Planning and Development of Costa Rica Water Resources: Current Status and Perspectives
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Planning and development of Costa Rica water resources: current status and perspectives Planificación y desarrollo de los recursos de agua de Costa Rica: situación actual y perspectivas Isabel Guzmán-Arias1 Julio C. Calvo-Alvarado2 Fecha de recepción: 26 de marzo del 2013 Fecha de aprobación: 4 de agosto del 2013 Guzmán-Arias, I; Calvo-Alvarado, J. Planning and development of Costa Rica water resources: current status and perspectives. Tecnología en Marcha. Vol. 26, Nº 4. Pág 52-63 1 Escuela de Ingeniería Agrícola, Instituto Tecnológico de Costa Rica, Cartago-Costa Rica. Correo: [email protected]. 2 Escuela de Ingeniería Forestal, Instituto Tecnológico de Costa Rica, Cartago-Costa Rica. Correo: [email protected]. Tecnología en Marcha, Vol. 26, N.° 4, Octubre-Diciembre 2013 53 Palabras clave la planificación y la gestión de los recursos hídricos y que la ley actual del agua es obsoleta. Por lo Tanto, Recursos Hídricos; Planificación; Balance Hídrico; es urgente adoptar una nueva ley sobre el agua con Costa Rica. una visión moderna para conducir la reorganización del sector, redefinir un nuevo esquema de tarifas Resumen de agua para financiar la investigación, el desarrollo, la planificación y la conservación del recurso. Sin En este artículo se describe la situación actual de esta herramienta legal, los recursos hídricos del país disponibilidad y demanda de recursos hídricos de seguirán siendo sobreexplotados, creando desequili- Costa Rica, así como la evolución del marco legal e brios y conflictos entre sectores sociales y producti- institucional para la planificación y la gestión. vos, el aumento de vulnerabilidad a la contaminación Costa Rica tiene 51 100 km2 de superficie y contie- y los riesgos para la salud pública. ne 34 cuencas nacionales. La vertiente del Caribe representa el 46,4% del país, mientras que la ver- tiente del Pacífico corresponde a 53,6%. Costa Rica Key Words también tiene el 34,3% del territorio en dos cuencas Water Resources; Planning; Water Balance; transfronterizas, Rio San Juan con Nicaragua y el Río Costa Rica. Sixaola en Panamá. En el territorio hay 12 embalses hidroeléctricos Abstract que suman un total de 95 km2 de superficie y 217 cuerpos de agua naturales que cubren 40,5 km2 de This article describes the current status of water superficie. El balance hídrico anual promedio a nivel resources availability and demand in Costa Rica nacional para el período 1970-2002 es la siguiente: as well as the evolution of legal and institutional 3297 mm de precipitación, 2.215 mm de escorren- framework in the planning and management of this tía y 996 mm de evapotranspiración. Se estima que valuable natural resource. el suministro potencial agua de Costa Rica es equi- Costa Rica, in its 51 100 km2 of area, contains 34 3 valente a 113 km de escorrentía que corresponde national watersheds. The Caribbean slope equal para el 2005 a una disponibilidad de agua per cápita to 46,4% of the country, while the Pacific slope to 3 de 26 221 m /persona/año. El volumen utilizable 53,6%. Costa Rica also has 34,3% of the territory aguas subterráneas a nivel nacional se estima en 11 in two transboundary basins; Rio San Juan with 3 km de agua, lo que resulta en un flujo sostenible de Nicaragua and Rio Sixaola with Panama. There are 3 350 m / s. 12 hydroelectrical reservoirs which total 95 km2 of Se estima que en 2005, las extracciones de agua area and 217 natural water bodies with 40,5 km2 of para diversos usos ascendieron a unos 22 km3 o el area. The nationwide average annual water balance 20% del volumen de agua disponible. La extracción for the period 1970-2002 is: 3297 mm of rainfall, de agua para la generación de energía hydroeléctri- 2215 mm of runoff and 996 mm of evapotranspira- ca representó el 72% del total, seguido de la agricul- tion. It is estimated that the potential water supply tura con un 21,2%. El uso para el consumo humano, for Costa Rica is equivalent to 113 km3 of runoff and el turismo, la industria y la agroindustria representó that the 2005 per capita’s Water Availability equals el 6,8% del total y un 88% de este volumen proviene 26 221 m3/person/year. The nationwide ground- de fuentes subterráneas, lo que destaca la impor- water usable volume is estimated to be 11 km3 of tancia estratégica de la protección y la explotación water, resulting in a sustainable flow of 350 m3 /s. sostenible de los acuíferos del país. Las proyecciones It is estimated that in 2005, withdrawals of water del uso del agua para el año 2020 para todos los for various uses totaled about 22 km3 or 20% of usos alcanzan a 37,87 km3, equivalentes a más del the volume of available water. Water withdrawals 33% de la disponibilidad total de los recursos hídri- for power generation accounted for 72% of the cos del país. total, followed by agriculture with 21,2%. The use for Los dos problemas principales son la ausencia de human consumption, tourism, industry and agribusi- una única institución con plena responsabilidad en ness accounted for 6,8% of total removal and 88% Tecnología en Marcha, 54 Vol. 26, N.° 4, Octubre-Diciembre 2013 of this volume comes from groundwater sources, Methodology highlighting the strategic importance of the pro- Water resources use and demand data was extrac- tection and sustainable exploitation of the aquifers ted and projected from state agencies data bases in the country. The water use projections for 2020 and technical reports. Information about water 3 for all uses will reach 37,87 km , equivalent to more resources characteristics and availability, as well as, than 33% of the total availability of water resources the legal, political and administrative framework of the country. associated with water resources management and The major problems are associated with the absen- planning were obtained from publications and ce of a single institution with full responsibility for technical reports. Once this information was sum- marized, a general discussion and recommendations planning and management of water resources and were provided to support efforts for developing an that current water law is obsolete. Hence it is urgent integrated water resources management approach. to adopt a new water law with a modern vision to drive the reorganization of the sector, redefine a new water tariff scheme to fund research, development Results and discussion and resource planning and conservation. Without Water Resources of Costa Rica this legal tool, the country’s water resources will continue to be overexploited, creating imbalances Hydrological characteristics of Costa Rica. Costa Rica and conflicts between social and productive sectors, has special hydrological characteristics due to a increasing the vulnerability to pollution, overused combination of several factors. First, the country is and public health risks. divided longitudinally by the Talamanca, Central and Guanacaste’s mountain range, dividing the country in the Caribbean and the Pacific slopes. Because of the Introduction steep terrain and the prevailing trade winds there is a strong influence of orographic precipitation (Calvo- Costa Rica has favorable climatic characteristics Alvarado, 1990). The northwest-southeast ridges that in conjunction with its mountainous topogra- of the Caribbean slope are rainy almost all year phy make the country a rich water nation. Despite round by the direct influence of the northeast trade this privileged status, this resource has not been winds, active from November through March. Then thoroughly evaluated and managed to ensure its between May to October throughout the country sustainable use. Consequently, it is imperative to is influenced by the passage of the Intertropical promote a culture of water planning and conserva- Convergence Zone and by the southwest trade tion to cope with current and future water demands winds. In this way only the Pacific Slope experiences for all users, including ecosystems needs. Therefore, a dry season between December to April, because it is urgent to address this issue with a renewed the humidity coming from the Northeast Tradewinds approach and to avoid old policies that had relied is retained on the Caribbean slope. Hence the mainly in considering only water demand by neglec- rivers of the Caribbean slope have a plentiful flow ting problems such as water temporal and geogra- throughout the year, while the rivers of the Pacific slope experience low flows during the dry season phical availability, high water pollution, lack of waste (Calvo-Alvarado, 1990). According to Manso et al. water treatment, ecosystem demands and other (2005), both temporal and spatial distribution of important institutional and legal aspects required for rainfall in Costa Rica is also modulated by changes in an integrated water management. oceanic and weather phenomena as El Niño (warm This article aims to present the state of Costa Rica’s phase) and its opposite, La Niña (cold phase), which water resource characteristics, availability, use and are considered the highest expressions of climatic future demand, as well as, the institutional and legal variability. management framework as a basic input to help Availability of surface and groundwater resources. Costa understand the problems and develop future pro- Rica has 51 100 km2 of area and 34 national water- posals to build long-term water resources policies sheds (figure 1 and table 1). The Caribbean slope and planning. equal to 46,4% of the country, while the Pacific slope Tecnología en Marcha, Vol. 26, N.° 4, Octubre-Diciembre 2013 55 to 53,6%. Costa Rica also has 34,3% of the territory (UNESCO, 2007). With regard to groundwater, it is in two transboundary basins (Calvo-Alvarado 1990): estimated that nationwide there is a usable volume a) The North Slope of the country shares the San of 11 km3 of water, resulting in a sustainable flow of Juan River basin (excluding the Lake of Nicaragua), 350 m3 /s (Reynolds, 1997).