Tangjiashan Barrier Lake

Tangjiashan Lake was created on 12 May 2008 when earthquake-triggered landslides collapsed into the Jianjiang River valley north of Beichuan, blocking the river and creating a large barrier lake behind the debris dam. The lake — visible from the high ground above the old county seat — is a direct physical product of the earthquake: a new feature in the landscape that did not exist before that morning.

The lake can be viewed from several points along the road that passes through the area between the old county seat and the new Yongchang town. The dramatic scar on the surrounding mountain slopes, still clearly visible as lighter rock exposed by the collapse, shows the scale of the landslide event. The contrast between the placid-looking lake and the knowledge of how it was formed is the most geologically immediate piece of the Beichuan story.

things to do sight
A story
After the earthquake, the landslide that buried the Jianjiang River at Tangjiashan created a barrier lake that threatened to flood the towns downstream — including Mianyang, with a population of over a million. The drainage operation in June 2008, in which military engineers excavated a spillway channel through the landslide dam while a million people were evacuated from the downstream flood zone, was one of the most tense weeks of the post-earthquake emergency response. The lake that remains is a permanent geological feature created in a single morning.