Water in El Chaltén

Western Southern Patagonia holds one of the largest freshwater reserves on the planet. Ice fields, glaciers, large lakes, rivers, waterfalls and streams make up a network that is constantly on the move, and that you will have close by on every hike.

Nature · 4 min read

Glacial origin

Thanks to the heavy snowfall on the high peaks of the Andes, and to a delicate climatic balance, the heirs of the last great ice age survive at these latitudes: the ice fields and glaciers. What you see today is a small sample of the ice sheets that covered the region some 20,000 years ago, when that ice age reached its greatest extent.

Glacier front with walls of blue ice and crevasses, above a lake
Glacier ice is fresh water stored for centuries.

The largest of all is the Southern Patagonian Ice Field, which stretches along the Andes between Argentina and Chile. After Antarctica and Greenland, it is the largest expanse of continental ice on the planet, and one of the world’s great freshwater reserves. The glaciers of Los Glaciares National Park flow down from it, and their meltwater, together with snowmelt, feeds the lakes and rivers of the area.

The Southern Patagonian Ice Field is the largest expanse of continental ice on the planet after Antarctica and Greenland.

From Fitz Roy to the Atlantic

The water you see flowing through El Chaltén makes a long journey to the sea. In the Argentine sector of the National Park, all of it ends up in a single river, the Santa Cruz, which crosses the province from west to east. This is the route from town:

  1. Lago del Desierto. North of town, surrounded by forests and hanging glaciers. The De las Vueltas River begins here.
  2. De las Vueltas River. It runs down the valley and is joined by other rivers, such as the Eléctrico. At El Chaltén it meets the Fitz Roy River, which flows out of Laguna Torre.
  3. Lake Viedma. The De las Vueltas River empties into this large lake, which is also fed by the Viedma Glacier.
  4. La Leona River. It flows south out of Lake Viedma and carries its water to Lake Argentino.
  5. Lake Argentino and the Santa Cruz River. The Santa Cruz River flows out of Lake Argentino and crosses the steppe to the Atlantic Ocean.

A drop that breaks away from a glacier on Fitz Roy can end up, hundreds of kilometers later, in the sea.

Clear mountain river running between rocks and lenga forest
The Eléctrico River, one of those that feed the De las Vueltas River.

The color of the lakes

Lakes and rivers fed by glaciers have very distinctive colors: turquoise, light blue, greenish or milky grey. They come from glacial flour, an extremely fine rock dust that glaciers produce as they grind the ground they move over. The dust stays suspended in the water and reflects light.

That is why Laguna Torre, at the foot of its glacier, looks grey, Lake Viedma has a milky tone, and the rivers coming down from the glaciers are cloudier than the crystal-clear streams that rise in the forest.

Caring for the water

Water will be with you on every hike and excursion: you will cross rivers and streams, walk along lagoons, sail on lakes and see glaciers and waterfalls. It is water of very high quality, and that is exactly why it needs protecting: any pollution stays in the system and travels downstream.

Lago del Desierto surrounded by forested mountains, with snow-capped peaks in the background
Lago del Desierto, where the De las Vueltas River begins.
  • Do not wash dishes or clothes, or wash yourself, in rivers, lagoons or streams. At campsites, use the washing areas, and never throw soap or food scraps into the water.
  • Use the campsite toilets. If there are none nearby, move well away from any watercourse and bury your waste.
  • Carry all your trash back to town.
  • If you go fishing or kayaking, check, clean and dry your gear when moving from one river to another, so you don’t spread didymo, an invasive alga.

When you arrive in El Chaltén, stop by the National Park Visitor Center: the rangers will tell you about trail and campsite conditions and how to look after this place. Addresses in Visitor Information Centres, and more tips in Recommendations.

Frequently asked questions

Updated: November 3, 2026

Almost all of it comes from the ice and snow of the Andes: meltwater from the glaciers flowing down from the Southern Patagonian Ice Field and from the mountains around Fitz Roy and Cerro Torre, plus the rain and snow that come in from the west.

The De las Vueltas River begins at Lago del Desierto, flows past El Chaltén and empties into Lake Viedma. From there the water follows the La Leona River to Lake Argentino, and then the Santa Cruz River, which crosses the steppe to the Atlantic Ocean.

Because of glacial flour: a very fine rock dust that glaciers produce as they grind the ground beneath them. It stays suspended in the water and reflects light, which is why glacier-fed lakes look turquoise, light blue or grey.

It is a vast expanse of ice stretching along the Andes between Argentina and Chile. After Antarctica and Greenland, it is the largest expanse of continental ice on the planet. The glaciers of Los Glaciares National Park flow down from it, and their meltwater feeds the lakes and rivers of El Chaltén.

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