Tunisia's Sidi Bou Said is running out of time as landslides follow storm

Sidi Bou Saïd, Tunisia's postcard-perfect coastal village overlooking the Mediterranean, has long symbolised artistic heritage, tourism prestige, and national identity. But after extreme rainfall battered the town earlier this year, cracks spread across parts of its iconic hilltop, forcing evacuations, triggering emergency government meetings, and raising fears that one of North Africa's most recognisable heritage sites is entering a dangerous new era.

Within 48 hours in January, the town recorded nearly 300 millimetres of rainfall, roughly three-quarters of its annual average. The deluge forced authorities to evacuate eight properties deemed at immediate risk of collapse, restrict heavy vehicle access to vulnerable areas, and warn residents to monitor their homes for structural damage.

The emergency response was swift and sweeping: authorities banned large, loudspeakers, suspended public events, and prohibited tourist buses and heavy transport vehicles from accessing hilltop parking zones to reduce pressure on terrain already considered geologically fragile.

Yet scientists and residents agree the crisis was decades in the making.

Geologists have long warned that Sidi Bou Saïd's dramatic coastal setting is also its greatest vulnerability. The village sits atop steep slopes composed of sandstone, clay, and loose sandy deposits, materials highly susceptible to water saturation and ground movement.

"Clay layers can lose up to 70 per cent of their cohesion once saturated," said Chokri Yaïch, a university professor specialising in geological sciences. "When combined with steep slopes and fragile soil composition, even short periods of intense rainfall can destabilise the hill."

The January storm added approximately 400 kilograms of additional weight per square meter of soil, enough to disrupt already fragile ground stability, according to Yaich, but the threat extends beyond rainfall alone. Marine erosion further compounds vulnerability: parts of the coastal base are retreating by up to 50 centimetres annually as waves gradually weaken the hill's structural foundation.

Geomorphologist Wadii El Aroui emphasises that these risks have been documented for generations. "Sidi Bou Saïd has always been predisposed to landslides," he said. "The rainfall simply acted as a triggering factor for conditions that have existed for decades."

Accelerating coastal risk

Experts warn that climate change is intensifying structural threats along Tunisia's coastline. Stronger storms, rising sea levels, and increasing erosion are placing mounting pressure on heritage sites built along cliffs and vulnerable coastal hills.

Yaïch points to a cascading environmental problem. "Repeated storm surges are causing long-term sediment loss along Tunisian beaches, weakening natural coastal defences. When sand disappears, beaches lose their protective barrier, and storm waves then hit cliffs directly, accelerating destabilisation."

Scientists also warn that rainfall patterns are becoming increasingly intense and unpredictable, heightening the likelihood of sudden landslide-triggering events. What was once predictable becomes erratic; what was rare becomes routine.

Environmental stress has coincided with rapid tourism growth and infrastructure expansion. Construction activity on Sidi Bou Saïd's hill has increased by roughly 40 per cent over the past three decades. But the strain extends far beyond buildings themselves.

"Sidi Bou Saïd receives hundreds of thousands of visitors each year," said Shadi Sfaxi, head of Tunisia's independent tourist guides union. "During peak seasons, dozens of large buses transport tourists daily to the hilltop parking areas. Each vehicle carries significant weight, adding pressure to an already fragile landscape."

Sfaxi emphasises that warnings about excessive visitor capacity predate the crisis by years.

"The problem is not tourism itself. It is the absence of sustainable visitor management," he said. "Sustainable tourism is not a separate activity. It is a model of development that requires coordination between ministries, infrastructure planning, transport policy, and heritage protection."

He notes that alternatives once existed. In previous decades, lighter shuttle systems transported visitors up the hill rather than heavy buses. Over time, these measures were phased out in favour of more efficient but structurally damaging transportation models.

"This was a predictable strain. Warnings were raised years ago that the site's capacity was being exceeded," Sfaxi said. The landslides, in his view, expose the limits of a tourism model that depends on concentrated visitor flows in fragile coastal zones.

Despite mounting environmental risks, Sidi Bou Saïd is not an unregulated urban space. Preservation laws governing its architecture date back more than a century. Aly Cherif, a Sidi Bou Saïd resident and member of the committee preparing the town's UNESCO World Heritage nomination, noted that the village was officially classified as protected national heritage in 1915.

"There are strict regulations controlling construction styles, colours, and urban design," Cherif explained. "Sidi Bou Saïd has always been treated as a protected cultural landscape."

However, these rules were primarily designed to preserve aesthetics and historical identity rather than to address climate-driven environmental threats. Heritage protection, it turns out, does not automatically mean environmental protection.

Government response

Following the landslides, Tunisian authorities launched both immediate and stabilisation measures. The regional disaster response committee ordered the temporary evacuation of eight vulnerable properties and restricted heavy buses and trucks from fragile sections of the hill. Authorities intensified drainage maintenance operations, clearing storm water channels and reinforcing water evacuation infrastructure to reduce soil saturation during future storms.

By February, Tunisia's Ministry of Equipment and Housing announced a stabilisation project targeting the hillside and coastal strip, integrating Sidi Bou Saïd's protection into broader national infrastructure planning. President Kais Saied later emphasised the importance of safeguarding Tunisia's cultural heritage as a national priority.

The crisis also carries implications for the village's international standing. Sidi Bou Saïd is currently under review for UNESCO World Heritage status, a designation that could strengthen conservation efforts and unlock international funding.

"UNESCO provides recognition," Cherif said. "But recognition also makes it easier to access global funding programs dedicated to heritage protection."

He added that natural hazards alone do not disqualify heritage sites from UNESCO classification. "What matters is how authorities respond to threats. Demonstrating political commitment can strengthen the nomination."

Heritage crisis

For the families who inhabit this iconic landscape, the crisis has transformed daily life. "Considering the scale of the rainfall, the fact that no lives were lost remains a blessing," Cherif said. But survival came at a high cost.

Authorities ordered evacuations of homes at risk of ground movement, forcing families to abandon properties often passed down through generations. Some residents initially resisted, preferring to remain in their homes despite the danger.

Cherif describes Sidi Bou Saïd as a "living village" rather than a static monument. "It is not only architecture. It is social memory and daily life."

That daily life is also tied to tourism-driven livelihoods, an economic reality now disrupted by safety restrictions. Hassan, 45, a business owner operating near the Sidi Aziz upper parking area, exemplifies the human cost.

"We have worked here since 2011. Suddenly, we found ourselves without work," he said. He is among eleven families whose businesses were closed as a precautionary measure.

"When tourism stops, everything stops," Hassan said. "Families need protection, but they also need solutions." Uncertainty surrounding relocation and compensation remains a major concern for displaced residents and workers.

Engineering solutions

Long-term protection of Sidi Bou Saïd will require structural engineering, environmental adaptation, and stronger collaboration between scientists and policymakers, experts say.

Yaïch recommends a comprehensive approach: beach restoration projects to rebuild natural coastal defences, offshore breakwaters to reduce wave impact, and modernisation of drainage infrastructure to limit water infiltration into fragile clay layers. He also stresses stricter monitoring of private water systems, including swimming pools and sewage networks, which may leak into the soil and compound saturation problems.

El Aroui emphasises the need for preventive monitoring systems capable of detecting early warning signs of ground movement. He argues that scientific landslide-risk maps should systematically guide future urban planning, tools that he says have existed for years but were not consistently integrated into policy.

"There has historically been a disconnect between universities and decision-makers," El Aroui said. "If scientific risk maps had been systematically applied, many vulnerabilities could have been reduced."

Both experts agree on one critical priority: controlling water infiltration. "Water is the main driver of landslides here," Yaïch said. "If drainage systems fail, rainwater will carve its own path through the hill." Prevention, in other words, is fundamentally a problem of water management.

"When prevention is delayed," Yaïch said, "disaster becomes inevitable."

For now, evacuation orders, emergency repairs, and policy debates continue. Residents, scientists, and policymakers are racing against geological forces reshaping one of Tunisia's most cherished landscapes, and against time itself.

This article is published in collaboration with Egab.