◾️ Kumamoto, home to some of the richest groundwater in the world

For many people living in Japan, Kumamoto is a place that brings to mind the magnificent scenery of the volcanic caldera, one of the most impressive castles in Japan, well-priced and tasty rice, and friendly locals who happily share a drink and a laugh with anyone. All of this is true, but is it the essence of Kumamoto? The answer is No. The land of Kumamoto is easily defined by these distinctive traits. But what few people know is that there is a much deeper and fascinating story embedded in the soil of Kumamoto. This story is the essence of everything that binds these traits together, that is Kumamoto.

The truly breathtaking scenery of the volcanic Aso caldera that has stolen the heart of so many visitors, and Kumamoto Castle, which still stands proudly reaffirming its place as the symbol of the city even after being severely damaged by the 2016 earthquake. Major sights such as these earn Kumamoto a given place as one of the major actors in the world of Japanese tourism. But few connect Kumamoto to groundwater so clean and plentiful that you can rarely find its counterpart, even on a global scale.

Tap water in Kumamoto City provides the foundation for the everyday life of almost 1 million people. Almost all of this is covered by unprocessed groundwater. Utilizing rivers for water is normal, but the fact that a city of this size is supplied only by groundwater is very rare. In Japan, of course, Kumamoto is the only place that can make this claim. High-quality mineral water flows from any household tap. In most Japanese cities you need a water purifier to drink tap water but in Kumamoto, you can always access delicious water. To clarify even further, even the water that flows from the showers and flush the toilets is crystal-clear top-class mineral water!

The explanation as to why Kumamoto is blessed with this unique feature can be found in the Aso volcano. During a period of about 270,000 years to 90,000 years ago, four large pyroclastic flow eruptions changed the topography of not only Kumamoto but large parts of south Japan. Due to these four eruptions, a thick layer of volcanic soil that easily absorbs and accumulates water was formed in Kumamoto. Furthermore, about 400 years ago, the samurai who controlled Kumamoto made large-scale cultivation of the lands increasing the number of paddy fields rapidly. Paddy fields, upland fields, grasslands, and forestlands, places where water can soak in and be stored are often referred to as “groundwater recharge areas”. Thanks to the increased recharge possibility a unique water circulation system, which also serves as a huge production machine for mineral water, came to be in Kumamoto.

The rain that falls in Aso is absorbed and soaks into the ground, a 20-year cycle polish and refines it through the layer of volcanic earth that is the legacy of Aso’s violent past, at long last the water emerges once again to support the everyday lives of over a 1 million people.

Tourism is often about what you see which makes a 20-year cycle hidden underground hard to appreciate. But that is exactly why this “invisible story” deserves to be told and truly should be shared with the world. Not only because it is rare and fascinating, but because it is the driving force and essence of the wonderful land of Kumamoto.

◾️ Various shapes of water, and their blessing

“Mineral water straight from the tap” is a common phrase used when the people who live in Kumamoto talk about water, but the fact that the water from the faucet is the closest and most direct shape that Kumamoto’s groundwater takes as it appears in people’s life should be easy to understand even for outsiders. Kumamoto’s tap water actually contains 30 to 100% more mineral components such as calcium, potassium, magnesium, and silicon than the average mineral water sold on the market. This tap-water that nurtures the food culture and improves people’s health is a blessing that the people of Kumamoto always keep close in their hearts.

Natural spring water gushes forth all over Kumamoto. Some of these springs, such as the Shirakawa river source, Kikuchi river source, and Lake Ezu, are also known as sightseeing spots due to the beauty and raw power of the springs, but there are countless other river sources and natural springs around Kumamoto. There are still many small communities where people live by utilizing and sharing the water from such springs. Kinpo-zan is one area where you can find such small villages that once a year gather to celebrate the blessing of the water. Gratitude towards water is a central part of Kumamoto’s culture and has been carefully protected and passed down through generations.

Another of the many shapes that the water takes, which is widely beloved and one of the main reasons why visitors travel from afar, is hot springs. In Japan known as ‘onsen’. Even in Japan, the land of onsen, Kumamoto’s presence as a heaven for onsen-lovers is undeniable. Famous hot spring areas such as Kurokawa onsen, Yamaga onsen, Tamana onsen, and Ueki onsen are only a few in an endless line-up of onsen areas scattered around Kumamoto. This hot spring culture is also the product of a union between the groundwater and volcanic activity which heats and forces this heavenly water to reappear and bless Kumamoto.

In Kumamoto, there is a Japanese garden called Suizenji Park. Constructed in the latter half of the 17th century, this park is characterized by its artificial hills but even more by its large central pond that consists of spring water. Ponds are normal in Japanese gardens but very few are actual natural springs. Thanks to this, the water is extremely clear and you can watch carps, turtles, and water birds that almost seem to be floating in the air as they swim in the serene lake. Step down to the water’s edge and submerge your hands in the clear water, feel the connection through time that binds Suizenji Park as a cultural heritage of the samurai era together with the present through the treasure of Kumamoto, the ever-flowing groundwater.