Teresa Torregrosa

Abstract In the Marina Baja region there is a tradition of fierce competition for water resources which necessitates the regulation of institutions in order to satisfy the interests of the different water users. The management of the water resources in
this region is based on the water exchange between the different users with no legal modification of the water concessions. This situation requires continuous negotiation in order to maintain the balance between urban, tourism and the agricultural demand. In this article we define, describe and analyse the equilibrium model for water resources of the Marina Baja District using a simultaneous equations model (SEM). We analyse variables that influence the water management model through a simultaneous relationship between the above-mentioned demands in the region
of the Marina Baja, using a methodology that directly links urban and irrigation demands and makes them relevant to one another from a socioeconomic point of view.
Keywords Integrated water resource management · Urban demand ·Agricultural demand · Competence of uses · Simultaneous equation model

The study analyzes variables that influence the water management model based on a simultaneous relationship between competing demands in the Marina Baja of Alicante, using a methodology that directly links together urban and irrigation demands, making them relevant to each other from a socioeconomic point of view.
The paper identifies the relevant variables of this model and the agent behaviour in a closed and joint system. It also aims to demonstrate that by considering water demands for different yet
simultaneous uses and regarding clean and reclaimed waters as integrated resources, the system could remain in equilibrium without external water supplies.
Keywords: simultaneous equation model; urban demand; agricultural demand; competition of uses; Spain

Abstract The water problems in Marina Baja district, located in the north of Alicante Province, southeast Spain, gives rise to very interesting practices in the management of this scarce resource. The key issue in water use both in the Jucar Catchment and in Marina Baja district is the growing demand for water in inland areas for intensive crop irrigation (principally fruit, medlars and citrus fruit) and the growth in demand for water for urban use, as well as for use in the tourist industry and its related services mainly in the towns in the coastal areas, due to strong growth in tourism. This trend of increasing demand has created a tense situation as well as conflict between existing water uses and the need for integrated water management in the area. This step implies that procedures for water exchange contracts have to be developed, that are significantly different from emerging water markets.
Keywords Agreement; competition; rivalries between water uses; water exchange; water supply consortium

ABSTRACT
One of the most controversial issues in recent years in water management has been finding a balance between available resources and water needs related to certain territories. The changes brought about by a new awareness over the need to preserve the environment, the social perception of the ownership of the river chan-nels, the need for adjust financial costs arising from the waterworks and the compliance with European standards urgently require redesign of water supply policies in force at this time. The Júcar-Vinalopó water transfer, considered as an historic aspiration for many years in the region, has been regarded as a key element for solving the depletion of groundwater in a large area lo-cated in the southeast of the Iberian Peninsula, mainly for irrigation purposes. In this paper we present an approach to the economic aspects related to the implementation of the project, its investment and financing arrangements and the question of the subsequent management with the impact of the well-known “recovery cost principle", highlighting the current difficulties in carrying out projects of this size, due to severe limitations, as social and economic conditions of the transfer.
Keywords: Water Transfer; Cost Recovery; Groundwater; Water Cost

Resumen
La integración del sistema natural o físico toma como punto de partida el ciclo hidrológico, y se basa en la integración de los recursos tierra y agua, en la calidad y cantidad de los recursos hídricos, en la integración de las aguas superficiales y subterráneas junto con recursos alternativos y por último, en las interrelaciones entre actividades agrícolas, bosques y procesos de urbanización con los impactos hídricos y de calidad asociados. Y es aquí en donde centramos el trabajo presentado, la delimitación del sistema físico en la Comarca de la Marina Baja y su adecuación a los requerimientos de una Gestión Integrada de Recursos Hídricos. Desde el punto de vista del medio físico, consideramos que existe una integración física de recursos hídricos cuando los recursos son utilizados de manera complementaria, las demandas identificables y acordes a los recursos disponibles, con cierto margen de maniobra y garantizado todo ello por un marco legal que asegure la obtención de recursos, en cantidad y calidad óptimas para satisfacer las demandas consolidadas y previstas de manera sostenible.
Palabras Clave: sistema físico, gestión integrada de recursos hídricos, uso urbano, uso agrícola, competencia de usos.


Abstract
The collective use of resources requires the planned and coordinated use of a variety of sources.  The proportions in which the quantities of water from one source or another are combined will depend on the stage of the natural water cycle, the current reserves within the system, both surface water and that stored in aquifers, the quality available and, above all, the objectives set for the exploitation of the system. And here is where we focused the presented paper, the delimitation of the physical system in Marina Baja District. We believe that physical integration of water resources occurs when resources are used in a complementary manner, with demand which is both identifiable and in keeping with available resources, and with a certain margin for manoeuvre, all guaranteed by a legal framework which assures the securing of resources at optimal levels of quantity and quality in order to satisfy consolidated and forecast demand in a sustainable manner
Keywords: Physical system, integrated water resource management, urban water use, agricultural water use, use competence.

La economía es una actividad institucionalizada y de ahí la importancia de identificar y analizar las instituciones implicadas en cada fenómeno económico. En la gestión de los recursos hídricos la importancia de los aspectos institucionales ha quedado patente en la reciente historia económica española. En muchas ocasiones, el éxito o fracaso de un modelo de gestión de los recursos hídricos depende, en gran medida, de las instituciones encargadas y básicamente aquellas situadas en la escala más desagregada posible.
Con este trabajo se trata de analizar las razones del surgimiento de una institución que, en la actualidad, es clave en la gestión del suministro de agua en una zona donde la articulación de los usos agrarios, urbanos y turísticos –no olvidemos que en la misma se ubica el municipio de Benidorm-, ha permitido mejorar la eficiencia del sistema como un todo. Por otro lado, esta investigación también aporta claves sobre el funcionamiento económico de los Consorcios Administrativos, figura administrativa a la que se ha prestado poca atención desde el punto de vista económico y que con este trabajo se aportan elementos para su análisis.

In the paper we provide an overview on how the issue of natural resources,
especially water, have been incorporated into economic reasoning in a progressive
manner. As we shall see, this does not mean that we are facing a new theoretical
framework around the natural resources management. But progress has been so
important in recent years that there is no doubt that this is a new deal that should
allow in the years to advance the theoretical reasoning and the most efficient
solutions for our societies.
Keywords: water economy, water uses, New Water Economy, IWRM

En las páginas siguientes hacemos un repaso general acerca de cómo la cuestión de
los recursos naturales y, especialmente, el agua, han ido incorporándose a los
razonamientos económicos de una forma progresiva. Como veremos, esto no
significa que nos encontremos ante un marco teórico nuevo en cuanto a la gestión
de los recursos naturales. Pero los avances han sido tan importantes durante los
últimos años, que no cabe duda que estamos ante un nuevo panorama que debe
permitir en los próximos años avanzar en los razonamientos teóricos y en las
soluciones más eficientes para nuestras sociedades.
Palabras Clave: economía del agua, usos del agua, nueva economía del agua,
GIRH

Groundwaters and the Tragedy of the Commons in
Vinalopó (Alicante, Sopain)
ABSTRACT
In a market economy, different economic goods are managed trying to look for maximum efficiency, especially for the owners. Collective management is applied in the case of some goods with specific characteristics, such as the difficulty of its divisibility and private appropriation. Groundwater falls into this group. Water located under large areas of land to facilitate its exploitation to a large number of users in order to get the highest profit. In Spain, this situation was favoured by the consideration of groundwater as a private good by the 1879 Water Act, in force until 1985, to distinguish from the surface waters, which had the character of the public domain. This legal framework created a strong process of water extractions especially in arid areas, which has resulted in unsustainable situations today. In the case studied here, we tried to analyze, not only the private behaviour in the process, but how public policy also contributed to this situation in the regions of Vinalopó, showing that sometimes, public intervention can contribute to what has been called “the tragedy of the commons”
Keywords: water economics, groundwater aquifers, tragedy of the commons, common resource
management, public policy.
JEL Classification: Q21, Q25, R58