Lake Kasumigaura: sailboats, lotus fields, and fireworks
Japan's second-largest lake by surface area, yet barely four meters deep on average. Around Lake Kasumigaura, that unusual combination shaped a distinctive way of life.
Lake Kasumigaura spreads across southern Ibaraki Prefecture, covering about 220 square kilometers — second in area only to Lake Biwa among Japan's lakes. Roughly 56 rivers, large and small, including the Sakura and Koise rivers, flow into it, feeding a rich fishery and farmland.
That water and land gave rise to a distinctive sail-net fishing method, some of Japan's largest lotus root farms, and Tsuchiura's fireworks competition, ranked among Japan's three great fireworks festivals. Here's the story behind the lake.
A lake that is wide but shallow
Average depth of about 4 meters, Japan's second-largest lakeKasumigaura
At about 220 square kilometers, Lake Kasumigaura ranks second in area among Japan's lakes, after Lake Biwa. Yet its average depth is only around 4 meters, making it unusually shallow for its size. Strictly speaking, 'Kasumigaura' refers to the Nishiura basin, though the name is also used more broadly for the whole water system, including Kitaura and the Hitachi-Tone River. The Kasumigaura Ohashi Bridge, linking Tsuchiura, Kasumigaura, and Namegata, opened in 1987 and dramatically shortened travel between the shores.
Source:Lake Kasumigaura - WikipediaWhat Kind of Lake Is Kasumigaura? - Kasumigaura Environmental Science Center
Sail-net fishing: an invention by Orimoto Ryohei
Invented in 1880 for icefish (shirauo) fishing
'Sail-net fishing' — dragging a net behind a sailboat — was devised in 1880 by Orimoto Ryohei of Saka village, now part of Kasumigaura City, after three years of trial and error. He reportedly got the idea from watching takasebune river boats catch the wind and glide across the water, and rather than keeping the technique to himself, he shared it widely among local fishermen. Today, sightseeing sailboats recreate the practice on the lake from summer into autumn.
Source:Orimoto Ryohei, Inventor of the Sail-Net Fishing Boat - Kasumigaura City
Tsuchiura's lotus root fields: roughly half the nation's supply
About 50% of national shipments come from the Kasumigaura shoreline
The shores of Lake Kasumigaura, especially around Tsuchiura, form one of Japan's leading lotus root growing regions. In 2022, Ibaraki Prefecture shipped about 28,200 of the nation's 56,200 metric tons of lotus root — roughly 50% of the total. Lotus root is said to grow sweeter from late autumn into winter, so the harvest peaks between November and February, when fields fill with workers digging up the roots.
Source:Japan's No. 1 Lotus Root - Ibaraki Lotus Root Wide-Area Branding CouncilSurvey of Regional Specialty Vegetable Production - ALIC
The Tsuchiura fireworks competition: born from an act of remembrance
Started in 1925 by a temple priest, funded from his own pocket
Tsuchiura's fireworks festival traces back to 1925, when Akimoto Baiho, the 24th head priest of Shinryuji Temple, funded a fireworks display from his own pocket to honor airmen of the Kasumigaura Naval Air Corps who had died in service, and to help revive the local economy after the Great Kanto Earthquake. Today, competitors are judged across three categories — Star Mine, 10-gou shells, and creative fireworks — and it's ranked alongside Omagari (Akita) and Nagaoka (Niigata) as one of Japan's three great fireworks festivals, with the Prime Minister's Award as its top honor.
Source:Tsuchiura All-Japan Fireworks Competition - Wikipedia
FAQ
Is Lake Kasumigaura saltwater or freshwater?
Today it functions much like a freshwater lake, since a floodgate at its outlet restricts the inflow of seawater. Historically, though, it was a brackish lake loosely connected to the Pacific, which is part of why its fisheries developed around a mix of marine and freshwater species.
Are the sail-net fishing boats still used for actual fishing?
Motorized boats replaced them for commercial fishing long ago, but sightseeing sail-net boats still operate from early summer through autumn, timed to festivals and events, and remain a popular subject for photographers visiting the lake.
Sources & references
- Lake Kasumigaura - Wikipedia
- What Kind of Lake Is Kasumigaura? - Kasumigaura Environmental Science Center
- Orimoto Ryohei, Inventor of the Sail-Net Fishing Boat - Kasumigaura City
- Japan's No. 1 Lotus Root - Ibaraki Lotus Root Wide-Area Branding Council
- Survey of Regional Specialty Vegetable Production - ALIC
- Tsuchiura All-Japan Fireworks Competition - Wikipedia