Daily Landslide Observatory Report: March 21, 2026
1. Hawaii: Record Rainfall Triggers Life-Threatening Floods and Landslides
A powerful “Kona Low” storm system continues to batter the Hawaiian Islands, with the North Shore of Oʻahu facing catastrophic conditions as of March 20–21, 2026.
- The Event: Extreme rainfall—exceeding 400 mm (16 inches) at higher peaks within 24 hours—has saturated soils to the point of failure. Flash flooding and associated landslides have washed away roads and inundated homes in Haleiwa and Waialua.
- Risk Reduction: Authorities issued urgent evacuation orders for over 5,500 people. A primary concern is the aging Wahiawā Dam, which nearly reached its capacity (84 feet, just 6 feet shy of failure). Emergency services have rescued more than 230 people so far.
- Geotechnical Outlook: With grounds fully saturated from previous storms, even moderate additional rain is expected to trigger secondary landslides throughout the weekend.
- More Info: The Guardian Report | The Watchers Technical Update
2. USA: Major Landslide Shuts Down I-5 Near Bellingham, Washington
A significant landslide occurred on the night of March 19 and remains a major infrastructure crisis as of March 21, blocking all northbound lanes of Interstate 5 south of Bellingham.
- The Impact: Approximately 2,000–3,000 cubic yards of debris—equivalent to 300 dump trucks—is currently blocking the highway near North Lake Samish Drive.
- Mechanism: Engineering geologists suggest the slide was caused by joint failures in the bedrock of the Chuckanut Mountains, exacerbated by an intense “Atmospheric River” that has dumped up to 4 inches of rain in the region over the last several days.
- Risk Management: WSDOT geotechnical engineers are conducting on-site inspections today to determine the stability of the remaining slope before clearance can begin. Northbound traffic is being diverted, causing significant regional delays.
- More Info: Cascadia Daily News
3. Ethiopia: Death Toll Rises to 128 in Gamo Zone Landslides
New data released in the last 24 hours (March 20) indicates that the humanitarian toll of the mid-March landslides in South Ethiopia has continued to rise.
- Status Update: Local officials in the Gamo Zone confirmed that at least 70 people are dead, but search efforts for up to 128 missing persons continue across the woredas of Gacho Baba, Kamba, and Bonke.
- Damage Assessment: The disaster has displaced 575 households (roughly 3,480 people) and completely destroyed 190 homes. Flooding of the Kulfo River has also damaged over 30 buildings in the city of Arba Minch.
- Causal Link: The failures were triggered by exceptional rainfall in the Ethiopian Highlands, acting on steep terrain with high social vulnerability.
- More Info: GLIDEnumber Global Database | ReliefWeb Disaster Alert
Visual & Graphic Resources
- Satellite Monitoring: Use the GDACS (Global Disaster Awareness and Coordination System) live portal to find real-time flood and landslide alert maps for Ethiopia and Hawaii to embed in your post.
- Technical Schematic: For an “In-Depth” sidebar, a diagram of Pore-Water Pressure ($\mu$) versus Effective Stress ($\sigma’$) would effectively explain why the bedrock joint failure occurred in Washington after the Atmospheric River event.
- Open Access Photos: You can find public domain satellite imagery of these storm systems via NASA Worldview.