The landslide which struck on Friday blocked a section of Baimu River in Ya'an City.
Rising water washed out a small hydropower station in Tianquan County, causing one dead and three missing, while incurring power outage and disruption of wireless signals, state-run Xinhua news agency reported.
Local authorities had yesterday made an emergent work to open a channel for discharging the flooding water.
On Sunday, the risk of the barrier lake has been basically removed.