Background

As part of a city’s infrastructure, the essential public lines or networks provide well-being and quality of life, since they provide inputs for meeting everyone’s basic needs. In fact, one of the factors used to measure human development is the quality and efficiency of public services.  When natural phenomena occur, they impact not only life, but also property and infrastructure, among them these essential networks.  All actions aimed at reducing risk of disaster to essential networks will reduce the potential of a disaster and make it possible to quickly restore public services to society in its wake.

In defining activities for disaster risk reduction, an assessment must be made of the potential impact on infrastructure of different events and, to that end, better knowledge gained of the hazard and level of exposure of exposed elements, as well as better assessment made of expected loss or damage.  The Costa Rican Water and Sanitation Institute (AyA), aware of the needs for assessment of the country’s infrastructure in the event of disasters, has requested support from the World Bank to develop probabilistic seismic risk models for some of its infrastructure through the use of the CAPRA technological platform, and to build institutional capacities for risk assessment and for the design and implementation of vulnerability reduction measures.

In view of the situation described above, a technical assistance project (TAP) is now in execution, whose main goal is to build institutional capacities for probabilistic seismic risk assessment of existing water system infrastructure, through analysis and evaluation of the country’s three systems:  San José Greater Metropolitan Area, San Isidro, and Higuito.

Under the TAP, activities are being carried out to compile and analyze seismic hazard and local impacts in areas where the selected water and sanitation systems are located, to compile data on the main networks, the vulnerability curves for each component, and to assess maximum probable physical and economic losses resulting from potential seismic events. One output will be a seismic risk reduction program for Costa Rica’s water and sanitation systems.

Achievements

Compilation and analysis of the seismic hazard and site impacts 

Several regional and local studies of seismic hazard and microzoning for Costa Rica have been prepared. To execute the TAP, it was necessary to compile, analyze, and identify the seismic hazard parameters and transfer functions to create an .ame file for modeling using CAPRA.  Although this activity was carried out under a specific consulting assignment, today the Technical Advisory Committee (CAT) on Engineering and Risks is incorporating this assessment in different projects under way in the country, through the use of the CAPRA platform.  

Identification of exposed elements of the selected water and sanitation systems

In order to unify and standardize databases containing data on the characteristics of the selected networks, AyA prepared the existing inventories for use in modeling with CAPRA.  It was also necessary to conduct on-site surveys of some components for which data was lacking.  This activity has now been completed.

Establishment of vulnerability functions and their assignment to water and sanitation networks

The country had not prepared representative vulnerability curves for the different components of the basic water and sanitation systems.  Therefore, research had to be carried out on vulnerability functions prepared in other countries that could be used for the seismic risk modeling.  With ongoing advice from the consultant group hired by the World Bank, AyA selected the curves to be used in the seismic risk model. This activity is now in its final stage and the formats required for use with CAPRA are being adjusted.

Probabilistic seismic risk assessment

This activity seeks to integrate, through the CAPRA-GIS platform, knowledge of hazard, exposure, and vulnerability to determine probable physical and economic losses for the water and sanitation systems analyzed.  At present, AyA is collaborating with the National Institute of Insurance (INS) in conducting pilot tests in specific areas of the selected systems.  To make runs for systems, specific training will be provided for AyA professionals.

Seismic risk reduction program for Costa Rica’s water and sanitation systems 

One of the essential outputs of the TAP is a seismic risk reduction program prepared as guidance for the Government of Costa Rica, led by AyA, in projects and investments required in the short, medium, and long-term to obtain better knowledge, establish prevention and mitigation activities, and identify possible financial instruments for seismic risk reduction for the country’s water and sanitation networks. Thus far, AyA has identified actions for incorporation in the program.  However, based on the results of the CAPRA modelings, required action priorities will be set.  As part of these activities, AyA officials will visit cities in Colombia where risk reduction elements have been incorporated in their investment plan in order to gain awareness of lessons learned and take them into account in Program formulation.  This output will be available in January 2012.

Implement of the Seismic Risk Reduction Program in Costa Rica’s water and sanitation networks

• Safe location: Reducing risk (existing and future) resulting from poor location of infrastructure in relation to existing hazards.
• Safe construction:  Reducing risk (existing and future) resulting from inadequate design and/or construction of infrastructure vis-à-vis the requirements of the area. 
• Safe operation:  Reducing risk (existing and future) resulting from flows of services (operation and environmental impacts).

AyA will have a seismic risk reduction program for its networks that has been endorsed by the Technical Committee on Engineering and Risks of the National Emergencies Committee, for whose implementation resources are required.