Study: The 22 April 1991 Earthquake in Limón, Costa Rica
22 April 1991, a 7.4 magnitude earthquake hit Costa Rica's Atlantic
region and caused severe damage to Limón City's sanitation
infrastructure. The earthquake cut off the supply of water from
the Banano River basin, which provided the Costa Rican Aqueducts
and Sewerage Institute (AyA) with 71% of the drinking water used
by Limón residents, companies and institutions. This disaster
forced AyA to carry out a series of emergency measures over several
months to satisfy the demand for water and temporarily rehabilitate
the affected systems before eventually replacing part of the infrastructure
after securing external funding.
objectives of the case study were to analyze the characteristics
of the event, the water and sanitation system infrastructure in
place, and the area's capacity to apply the disaster mitigation
guidelines developed by PAHO/WHO for such systems. The initial vulnerability
assessment and determination of the mitigation measures required
was made based on the information available before the earthquake.
In this way, the vulnerability assessment was later compared to
the actual situation on the ground in order to evaluate the accuracy
of the methodology employed.
analysis was based on the guidelines produced by PAHO/WHO's Pan
American Center for Sanitary Engineering and Environmental Sciences
(PAHO/CEPIS) and included in the publication Natural Disaster Mitigation
in Drinking Water and Sewerage Systems - Guidelines for Vulnerability
Analysis (PAHO, 1998), which is available in English.