1996 Arinsal Avalanches: Evacuations and Defenses Save Lives

On 8 February 1996, two avalanches hit Arinsal in quick succession, burying roads, the river, vehicles, and eight buildings under up to six metres of snow, trees, and debris. No one was killed or injured thanks to the evacuation of around 300 residents and visitors.

Heavy snow that winter had already suspended ski operations. Workers including Albert Reyes waited near the 1,500-metre chairlift base. Around 10am—about an hour before police closed the road—the first slide from Percanela triggered naturally, blocking roughly 100 metres of roadway. The ski station notified firefighters, police, and Red Cross teams, who spent hours probing the site with station staff to ensure no one was trapped.

Local fears then focused on Les Fonts, a major slide path dormant for years but long recognised as dangerous. This led to precautionary evacuations. Reyes was among the last to leave his home at 5:45pm under police escort, with guards posted to enforce compliance despite snow hampering departures.

Between 6pm and 7pm—some 10 hours after Percanela—the much larger Les Fonts avalanche released nearly 1.8 million cubic metres of snow from almost the entire basin. It created a 1.2- to 2-metre fracture in the snowpack, surged across the road at over 300 km/h with pressures above 600 kPa, dammed the river, damaged infrastructure, and shifted a police vehicle through wind and spray. Firefighter Oscar Santos inspected the area, directed hotel clearances, and organised search teams of firefighters, police, and piste workers to check for trapped cars or pedestrians. "There were no deaths or injuries," Santos said.

Sergi Riba of Nivorisk called the event a turning point. His 3D simulations showed the avalanche's force far exceeded damage thresholds for standard buildings, making evacuations essential to avert catastrophe. It prompted national changes, including nine GAZEX systems—fixed tubes for controlled explosions—installed starting in 1999 and completed by 2007 in the Fonts release area. Two 18-metre containment dykes and an upstream flat zone were added in the impact area to redirect flows away from homes. "These measures complement each other and all but ensure an avalanche cannot reach the village," Riba said.

Systems have since gained reliability. Early radio activation sometimes failed, causing issues, so 4G control was added in 2018. Each winter sees about 10 preventive blasts, even for 30-40cm accumulations, supported by post-snowfall reconnaissance flights, helicopter manual detonations if required, and a nivometeorological station tracking snow and weather in real time. Risk level 3 requires confinement; level 4 prompts evacuations, as occurred in 1996, with blast areas closed temporarily during operations.

A 2015 preventive blast at Fonts released a wet snow slide reaching Prats Sobirans road but caused no harm, reinforcing the need for vigilance. The 2022 Arinsal Emergency Plan improved team coordination, procedures, and response capabilities. Marking 30 years since the event, Protecció Civil has highlighted on social media how preventive systems, constant monitoring, and refined protocols now offer much stronger safeguards. "We carry out preventive blasts whenever we detect small snow build-ups," Riba added, stressing the shift to earlier action. "After every snowfall, we conduct reconnaissance flights to secure the area."