The Same Mountains That Make Japan's Snow Also Make Its Water

In the 1890s a Dutch engineer working on Japan’s rivers looked at one running out of the Tateyama range in Toyama and reportedly said: this is not a river, it is a waterfall.

The line is usually attributed to Johannis de Rijke and to the Jōganji River. Records from the Toyama prefectural assembly, examined in 2020, indicate it was actually Anthonie Rouwenhorst Mulder, and that he was talking about the neighbouring Hayatsuki River. The misattribution stuck because de Rijke was the more famous man.

The reaction was fair either way. The Jōganji drops from the Tateyama range to the Sea of Japan — roughly 3,000 m of descent in about 56 km. European rivers of that length fall a tiny fraction of it.

And that steepness comes from exactly the same arrangement that buries Japan in snow.

One piece of geography, two consequences

Japan is a young mountain range on a subduction zone, and it is narrow. On the Sea of Japan side, peaks above 2,000 m sit only tens of kilometres from the water.

That produces the snow. Cold Siberian air crosses the warm Sea of Japan, saturates with moisture in a few hundred kilometres, hits those mountains, is forced upward, and unloads. When we ranked all 3,108 ski areas on earth by snowfall, 60 of the top 100 were Japanese, and the top one — Okutadami Maruyama, at 796 cm a season — sits in Niigata, on that coast.

And it produces the rivers. Water leaving a 3,000 m peak has only tens of kilometres to reach the sea. It cannot meander. It runs, fast, in a steep straight line.

What speed does to water

Water dissolves minerals from the rock it moves through. How much depends on contact time and on what the rock is.

Japanese water is in a hurry. It falls as snow high on volcanic and granitic rock, melts, and is at the sea within days. There is very little time to pick anything up.

The result is very soft water — low in dissolved calcium and magnesium. Most of Europe, where rivers run slowly across limestone for hundreds of kilometres, is the opposite.

This is not a small technical footnote. It shapes what Japan tastes like.

Sake. Soft water ferments slowly and yields a rounder, softer style. Niigata — the same prefecture at the top of our snowfall table — is one of Japan’s great sake regions, and that is not a coincidence. The snow that falls on the mountains in January is the water in the tank in March.

Dashi. The stock underneath most Japanese cooking is kombu and dried bonito steeped in water. Soft water extracts their glutamates cleanly. Try the same technique with hard water and it does not work as well. Ramen broth, in a ski town, at nine at night, is downstream of the same geology.

Onsen. The volcanic activity that raised the mountains also heats the groundwater. Nozawa Onsen and Zao are ski resorts because of the mountains and hot-spring towns because of the volcanism — one cause, two results.

A myth worth killing

You will sometimes read that Japan’s soft water is why the powder is dry.

It is not, and the claim does not survive a moment’s thought. Snow forms from water vapour in the atmosphere, and vapour is essentially distilled — it carries no minerals from any river. Ground water plays no part in it.

Japanese powder is dry because it is cold. Hokkaido’s air temperature at resort elevation stays reliably well below freezing, so crystals form cold, fall cold and land cold, keeping their structure. Honshu is warmer and its snow is measurably heavier — which is exactly why Niigata leads on snowfall volume while Hokkaido has the reputation for quality.

So the relationship between snow and water in Japan is real, but it runs the other way round. The mountains cause both. Neither causes the other.

What to do with this on a ski trip

Drink the tap water. It is soft and it is good, which is not true everywhere.

Drink the local sake. In Niigata, Nagano and Toyama the brewery is often within sight of the mountain you skied. Ask for the local one — jizake — rather than a national brand.

Go to the onsen after skiing, not before dinner. The Japanese order is ski, bathe, eat, drink. There is a reason it has survived.

In Toyama, look at the rivers. Drive out of Tateyama Sanroku toward the coast and you can watch a river behave like a waterfall for 50 km. It is the clearest visible expression of why you got so much snow that morning.

Where the numbers come from

Snowfall figures are the average of the three most recent completed seasons (2023/24–2025/26), from Open-Meteo historical data based on the ERA5 reanalysis, applied identically to all 3,108 ski areas worldwide. The model grid is 10–30 km across, so nearby resorts share a value and small differences between neighbours are not meaningful; regional comparisons are.

The Jōganji River’s gradient and the Mulder attribution are drawn from Toyama prefectural records as reported in 2020, which corrected a century of crediting the remark to de Rijke.