As families this week mourned the loss of relatives and their homes, people are asking: “What went wrong?”
Seismologists and engineers say much of the damage wrought by the Jan. 8 earthquake could have been prevented if municipalities had enforced seismic codes and prohibited construction in high-risk areas.
For Olman Vargas, head of the Federated Association of Engineers and Architects, some 60 percent of the damage was avoidable.
Walter Montero, geologist at the University of Costa Rica (UCR), said the now-devastated highway running from Vara Blanca to San Miguel de Sarapiquí was poorly designed. The road dipped onto the mountainside, rather than sticking to the safer and flatter crest between the Sarapiquí and Angel rivers, Montero said.
Homebuilding was also poorly regulated, scientists said. People built homes on the sides of mountains, leaving themselves vulnerable to landslides, said Alvaro Poveda, an engineer who inspected the affected areas this week. Others built homes on the edge of steep drops, risking a fall down the mountain if the soil caved.
Other houses were poorly constructed and vulnerable to collapse, Poveda said. In Poasito, just a few kilometers from the epicenter, Poveda saw a house in perfect condition 200 meters away from a house with a collapsed wall. The difference? One was built with more concrete.
“It’s like cake. Two cakes might look the same … but the flour is different,” he said. After visiting 70 percent of the affected area this week, inspectors identified 400 houses as destroyed and another 400 as heavily damaged, said National Emergency Commission (CNE) spokesman Reinaldo Carballo.
Municipalities, the Health Ministry, and CNE are responsible for ensuring houses are built in secure areas, said Heiner Méndez, a lawyer and former San José city official.
But José Joaquín Brenes, mayor of the hard-hit canton of Poás, said evacuating unsafe houses is a costly and time-consuming process. If the occupants do not comply with an order to evacuate, the municipality must bring a case before a three-judge tribunal. Meanwhile, people continue to build without permits from the municipality, which does not yet have a zoning plan.
“These people are very difficult to control,” Brenes said.
Carballo said the CNE also knew that people were living in risky areas – on river banks and mountain slopes. And the CNE knew an active fault near Poás Volcano could someday cause an earthquake.
But, he said, CNE could not predict when the quake would occur or what magnitude. It would not make sense, he said, to relocate everyone living in substandard housing near active fault lines, which crisscross the country.
Mass relocation is not the solution, acknowledged Mauricio Mora, a UCR seismologist. “But if we apply rules on construction and city planning … we can minimize the damage.”