Momiji Lake — A Lakeside Forest of 10,000 Maples
A Magical Contrast of Clear Water and Autumn Foliage
The reservoir created by Minowa Dam is commonly known as Momiji Lake, or “Maple Lake.” Approximately 10,000 maple trees have been planted around the lakeshore, creating an extraordinary display of autumn colors.
In late autumn, the vivid foliage forms a striking contrast with the clear blue surface of the lake. The scenery can resemble a traditional Japanese landscape painting, attracting large numbers of visitors and sightseeing buses during the peak autumn season.
The combination of colorful forests, tranquil water, and surrounding mountains makes Momiji Lake one of the most memorable places to experience the changing seasons in the Ina Valley.
A Place to Enjoy Throughout the Four Seasons
Momiji Lake is not only an autumn destination. Parks, campsites, and walking trails have been developed around the reservoir, providing opportunities to enjoy the landscape throughout the year.
In spring, fresh green leaves brighten the lakeshore. Summer brings the refreshing sound of clear streams and a cool mountain atmosphere. Autumn transforms the entire area with spectacular foliage, while winter brings a quiet landscape covered in snow.
Each season reveals a different character of Momiji Lake, making it a relaxing destination for both local residents and travelers looking to spend time in nature.
One of the Ina Valley’s Famous Autumn Destinations
Minowa Town lies in the Ina Valley, a richly forested region surrounded by the Central Alps and Southern Alps. In autumn, the mountains and valleys throughout the area are transformed by colorful foliage.
Among the many scenic locations in the region, Momiji Lake has become particularly well known as a major autumn destination. It has even been ranked No. 1 for three consecutive years in a nationwide recommended autumn foliage spot ranking.
The scale of the maple forest and the beauty of the lakeside scenery have made Momiji Lake one of the signature landscapes of Shinshu’s autumn season.
Why Minowa Dam Was Built
A Dam Created to Protect the Community
The Sawagawa River, where Minowa Dam was constructed, rises on Mount Moriya, 1,650 meters above sea level. The river is approximately 16.8 kilometers long and has a drainage basin of about 50.4 square kilometers.
Although the Sawagawa is now known as a clear mountain stream, the surrounding communities were once repeatedly affected by flooding during the rainy season and typhoons.
At the same time, groundwater was an important source of water for the region. As urbanization progressed and demand for water increased, there was a growing need for a more stable water supply.
Nagano Prefecture began preliminary investigations in 1972, followed by a full implementation survey in 1974. Construction began in 1980, and after 12 years of work, the dam was completed in 1992.
Supporting the Region’s Water Supply
In the same year that Minowa Dam was completed, the Minowa Water Purification Plant also began operating. Water from the dam has helped supply approximately 50,000 residents across five municipalities: Minowa Town, Minamiminowa Village, Ina City, Miyada Village, and Komagane City.
Minowa Dam therefore has an important role far beyond its scenic appeal. It is an essential piece of regional infrastructure supporting both disaster prevention and daily life.
A Forest Created with Local Memories in Mind
The beautiful maple forest around Momiji Lake has a story connected with the communities that once existed in the area before the dam was built.
Seedlings were donated with the hope that the future reservoir would become a place cherished by local residents and would preserve the feelings and memories of the people connected with the former settlements.
The trees were planted over a period of 10 years. Today, those efforts have transformed the lakeshore into a spectacular autumn landscape, allowing the area to remain closely connected with the people who live around it.
Parks and Activities Around the Lake
There are 13 parks of various sizes around Momiji Lake. Visitors can enjoy hiking, cycling, forest bathing, camping, and leisurely walks while taking in the surrounding natural scenery.
The area is particularly lively during the autumn Momiji Festival. Parts of the lakeshore are illuminated after dark, creating an atmospheric landscape that looks completely different from the daytime scenery.
Local specialties are also sold during the festival, while music events and other activities add to the festive atmosphere. During the foliage season, the entire area takes on a warm and colorful autumn character.
Access to Minowa Dam and Momiji Lake
By car, Minowa Dam can be reached from the Ina-Kita Interchange of the Chuo Expressway. From the interchange, travel south along National Route 153 and follow the signs near the Matsushima intersection.
From there, follow Prefectural Route 442 upstream along the Sawagawa River. As the road continues into the mountains, the scenery gradually opens onto Momiji Lake and Minowa Dam.
A Beautiful Meeting of Nature and Human Life
Minowa Dam and Momiji Lake offer more than beautiful scenery: they are a place where the natural landscape and the needs of the local community have become closely intertwined.
The dam was built to control floods and secure water resources, while the surrounding forests have become a beloved destination for recreation and seasonal sightseeing. The approximately 10,000 maple trees are particularly spectacular in autumn, when their brilliant colors are reflected on the calm surface of the lake.
Whether visiting during the vivid autumn foliage season, the fresh greens of spring, the refreshing summer months, or the quiet snow-covered winter, travelers can experience a different side of the Ina Valley.
For anyone exploring southern Nagano, a visit to Momiji Lake offers an opportunity to enjoy the beauty of Shinshu while also discovering how nature, infrastructure, and local memories can come together to create a remarkable landscape.