From the night of December 3 to December 4, heavy rains combined with simultaneous water discharges from multiple reservoirs inundated thousands of homes across the South Central Coast and Central Highlands. Many transport routes were severely damaged or cut off by landslides.
In Lam Dong Province, rising upstream floodwaters forced the Song Quao, Song Luy, and Song Long Song reservoirsto increase discharge to ensure dam safety. Numerous communes and wards in the province’s southeast were submerged.
In Lien Huong Commune, around 1,000 homes were surrounded by floodwaters overnight, forcing residents to flee. “Within just an hour, water rose to waist level. We only had time to grab the children and a few clothes before escaping to the main road for help. Most of our belongings were washed away", said local resident Nguyen Thi Huong.
By the afternoon of December 4, the flooding had submerged thousands of houses, sunk or swept away about 250 fishing boats, and caused severe losses to local fishermen. In Ham Thang Ward, floodwaters rose so quickly that authorities had to evacuate 1,500 households.
Major roads and infrastructure were heavily affected. National Highway 1A was paralyzed for hours in Hong Son and Song Luy communes. The Phan Thiet–Dau Giay Expressway was closed at Km25 due to deep flooding, while railway traffic through the Ma Lam–Long Thanh section was suspended as rising water overtopped bridges.
Lam Dong authorities dispatched inspection teams to flooded areas and instructed localities to prioritize protecting residents’ lives, setting up temporary shelters, and ensuring supplies of food, clean water, lighting, medicine, and other essentials.
In Khanh Hoa Province, prolonged overnight rainfall caused widespread localized flooding. Streets in Bac Nha Trang and Tay Nha Trang were submerged 30–50 cm, disrupting traffic and daily activities. Local resident Nguyen Van Binh from Vinh Phuong Commune reported that water began rising on the evening of December 3, forcing his family to stay awake all night to move furniture. Low-lying areas in Phu Trung in Tay Nha Trang Ward were also flooded—regions that had already suffered severe damage in late November’s storms.
In response, provincial authorities ordered reservoir operators to reduce discharge rates and regulate flows to minimize downstream flooding. Several schools were closed on December 4 to ensure student safety.
Multiple mountain passes in Lam Dong Province also suffered fresh landslides. On the morning of December 4, new slides along the Mimosa Pass in the National Highway 20 in Xuan Huong – Da Lat Ward blocked traffic for more than 10 hours before partial clearance restored one lane in each direction. At midday, a major landslide at Km224+600 – Km224+700 on the Prenn Pass cut off traffic entirely. The Lam Dong Department of Construction immediately banned all vehicles from the area until further notice, diverting traffic through the Mimosa, Sacom, and Ta Nung routes.
Earlier, on the night of December 3, heavy rains had also triggered slides along the Gia Bac Pass in the National Highway 28, sending mud, rocks, and fallen trees onto the road and blocking it.
By the evening of December 4, the Disaster and Dyke Management Authority under the Ministry of Agriculture and Environment reported that heavy rains from Thua Thien Hue to Lam Dong had caused flooding on rivers in Lam Dong, Khanh Hoa, and Quang Ngai. In Lam Dong Province alone, one person was confirmed dead and 3,296 homes were submerged.
