The Tangjiashan barrier lake is getting closer to bursting. Aftershocks and rainfall continue to increase the risk. The Ministry of Water Resources says the water has already started seeping out of the barrier dam as they monitor the lake's water levels.
A general view shows excavators digging division channels near the Tangjiashan lake in earthquake-hit Beichuan County, Sichuan Province June 1, 2008. Engineers have completed work to drain a lake formed by last month's earthquake that had threatened to inundate towns downstream and add to the toll of China's deadliest natural disaster in more than 30 years. [Agencies]
The Tangjiashan barrier lake held a volume of more than 212 million cubic meters at 7 p.m. Wednesday.
The water level has been inching up standing at almost 738 meters at 7 p.m. Wednesday. That was up 19 centimeters from 2 p.m. The water level was just 2.03 meters from the lowest point of the blockage.
Soldiers have dug a 475 meter channel to reduce the risk of bursting. But when the lake will be drained will be determined by water inflows from its upper reaches.
Meteorologists expect more rains around the Tangjiashan lake later this week.
A video supervision system has been set up monitoring 14 spots on the barrier lake and downstream. It's able to send simultaneous images to relief headquarters.
Water resources experts say it's a high risk situation and departments are on high alert to respond to the emergency.
Zhang Jian, Water Resources Expert of Mianyang Quake Relief Headquarters said "We will broadcast our videos on TV, and provide updates of the latest situation. It will help local people in downstream areas know what's happening and be ready. It will also help every phase of our relief work to run smoothly."
250,000 residents in Mianyang city have been relocated since the end of last month, as the Tangjiashan barrier lake, which may breach its barrier, threatens their safety.
(CCTV June 5, 2008)