Day Six Photos and Reflections

The following information and photographs come from the team visiting Llaca Lake and the Ranrapalca glacier. In addition to Nelson Santillan and Wayne Lamphiere, participants in this site visit included Matts Erikisson, Julio Alegria, Milan Shrestha, Adina Racoviteanu, Martin Leon Geyer, Pradeep Mool, Elliot O’Brien, Joe Teplitz, and Bob Davis.


At nearly 5000m in elevation, Llaca Lake is located in Peru’s Huascaran National Park. This is a glacial lake at the base of the Ranrapalca glacier and surrounded by high Cordillera Blanca peaks including Ranrapalca (6162m). In 1975, the lake was lowered 11 meters and dammed to prevent flooding, store water and control waves overtopping the glacial moraine and cascading down the valley below.

Llaca is was of 15 Cordillera Blanca lakes vulnerable to avalanches and considered dangerous enough to justify construction of a flood control dam. There are another 19 lakes in the region that have some sort of hazard control engineering—tunnels or cuts—to control or store glacier waters.

Llaca Lake in the foreground, with Ranrapalca glacier and peak in the background.


Scientists from Peru, the Himalayas, and the U.S. discussed the status of Llaca Lake and glacier and the likelihood that climate change and rapid glacier retreat is making the glacier much more unstable and hazardous.

Below, scientists on the field trip participated in taped interviews and discussed the possibilities for glacial lake engineering in other parts of the world, such as the Himalayas. They also agreed that there is much more scrutiny of environmental impacts of dam construction and glacier lake engineering now than when these first dams were constructed 35 years ago.