge～J
Sanage Bridge

74%

9%

37%
5%
5%

The evaluation of the impressionof water quality in spring tideshows, between Asahi Bridge andKameya Bridge, the rate of“color” is smaller and rates of“smell” and “litter” are larger
than the upstream.
The evaluation of the impressionof water quality shows, between
Asahi Bridge and Kameya Bridge,
the rate of “color” is bigger andrates of “smell” and “clearness”
are smaller than that of the
upstream.

Increase

55%

48%

Composition ratio of the impression is different fromupstream and downstream part of Asahi Bridge.

0%

Oseko Bridge～
theKameya Bridge
number of
4 ＊data
samples

Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge
J
12

50

11

J
Zyohoku
Bridge～Sanage Bridge
19＊not enough data.

５５

Smell from spring to early summerin spring and neap tide

The １st・３rd・５th stage ： With TRWKR
the ７th・９th・11th stage： No TRWKRNo rain on the day and the previous day

Spring tide from spring to early summer The 1st・3rd・5th・7th・9th・11th stage
from April to Juneditch smell

smell like rotten eggs

100%

5

14

90%

7

80%
70%

30%
20%
10%

3
3

10
20

41

others7

1038

decrease
49
46
43
Composition ratio of the impression is different fromupstream and downstream part of Asahi Bridge.

0%
theOseko Bridge～
number of Kameya Bridge
data
samples
14

Meijo STP

40%

3
2

smell of ocean

36

60%
50%

smell of pulp

Increase
54

Nagoya Port

composition ratio of the type of smell(%)

sludge smell

60

Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge
J
13
10
59

49

J
Zyohoku
Bridge～Sanage Bridge
29

The 1st・3rd・5th・7th・9th・11th stage
from April to June

Neap tide from spring to early summer
composition ratio of the type of smell(%)

sludge smell

ditch smell

smell like rotten eggs

100%
90%
80%

10

33

70%
60%

86

50%
40%
30%

67

Rates of“ditch smell”
and “sludge 22
smell” arehigh in thatorder, and therate of “ditch
smell” isaccounts for 64
over 60%.

smell of pulp22smell of ocean

others

22

8
8
8

78

76

■ Which type of smell is it from spring
to early summer in spring and neap
tide?
→Between Asahi Bridge and Kameya
Bridge, the rate of “sludge smell” islarger and the rate of “ditch smell” issmaller than the upstream.
It is considered the evaluation ofwater quality is influenced by “sludge
smell”.
Composition ratio of the impression isdifferent in the upstream anddownstream part of Asahi Bridge.

Between Asahi Bridge andMatsushige Bridge in the neap tide,
rates of “ditch smell” and “sludge smell”
are high in that order, and the rate of“ditch smell” is accounts for over 60%.

In spring tide, rates of “ditch smell”
and “smell like rotten eggs” aresmaller and the rate of “sludge
smell” is larger than that in neap tide.

20%
10%

14

0%

the
number ofsamplesdata

Oseko Bridge～
Kameya Bridge
3 ＊Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge
J
7 ＊
41
9 ＊

Zyohoku
Bridge～J
Sanage Bridge ＊Not enough data.
11

５６

Evaluation of the impression of water quality
from autumn to early winter in spring and neap tide
The 2nd・4th・6th・8th・10th・12th stage
from September to December②smell③clearness④garbagelitter⑤bubbles

100%
80%

25%

60%

30%
20%
10%

Increase

18%

38%
decrease

27%

6%

58%

50%

62%

50%

Composition ratio of the impression is different fromupstream and downstream part of Asahi Bridge.

Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
J
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge12

5%41%

The rate of “color” is the highest
and accounts for 41% to 62%.

0%

the Oseko Bridge～
number ofKameya Bridge
12
data
samplescomposition ratio of the assessment of the impression
（％）

17%

8%
Nagoya Port

40%

25%

⑦others

9%

42%

70%
50%

2%

17%

90%

⑥the look of creatures

Meijo STP

composition ratio of the assessment of theimpression（％）

Spring tide from autumn to early winter①colorJ
Zyohoku
Bridge～Sanage Bridge

8＊

52

22

The 2nd・4th・6th・8th・10th・12th stage
from September to December

Neap tide from autumn to early winter①color②smell③clearness④garbagelitter⑤bubbles⑥the look of creatures

100%

Increase

90%
80%
70%
60%

42%

15%

3%
38%

8%

40%

decrease

30%
10%Increase

25%

67%

50%

20%

⑦others

8%
24%

73%

The ２nd・４th・６th stage ： With TRWKR
The ８th・10th・12th stage： No TRWKRNo rain on the day and the previous day

75%■ How is the impression of the water
quality from autumn to early winterin spring and neap tide?
→ According to the evaluation of theimpression of water quality in springtide, the rate of “color” is the highest
in the entire interval and accounts for
41% to 62%.
Between Asahi Bridge and Kameya
Bridge, the rate of “clearness” issmaller and the rate of “litter”(17% to 25%) is larger than upstream.
Composition ratio of the impression isdifferent from upstream anddownstream of Asahi Bridge.
According to the evaluation of theimpression of water quality in neap tide,
between Matsushige Bridge andKameya Bridge, the rate of “color” issmaller and rates of “litter” and“clearness” are larger than upstream.
Especially the rate of “litter” ishigh(42%). Composition ratio of theimpression is different in upstream anddownstream of Matsushige Bridge.

8%

50%
33%

31%

Composition ratio of the impression is different fromupstream and downstream part of Matsushige Bridge.

0%

the Oseko Bridge～
number ofKameya Bridge
3 ＊samplesdata

Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge
J
12

34

8

＊

Zyohoku
Bridge～J
Sanage Bridge
13＊Not enough data

５７

Smell from autumn to early winterin spring and neap tide
Spring tide from autumn to early wintercomposition ratio of the type of smell(%)

sludge smell

100%
90%
80%
70%

ditch smell

smell like rotten eggs

60%
40%
30%

The 2nd・4th・6th・8th・10th・12th stage
from September to December

smell of ocean

others

5

6
6
6
13

50%

smell of pulp

The ２nd・４th・６th stage ： With TRWKR
The ８th・10th・12th stage： No TRWKRNo rain on the day and the previous day

100
69

Rates of7
“ditch smell”
and “sludge
24smell” arehigh in thatorder, andthe rate of“ditch smell”
is over 60%.

24

2
50

35

62

50

20%

41

10%

0%
the
number ofsamplesdata

Oseko Bridge～
Kameya Bridge
16

Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
J
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge6 ＊6＊42JZyohoku
Bridge～Sanage Bridge
17

The 2nd・4th・6th・8th・10th・12th stage
from September to December

Neap tide from autumn to early wintercomposition ratio of the type of smell(%)

sludge smell

ditch smell

smell like rotten eggs

100%
90%

25

80%

40

70%
60%

25

50%
40%
30%
20%

50

60

Rates of12
“ditch smell”,“sludge15
smell” and“smell likerotten eggs”
are high inthat order,
and the rate69
of “ditchsmell” isabout 70%.

■ Which type of smell is it fromautumn to early winter in spring andneap tide?

smell of pulp

4smell of ocean

29

others

23
15

29

15

42

47

→Between Asahi Bridge andMatsushige Bridge in spring tide,
rates of “ditch smell” and “sludge
smell” are high in that order, and therate of “ditch smell” is over 60%.
Between Asahi Bridge andMatsushige Bridge in neap tide,
rates of “ditch smell”, “sludge
smell” and “smell like rotten eggs”
are high in that order, and the rate of“ditch smell” is about 70%.
In spring tide, rates of “ditch
smell” and “smell like rotten eggs”
are smaller and the rate of “sludge
smell” is larger than that in neap tide.

10%
0%

the
number ofsamplesdata

Oseko Bridge～
Kameya Bridge
4 ＊Kameya Bridge～ Matsushige Bridge～ Asahi Bridge～
Matsushige Bridge
Asahi Bridge
Zyohoku
Bridge
J
5 ＊
7 ＊
26

J
Zyohoku
Bridge～Sanage Bridge＊Not enough data
13

５８

11. Survey activities spread into Shin-Horikawa
by the Horikawa Sen-nin Chosatai (HSC)
Ｓｈｉｎ－Ｈｏｒｉｋａｗａ
Kinen Bridge

Uzura Zridge

Oi Bridge

Ａｔｓｕｔａ Bridge

Yamazaki RiverＯe RiverKojo Horikawa to Seikatsu wo
Kangaeru kai

Team NTT Smile Nagoya

５９Impression of the Water Pollution in Shin-Horikawa
D irtySlightly dirty

O rdinary

Slightly clean

Clean

100%

Im pression of the W ater
Pollution, com ponent ratio

90%
80%

■ How about the impression of the Water
Pollution？

11

22

70%

67

67

73

60%
50%

Worse in upstream than in downstream

40%
30%

67

20%

33

33

A tsuta Bridge

O i Bridge

Kinen Bridge

99→“dirty”-”slight dirty” around Uzura, ,Kinen
and Oi Bridge in upstream of Shin-Horikawa,and “slight dirty” - “slight clean” around
Atsuta Bridge in downstream.
The impression of the water pollution isworse in upstream than in downstream.

27

10%
0%
Num ber of Date

12

U zura Bridge
11

Transparency in Shin-Horikawa■How about transparency ?

100→Over 70cm(acceptable range for citizens)around Kinen Bridge in upstream of ShinHorikawa and Atsuta Bridge in downstream of
Shin-Horikawa.
However, only 46cm around Oi Bridge.

T ransparency(ｃｍ)

90
80
70
60

Low transparency around Oi Bridge

50
40
30

79

71
45

20
10
0
Num ber of Date

Atsuta Bridge

O iBridge

99Kinen Bridge
10＊We defined ”Clean “-”Ordinary” asacceptable range for citizens,transparency over 70cm in number.

６０

COD in Shin-Horikawa
20■ How much was COD?

18

19

ＣＯＤ(mg/L)

16→Under 20mg/L around Kinen and
Oi Bridge.
This rate is a little high and under
14mg/L around Atsuta Bridge.
It seemed that COD was higher in
upstream than in downstream.

18

14
12

COD of upstream was higher than that of downstream.

14

10
8
6
4
2
0
A tsuta Bridge

O i Bridge

Kinen Bridge

9

9

10

Num ber of Date

Occurrence of bubbles in Shin-Horikawa
B u b b le s flo w e d fro m u p stre am

B u b b le s flo w e d fro m d o w n stre am

B u b b le s w e re n o t se e n

9O ccurrence of bubbles,com ponent ratio100%

B u b b le s risin g fro m th e b o tto m o f th e rive r

90%

There were many bubbles rising fromthe bottom of river

80%
70%

64

60%

89
100

50%

91

40%

■ How do bubbles occur?
→It seemed that bubbles occur
around Uzura, Kinen and Oi
Bridge on Shin-Horikawa
Around Uzura Bridge of upstream
the 91% of bubbles were risingfrom the bottom of river.
There were not bubbles around
Atsuta Bridge of downstream.

30%
20%

36

10%

11

0%
A tsuta Bridge
Num ber of Date9

O i Bridge

Kinen Bridge

U zura Bridge

9

11

10

６１

Occurrence of smell in Shin-Horikawa
T errible sm ell

Sort of terrible sm ell

Sm ellSlight sm ell

N o sm ell

O ccurrence of sm ell, com ponent
ratio

100%
90%

22

80%

46
59

70%
78

60%

34

■ How does smell occur?

50%
40%

27

11

30%

There were a lot of “Terrible
smell” or “smell” aroundUzura, Kinen and Oi Bridge,
upstream of ShinHorikawa.

33

20%

18

33
22

10%

8

9

O i Bridge

Kinen Bridge

U zura Bridge

9

12

11

0%
A tsuta Bridge
Num ber of Date

9

Kind of smell in Shin-Horikawa
Sm ellof D itch
Sm ellof Pulp

Sm ellof Sludge
Sm ellof Sea

K ind of sm ell, com ponenet
ratio

100%
13

90%

Sm ellof Rotten Egg
Sm ellof others

8→The persentage of “Terrible
smell” – “Bad smell” isbetween 27% and 44% at
Uzura, Kinen and Oi Bridge(upstream).
The kinds of smell were“Ditch”, ”Sludge” and“Rotten Egg”.
There were “Slight smell”
and “No smell” around
Atsuta Bridge (downstream).

17

80%
25

70%

17

67

60%
50%

92

40%

There were many kinds ofsmell, “Ditch”-”Sludge” and“Rotten Egg” around Uzura,
Kinen and Oi bridge
upstream on Shin-Horikawa.

66

62

30%
20%

33

10%
0%
A tsuta Bridge
Num ber of Date3

O i Bridge

Kinen Bridge

U zura Bridge

8

12

6

６２

Component ratio of colors in Shin-Horikawa[1]Colorless[8]Pale yellow green ash[12]Pale yellow gray

100%
90%

[2]M ilky w hite
[9]Y ellow green ash[15]G reen brow n

W hat Colors w ere m ainly
seen, com ponent ratio

33

18

8

11

70%

25

60%
50%
40%

46

8

45
56

30%
20%
10%

9

42

11

18

11

11

A tsuta Bridge

O i Bridge

Kinen Bridge

U zura Bridge

9

9

12

11

0%
Num ber of Date

■ What colors sere seen
frequently?

9

17

22

80%

[7]Y ellow ish gray[10]G reenish G ray→Greenish gray, Yellow green ash
and Pale yellow green ash
appeared frequently around Uzura,
Kinen and Oi Bridge in upstreamof Shin-Horikawa. And Milky white
also appeared around Uzura andKinen Bridge. It is assumed to becaused by sulfide.
And Green brown also appeared
Kinen, Oi and Atsuta Bridge.
It is assumed to be caused by thephytoplankton such as the redtide.

The Point of Kinen Bridge

May 28th 2013
Gray green

June 25th 2013
Pale yellow green ash

Photo&report：Team NTT Smile Nagoya

July 30th 2013
Pale yellow green ash

August 28th 2013
Milky white

６３

Review; Current Condition & Pollution Mechanism of Horikawa
Based on 3,083 surveys for 6.5 years by HSC
Bad impression of the waterpollution between Johoku Bridge
and Matsushige Bridge.

How do we evaluate Impressionof the Water Pollution (13th stage)

Floating Scum

Color of water

60%

Clearness 18%
Litter
14%
Smell
7%

Especially between Asahi Bridge and Matsushige Bridge
・Many bubbles from the bottom
・Terrible smell

Bad impression of the water pollution
Many babbles from the bottom
Around the Matsushige
pump station
Minatoshinbashi
BridgeNagoyaport ▼high tide

Terrible smell
Many floating litter

Many floating litter
Oseko
BridgeMatsushige
KameyaBridgeBridgeAsahi
BridgeJohoku Sanage
Bridge Bridge

Shonai River
Motoiru-himon▼low tide
Water level, stream direction, flow ratechanges by tide level.
Difference of tide level reaches 2m & over.
Worsening of color,
deterioration of clearness
Deterioration of smell (Rotten Egg)
Red tideBlue tide

Rising sludge
Deterioration of smell(sludge & ditch smell)

Sedimentationof sludge
Detriorationof color,
clearness,and
smell

Rising of sludge

６４

Exposure of sludge
when tide is low at spring tide.

■ Season of bad impression of the water pollution①High temperature②Large difference of tide level between high and low,
and low tide level on daytime(around midsummer)

Early summer
to early autumn(July to September)■ Why is impression especially between Asahi and Matsushige Bridge worse?
①Rising and exposure of sludge②Run upstream of red tide & blue tide generated downstream by flood tide.
It is assumed that the span between Asahi and Matsushige Bridge is compositely
influenced by the reason above.

Downstream
Growth of plankton Lack of Oxygen at
the bottom
Red tide・Brownsuspended
solidsBlue tide・Getting clouded
・Bubbles from bottom
・Smell of Rotten Egg

Deterioration of color,
clearness and smell(Rotten Egg)

Matsushige – Asahi Bridge

Sedimentation of scum
Lack of Oxygenat the bottom

Sediment is changed into sludge.
Exposure of sludge
on low tide

Rising of sludge byflood tide & falling tide

Deterioration of color, clearness
and smell(sludge & ditch smell)Run upstream of red tide & blue tideby flood tide

６５

12. Living things

The 6th Survey of Living Things in Horikawa, July 6th 2013(Sat.)
Hosted by conference of biodiversity in Horikawa

A lot of members of
HSC attended.

“Carp, current situationof urban river”
June 17th 2013
Reported by
Goyousui-gaien aigokai
Chosatai

６６

Run upstream of brackish water and wide ranging fish
■Young mulet(about 3cm)
at the Nishikibashi Bridge(first day of confirmation）
May 9th 2007
March 22nd 2008
May 3rd 2009
May 25th 2010
April 26th 2011
April 27th 2012
April 29th 2013

■Young dikkop
at the Nishikibashi Bridge(first day of confirmation）
April 22nd 2008
April 22nd 2009
April 25th 2010
April 13th 2011
April 18th 2012
April 16th 2013

Horikawa got in lack of Oxygen by spring tideand heavy rain on June 21st 2013.
Around the Nayabashi Bridge. Reported by secretariat

By the “Chunichi Newspaper”
June 2nd 2013(Sat)At Nishikibashi Bridge
At AM on June 22nd 2013

■Eel
At the Nayabashi Bridge, June 21st 2013
Shooting by the river planning survey groop

６７

Heavy rain & spring tide, July 21st 2013
Horikawa got in lack of Oxygen. At Nayabashi Bridge Reported by secretariat

Water surface

Group of goby

14:06

Group of fish comes close to
the quay, because water flow
may be calm.

14:10

14:10

15:00

14:11

Fish moves intensely andbegins to suffer

Floating garbage was swept
to upstream rapidly.

15:11

Dead fish and dying
fish can be seen.

15:39

Swept garbage was backed todownstream.

15:47

Waving generated byfish can be seen.

A lot of fishes ran into
between quay and bankprotection.

15:59

Around quay of Nayabashi Bridge, June 21st 2013, Reported by secretariat

６８

Horikawa River clarification experiment with water spinach. 2013/6/21-2013/8/30
Ena Agricultural High School & Horikawa Lions Club had joint experiment this year again.

START
6/21

5th Week
7/28

1st Week
6/28

6th Week
8/2

2nd Week
7/5）

7th Week
8/12

3rd Week
7/12

8th Week
8/16

4th Week
7/22

9th Week
8/23

10th Week
8/30

MulletGoby

Northern snakehead

Mosquito fish

Pond slider

Soft-shelled turtle

Spot billed duck

Living things
swarming overfloating water spinach

６９Conclusion of the 3rd Horikawa River general investigation.
On May 18th (neap tide), Color of the water didn’t change when the water bus passed.
On May 25th (Spring tide), Color of the water changed into gray and Bubbles were rolled upnear Shinsuzaki bridge. It is thought to be the causes of sludge rolled up from the water bed.

■ 2013/5/18 Neap tide

During Neap tide … Sludge were not rolled up

Shinsuzaki Bridge

Sumiyoshi Bridge■ 2013/5/25 Spring tide

During Spring tide … Sludge were rolled up

Shinsuzaki Bridge

Sumiyoshi Bridge

７０

Conclusion of the 3rd Horikawa River general investigation 2013/5/18, 5/25
Impression of water clearness
There are no remarkable changes.

■ 2013/5/18 Neap tide

■ 2013/5/25 Spring tide

Water Bus operating

Water Bus operating

７１

Conclusion of the 3rd Horikawa River general investigation 2013/5/18, 5/25
Transparency■ 2013/5/18 Neap tide

■ 2013/5/25 Spring tide

Water Bus operating

Water Bus operating
Transparency became lower→Sludge were coming up

Transparency became lower as time passed during Spring tide. This is because Sludge
were coming up. There were no remarkable changes during Neap tide.

７２

Conclusion of the 3rd Horikawa River general investigation 2013/5/18, 5/25
Smell of water■ 2013/5/18 Neap tide

Water Bus operating■ 2013/5/25 Spring tide

Water Bus operating

Smell of water
become bad

Smell of water became bad as time passed during Spring tide.

７３

14.Progress of Citizen’s Awareness Activities of studies

第５回 堀川生物多様性対策会議
平成２５年２月４日（月）主催：堀川生物多様性対策会議
報告：事務局

堀川１０００人調査隊2010
第１２回調査隊会議
平成２５年２月２３日(土)報告：事務局

中日新聞
平成２５年２月２４日（日） 朝刊より

第１回 中川運河再生プラットフォーム開催
平成２５年２月２６日（火）報告：事務局

伊勢湾流域圏再生フォーラム開催
平成２５年３月２日 （土）報告：事務局

堀川まちづくりの会(仮称） 第３回準備会
平成２５年３月２６日
報告：事務局

堀川まちづくりのこれから
平成２５年５月３０日（木）報告：御用水跡街園愛護会調査隊

７４

Activities of studies

中日新聞
平成２５年６月１２日（水）朝刊より

辻小学校２年生 校外学習
平成２５年６月５日（水）飯田小学校３年生 黒川観察会
平成２５年６月７日（金）主催・協力・報告
黒川ドリーム会、御用水跡街園愛護会調査隊
河川計画課調査隊、事務局
水質調査
御用水跡街園愛護会調査隊
平成２５年２月９日（土）名北小学校３年生 黒川学習会
平成２５年６月１０日（月）笹島小学校５年生 黒川観察会
平成２５年６月２４日（水）大杉小学校２年生 黒川観察会
平成２５年６月１３日（木）八熊小学校３年生 黒川体験学習
平成２５年６月２８日（金）

名北小学校３年生 黒川観察会
平成２５年６月１７日（月）支援センタ－「なないろ」の皆さん
平成２５年７月１１日（木）生き物調査と清掃活動

堀川生き物調査
平成２５年７月６日（土）７５Activities of “Free Survey Groups” & “Cheering Groups”

堀川ギャラリー写真展 三味線の生演奏
平成２５年３月７日（木）報告：御用水跡街園愛護会調査隊

清掃活動
平成２５年２月１６日（土）御用水跡街園愛護会調査隊

堀川の野草料理教室
生活支援センタ－「なないろ」 にて開催
平成２５年３月１８日（月）報告：御用水跡街園愛護会調査隊

朝日新聞 平成２５年４月１９日（金） 夕刊より
清掃活動・駅ちかウォーキング写真展示
平成２５年３月２４日（日）御用水跡街園愛護会調査隊

中日新聞
平成２５年２月２８日（木） 朝刊より

名古屋友禅工房見学
平成２５年３月３０日(土）
報告：御用水跡街園
愛護会調査隊

定点調査・清掃活動 中日本建設コンサルタント㈱かわせみ調査隊

魚捕り 平成２５年４月１日（月）報告：御用水跡街園愛護会調査隊

第７２回目の水質調査活動を実施
地球倶楽部調査隊
平成２５年４月１７日（水）報告：事務局

７６

Activities of “Free Survey Groups” & “Cheering Groups”
春の堀川一斉大そうじ
平成２５年４月２０日（土）主催：クリーン堀川 報告：事務局

納屋橋１００年 歴史紐解きマップ
マップ作成：「納屋橋１００年・歴史紐解
きワークショップ」参加者の皆さん、名古屋市緑政土木局河川計画課

中日新聞 平成２５年５月８日（水）朝刊より

中日新聞
平成２５年
５月１７日（金）夕刊より

なごや北ホームニュース
平成２５年５月１１日（土）より

鯱城・堀川と生活を考える会
平成２４年度の活動報告書

７７

Activities of “Free Survey Groups” & “Cheering Groups”

北清水親水広場付近の清掃活動
黒川ドリーム会平成２５年６月１日（土）報告：御用水跡街園愛護会調査隊山田隊長

中日新聞 平成２５年６月２日（月） 朝刊より

「御用水跡街園を花で飾ろう」運動
生活支援センタ－「なないろ」
平成２５年６月１１日（火）報告：御用水跡街園愛護会調査隊

朝日新聞 平成２５年６月１４日（金）

地域情報誌「北区プリモ」
黒川ドリーム会 特集
平成２５年７月２７日（土）堀川写真コンテスト
平成２５年５月２８日（火）～６月１６日（日）開催：名古屋堀川ライオンズクラブ

中日新聞
平成２５年７月４日（木）
朝刊より

７８

Activities of “Free Survey Groups” & “Cheering Groups” 活動報告
「上流は下流を思い、下流は上流に感謝する」
水源の里を守ろう 木曽川流域みん・みんの会
活動レポート：環境ボランティアサークル「亀の子隊」

ヘドロ臭が激減し、ハゼが戻る！！レポート
自由研究隊 イワシ調査隊

クリーン堀川
会報誌（第１６号
２０１３．３発行）
中日新聞
平成２５年
７月１４日（日）朝刊より

名古屋都市センター ニュースレター ２０１３．７
堀川・納屋橋のレポート 掲載
レトロ納屋橋１００年実行委員会の皆さん
納屋橋の欄干を磨き周辺の清掃活動
平成２５年７月１３日（土）伊勢湾流域圏
再生ネットワーク事務局さん
活動レポート鯱城・堀川と生活を考える会・名古屋市高年大学鯱城学園・OBの皆さん
９００人を超える規模で、堀川全域の一斉清掃を実施
平成２５年７月１３日（土）７９Activities of “Free Survey Groups” & “Cheering Groups”
岐阜県恵那農業高校 堀川のヘドロ分析実験を継続中
平成２４年１２月８日（土）～東日本大震災津波被災農地での空芯菜栽培による塩分吸収実験報告

平成２５年１月３０日（木）平成２５年２月２８日（木）平成２５年３月２８日（木）平成２５年４月１８日（木）●水槽での汚泥実験を開始 平成２５年６月２６日（水）汚泥実験 平成２５年７月３０日（火）汚泥実験 ４日目 平成２５年６月３０日（日）平成２５年２月２４日(日）
中日新聞より８０堀川フラワーフェスティバル２０１３
平成２５年５月１０日（金）報告：御用水跡街園愛護会調査隊・事務局

Events

中日新聞
平成２５年５月１１日（土） 朝刊より

朝日新聞 平成２５年５月１１日（土） 朝刊より

堀川友禅流し平成２５年４月６日（土）主催：北区役所・
北区まちづくり推進協議会
報告：御用水跡街園愛護会調査隊・事務局

名古屋堀川ライオンズクラブ
設立１０周年記念事業「堀川狂言会」
平成２５年４月６日（土）中日新聞
平成２５年４月９日(火） 朝刊より

平成２５年５月１２日（日）平成２５年５月１８日（土）８１Events

なごや水フェスタ 平成２５年６月２日（日）開催：名古屋市上下水道局
参加：名古屋市高年大学２７期環境学科調査隊
名古屋グランパス応援隊
名古屋堀川ライオンズクラブ
報告：事務局
春の環境デーなごや２０１３ 堀川体験乗船「身近な自然体験会～船から発見！ 私たちの堀川」開催 ２０１３年６月１日（土）主催：名古屋市環境局
運営協力：名古屋堀川ライオンズクラブ

中日新聞

平成２５年６月３日（月） 朝刊より

日本経済新聞平成２５年２月１８日（月） 朝刊よりなやばし沖縄夜イチ
平成２５年７月２９日（土）報告：御用水跡街園愛護会調査隊

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