The Summary of survey
by Horikawa Sen-nin Chosatai 2010 (HSC).
■ Horikawa Sen-nin Chosatai started accepting participation on
26th March, 2007
Thousands of citizens started survey to verify the effect of the raw water from the Kiso
River (TRWKR)

1. Survey Items
1) Impression,2) Transparency,

3) Color,

4) Bubbles,5) Smell,6) Garbages,

7) Living things …etc.
The Shonai River

2. Survey Period● Motoiri Slicewayst

1 Stage: Apr. – Jun. 2007
2nd Stage: Sep. – Dec. 2007

Sanage Bridge ●Kitashimizu Bridge ●rd3 Stage: Apr. – Jun. 2008※

4th Stage: Sep. – Dec. 2008
5th Stage: Apr. – Jun. 2009
6th Stage Sep. – Dec. 2009

● Nayabashi Bridge
The Shin-Horikawa River

Oto Bridge ●(22nd Apr. 2007 ～ 16th Dec. 2009)

Nakagawa Canal

1,758

The Horikawa River

14,123 Citizens

4. Number of Survey Reports

Injection Point ofTRWKR

Nagoya Castle● Koshio Bridge

3. Number of Participants of HSC
1,762 Groups

The Yada River※：Verifying the effectof TRWKR● Kizaemon Bridge● Minatoshinbashi Bridge

Nagoya Port It was confirmed that there are many changes by the effect ofTRWKR from the Matsushige Bridge to the Sanage Bridge.
○： Improvements were seen.
Method ofEvaluation

Items

MinatoshinOhseko～ Matsushige Asahi
bashi～Johoku
Matsushige ～Asahi～Ohseko
BridgeBridgeBridgeBridgeImprovements
Impression of stage by stage
Clearness
Improvements by
TRWKR

Transparency

Improvements
stage by stage
Improvements by
TRWKR

○

○

○

○

○

○

○
○

Johoku～SanageBridge○○○

Improvements
stage by stage

○

○

○

Improvements by
TRWKR

○○

○

Bubbles

Improvements
stage by stage○SmellImprovements
stage by stage

COD○○ It was understood that water quality from fall to early winter is better
than from spring to early summer.

○1. Water Quality
1) Impression on the 5th stage has been improved 21% on average (10-37%) than it on
the 1st stage.
2) Impression after TRWKR on the 5th stage has been improved 13% on average(11-17%) than before TRWKR.

2. Transparency
1) Transparency on the 5th stage has been improved average 9 cm than it on the 1ststage by TRWKR.
2) Transparency after TRWKR on the 5th stage has been improved average 12 cm
than before TRWKR.

3. COD
3) COD on the 5th stage after TRWKR has been improved 3 mg/l on average(2-4mg/l) than on the 1st stage.
4) COD after TRWKR has been improved 2mg/l on average (2-3mg/l) than before
TRWKR.

4. Bubbles
The rate of no bubble on the 5th stage increased 20% on average (15-25%) than on the
1st stage just after aqueducts.

5. Smell
The rate of smell (“odor” and “little odor”) on the 5th stage increased average 26%(17-34%) than on the 1st stage (just after aqueducts) .

6. Garbage
The garbage in suspended or on the street is generally decreased.

7. Living things
Behavior of living things and their habitats surrounding their growing environment
was changed as follows.
・ There was no waterweed for one year after TRWKR, however many waterweed
was growing until the Sujikai bridge.
・ We could see many young mullets around the Koshio bridge.
… Etc.

■ The water environment has been synergistic improved by therecover of the self-purification capacity.
It is considered the water environment of the Horikawa River for thesethree years has been improved by some synergistic effects.
Their synergistic effects are the social and environmental changes
surround the Horikawa River, improvement of consciousness for theHorikawa River basin, the recover of the self-purification capacity, theimplementation of additional sewer maintenance and not only the directly
effect by TRWKR.
We hope that the water environment for the Horikawa River will be
improved more by the implementation for the cleanup action continuity of
citizen and water purification by TRWKR.