In the past, the right bank dyke of the Cau River was located at the riverbank.
Since 2002, to serve its socioeconomic development, Bac Ninh relocated the dyke about 40-50 meters away from its original position. Many households that were inside the dyke area are now outside of it.
Along the right bank dyke of the Cau River, the encroachment of the flood escape corridor and dyke protection occurs throughout a section of more than 8 km.
The Sub-Department of Irrigation and Water Resources of Bac Ninh has recorded 58 constructions violating the dyke protection corridor and flood escape corridor in Tam Da Commune of Yen Phong District since 2021.
Last Sunday, five homes and two incomplete buildings in Bac Ninh City collapsed into the river.
A five-story house under construction in Bac Ninh Province’s Tam Da Commune is only about 10 meters from the water's edge.
Nguyen Van Hai, the commune’s vice chairman, said the house does not have a land use right certificate and that people have expanded the foundation by encroaching on the riverbank.
“Tam Da Commune has a very dense population. People have been living along both sides of the river for hundreds of years, passed down from generation to generation. When they started rebuilding houses, we did visit and warn them not to encroach on the river, but then they still took advantage of it," he said.
Besides solid constructions, most of the houses encroaching on the flood protection and escape corridor of the Cau River are temporary, built with steel frames and covered with corrugated iron roofs.
Tho Ha ancient village in Bac Giang Province, is located opposite the area where houses fell into the river last week.
It has a population density of 20,000 people/km2, more than 40 times Bac Giang’s average population density, nearly 10 times that of Hanoi, and more than 60 times that of the whole country.
With a dense population and limited land area, people have to build houses right up to the river's edge.
People dump garbage into the Cau River.
Dam Phuong Bac, head of Bac Ninh’s Sub-Department of Irrigation and Water Resources, said there were four causes leading to the recent erosion at the river.
The objective reasons include the main flow pressing towards one side causing erosion, weak soil foundation, and the river's curvature; the subjective reasons are construction overload and dumping of garbage and construction waste that has obstructed and altered the flow.
In fact, erosion has been occurring along the bank for about two years now, and Bac Ninh has already invested in building embankments for protection.
The five houses and two buildings under construction collapsed into the river last Sunday in Bac Ninh.
Local authorities have since evacuated 12 other families who live nearby.
Bac Ninh Province has declared an emergency regarding dyke erosion, requesting relevant departments to quickly come up with a relocation and resettlement plan for people in the area, as well as to survey and assess the erosion to devise a suitable remedy.
