Dozens of houses and stores in the Mekong Delta province of An Giang rushed to move out Monday after part of National Highway 91 collapsed into the Hau River.
The erosion, which started at around 5a.m. Monday, took a 70 meters long section of the road. Traffic on the highway was stopped for some time. As it was prime time at the Sam Mountain Deity festival at Chau Doc Town, vehicles were instructed to take other routes, including ferryboats.
Authorities said the situation will get worse and a further 180 meters of the road will be lost to the river in a couple days.
The Hau River has been getting closer to the road late last month when two houses fell into it and people in three others houses had to move out quickly. The erosion that time took a part 50 meters part of the highway and moved the river 15 meters closer to residents' homes.
Cao Van Be, director of the An Giang Department of Natural Resources and Environment, said a study of the river bottom near the highway found many underwater rivulets and big holes. "Those are severe threats to National Highway 91," Be said.
Around 340 meters from the latest erosion spot, authorities have found an underwater rivulet 20 meters deep, 70 meters wide and nearly 400 meters long, which is getting nearer to the river's banks.
There's also a hole 20 meters deep with a diameter of 60 meters near the spot around 30 meters from the river bank.
The Natural Resources and Environment Department has raised warning about severe erosion at any time.
It has ordered local governments to quickly move people living in riverside homes further inland to reduce the pressure on the river bank.
The An Giang Transport Department has started to take measures to strengthen the road and protect vehicles travelling on it.