What is Niyodo Blue?

The Niyodo River, which runs through almost the center of Kochi Prefecture, flows from Mt. Ishizuchi, the highest mountain in western Japan, and has been selected as a river with the best water quality eight times in the past 10 years by the Ministry of Land, Infrastructure, Transport and Tourism.

Local people started calling the beautiful blue color of the water Niyodo Blue. The blue water, suggestive of an overseas paradise, can be called transparent aqua blue or emerald green.
Because of that, Niyodo Blue doesn’t refer to a specific area and is much like a tagline that represents the beauty of this river.

In recent years, many tourists and photographers have visited the Niyodo River to take a look at Niyodo Blue.
The Niyodo River, which is said to be a miraculous clear stream, has created not only beautiful waterfront scenery but also people’s lives with the water and culture of the area.

The transparent blue water is not the only attraction that represents the Niyodo River.
Areas around the mouth of the Niyodo River are well known among surfers because some of the world’s best waves rise in these areas.
As well as surfing, there are many places and facilities in the basin where you can enjoy outdoor life, such as canoeing, fishing and barbecues.
Many bridges with no parapets that are submerged when flooding occurs cross the Niyodo River at important points and have become part of the scenery that represents Kochi.

Why does the water appear blue?

In general, water containing fewer impurities only reflects blue light (short wavelength light), which is why water is thought to appear blue.
The Niyodo River is actually quite steep and flows fast, so impurities are less likely to remain. In addition, algae are less likely to grow due to the relatively low water temperature, which is why the water remains transparent.

The color of the Niyodo River varies depending on the season and location due to the mix of sunlight and color of the sky. Niyodo Blue, which changes color due to the growth of algae and the strength of light, is at its best from mid-August to mid-January. There are many gorges and places in the Niyodo River basin where you can feel the power of Niyodo Blue, which appeals to people’s emotions.

→Go to the website featuring Niyodo Blue viewing places.

Industries that have been developed by the river

Kochi Prefecture has been famous for being a production area of materials used to make washi paper such as paper mulberry and paper bush for many years. The Niyodo River basin is the center of Tosa washi production, which is one of the three major washi production areas, along with Echizen and Mino. Underground water of the clean Niyodo River provides the water quality and abundant water resources perfect for making washi paper, enabling the production of a large quantity of high-quality Tosa washi paper.

Some breweries in the Niyodo River basin have continued the long tradition of sake making.
These breweries use abundant spring water for sake production, and the basin has prospered as a town of sake production for many years. The soft spring water of the Niyodo River features a slight sweetness and mild taste that lingers in your throat.