TAIPEI (Taiwan News) — While surveying the local landscape following the April 3 earthquake, the Hualien branch office of the Forestry and Nature Conservation Agency discovered a newly formed barrier lake, also known as a quake lake, in Xiulin Township.
The volume of the lake is estimated to be about 430,000 cubic meters, held back by a dam about 30 meters high, reported UDN. Barrier lakes, formed in the aftermath of earthquakes and landslides, are potentially dangerous due to the unstable nature of the lakebed and surrounding coastal sediment.
The agency previously recorded a small pond and tributary stream near the upper reaches of the Mugua River. Following a landslide on April 3 caused by the 7.2 magnitude quake, a natural dam was formed creating the lake, which now covers approximately 5.6 hectares.
The local government has organized a team of scientists to analyze and monitor the new lake, to determine if it poses a threat to settlements or infrastructure downriver.
If the natural dam fails, then two villages downstream, Dowmung and Rongshu, may be in danger. There are also two Taipower hydroelectric dams downstream which could be affected, per UDN.
The local government advised the public to stay away from the area for the time being as the new landscape settles. The unpredictable nature of such lakes means that they could fail in the short-term, or alternately, become a landscape feature that remains for thousands of years.
If the quake lake is deemed to be a serious threat to communities downstream, the government may decide to construct an artificial spillway to safely drain the lake in the months or years ahead.
