Measures to makeHorikawa River Limpid
Implementation by Nagoya City
Sep. 9th 2017
Greenification & Public Works Bureau
River Planning Division
Waterworks and Sewerage Bureau
Sewerage Planning Division1

Points of the Report
Topics in FY 2017
- Expansion of covering sand section(Habashita Bridge – Nisiki Bridge)- Measures against stenchat Shin-Horikawa River- Construction of simple treatment sophistication
facilities (Meijo Water treatment Center)- Water circulation of Nakagawa Canal2

■Implementation to make Horikawa River Limpid
in Gojo Bridge area
◆Expansion of covering sand section

Nagoya Castle

Before experiments

Habashita Bridge

Scheduled construction section
Lentgh：1,100m
Expansion of covering sand section
from Habashita Bridge to Nishiki Bridge

Clarification experiments section in 2014
（Gojo Bridge～Naka Bridge）
Length：300m

Keiun Bridge
Gojo Bridge
Naka Bridge
Sakura Bridge After experiments
Nishiki Bridge
Naya Bridge

Check point
・Restraint of hoisting of sluge at covering part・Transparency of the waterside
・State of living things3 Measures against Smell of Shin-Horikawa River
Horidome Water Treatment Center
Shinsuzaki Bridge

Considering of Measures

MukohdaBridge

Sumiyoshi Bridge Tateishi Bridge

Hataya BridgeShinhorita
BridgeShiratori Bridge(Completion scheduledby Mar. 2018)
Nagoya Port ¯

UchidaBridgeHinode Bridge

Ukishima
BridgeSurvey Work• Surveying to identify the shape of riverbed(Upstream and downstream zone was surveyed in 2016)
Elevation
T.P. (m)
0.0
-1.0
-2.0
-3.0
-4.0
-5.0

Outcomes of Survey
Miyano-Watashi Port
(River confluence)

-6.0
-7.0

Synodic Mean Low Water (T.P. -1.4)

Shin-Uchida Bridge

OoiBridge

Maizuru
BridgeTateishi Bridge
Thickness:
About 0.8m

Removal ofSludge

Shin-Horikawa River

Horikawa RiverOoi Bridge• Considering of effective countermeasures
based on water quality survey and precise
surveyThickness:
About 2m

Maizuru Bridge

Nakagawa CanalUkishima Bridge

Length of Sedimentary Sludge: about 400m

…Location of Sedimentary Sludge

Surveyed
In 2016

Surveyed
In 2017

Horidome Water
Treatment Center
Surveyed
In 20164

Improvement of water quality◆Removal of sludge
・Removal of sludge on water route from Shiga Bridge toShin-Horikawa River confluence (1994〜2007)
・Removal of sludge and river bed excavation at theKurokawa
area

Nayabashi
areaOtoBridge

same time implemented from downstream

Now Removing sludge around Oto Bridge
Up to now, removed 150,000m3：現在の断面Sumiyoshi

Dredging of sludge
confluence

Bank protection works
River-bed excavation
and Removal of sludge

5

■Making Additional
water sources

H25.3

①

◆Use of shallow ground waterin the upstream area②

Seko Bridge
0.01m3/s
H17.11③①②
Kizune Bridge
Sanage Bridge ③
0.01m /s
④
H27.3
⑤⑤⑥
★
★：Installed by Mar. 2018⑦
（Upstream of Kinjo Bridge）

Tsujie Bridge
0.01m3/s④

Nagoya Castle

Shiga Bridge
0.01m3/s⑦

H26.3

Sanage Bridge
0.01m3/s

3

Meijo Park

H16.10⑥

H20.3

Shimizu wakuwaku
0.0005m3/s

H28.3

Nakatsuchi Bridge
0.01m3/s

6

■Improvement of water quality◆Making shallows and deeps
Setting wooden piles and ripraps generates variable stream on the river for enforcing
river s self-purification function and creating habitats with growth of plants.

…fish spawning andplants’ seed ashore…change of stream
Installed in 2016
（Downstream of Meoto Bridge）

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■Improvement of water quality
Installed in 2010
（Meoto Bridge〜Kurokawa No.1 Bridge）

Before（2009）

Before（2011）

After（2013）

Installed in 2013（Upstream of Kurokawa No.2 Bridge）

Before（2012）

Installed in 2012
（Downstream of Kurokawa No.2 Bridge）

Installed in 2015
（Downstream of Ruriko Bridge）

After（2015）

Before（2015）

Some of the creatures seen in the upstream of Horikawa River

Japanese mitten crab

Little egret

After（2016）◆Improvement
Mallard

Pale chubAfter（2013）

・Variety and amount offish have increased.
・Benthos have increased.
・Plants have grow up more.

8

■Removal and reduction of inflow pollutants◆ Advanced water treatment
at the Meijo Water Treatment Center (since May 2010)
ＳＳmg/l43

After installation

3.32102007-09

Considerable
Reduction
Average: 1.0 or less1

1

Less than 12014

2015

2016

Minute Suspended Solids (SS) in treated water are
removed more by the filtration devices.
9■ Removal and reduction of inflow of pollutants◆Control of combined sewer overflow（Installation of advanced primary treatment facility）
Install advanced primary treatment facilities at maintained area by
combined sewer system in order to improve water quality of primary
treatment to be carried out in rainy weather.

◆Meijo Water Treatment Center・Started construction in 2017
・Scheduled to start operation in 2019

Fig.1 Process flow in Temma-cho Water
Treatment Center

Pic.1 Special filter material

10■Removal and reduction of inflow of pollutants◆Control of combined sewer overflow（rainwater storage facility）
Construct rainwater storage facilities to reduce pollution load for
Horikawa River in rainy weather by storing high polluted first flush
rainwater temporarily.
Horikawa Ugan Rain- Horikawa Sagan RainOzone Stormwater
water Resevoir for
Reservoir forwater Resevoir forpollution control
pollution control
pollution control

Started operation in 2006 Started operation in 2010
（12,000ｍ3）（13,000ｍ3）

Scheduled to start
operation in 201811（14,000ｍ3）

■Removal and reduction of inflow of pollutants◆Horikawa Ugan
Rain-water Resevoirfor pollution control
・Started operationin September 2010
・About 13,000㎥

Cumulative stored water
volume in 2016
About 730,000㎥

堀川左岸雨水滞水池
約14,000m3(20年度着手)(30年度稼働予定)

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■Removal and reduction of inflow of pollutants◆Improvement of combined sewer system（Installation of Garbage Removal Device ）The amount of installation ofGarbage Removal Device
Total） of plans Installed 2017(planned)

Before126

Water Treatment
Centeroverflow111

1

Garbage Removal Device
AfterGarbage in sewage
overflows together
with rainwater

Water Treatment
Centeroverflow

Rainwater treated by thegarbage removal devices
overflow

Removed garbage is treated at
Water Treatment Centertogether with sewage

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■Ｒｅｍｏｖａｌ ａｎｄ ｒｅｄｕｃｔｉｏｎ ｏｆ ｉｎｆｌｏｗ ｏｆ ｐｏｌｌｕｔａｎｔｓ◆Garbage catcher（Near Johoku Bridge) since 2006

garbage basket

Sanage Bridge
inflow gate

capturing fence

The exterior Garbage catcher

Meijo Park

Cross Section

Result of collection in 2013 ０．８ t
Result of collection in 2014 ０．７ t
Result of collection in 2015 １．４ t
Result of collection in 2016 １．３ t

Nagoya Castle
Koshio Bridge
Naya Bridge

The slack of fence was solved in March, 2015.

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■Additional Water Resource◆Utilization of Reclaimed Wastewater(Excluding Winter)
Conducting reclaimed wastewater treated by membrane
filtration at the Moriyama Water Treatment Center
Water Supply： Up to 4,000m3/day（0.046m3/ｓ）

Moriyama Water
Treatment Center

Flat membrane
unit aerobic tank
(400sheets×12units)

Shonai Irrigation

Upper stage embrane case(200 cartridges inside)
Horikawa River

Lower stage membrane case(200 cartridges inside)

Flat membrane unit

※Watering period is almost irrigation period（April〜October）（Except the period for Shonai irrigation channel（Novemver〜March））

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■Water Circulation of Nakagawa Canal◆Change of water circulation〜Mar.in 2004
until the closedown of
Tsuyuhashi Water Treatment Center

Apr.in 2004〜Sep.in 2017
under reconstruction

Oct.in 2017〜
30thousand m3/day

Tsuyuhashi
Matsushige
WTC
Pumping Station

60thousand m3/day

Matsushige
under reconstruction Pumping Station

30thousand m3/day

Nagoya Port

70thousand m3/day

Nakagawa Canal

Nakagawaguchi

Nakagawa Canal

70thousand m3/day

Horikawa River

Nakagawa Canal

130thousandm3/day

Tsuyuhashi
Matsushige
WTC
Pumping Station

130thousand m3/day

70thousand m3/day

70thousand m3/day

Nakagawaguchi

Nakagawaguchi

Nagoya Port

Nagoya Port・Discharge of reclaimed water was stopped
for reconstruction of Tsuyuhashi WTC.
・Water was drained into Horikawa River as muchas drawn water from Nakagawaguchi.

・Tsuyuhashi WTC has operated.
conventional activated sludge process ⇒advanced watertreatment（60thousand m3/day）
・Water is drained into Horikawa River as much as drawn
water from Nakagawaguchi and discharged water fromTsuyuhashi WTC.

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■Fully renovated construction ofTsuyuhashi Water Treatment Center・ Because of terrible aging , we started to renovate it from 2003.
・ For the purpose of water quality preservation of public water area , weintroduced advanced water treatment that can remove nitrogen andphosphorus more than before.

Fully renovated construction

Commencement on Sep 5th, 201717

■About advanced water treatment
Process of anaerobic ‒ anoxia ‒ aerobic

Rapid filtration

The process can remove nitrogen and phosphorus
which causes eutrophication more than normal
conventional activated sludge process.

・Removeing more suspeded Solids byOrganic
substance =OSPhosphorus =P

Anmonia =NA

Reactor tank
NitrogengasAsand filtration
・Improving transparency

Final settling tank

Rapid filtration

NAP

NA
NAsewageA

NAPOSPOSOSA
P

Anaerobictank
Nitricic acid=OSNA

Anoxiatank

Aerobictank

AdvancedtreatedwaterP

SludgeSludge treatment center

Contrivance of advanced water treatment（image）

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