Why did ”Kegon Falls” change to "Kegon Walls" ?

One of Japan's representative waterfalls, Kegon Falls, is facing significant challenges.


Standing at a height of 97 meters, Kegon Falls is a spectacular sight and one of Nikko's iconic tourist spots. However, due to a severe lack of rain since autumn 2023, its scenery has dramatically changed.

Let's introduce the current state of Kegon Falls, which has been altered by record-low rainfall.


**Current State of Kegon Falls**

Today is June 19, 2024. Normally, the rainy season would have begun by now, but this year it's significantly delayed, with temperatures in Nikko nearing 30 degrees Celsius.

Kegon Falls cascades down from Lake Chuzenji, located beyond the Irohazaka Slope.

Due to the lack of rain, the volume of water flowing into Kegon Falls has drastically decreased. As a result, it has transformed into a landscape resembling "Kegon Walls."

For those who have traveled far to see this grand scenery, it might be quite disappointing. While this altered view of Kegon Falls is a rare sight in itself, it lacks the usual thunderous roar and resembles more of a misty shower. The surrounding "Twelve Falls," quietly flowing down, actually seem more prominent.


By the way, last autumn before we worried about the water level, this is what the scenery looked like.

I hope we can continue to see this landscape for a long time, but if the abnormal weather continues, Kegon Falls may disappear someday. Let's examine the two potential futures where Kegon Falls will disappear.


**Possibility 1: Drastic Reduction in Precipitation**

If we continue to experience such conditions, with no prolonged autumn rains and little winter snowfall, the water levels of Lake Chuzenji will only diminish further. If global warming continues to accelerate, what will happen?

Compared to decades ago, summers have become extremely hot, and winters see less snowfall. Subjectively, the seasons of spring and autumn are becoming shorter and shorter.

The frequency of Lake Chuzenji's water levels decreasing every few decades has now become every few years. If Kegon Falls were to become a thing of the past for future generations, it would indeed be a great loss.


**Possibility 2: Collapse Due to a Major Flood**

Another scenario is the potential collapse of Kegon Falls.

Located in Lake Chuzenji, one of the highest elevation lakes in Japan, the formation of Kegon Falls and Lake Chuzenji itself was greatly influenced by volcanic activity from Mt. Nantai.

Over 10,000 years ago, a major eruption of Mt. Nantai blocked river flows, resulting in the formation of Lake Chuzenji. The volcanic ash and pumice deposited in the area were easily washed away by heavy rains, causing repeated landslides on parts of Mt. Nantai.

During the 1902 typhoon, sediment flowed down to the city of Nikko downstream, causing significant damage, including the collapse of the then-existing Shinkyo Bridge.

The surroundings of Kegon Falls also contain a significant amount of easily collapsible volcanic ash and pumice.

Historically, Kegon Falls was believed to have been located about 800 meters downstream, and has repeatedly collapsed to its current position due to landslides.


In 1935, a rock slab at the top of the falls collapsed, directly hitting a tea house near the basin, resulting in the unfortunate loss of four lives. Another collapse occurred in 1986, prompting mitigation efforts.


What we need to consider here is the opposite story of the drastic reduction in precipitation mentioned earlier. With the increase in typhoons and floods caused by linear rain bands, abnormal weather patterns that pour heavily down are becoming more frequent.

Kegon Falls, which gradually collapses, may collapse in a short period of time if a record heavy rain occurs. This is a story told by history, and it's not a matter of whether it will collapse or not, but rather when it will collapse.

Eventually, it is certain that a level of sediment collapse will occur that cannot be controlled by civil engineering works.


In any case, in the future, Kegon Falls will disappear, and the scenery around Lake Chuzenji will surely change completely.



We've discussed the possibility of Kegon Falls, a tourist attraction, disappearing.

While we want to continue enjoying this view, we may feel that we are merely gazing at a fleeting moment in tens of thousands of years.