Introduction
Why are dams becoming popular for sightseers?
What are dam enthusiasts so fascinated about? A deep-dive into dams!
3 Great Dam Tours in Japan
>1. Matsubara Dam Pleasure Boat (Hita City, Oita Prefecture)
>2. Yamba Dam Lunch Tour (Naganohara machi, Gunma Prefecture)
>3. Nagashima Dam Interior Tour (Shimada City, Kawanehoncho, Haibara Ward, Shizuoka Prefecture)
Conclusion

Currently, dams are growing in popularity as tourist spots in Japan. They are huge infrastructures that block rivers and support our lives. Dams used to be widely criticized for their negative impact on nature but nowadays, a culture of dam enthusiasm is emerging. Many people find themselves fascinated by the visual impact and infrastructural role of dams.
This time, I will introduce the features and highlights of dams, along with some specific dams that offer tours of their facilities. If you learn the reasons why dam enthusiasts are fascinated by dams, you might come to understand the beauty of dams that goes beyond their infrastructural roles.

The massive Infrastructure overwhelms you! Why are dams becoming popular?

Dams have been built all over Japan. They are infrastructures that store rainwater and provide essential water for human life. It is said that nationwide, there are approximately 2,700 dams. Now, dams have become tourism resources that attract people. What kinds of things about dams captivate people? I will try to explore their features along with their basic information.

What is the role of dams?

Dams are indispensable for storing water for our lives. They have been constructed as massive water storages, which continuously store rainwater within their walls. Their water is directed for agricultural irrigation and daily use, and in the case of droughts and river-water shortages, the dam will release its contents into the river.


Ogo-uchi Dam in Okutama Tokyo

Japan has one of the higher precipitation rates in the world, which may make dams seem unnecessary. However, dams have one more important role in Japan, and that is flod control. Many Japanese rivers are long and steep. Once heavy rain falls they can flood easily, and in order to prevent this, dams have the important role of storing large amounts of rainfall and keeping them from suddenly moving from upstream to downstream. In Japan where typhoons are a common occurrence, dams are an indispensable infrastructure.
Other than that, dams have the function of powering subways with hydroelectricity, making themselves tight-knit parts with our daily lives.

What are dam enthusiasts so fascinated about? A deep-dive into dams!

From the point of view of Japan’s topography and weather, dams are indispensable. However, what are the reasons that dams have been attracting more and more people to visit and sightsee? I will introduce the highlights of dams.

Dams are overwhelming in person!


Japan’s oldest stone masonry multiple arch type Honenike Dam (Kagawa Prefecture)

If you see a dam for the first time, you might be astonished by its enormous size. Since the height of a dam is legally defined as 15m or more, dams are at their smallest size, a 15m-high wall towering before you. The contrast between the massive man-made structure and surrounding nature, is another fascinating thing about dams. 

The different types of dams

Although we tend to bundle them together as just “dams”, did you know that there are many types of them? Since dams take on different shapes depending on their topography and role, I heard that dam enthusiasts who have a lot of knowledge, can distinguish various dam types at one glance. What are typical types of dams?

■Gravity Dam
This is the most common type of dam. These dams are made from huge quantities of concrete, and are designed to block water with their sheer weight. At first glance it looks they look like flat walls, but if you view it from the side, you would notice it is a triangular shape that spreads towards the ground. The sense of stability gives quite the impression to anybody who sees it.

■Arch Dam

Kurobe Dam in Toyama Prefecture, the largest dam in Japan

A dam built with a horizontal arch. The wall is thin compared to a Gravity Dam, but the arch shape allows for dispersal of the water force on both sides of the dam. This type of structure needs stable bedrock to support the stress of water on both sides. The Kurobe Dam in Toyama Prefecture, the representative dam of Japan, is constructed with this design.

■Buttress Dam

Marunuma Dam, Gunma Prefecture, the highest bank in Japan
This style of dam is attached to a hollow shelf, called a buttress, on the wall surface. The buttress allows the water pressure on the wall to disperse. 

■Rock Fill Dam

Tokuyama Dam, Gifu Prefecture, a rock fill dam
Usually dams are made by using concrete, but a rock fill dam is constructed by rocks, earth and sand.  The center of the dam is solidified sand that makes it difficult for water to pass through. Stable rocks surround the sand.

Watch the dam discharge

The moment of discharge is when you can truly feel the scale of a dam. There are various types of discharging mechanisms. The “roller gate system” in which the gate moves up and down to release the water all at once, or the “natural adjustment system”, in which water automatically flows out when the amount of water exceeds a set level.  


Habu Dam gate in Aichi Prefecture
Both methods are designed to release water only in emergencies and it is rare to see the magnificent discharge escape during normal times. However, some of the large dams release water on scheduled days and times for tourists. 

Miyagase Dam, Kanagawa Prefecture, periodically discharges for tourists
In that case, instead of releasing water from the gate, it is discharged from the valve attached to the lower part of the gate. Viewing the huge amount of water gushing out from a small hole is the highlight! There is no doubt that you will be fascinated by the astonishing appearance. Nature’s force pushing water out of the dam with a roar is an astounding sight!

The History of Dams


Hakusui Dam, Oita Prefecture, called “The most beautiful dam in Japan”
Some dam enthusiasts like dams because of each structure’s history. Since all dams are man-made infrastructures, every dam has its own human histories. Many dams went through countless conflicts with local communities, have special anecdotes from their construction, or experienced great environmental change in their lifetimes. Following the historical ups and downs until each dams’ completion, is one of the many ways to enjoy dams.
Of course, it is also important to look at the real-life effects of the dam, on mitigating fluvial damage to human communities. Part of learning the appeal of dams, is thinking about their fierce battles with natural disasters!

Enjoy collecting “dam cards” and eating “dam curry”!

Recently, dam souvenirs and special foods have been created for tourists to enjoy during their visits to dams. Typical examples are dam cards and dam curry.

■Dam Cards
Dam cards are handed out to people who visit a dam with various information regarding the structure. On the front, there is a picture of the dam and name, the design of the dam and summary that indicates the type and function written in an alphabet code. The back of the card has information about the location, total water storage, shape and numbers of gates, and each dam’s unique characteristics. More than 1,000 kinds of dam cards are handed out all over Japan, including those officially issued by the Ministry of Land and those that are not. Usually they are free of charge, so please try to get them when you visit a dam site.

■Dam Curry

Dam Curry

Speaking of special foods related to dams, dam curry cannot be missed. A “dam” is created on the platter with rice, which can be broken to create a sight similar to a real-life dam’s discharge. This gimmick made dam curries incredibly popular. The most famous dam curry is at Kurobe Dam, but many other dams serve similar curries too. When you visit a dam, why don’t you try looking for dam curry at their shops?

Enjoy the dams with their surrounding nature! 3 Great Dam Tours in Japan

I recommend attending a dam tour for those who want to see a dam, but are not confident in the extent of their knowledge. In this final section of the article, I will introduce 3 great dam tours in Japan.

1. Matsubara Dam Pleasure Boat (Hita City, Oita Prefecture)

This is a tour to see Matsubara Dam and Shimouke Dam in Oita Prefecture. The main activity is a relaxing ride on the pleasure boat cruise on Matsubara Dam Lake, which stretches upstream from Matsubara Dam. The pleasure boat takes you around the so-called “Bairin Lake” (Plum Grove Lake), which was created by the dam, through a natural scenery of birds and lively trees. You might also see the submerged remains of roads and houses that predated the dam lake. Those underwater artifacts are signs of a gone era, and the villages that took root in the land before.


Matsubara Dam and Bairin Lake
On this pleasure boat, it is possible to go below Shimouke Dam, which stands right next to Matsubara Dam (depending on the water level). You can enjoy the rare experience of looking up at the only arch concrete dam on the Chikugo River from directly below.

【Information】
Operation Season: From October 2020 (tours not in operation as of September 2020)
Departure time: 10:00/12:00/14:00 *Varies according to the weather forecast or reservation status
Price: Adult ¥1,700 / elementary school student ¥800 / preschool ¥0
Reservation: required by the day before
Contact information: 080-6409-8718
Official website: Matsubara Dam Tour

2. Yamba Damu Lunch Tour (Naganohara machi, Gunma Prefecture)


Yamba Dam under construction (completed in April 2020)
This is a tour to see the Yamba Dam, which has just been completed and began full-scale operation on April 1, 2020. I recommend this dam for a group bus tour. The staff at the Michi-no-Eki (roadside station) Yamba Furusato-kan will board the charter bus and guide you around the dam. The tour lasts about one hour, and includes Yamba Dam and its surrounding tourist spots such as Fudo Falls. This is a great tour that not only gives you a local’s explanation, but also Yamba Dam Curry for lunch. Of course, you can get a dam card too. 

【Information】
Time required: About 1 hour
Price: One person ¥1,500 (from minimum 10 people) 
Reservation: Reservation required 5 days before visit
Contact information: 0279-83-8088
Official website: Yamba Dam Tour

3. Nagashima Dam Interior Tour (Shimada City, Kawanehoncho, Haibara Ward, Shizuoka Prefecture)


You can visit inside Nagashima Dam

This tour takes you inside the Nagashima Dam, which has a height of 109m and a width of 308m, and is located in Kawanehoncho, Haibara Ward, Shizuoka Prefecture. You can actually walk inside the main dam, through facilities such as the Audit Corridor used for patrolling and operating the dam, and the Gate Room, equipped with gate operation systems for controlling discharge. Since your tour will be accompanied by a management staff’s commentary, you will come out with a load of newfound knowledge, and a new appreciation for the many things making the dam special!
*When attending this tour, It is required to buy a round-trip ticket between Kanaya Station (the first station of the Oigawa Main Line) and Nagashima Dam Station (Igawa Line) when you attend this tour.

【Information】
Tour Date: Weekdays only
Time required: About 7 hours in total 
*Time including train round trip. The dam tour itself takes around 50 minutes.
Price: Adult ¥3,880 / child ¥1,940 
Reservation: Required 7 days before the tour. Reservation acceptance starts one month before the tour.  
Contact information: 0547-45-4112
Official website: Nagashima Dam Tour

Get Up-Close with the Massive Infrastructure of Dams!

The dams supporting our lives are not something that we see on a daily basis, but their powerful demeanors are sure to overwhelm you at first sight. The real feeling of being up-close to a dam is something best experienced firsthand, and is a greatly recommended experience. What type of dam are you looking at? What role does it have in aiding human livelihoods? You are sure to be fascinated by the deep world of dam enthusiasm!