Construction team begins lowering Matai'an Creek barrier lake

Taipei, Dec. 31 (CNA) A construction team has reached the crest of a barrier lake on Matai'an Creek in eastern Taiwan and begun efforts to gradually eliminate the rock and sediment blockage that formed the lake to drain the water and restore river flow, following a deadly overflow in September.

The Forestry and Nature Conservation Agency's (FANCA) Hualien Branch said Wednesday it commissioned the same contractor that previously removed the blockage that created Yanzikou barrier lake in Taroko Gorge to carry out the work during the non-flood season.

FANCA said the team advanced upstream along the creek bed, which has been raised and leveled by sediment deposited after earlier overflows, allowing tracked machinery to pass.

On Dec. 15, a 19-member crew deployed nine medium to large-sized excavators and bulldozers. However, about 500 meters from the overflow point, a collapse on the left bank buried several vehicles, though all operators escaped unharmed.

The team redeployed on Dec. 28 with 14 workers and five vehicles, successfully reaching the dam crest from where they proceeded to remove the rocks and sediment that created the barrier lake, FANCA said.

The agency said access along the original creek bed is only possible during the non-flood season and suitable for short-term operations. A separate access road under construction along the south bank will serve as a long-term route.

FANCA said the new road is expected to be completed by June next year, enabling continued slope stabilization, sediment control and emergency response.

Recent monitoring shows the barrier lake has held between 280,000 and 300,000 cubic meters of water in recent weeks, about 0.3 percent of its pre-overflow level, with unstable left-bank slopes and massive sediment deposits remaining key challenges.