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Pollution of the Yamato River, Japan


Description

The Yamato River used to be a familiar river widely known as a place of river play until the 1950s.  However, along with the high economic growth, the development of the watershed developed as a residential area in the Keihanshin metropolitan area.  When the industry was concentrated, the water quality deteriorated sharply due to household drainage, factory drainage, and livestock drainage.  Since the 1960s, the Yamato River's water quality had a poor condition making it unsuitable for the use of water and other hydrophilic and living creatures.  70% of the causes of pollution in the Yamato River were domestic wastewater. At that time, the sewerage coverage rate of households in the Yamato River basin was less than 20%. This means that domestic drainage flowed into the river without any treatment [1].

A typical organism affected by this deterioration in water quality was sweetfish (ayu; Plecoglossus altivelis in its scientific name [2]). Before the war and shortly after the war, sweetfish's upswimming had been confirmed and reported in the Yamato river basin.  However, the number of natural sweetfish's upswimming started to decline sharply from around 1965.  On the other hand, the BOD value of the f Yamato River was excessive (see Project Details) in 1970, becoming the dirtiest water quality in observation history.  From around the time, it was not possible to confirm the upswimming of sweetfish.[1]  Then, the Yamato River became one of the dirtiest rivers in the country [3].

In response to this situation, the relevant organizations of the basin, the residents, etc. began to mobilize with their efforts[4].  Since the cause of pollution was from domestic wastewater, they conducted steady activities such as the review of wastewater and cleaning activities of the river [5].  On the administration side, four major efforts have been made so far.  In March 1991, the Yamato River Water Quality Improvement Emergency Five-Year Plan (commonly known as Aqua Road Yamato River Project), which aimed to improve the water quality suitable for water play, was compiled [1].  Furthermore, in November 1993, in order to improve the water quality, as a comprehensive measure that the relevant organizations of the basin cooperated, the Yamatogawa Kiryu Renaissance Council was established to make plans such as river business, sewerage business, spread enlightenment activities, and to carry out various efforts [1].  One year later, the Water Environment Improvement Emergency Plan (commonly known as Yamato River Clean Flow Renaissance 21) and the second phase Water Environment Improvement Emergency Action Plan (Yamato River Clean Flow Renaissance II) were formulated in October 2002[1].  The Yamato River Water Environment Council was established in September 2005, and the C Project Plan 2006 (Water Environment Edition) was formulated in September of the following year, following the declaration of the Yamato River Water Environment Summit [1]. The objectives of this plan were: (i) securement of a water environment that can be playful in summer; (ii) creation of a safe and comfortable waterfront environment; (iii) conservation of a water environment where various animals and plants can live and grow; (iv) creation of river landscapes so the Yamato River; and (v) Early achievement of the environmental standards [1].  The Yamato River Water Environment Improvement Plan has been formulated as the latest policy, which set the directionality of water environment improvement [1].  In addition, various efforts have been carried out such as promoting connection to sewers and promoting conversion to merger septic tanks, social experiments to improve water quality in priority rivers, and partial revision of the septic tank maintenance assistance system [6].

Through these efforts, the government began maintaining environmental standards established by the country from around 2009 [7].  In 2010 and 2011, the Yamato River ranked first in the nation as "a river whose water quality has been significantly improved over the past 10 years" among the first-class rivers managed by the country [7].  In 2015, the water quality of the Yamato River became 2.6 mg/l (BOD 75% value) and recorded the most beautiful water quality in the observation history of the river [1]. This is about nine times lower than that in 1970, when water quality deterioration peaked.  As a result of measuring the elements contained in the "otolith" of sweetfish collected in the lower reaches of the Yamato River in 2004 and 2005, the upswimming of natural sweetfish was confirmed [2].  In 2007, egg laying of sweetfish was confirmed for the first time after pollution [8].

Basic Data

NamePollution of the Yamato River, Japan
CountryJapan
ProvinceOsaka and Nara
SiteOsaka, Sakai, Yao, Nara, Yamatotakada, Yamatokōriyama
Accuracy of LocationMEDIUM regional level

Source of Conflict

Type of Conflict (1st level)Water Management
Type of Conflict (2nd level)Water access rights and entitlements
Landfills, toxic waste treatment, uncontrolled dump sites
Urban development conflicts
Aquaculture and fisheries
Specific CommoditiesWater
Industrial waste
Domestic municipal waste

Project Details and Actors

Project DetailsYamato River is about 68 kilometers in length. [8]

The population in the Yamato River basin in Nara and Osaka Prefectures was less than 1 million until the 1950s while it reached 2 million during the 1980s. [1]

Approx. 85% of Nara Prefecture's population is concentrated in the Yamato River basin. [4]

It is currently used as drinking water in 10 municipalities in Osaka and Nara prefectures. [6]

The sewerage penetration rate in the Yamato River basin continued to fall below the national average until 2001. It was 86.9% in 2015, exceeding the national average of 77.8%. [1]

Approx. 70% of the causes of soiling in 2013 were “living wastewater”, following factories, etc. (13.2%), livestock (10.1%), and nature (3.9%). [1]

The Yamato River basin is characterized by annual precipitation less than the national average and less water flowing into the river. Therefore, the river is particularly polluted in winter (December-February) when the amount of water decreases. [1]

As for the water quality of the Yamato River, the average water quality (BOD 75% value) at eight locations in the main river was 11.6 mg/l. [4] Although it fell below the environmental standard (5 mg/l) for the first time in 2004, BOD values continued to exceed 5 mg/l for several years starting in 2005. However, since 2008, the main river has continued to fulfill the environmental standard, and it fell to BOD value 2.3mg/l in 2015. [1]

Measurements were done in the spring of 2004 on the elements contained in the "otoliths" of three sweetfish collected in the lower Yamato River and on 15 sweetfish collected in the vicinity of Kawachi Bridge in the spring of 2005. It turned out that all of them are natural sweetfish which swam up, testifying to increased quality of the water. [5]

The Yamato River is one of the many rivers in Japan where "cormorant fishing" was practiced. The birds are roped together and the fishermen tie string around each one’s throat to stop them eating the fish they catch. The practice has been in decline, and nowadays attracts tourists.

Project Area (in hectares)107,000
Type of PopulationSemi-urban
Potential Affected Population2,000,000
Start Date1960
End Date2009
Relevant government actors-Ministry of Land, Infrastructure, Transport and Tourism Kinki -Regional Development Bureau, Yamato River river office

-Osaka Prefectural Government

-Nara Prefecture

-Matsubara city
International and Financial InstitutionsLions Club from United States of America - They preside over Yamato River water quality improvement activity.
Environmental justice organisations and other supporters-Yamato River Clean Flow Revival Network (http://yamato-river.net/index.html)

-Yamato River Natural Sweetfish Study Group

-Kashiwara E-net (https://kashiwara-e.net/)

The Conflict and the Mobilization

Intensity of Conflict (at highest level)MEDIUM (street protests, visible mobilization)
When did the mobilization beginMobilization for reparations once impacts have been felt
Groups MobilizingLocal government/political parties
Neighbours/citizens/communities
Recreational users
Local scientists/professionals
Fisher people
Forms of MobilizationCommunity-based participative research (popular epidemiology studies, etc..)
Development of a network/collective action
Involvement of national and international NGOs
Public campaigns
Appeals/recourse to economic valuation of the environment
Research and administrative guidance; Setting administrative goals; Facility maintenance

Impacts

Environmental ImpactsVisible: Biodiversity loss (wildlife, agro-diversity), Loss of landscape/aesthetic degradation, Surface water pollution / Decreasing water (physico-chemical, biological) quality
Potential: Food insecurity (crop damage), Soil contamination, Waste overflow, Oil spills, Groundwater pollution or depletion, Large-scale disturbance of hydro and geological systems, Reduced ecological / hydrological connectivity
Health ImpactsVisible: Accidents
Socio-economic ImpactsVisible: Loss of traditional knowledge/practices/cultures, Loss of landscape/sense of place

Outcome

Project StatusIn operation
Pathways for conflict outcome / responseEnvironmental improvements, rehabilitation/restoration of area
Institutional changes
New legislation
Strengthening of participation
Application of existing regulations
Do you consider this as a success?Not Sure
Why? Explain briefly.Improvement of water quality standards alone is not enough for the restoration of biodiversity. There are still many issues to be improved in order to realize the potentiality of the river as habitat, growth spawning, and hatching of more aquatic life [12].

It is considered extremely important to deepen the understanding and to strengthen the cooperation of various stakeholders in these areas and to make it an approach in the whole basin area [12].

Sources and Materials

Legislations

Water environment improvement emergency plan (accessed on 12-04-2019)
http://www.mlit.go.jp/river/shinngikai_blog/past_shinngikai/shinngikai/kondankai/mizukankaizen/pdf01/mk_sei_renaissance21_01.pdf

Second Phase Water Environment Improvement Emergency Action Plan (accessed on 12-04-2019)
https://www.kkr.mlit.go.jp/yamato/environment/project/renaissance/about.html

C Project Plan 2006 (Water Environment) (accessed on 12-04-2019)
https://www.kkr.mlit.go.jp/yamato/environment/project/cproject/cproject.html

Yamato River water environment improvement plan (accessed on 12-04-2019)
https://www.kkr.mlit.go.jp/yamato/environment/pdf/envplan/envplan2402.pdf

References

[3] Yamamoto K. and Inoue H., Consideration on environmental improvement of river based on water quality survey of Hatsuse River (the Yamato River basin), Research note (accessed on 10-04-2019)
https://www.jstage.jst.go.jp/article/jriet1972/29/5/29_5_386/_pdf/-char/ja

[2] Ueno H. et al, 2012, Confirmation of natural upswimming using otolith Sr/Ca ratio of sweetfish of Yamato River, Bulletin of Osaka University of Education, Third Division, Volume 61, 17-21, (accessed on 10-04-2019)
https://opac-ir.lib.osaka-kyoiku.ac.jp/webopac/KJ3_6101_017._?key=PYBGDH

[10] Nagata Y., River maintenance fund furtherance business, "Mass runaway program of natural sweetfish in the urban river" Yamato River "", Achievement report (accessed on 12-04-2019)
http://public-report.kasen.or.jp/243201002.pdf

Yoshiaki Tsuzuki & Minoru Yoneda, 2011, Pollutant runoff yields in the Yamato-gawa River, Japan, to be applied for EAH books of municipal wastewater intending pollutant discharge reduction

Journal of Hydrology 400(3-4):465-476.
https://www.researchgate.net/publication/215750467_Pollutant_runoff_yields_in_the_Yamato-gawa_River_Japan_to_be_applied_for_EAH_books_of_municipal_wastewater_intending_pollutant_discharge_reduction

Links

[6] Miyatake et al., Water quality pollution in Osaka bay, Group 1 (accessed on 10-04-2019)
http://www.econ.ryukoku.ac.jp/~tlee/seminar-7.files/G1-大阪湾の環境問題3%EF%BC%9A琵琶湖・淀川・大和川・大阪湾.pdf

[7] Osaka Prefectural Government, Make Yamato River Cleaner! (accessed on 10-04-2019)
http://www.pref.osaka.lg.jp/jigyoshoshido/kawachiiki/mo-top.html

[8] Sankei West, 6 April 2014, "Japan's dirtiest river = Yamatogawa" is reviving ... Figures of wild birds, figures of fish, and water quality improvement (accessed on 10-04-2019)
https://www.sankei.com/west/news/140406/wst1404060013-n1.html

Yamato River water system (accessed on 12-04-2019)
https://river.longseller.org/ws/860603.html

Reason why Yamatogawa is dirty (accessed on 12-04-2019)
https://minimalist.joho.info/zatsugaku/yamatogawa-kitanai-suishitsu-tsuri/

Eco Nara, Water pollution problem of Yamato River (accessed on 12-04-2019)
http://www.eco.pref.nara.jp/kankyo/osemmondai.html

[1] River office of Yamato River, Ministry of Land, Infrastructure, Transport and Tourism Kinki Regional Development Bureau, Water environment of Yamato River - For improvement of water environment (accessed on 10-04-2019)
https://www.kkr.mlit.go.jp/yamato/environment/outline/water1.html

Yamatogawa Integrated Watershed Environment Improvement Project Evaluation
http://www.mlit.go.jp/tec/hyouka/public/jghks/karute/img/14230686003/14230686003_0.pdf

History of Yamato River
http://www.kashiwara-bunka.jp/yamatogawa/yamatogawa_pdf/yamatoriver.pdf

[9] Lions Club
https://ja.wikipedia.org/wiki/ライオンズクラブ

[5] Kashiwara E-net, 20 August 2012, Sweetfish has backed to Yamato River (accessed on 10-04-2019)
https://kashiwara-e.net/find/1614/

Sweetfish has returned to Yamato River! (accessed on 12-04-2019)
http://www.kashiwara-bunka.jp/yamatogawa/yamatogawa_pdf/ayu.pdf

[4] Yamato River Fresh Stream Revival Network, Revive! The Yamato River CFresh Stream Revival Project (accessed on 10-04-2019)
http://yamato-river.net/water-quality.html

Other Documents

State of the river since the 1970s (2) The water quality significantly deteriorated due to household drainage, rubbish and manure.
https://file.ejatlas.org/docs/1970年代以降の川の様子.jpg

Children playing with water In the 1960s, many children used to be playing in the river.
https://file.ejatlas.org/docs/1970年代以降の川の様子_1_.jpg

Dead fish Many water quality accidents occur in the Yamato River water system.
https://file.ejatlas.org/docs/Dead_fish.jpg

Sweetfish's upstream In recent years, spawning of natural sweetfish and juvenile sweetfish have been confirmed annually downstream.
https://file.ejatlas.org/docs/アユの遡上.jpg

Collected sweetfish Collected sweetfish by Emeritus Professor Yoshikazu Nagata, Osaka University of Education
https://file.ejatlas.org/docs/採集されたアユ.jpg

Otolith Otolith
https://file.ejatlas.org/docs/耳石.gif

Children playing with water By the 1960s, many children used to be playing in the river.
https://file.ejatlas.org/docs/水遊びする子供たち.jpg

Yamato River Waterside Festival Every year since 2006, the waterside event takes place downstream, and the children enjoy water play.
https://file.ejatlas.org/docs/大和川水辺まつり.jpg

Oil fence to prevent oil spill Related organizations cooperate and store oil fences and adsorption mats to prevent the spread of oil downstream and the spread of damage in river offices, civil engineering offices, municipalities, etc., and prepare for emergency response.
https://file.ejatlas.org/docs/油の流出を防ぐオイルフェンス.jpg

Kashiwara dam and fish path You can see the Kashiwara dam in the back. There is a new fishway in front.
https://file.ejatlas.org/docs/柏原堰堤と魚道.jpg

Sumiyoshi Taisha's The Sumiyoshi Taisha's God Passage, which carries the shrine and crosses the Yamato River, was revived for the first time in 41 years in 2004.
https://file.ejatlas.org/docs/住吉大社の_神輿渡御祭_.jpg

Meta Information

ContributorEnvJustice, ICTA-UAB/Natsuka Kuroda, [email protected]
Last update08/05/2019

Images

 

Collected sweetfish

Collected sweetfish by Emeritus Professor Yoshikazu Nagata, Osaka University of Education

Otolith

Otolith

State of the river since the 1970s (2)

The water quality significantly deteriorated due to household drainage, rubbish and manure.

Children playing with water

In the 1960s, many children used to be playing in the river.

Dead fish

Many water quality accidents occur in the Yamato River water system.

Yamato River Waterside Festival

Every year since 2006, the waterside event takes place downstream, and the children enjoy water play.

Kashiwara dam and fish path

You can see the Kashiwara dam in the back. There is a new fishway in front.

Sumiyoshi Taisha's

The Sumiyoshi Taisha's God Passage, which carries the shrine and crosses the Yamato River, was revived for the first time in 41 years in 2004.

Sweetfish's upstream

In recent years, spawning of natural sweetfish and juvenile sweetfish have been confirmed annually in the downstream.

Children playing with water

By the 1960s, many children used to play in the river.

Oil fence to prevent oil spill

Related organizations cooperate and store oil fences and adsorption mats to prevent the spread of oil into downstream and the spread of damage in river offices, civil engineering offices, municipalities, etc., and prepare for emergency response.