A partir de la expedicion del documento CONPES 3463 de 2007 (Consejo Nacional de Politica Economica y Social), que definio la politica del sector de agua potable y saneamiento basico a traves de los planes departamentales de agua, se puso en el centro de la mesa el tema de la regionalizacion del servicio. Esto ha generado debates en procura de definir cual es el concepto de regionalizacion mas adecuado para garantizar el aumento de la cobertura y la eficiencia del sector. Uno de los conceptos que mas ha tomado fuerza es el de Cuenca, como unidad de gestion basica para la prestacion del servicio. El concepto, que presenta a la cuenca como el territorio adecuado para realizar la gestion integral de los recursos hidricos, ha sido apoyado por organizaciones mundiales como la ONU y el Panel Intergubernamental del Cambio Climatico, asi como por los principales tratadistas y expertos de la gestion del recurso hidrico, que entienden la integracion natural del ciclo hidrico mediante interdependencias e interrelaciones entre los sistemas fisicos y bioticos. Palabras clave: Regionalizacion, Agua Potable, Saneamiento Basico, Economias de Escala, Analisis Territorial. ABSTRACT Based on the publication of the CONPES 3463 resolution in 2007, which defined the drinking water and basic sanitation policies through provincial plans for water, regionalization of the service became the key issue. This one has been long debated in an attempt to define what is the most appropriate concept to ensure increased coverage and efficiency in the sector. One concept that has taken hold is the Basin, such as the basic management unit for the service. The concept, which presents the basin as the appropriate territory for the integrated management of water resources has been supported by global organizations like the UN, the Intergovernmental Panel on Climate Change, and by leading scholars and experts on water resources management; they understand the natural water cycle as the integration of interdependencies and interrelationships between physical and biotic systems. Keywords: Regionalization, Water, Sanitation, Economies of Scale, Spatial Analysis.