HomeContact UsDonate NowSearchPrint Page  
LAKENET LogoProtecting and restoring the health of lakes throughout the worldProtecting and restoring the health of lakes throughout the world
  LakesMapsNewsIssues & SolutionsProgramsLinksCalendarAbout UsJoin LakeNet
Lake Profile

Biwa (Biwa-ko)

General Information

Description Lake Biwa is one of less than 20 ancient lakes in the world. Biwa's ancient beginnings mean species have had millions of years to evolve into new & unique species that exist nowhere else in the world. Biwa is the largest lake in Japan.
Country Japan
Latitude 35° 15' 0" (35.2500)
Longitude 136° 4' 0" (136.0667)


 Biwa global index map (LakeNet Explorer)
 Biwa locator map
 Ancient Lakes of the World
 Lake Basin Management Initiative (LakeNet Explorer)

Physical Characteristics

Description Lake Biwa is located in the upper reaches of the Yodo River Basin. More than 400 tributaries flow into the lake; only the Seta River flows out.
Volume 27.50 km3
Surface Area 670.00 km2
Depth Mean depth: 43.0 m
Maximum depth: 104.0 m
Age 2 million - 20 million years before present
Origin Tectonic
Type Fresh
Catchment Catchment size: 3,848.00 km2
Catchment/surface area ratio: 6:1


Economic Value Lake Biwa is a source of drinking water for 14 million people. The annual fish catch from Biwa is about 3,320 tons. (1997) Over 37 million people visit the lake each year. According to the Environment Agency of Japan, 7.8 million people and US$50,000 million worth of assets would be under the threat of flooding without Lake Biwa to act as flood control.
Major Cities Shiga, Kyoto, Osaka

Watershed Management

Description Lake Biwa is one of ten lakes designated under the Clean Lakes Law that must put together water quality conservation works and policies and gain the prime minister's approval for a management plan. The prefecture government has 43 people netting invasive fish eight hours a day; in addition, commercial fishermen are paid by the weight of their invasive catch.
Watershed Action Plan Developed
Issues Invasive black bass and bluegill fish threaten native crucian carp and eels. Large outbreaks of Elodea and Egeria have occured in Biwa from the 1960's onward. Since 1992 a freshwater mussel (Kawahibari-gai) has been found in the Biwa-Yodo River system. These mussels are known to attach to the inside of water pipes, interfering with water flow. Black bass are another invasive species threatening Biwa's native fauna.
Other Issues Invasive Species
Lake Levels (water quantity)
Nutrient pollution
Polluted runoff
Sediment contamination
Watershed habitat alteration
Specific Contaminants Mercury
Monitoring Launched, as a resolution to the conflicts as well as a tool for local economic and water resources development, was the Lake Biwa Comprehensive Development Project (LBCDP), the largest water resources development project in Japan.

Meanwhile, the environmental administration, particularly on water environment, of Shiga Prefecture, for which the conservation of Lake Biwa is the top-priority, has always led the one of the central government. Environmental consciousness of Shiga people for the lake gave birth to the Soap Movement, the most successful citizens' movement in Japan, and enabled the prefectural government to enact the Eutrophication Control Ordinance, the very first act for eutrophication control in Japan.

Monitoring Programs In-Lake
Water Quality
Biological Resources and Habitats
Lake Use

Water Quality
Biological Resources and Habitats
Land Use

Biodiversity Conservation

Description Lake Biwa is home to 12 indigenous fish species and 20 indigenous types of shellfish. Biwa has 16 species of phytoplankton and 16 species of zooplankton.
Designations LakeNet Biodiversity Priority
Ramsar Site
WWF Global 200
Ramsar Site Name Biwa-ko
Ramsar Designations 1, 4, 5
Species of Concern


Kosho Net
International Lake Environment Committee
Lake Biwa Research Institute
Shiga Prefecture Government
Lake Biwa Museum
Water and Culture Study Group, Japan
Akanoi-Biwako Environmental Citizensí Initiative
Lake Biwa-Yodo River Water Purification Organization

LakeNet Programs

World Lake Basin Management Initiative
Biodiversity Needs Assessment Survey
LakeNet 2000: A Dialogue on Participatory Watershed Management
LBMI Regional Experience Sharing & Review Workshop for Asia
U.S. NGO Delegation Visit to Japan, March 2003


Biwa  (PDF) Experience Brief. Final. 2/27/2006.
Biwa: World Bank Comments on Experience Brief  Experience Brief. Draft. World Bank. 3/22/2004.
Managing Lake Basins for Sustainable Use - Lake Basin Management Initiative Final Report (PDF)  Project Report. Final. English. 2/27/2006.


Biodiversity Conservation of the World's Lakes: A Preliminary Framework for Identifying Priorities
Biwa Ramsar Fact Sheet
Challenges Before Lake Biwa
ILEC Database
Lake Biwa Long-Term Limnological Survey Database
Living Lakes - Lake Biwa
Pollution at Lake Biwa


4/23/2004 - Towards a Lake Basin Management Initiative
2/25/2003 - Foreign fish havoc in Japan
10/16/2002 - Release of nonnative fish into Lake Biwa banned
1/18/2002 - Indigenous fish vanishing in Japan as invasion of American species spreads
2/28/2001 - Two new species of plankton found in Lake Biwa
3/21/2000 - Black bass leave Lake Biwa gasping
11/1/1999 - Invasive fish dine on Japan's native goby

Additional Data Sources

Birkett, C., and I. Mason. 1995. A new global lakes database for remote sensing programme studying climatically sensitive large lakes. Journal of Great Lakes Research, 21 (3) 307-318.
Duker, L. and L. Borre. 2001. Biodiversity conservation of the world's lakes: a preliminary framework for identifying priorities. LakeNet Report Series Number 2. Annapolis, Maryland USA.
International Lake Environment Committee, the United Nations Environment Program and Environment Agency, Government of Japan. 1997. World Lakes Database.
Ramsar Convention on Wetlands. The List of Wetlands of International Importance.

Search again


Visit Art.com



Lakes | Maps | News | Issues & Solutions | Programs | Links | Calendar | About Us | Join Us
Home | Contact Us | Donate Now | Search | Legal Information
Copyright © 2003-2004 LakeNet. Site developed by RelianceNet. Email the webmaster. Site statistics by Google Analytics.