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Water Supply Project in Lake Kasumigaura, Ibaraki, Japan

Fisher Cooperatives filed a court case against the water transfer project which destroys the biological communities and the ecosystems. The project has later been reconsidered by incorporating their opinions.


The Naka River, Lake Kasumigaura and the Tone River have played an important role in the stable and regional supply of water resources,  and have contributed to the industrial and economic development of the basin [1].  However, due to industrial development and urbanization, water blooms have been produced in Lake Kasumigaura since the early 1970s [2].  Various problems such as the occurrence of drought also occur in the Naka River and the Tone River, and efforts are being made to purify the water and secure stable water resources throughout the basin [1].

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Basic Data
Name of conflict:Water Supply Project in Lake Kasumigaura, Ibaraki, Japan
State or province:Ibaraki, Tochigi, Chiba
Location of conflict:Namegata, Kasumigaura, Miho, Inashiki, Tsuchiura, Ami
Accuracy of locationMEDIUM (Regional level)
Source of Conflict
Type of conflict. 1st level:Water Management
Type of conflict. 2nd level:Dams and water distribution conflicts
Land acquisition conflicts
Water access rights and entitlements
Wetlands and coastal zone management
Invasive species
Aquaculture and fisheries
Interbasin water transfers/transboundary water conflicts
Specific commodities:Land
Ecosystem Services
Project Details and Actors
Project details

Lake Kasumigaura belongs to the Tone River water system that flows through the Kanto Plain, and is a marine trace lake that enters the low-lying area in the southeastern part of Ibaraki Prefecture, on the left bank side of the lower part of the Tone River. The lake area is about 22 km2, and it is the second largest lake in Japan. In addition, the water storage amount is about 850 million m3, the water depth is an average of about 4 m (maximum 7 m), and the residence time is about 200 days. [10]

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Project area:21,990
Level of Investment:1,400,000,000
Type of populationSemi-urban
Affected Population:12,140,000
Start of the conflict:03/2009
End of the conflict:27/04/2017
Relevant government actors:-Ministry of Land, Infrastructure, Transport and Tourism, Kanto
-Regional Development Bureau, Lake Kasumigaura water supply construction office
-National Institute for Environmental Studies, National Research and Development Corporation
Environmental justice organizations (and other supporters) and their websites, if available:-Yamba tomorrow meeting (
-Japan River Keeper Alliance (
-Water Source Net (
Conflict and Mobilization
IntensityMEDIUM (street protests, visible mobilization)
Reaction stageIn REACTION to the implementation (during construction or operation)
Groups mobilizing:Local government/political parties
Fisher people
Forms of mobilization:Community-based participative research (popular epidemiology studies, etc..)
Creation of alternative reports/knowledge
Development of a network/collective action
Lawsuits, court cases, judicial activism
Media based activism/alternative media
Official complaint letters and petitions
Public campaigns
Impacts of the project
Environmental ImpactsVisible: Biodiversity loss (wildlife, agro-diversity), Desertification/Drought, Loss of landscape/aesthetic degradation, Surface water pollution / Decreasing water (physico-chemical, biological) quality, Large-scale disturbance of hydro and geological systems, Reduced ecological / hydrological connectivity
Potential: Food insecurity (crop damage), Soil contamination, Oil spills, Groundwater pollution or depletion
Health ImpactsPotential: Accidents
Socio-economical ImpactsVisible: Loss of landscape/sense of place
Potential: Lack of work security, labour absenteeism, firings, unemployment, Loss of traditional knowledge/practices/cultures, Violations of human rights
Project StatusUnder construction
Conflict outcome / response:Court decision (failure for environmental justice)
Negotiated alternative solution
Under negotiation
Do you consider this an environmental justice success? Was environmental justice served?:Not Sure
Briefly explain:Although the plaintiffs' fishery side lost their case, it seems that the plan has been reconsidered by incorporating their opinions. However, it is unpredictable what kind of environmental and economic impact will occur.
Sources and Materials
References to published books, academic articles, movies or published documentaries

Kuroda H. et al., The Sate of Water Quality and Watershed Management Plans in Lake Kasumigaura, Agricultural and Rural Development in Kasumigaura and Tone River Lower Basin-1 (accessed on 13-04-2019)
[click to view]

Links to general newspaper articles, blogs or other websites

[6] Change of exchange rate of US dollar / yen (accessed on 14-04-2019)
[click to view]

[7] Japan River Keeper Alliance (accessed 14-04-2019)
[click to view]

[2] National Institute for Environmental Studies, National Research and Development Corporation, "Is the water quality of Lake Kasumigaura improved?" (accessed on 14-04-2019)
[click to view]

[3] Kasumigaura water supply lawsuit (accessed on 14-04-2019)
[click to view]

[4] Yamba tomorrow meeting (accessed on 14-04-2019)
[click to view]

[5] Approach of Kasumigaura River Office (accessed on 14-04-2019)
[click to view]

[9] Water Source Net (accessed on 14-04-2019)
[click to view]

[10] Characteristics of basins and lakes (accessed on 15-04-2019)
[click to view]

Lake area (accessed on 13-04-2019)
[click to view]

Japan Water Agency (accessed on 15-04-2019)
[click to view]

[8] Yahoo Finance (accessed on 15-04-2019)
[click to view]

[1] Ministry of Land, Infrastructure, Transport, and Tourism, Kanto Regional Development Bureau, Lake Kasumigaura water supply construction office (accessed on 14-04-2019)
[click to view]

Other documents

The Sakura Pumping Station Water conducted from the Naka River with a pump installed in the basement is discharged to the Sakura River. It was built along the Sakura River in Kawada Town, Mito City, and in March 2001 all facility maintenance was completed, including the construction of a space building and the installation of pumps.
[click to view]

The Tone Pumping Station Equipped with three pumps, the water transfer from the Tone River to Lake Kasumigaura and from Kasumigaura to Tonegawa will be up to 25 m3 / sec.
[click to view]

Meeting after the settlment A meeting fishery cooperative union heads and lawyers after the settlement in Tokyo.
[click to view]

Water bloom Water bloom on the lake surface
[click to view]

The Tone Water Channel The Tone Water Channel takes water from the Tone River and release it to the Tone River.
[click to view]

The Kasumigaura Water Channel The Kasumigaura Water Channel takes water from Lake Kasumigaura and release it to Lake Kasumigaura.
[click to view]

The Mito Tunnel It is an underground tunnel from Naka Pumping Station in Mito City Watari Chisaki to Mito CIty Kawawada Town Chisaki in the Naka Water Supply Channel. Water flows up to 15 m3 / s from the Naka River towards Lake Kasumigaura and up to 11 m3 / s from Lake Kasumigaura toward the Naka River.
[click to view]

The Naka Pumping Stataion Water from the Naka River is delivered to the Sakura River and Lake Kasumigaura, and water from Lake Kasumigaura is released to the Naka River through the Naka Water Channel. In 2004, along the Naka River in Mito City Watari Town, the construction of the pumping station, the construction of the sedimentation basin and the installation of the water delivery pump were completed.
[click to view]

The Tone Water Supply Channel The Tone Water Supply Channel (approx. 2.6km in length) connects the Tone River and Lake Kasumigaura, and is established in the ground about 20-30m in depth. It is a joint facility with the Kasumigaura Development Project conducted by the Water Resources Development Corporation (now Japan Water Agency).
[click to view]

The Ishioka Tunnel It is an underground tunnel connecting 24.7 km from the Mito shaft in Mito City Kawada Town Chisaki to the Takahama Pumping Station in Ishioka City Mimura Kantaku Chisaki, of the Naka Water Supply Channel. Water flows up to 15 m3 / s from the Naka River towards Lake Kasumigaura and up to 11 m3 / s from Lake Kasumigaura toward the Naka River. Currently, the tunnel is being divided into six sections, and Takahama Airport-Yuri Shaft (Section 6) and Kamiinuma Shaft-Ibaraki Shaft (section 2) have been completed.
[click to view]

Meta information
Contributor:EnvJustice, ICTA-UAB/Natsuka Kuroda, [email protected]
Last update29/04/2019
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