Japan is situated in the Pacific Ocean, just off the east coast of the Asian mainland. Here, this archipelago nation covers a total area of 145,936 square miles spread out over 6,852 islands. Nearly three-quarters of this area is covered by mountains and forestland, with only .8% being occupied by bodies of water (including rivers, streams, wetlands, and lakes). This article takes a closer look at the ten largest lakes of Japan, by surface area.
Biwa Lake is by far the largest lake in Japan, covering a total surface area of 258.8 square miles. Biwa Lake is located to the northeast of Kyoto, which was once the capital of Japan. This large body of water is the most important reservoir in the area, providing water to over 15 million individuals. Additionally, it is an important part of the local ecosystem and serves as a breeding territory for a number of fish species. Biwa Lake is fed by rivers that flow out of the surrounding mountains. This water, in turn, feeds into the Seta River, which eventually makes its way into the Seto Inland Sea.
The second largest lake in Japan is Kasumigaura Lake, which has a total surface area of 64.7 square miles. The capital city of Tokyo is located 37.28 miles to the southeast of this lake. The Kasumigaura Lake provides drinking water to the surrounding communities and is also an important site for tourism and fishing activities. Previously, this lake was comprised of a mix of fresh and saltwater because it was connected to the Pacific Ocean by two rivers. Since the construction of a dam in 1963 blocked these two rivers from the ocean, Kasumigaura Lake has only held freshwater.
Saroma Lake is the third largest lake in Japan by surface area. Its surface covers a total of 58.64 square miles, located in the Abashiri-Quasi National Park. This park is a Marine Protected Area and was established in order to protect all of the waterways in this area, which is located along the coast of the Sea of Okhotsk. Saroma Lake has an average depth of approximately 29 feet, although its deepest point measures at 64 feet. Additionally, it has 51.2 miles of shoreline surrounding its waters, which are typically frozen over between the months of December and March.
Lake Inawashiro is located to the south of Mount Banai in the Fukushima Prefecture. Covering a total surface area of 39.88 square miles, it is the fourth largest lake in Japan. Its deepest point reaches 310 feet below the surface, although its average depth is recorded at 169 feet. Lake Inawashiro is an important resource in the region, supplying water for agriculture, industry, and human consumption. Additionally, this lake plays an important environmental role by providing a winter habitat for large swan populations that migrate to the area until the spring season.
Nakaumi Lake is the fifth largest lake in Japan. It covers a total surface area of 33.28 square miles, with a length of approximately 39.45 miles and a width of 14.2 miles. This lake is surrounded by 65 miles of shorelines and its deepest point measures at 56 feet. The Sakai Channel connects Nakaumi Lake to the Sea of Japan, allowing the seawater to flow into and mix with the freshwater of the lake. An infrastructure of roads and bridges allows car traffic to cross this lake, as well visit the two islands located here: Eshima Island and Daikon Island.
The sixth largest lake in Japan is Kussharo Lake, which covers a total surface area of 30.61 square miles. This lake is located in the Akan National Park, where it has a coastline length of around 35 miles. Kussharo Lake is considered a caldera lake, which means it was created as the result of a volcanic crater. The island jutting up from its center, known as Nakajima, is actually a volcanic cone. This volcanic activity means the water in the lake is relatively acidic and does not create an ideal habitat for many freshwater aquatic species.
Shinji Lake is the seventh largest lake in Japan, covering a total surface area of 30.54 square miles. Its size is nearly identical to the previously mentioned Kussharo Lake. Shinji Lake is located in the Shimane Prefecture, where it has a shoreline of around 30 miles. It is a popular tourist attraction in the region and offers tourists recreational activities such as boating and hot springs. Additionally, this lake is connected to the Sea of Japan and its brackish water provides the perfect habitat for a number of species, like eel, clam, and sea bass.
The eight largest lake in Japan is Shikotsu Lake, which covers a total surface area of 30.27 square miles. This lake is located in the Ishikari Prefectures, within the Shikotsu-Toya National Park. Its deepest point reaches 1,191 feet and it has an average overall depth of approximately 870.7 feet. Like Kussharo Lake, Shikotsu Lake is also a volcanic crater lake. During the late 19th century, red salmon was introduced to this lake; today, it is a popular fishing spot with tourists and locals alike.
Toya Lake is the ninth largest lake in Japan and has a total surface area of 27.29 square miles. This volcanic crater lake is located within the Shikotsu-Toya National Park. It is home to the Nakajima Island, which contains the Toya Lake Forest Museum. Toya Lake has approximately 29 miles of coastlines and has an average depth of 383.9 feet. It stretches around 6.2 miles at its longest point and 5.6 miles at its widest.
The tenth largest lake in Japan is Hamana Lake, which is located in the Shizuoka Prefecture. This lake covers a total surface area of 25 square miles. Because of its irregular shape, Hamana Lake has 71 miles of coastlines. Its deepest point reaches 54 feet below the surface of the water, although its average depth is only 16 feet. An earthquake in the late 15th century caused this lake to be connected to the ocean, resulting in an ecosystem of brackish water.