Translated by Richard Perkins
Gensen Kakenagashi (Free-flowing Spring) - Japanese Encyclopedia
Written by ニコ
For those who love hot springs, it might be very important to know whether or not the water comes from a natural hot spring. This article explains the qualities of natural hot spring water.
Check If It's a Natural Hot Spring Before You Go!
When choosing which hot-spring to go to, die-hard hot spring fans will make sure to check and see whether or not the water used in the baths comes from a natural hot spring or not.
Natural hot spring water, or gensen kakenagashi in Japanese, is water that comes directly from the ground (free-flowing) and is used in the baths at hot-spring facilities. One characteristic of the water used at these types of hot-springs is that the water that overflows from the baths is not reused.
You might say that the attraction of the baths that use natural hot spring water is that they enable you to enjoy the actual hot springs themselves.
On the other hand, there are also baths in which water is added afterward, from the public waterworks. These are baths that circulate continuously, that filter out and remove the chlorine of the water.
What’s the Appeal of Natural Hot Springs?
There are three main methods of obtaining natural hot spring water.
The first method is to use the hot spring water that flows out from the crevices of bedrock up to the ground. Natural hot springs are often discovered as a result of natural disasters, such as volcanic eruptions, earthquakes, and so on.
Another method is to drill into the ground and bury a pipe. This method involves using water pressure to force the hot spring to spout. This method is used most often when building an area specifically for hot springs.
The last method involves pumping a hot spring by using an electric pump that’s deep underground. Because this method involves the electrical power of a pump forcefully drawing up the water, the danger of the hot spring running dry, as well as the harmful effects occurring to the source of the water or underground are very real. It is said that if you intend to obtain natural hot spring water this way, you must be very careful and constantly maintain the equipment.
The natural hot spring water that flows freely upwards and is used in the baths has, until that point, not come into contact with the outside air. For that reason, you can enjoy the original color, smell, and sensation of the water. On the other hand, this water has not been filtered and disinfected in the same manner as that which comes from a tap, which means that the minerals and the like can cause damage to the bathtub, pipes, and other physical parts of the hot spring facilities themselves over time. Keeping a hot spring in proper working order takes tremendous effort by bath operators and hot spring resort owners.
How to Enjoy the Water that Flows Directly from a Hot Spring
As the water in a gensen kakenagashi hot spring comes directly from the ground, the temperature of the water tends to be well-over 60 degrees Celsius (140 degrees Fahrenheit). For those who prefer showers, or are accustomed to taking a bath at home or at a public bath, you might be quite surprised by just how hot the water from a natural hot spring is.
For those of us outside of Japan, you might find it surprising to know that no matter how hot a natural hot spring may be, you should never try to thin it out or cool it down using regular water. Why shouldn’t you do this? Enjoying the water directly from the hot spring is one of the attractions to bathing in it, which would be lost by adding treated water to it.
When it comes to smaller Japanese inns that are run by families you’ll often only be able to enter the baths there at certain times. Often these types of baths are drawn so that the water in the bath is at the perfect and most relaxing temperature when it comes time to use them. For larger Japanese inns or other types of lodgings with a hot spring, they often have equipment which they use to cool down the water.
You might say that finding out about the different ways in which each of the hot springs and other facilities run their baths is part of the fun of visiting and bathing in them.
The most important part of entering a hot spring that uses free-flowing water is relaxing. If you find that the water is a little hotter than you might like it, it is a good idea to first place your feet in the water and slowly submerge yourself, as you acclimatize to the temperature. This way, you can also leisurely enjoy the smell and sensation of the spring water as well. This is also a good idea as it allows you to enter the water without overheating yourself too. There are usually spaces around the side of the bath or chairs set up nearby that you can use as you get used to the waters.
Where Can You Enjoy a Natural Hot Spring?
As much as we might like every hot spring to rely solely on free-flowing springs, the reality is that it takes a great deal of effort to maintain baths that use this water. As a result, not all Japanese inns and the like in hot spring resorts are able to use natural hot spring water. Even in famous areas, it is essential to check in advance where the water that's used in a particular facility comes from if you would like to enjoy a free-flowing hot spring experience.
In Japan, there are a number of areas that focus on whether or not their baths come from a natural hot spring or not. One of those areas is Totsukawara-mura, located in the southernmost point of Nara prefecture. This is a rather rare place; the locals claim that this was the first area in Japan to fully utilize natural hot spring water in their baths - all of the water used at all of the public baths in Totsukawara-mura comes from natural, free-flowing hot spring sources.
After having done some sightseeing around Tokyo, those who’d like to enter a natural hot spring public bath will want to head over to Nashushiobara, in Ibaraki prefecture. Here you will find Ebisuya, a Japanese inn with a traditional hot spring that is said to help cure people from various ills. At this establishment, there is an area where you can cook for yourself, meaning that you can stay for a long time in their accommodations if you choose.
For those who will be making their way to North Eastern Japan, we recommend Hotel Taikan, at the Tsunagi hot springs in the city of Morioka, Iwate prefecture. There you can enjoy natural hot spring water that’s at the perfect temperature for bathing in. The hot water has been collected by utilizing a slope, collecting water from a natural hot spring that runs downwards.
Many of the natural hot springs have a similar effect on the skin as body lotion; the contents of the water help to moisten and refresh your skin. In many cases, hot springs are considered not only a relaxation spot, but also a beauty spa-like place. As a matter of fact, a great number of public baths and Japanese inns with hot springs offer their own unique brands of natural hot spring-based skin care products as well.
A good example of this is Onsen Mist, part of the Tsunagi Onsen. This is a skin care product that is used both before and after putting on make-up and is manufactured from the simple alkaline-based sulfur spring water. Numerous other hot springs have their own mists, hand creams, and other such skin care treatments available for both men and women. For those of you who have the opportunity to enter a bath that takes advantage of natural hot spring water, how about trying out one of the skin care products as well?