Lakes · Shiga
Lake Biwa
琵琶湖びわこBiwa-koJapan's largest and oldest lake, the 'mother lake' of Kansai
Lake Biwa (Biwa-ko) is Japan's largest freshwater lake, filling about a sixth of Shiga Prefecture. An ancient lake several hundred thousand years old in its present basin, it supplies drinking water to much of the Kansai region.
Overview
Lake Biwa takes its name from the biwa, the Japanese lute whose outline the lake is said to resemble. It stretches some 63 kilometres from north to south and is pinched in the middle at Katata, where the Biwako Bridge divides the large, deep northern basin (Hokko) from the small, shallow southern basin (Nanko). Around 120 rivers flow in; the only natural outlet is the Seta River, which becomes the Uji River and then the Yodo River before reaching Osaka Bay.
The lake sits in the heart of old Omi Province, on the corridor between the capital at Kyoto and eastern Japan, and its shores are lined with history: Otsu, briefly capital in the 7th century; the castle town of Hikone; the merchant towns of Omi-Hachiman and Nagahama. The Lake Biwa Canal, completed in 1890, carries its water to Kyoto, and the lake remains the principal water source for more than ten million people downstream.
For biologists Lake Biwa is one of the few ancient lakes on Earth, comparable in kind with Baikal or Tanganyika. Its long, continuous history has produced dozens of endemic species, from the Biwa trout to the nigorobuna crucian carp used for funazushi.
Landscape and formation
Lake Biwa lies in a tectonic basin between the Hira and Hiei ranges to the west and the Suzuka mountains to the east. A predecessor lake formed about four million years ago near present-day Iga, well to the south; subsidence moved the basin northwards over time, and the lake has occupied roughly its present position for around 400,000 years.
The north basin reaches a depth of about 104 metres off the Takashima shore, while the south basin averages only a few metres. Islands are few: Oki-shima, the only inhabited island in a Japanese freshwater lake, Chikubu-shima in the north and the small Take-shima and Okinoshiraishi.
Highlights
Chikubu-shima
竹生島Chikubu-shimaSacred island in the north basin with Hōgon-ji temple and Tsukubusuma Shrine, whose halls include National Treasures; reached by boat from Nagahama, Hikone or Imazu.
Oki-shima
沖島Oki-shimaFishing island off Omi-Hachiman with a small resident community – rare for an island in a lake.
Ukimidō
浮御堂UkimidōHall of Mangetsu-ji at Katata built out over the water on piles; one of the Eight Views of Omi.
Shirahige Shrine
白鬚神社Shirahige JinjaShrine on the west shore at Takashima, known for its vermilion torii standing in the lake.
Kaizu-Ōsaki
海津大崎Kaizu-ŌsakiCherry-lined lakeshore road in the far north, one of the best-known spring views of the lake.
Biwako Bridge
琵琶湖大橋Biwako ŌhashiBridge across the narrows between Katata and Moriyama, marking the division of the north and south basins.
Ecology
Lake Biwa supports a rich freshwater fauna, including dozens of endemic fish, snails and mussels, and in winter tens of thousands of migrating waterfowl. Reed beds (yoshi) along the shore are protected as spawning grounds and water filters. Eutrophication, invasive black bass and bluegill, and the decline of native fish are the lake's main conservation issues.
Flora
Reed beds
ヨシ群落yoshi gunrakuShore reed belts, protected by prefectural ordinance, that shelter spawning fish and breeding birds.
Submerged aquatic plants
Dense beds of waterweeds in the shallow south basin, whose growth fluctuates strongly with water quality.
Fauna
Biwa trout
ビワマスbiwamasuEndemic salmonid that runs up the inflowing rivers to spawn in autumn.
Nigorobuna
ニゴロブナnigorobunaEndemic crucian carp, the traditional fish for funazushi.
Isaza
イサザisazaSmall endemic goby of the deep north basin, eaten simmered in soy.
Lake Biwa giant catfish
ビワコオオナマズbiwako-ōnamazuEndemic catfish that can exceed a metre in length.
Wintering waterfowl
Bean geese, swans and many duck species winter in the north, especially around Kohoku.
Culture
The lake has shaped the culture of Omi for over a millennium. The Eight Views of Omi (Ōmi Hakkei), modelled on the Chinese Eight Views of Xiao-Xiang, fixed its classic scenes and were famously painted by Utagawa Hiroshige. Lakeside cuisine is built on freshwater fish, and the Omi merchants who traded from its ports became one of Japan's great commercial networks.
Eight Views of Omi
近江八景Ōmi HakkeiEight classic scenes around the south basin, including the evening bell of Mii-dera and the geese descending at Katata.
Funazushi
鮒寿司funazushiFish fermented for months in rice – an ancestor of modern sushi and Shiga's best-known local food.
- 彦根城Hikone-jō
Early 17th-century castle on the east shore, with an original keep designated a National Treasure.
- 延暦寺Enryaku-ji
Head temple of Tendai Buddhism on Mount Hiei, overlooking the lake from the west.
History
667
Emperor Tenji moves the capital to Ōtsu-no-miya on the south-west shore.
1603
Construction of Hikone Castle begins on the east shore.
1890
The first Lake Biwa Canal opens, carrying lake water to Kyoto; its Keage power station follows in 1891.
1950
The lake and its shores are designated Biwako Quasi-National Park.
1964
The Biwako Bridge opens across the narrows at Katata.
1977
A large freshwater red tide prompts a citizens' movement against phosphate detergents.
1980
Shiga's ordinance to prevent eutrophication of Lake Biwa takes effect.
1993
Lake Biwa is listed as a Ramsar wetland of international importance.
1996
The Lake Biwa Museum opens at Kusatsu.
Through the seasons
Spring
Cherry blossom along the shore at Kaizu-Ōsaki and around Hikone Castle; the fishing season for young ayu begins.
Summer
Beaches on the north and west shores, lake cruises and large fireworks displays over the water in August.
Autumn
Biwa trout run up the rivers; autumn colour in the hills around the lake and at temples such as Mii-dera.
Winter
Tens of thousands of waterfowl winter on the lake; the north shore regularly sees heavy snow, while the south stays mild.
Routes and trails
Biwaichi cycling circuit
A signposted ride of about 200 km around the whole lake, usually done in two to three days; a shorter loop uses the Biwako Bridge.
Boat to Chikubu-shima
Passenger boats cross from Nagahama, Hikone or Imazu to the island's temple and shrine.
South basin cruise
Sightseeing boats from Otsu port run across the south basin past the Eight Views sites.
Practical notes
- Otsu is about ten minutes from Kyoto by JR; the JR Biwako Line follows the east shore and the Kosei Line the west shore.
- Distances are large – the lake is over 60 km long – so plan one shore or one area per day without a car.
- Swimming is only advisable at designated beaches during the summer season.
- The north basin can bring sudden strong winds; small craft should follow local guidance.
Frequently asked questions
How big is Lake Biwa?
About 669 km², roughly a sixth of Shiga Prefecture. It is some 63 km long and up to about 104 m deep.
How old is Lake Biwa?
Its predecessor formed about four million years ago further south; the lake has been in roughly its present basin for around 400,000 years, making it one of the world's oldest lakes.
Does Kyoto get its water from Lake Biwa?
Yes. The Lake Biwa Canal, opened in 1890, still carries lake water to Kyoto, and the Yodo River system fed by the lake supplies Osaka and much of Kansai.
How do you get to Lake Biwa from Kyoto?
JR trains reach Otsu on the south-west shore in about ten minutes; the Biwako and Kosei lines continue along the east and west shores.
What is funazushi?
A fermented dish of crucian carp from the lake preserved in rice for months, considered an ancestral form of sushi.
Related
Sources
- 1.全国都道府県市区町村別面積調（湖沼面積） (opens in a new tab) — 国土地理院
- 2.琵琶湖 (opens in a new tab) — 滋賀県
- 3.Lake Biwa — Ramsar Sites Information Service (opens in a new tab) — Ramsar Convention Secretariat
- 4.滋賀県立琵琶湖博物館 (opens in a new tab) — 滋賀県立琵琶湖博物館