In Hiep Thanh Commune, floodwaters surged rapidly at around 1 a.m., inundating multiple residential clusters. Local officials continuously issued warnings, urging people to avoid fast-flowing sections and organizing overnight evacuations for the elderly and those living alone. Emergency hotlines were activated to ensure timely assistance.
Along National Highway 20, floodwaters cascading from upstream submerged the roadway by 0.3 to nearly 1 meter, halting all traffic. Dozens of households along the route reported water rushing into their homes, damaging furniture and appliances.
In Da Lat, heavy rainfall also flooded several low-lying neighborhoods and areas along the Cam Ly Stream, with water spilling into houses as residents struggled to protect their belongings in the middle of the night. Major mountain passes—including Mimosa, Prenn, and D’ran—experienced fallen trees that obstructed traffic, while landslides on the Mimosa Pass prompted authorities to barricade the route and temporarily ban vehicles.
Mr. Khue Khuc Ky Nguyen, Chairman of the People’s Committee of Song Luy Commune, reported on the morning of December 4 that sustained rains sent a surge of floodwaters downstream, inundating about 300 houses in Binh Nghia Hamlet.
Local authorities swiftly evacuated residents to safe areas and assisted in moving belongings and livestock to minimize losses. A stretch of National Highway 1A running through the commune was also submerged overnight; by around 8 a.m., waters had receded, and traffic had resumed.
In Hong Son Commune, rising floodwaters at dawn swamped multiple houses. Chairman Le Minh Luan said the locality deployed two canoes and additional personnel to evacuate residents. Another heavily flooded segment of National Highway 1A near the Gop Intersection forced authorities to halt traffic and redirect vehicles to the Hoa Thang–Hoa Phu bypass.
At the same time, large upstream inflows prompted several reservoirs—including Song Quao, Song Luy, and Song Long Song—to increase discharge through spillways to protect dam infrastructure as rain persisted across their catchments. As of 6 a.m. on December 4, the Song Quao reservoir raised its release from 350 to 500 cubic meters per second. Long Song began discharging at 4:30 a.m. at 1,200 cubic meters per second, with further increases possible. Song Luy also adjusted its outflow from 100 to 150 cubic meters per second depending on rainfall conditions.
Binh Thuan Irrigation Works Exploitation Company has urged downstream communes and wards to immediately alert residents and take proactive measures to safeguard lives and property.
Reservoir release overnight floods 1,000 households
The Song Long Song reservoir in Lam Dong Province released floodwaters at a rate of up to 1,200 cubic meters per second, triggering widespread inundation that affected more than 1,000 households. Numerous assets were swept away, with initial losses estimated at over VND30 million.
According to the Lien Huong Commune People’s Committee, rapidly rising floodwaters caused 38 fishing vessels to sink or break free from their moorings and drift toward the Lien Huong Port entrance. In Hamlets 1 and 2, more than 1,000 homes were inundated to depths of 1–1.5 meters, plunging daily life into overnight chaos.
Agricultural zones along both banks of the Long Song River—covering former Phu Lac and Phuoc The communes—also recorded more than 100 hectares of cropland under over 1.5 meters of water, with livestock and poultry washed away.
Local authorities are urgently assessing the damage and mobilizing forces to support affected residents in recovery efforts.
According to the Lam Dong Hydrometeorological Station, rainfall on the afternoon and evening of December 3 reached exceptionally high levels. Specifically, Thuan Hoa recorded 120.3 millimeters, Dan Hiep (Ham Thuan Bac) 107.6 millimeters, Phan Tien (Song Luy) 71.4 millimeters, Lac Xuan 66 millimeters, Suoi Vang (Lang Biang – Da Lat Ward) 58.6 millimeters, Lam Vien – Da Lat Ward 58.4 millimeters, and D’ran Commune 58 millimeters. Several locations were placed under high-risk landslide warnings.
Late on December 3, Mr. Vu Duc Nhuan, Chairman of the People’s Committee of Son Dien Commune, confirmed multiple landslides along National Highway 28, particularly on Gia Bac Pass, resulting in a full traffic cutoff. Initial reports indicated landslides at Km43, Km45, and Km50, where large volumes of earth, rocks, and uprooted forest trees swept onto the roadway, blocking all travel.
Authorities quickly implemented traffic controls at both ends of the pass and temporarily prohibited passage to ensure public safety.
Gia Bac Pass had already suffered repeated landslides during the heavy rains of November 2025, prompting Lam Dong Province to issue an emergency order to undertake critical slope-stabilization works.
