In Costa Rica, the Sarapiqui river and several of its tributaries have a long history of recurrent overflows, generally related to the intensity of the rainy season in the Northern Caribbean. Many of the communities are exposed to the river flooding which is being exacerbated by the growing population in the flood prone areas, which increases the overall vulnerability of the community in the affected areas.
The 6.2 magnitude earthquake of 8 January 2009 in the Cinchona area had an important impact on the landscape and hydrological variability in the Sarapiqui basin.
The earthquake and associated landslides changed the risk scenario in the basin by changing the drainage patterns, and coupled with new risk areas for flash floods, mudslides and fallen trees in the riverbed, the regular behaviour of the river has been changed by the accumulation of sediments resulting from the landslides blocs and increases the level of the riverbed. For these reasons, it is necessary to identify the new risks and to support the organization of the communities in the areas of potential impact.
In this regard, the World Meteorological Organization (WMO), the National Meteorological Institute (IMN), the National Commission of Risk Prevention and Emergency Response (CNE), and the Instituto Costarricense de Electricidad (ICE) have combined efforts to develop a early warning system (EWS) at the Sarapiqui basin and to support the strengthening of the local capacities for the prevention and response of these hazards, through the “Costa Rica Early Warning System for Hydrometeorological Hazards Project”.
The project was highlighted in two GPDRR events, including:
This project was funded by the World Bank Global Facility for Disaster Risk Reduction (GFDRR) and was implemented in close coordination with the United Nations Development Programme (UNDP).
The purpose of the Project was to develop an effective framework for an operational early warning system at the Pilot Site of the Sarapiqui river basin in order to: (a) strengthen cooperation efforts between IMN and CNE in collaboration with other national government agencies and non-governmental organizations at the local level; (b) promote replication at other sites; (c) integrate the Costa Rica legal framework and policy instruments with existing standard operational procedures and protocols; (d) develop a feedback mechanism aimed to improve the preventive approach, overall coordination and operation during its design and implementation; and (e) provide IMN and CNE with the necessary tools to optimize the information for decision making.
The overall objectives of the project were to:
- Carry out an analysis of threats, vulnerability and mapping of hydrometeorological events in the Sarapiqui River basin.
- Carry out the hydrological and hydraulic modelling of the basin and design a protocol based on the rain and flow thresholds that act as input to broadcast the early warnings for flash floods, avalanches and floods.
- Carry out an analysis and facilitate a community simulation exercise of the early warning systems and work with the local communities to ensure the early warning system incorporates the additional information/data from the technical part of this project.
The project has led to unprecedented coordination and cooperation among the three national agencies, IMN, ICE and CNE, at national level and with over 50 Sarapiqui River basin communities. A simulation exercise on 28 February drew over 800 participants – some 500 volunteered to participate in an evacuation exercise coordinated by CNE, the police, the Red Cross and local authorities.