Da Lat mountains are failing: a structural failure that requires immediate overhaul

On the night of Nov. 19, Mimosa Pass split open, and the entire roadbed slipped downslope, leaving a large void that nearly swallowed a passenger bus. That same night, an eight-year-old girl in Da Lat was rescued after rocks and soil collapsed behind her house while she was near the restroom.

A series of mountain passes around the city, Prenn, Ngoan Muc, D’ran, and Khanh Le, have been repeatedly eroded. Wherever the terrain is soil-based, the risk of landslides is present.

Land is slipping in multiple areas around Da Lat. With the ground saturated for prolonged periods, large sections of earth detach, not as small fragments, but as entire slabs sliding like liquid mud. As water breaks down the soil's natural bonds, it loses friction, strength, and structural stability.

Mimosa Pass in Da Lat is torn apart by landslides after days of heavy rains, Nov. 20. 2025. Photo by VnExpress

Steep hillsides rely on vegetation and intact soil layers to regulate water. The problem is not only the rainfall but our assumption that the land will stay stable regardless of how we build on it.

Houses have been constructed directly against slopes; new roads have been carved into steep terrain without adequate drainage. Some roads failed not only because of heavy rain but because their designs did not account for soil water content. When the ground becomes oversaturated, it can no longer bear weight, and the road surface is the first to give way.

To reduce the risk of landslides in Da Lat and other similar regions, three areas of action are essential:

First, restore natural structures. This does not mean reforestation for appearance’s sake, but the reintroduction of slope-stabilizing plants, and a review of hillside constructions that distort natural gradients, particularly residential clusters built along mountain faces.

Second, re-plan slope development. Construction of homes and roads cannot continue in areas with low safety coefficients. High-risk zones require periodic geological assessment.

Third, treat drainage as core safety infrastructure. Ditches, collection channels, wells, and water conduits must be designed to proper standards and kept unobstructed.

Fourth, during peak rainy seasons, real-time landslide maps and 24/7 warnings are necessary for road users, especially for passenger vehicles and freight transport.

Land slips because natural systems have been degraded. Instead of lamenting after each storm, what is needed is planning, responsibility, and long-term vision. Only by restoring balance between human development and natural systems can the land remain stable.