Water is a limited resource and its scarcity is getting steadily worse due to climate change and overexploitation of land. Together with energy, water is a key resource in any strategy aiming for sustainable economic growth. Therefore it is imperative to increase efficiency and savings in water use.
One of the most important challenges facing any society is the proper management and conservation of water resources. Let’s not forget that water is a limited resource and essential for everyday life and, furthermore, its scarcity is being exacerbated by climate change, particularly in Mediterranean regions. In these regions, ever growing population density coupled with low rainfall, unevenly spread over time, are causing the depletion or deterioration of the water resources, which will be difficult to turn around.
Throughout many areas of the Mediterranean basin, water quality sufficient to meet human needs has become an increasingly scarce resource; furthermore, its availability is an essential factor for economic development. In this scenario, efficient water management and protection of existing water resources are essential if we are to have an adequate supply, of both quantity and quality, at our disposal.
The water problems common to the Mediterranean region are clearly manifested in the Valencia region, characterized by a water demand that exceeds the supply and an uneven spatial distribution of water resources. In this geographical area, the average level of rainfall is below the Spanish average and, moreover, this is particularly low in the southernmost coastal districts. This is an area suffering profound water resource deficits, creating serious problems for both farming and even human consumption during periods of increased population pressure from tourism.
When analyzing the situation in Valencia it is important to consider that apart from the overall water balance, there are many areas with serious water shortages because there is an irregular distribution of resources and uses. Some areas like Vinalopó-Alacantí, Vega Baja del Segura and to a lesser extent, the northern coast of Castellon, face severe deficits that worsen in the summer.
It is not simple to adopt solutions to these problems and always requires action to be taken both in terms of supply and demand. In the latter case agricultural consumption acquires particular prominence. The fact that land flooding irrigation systems still represent the majority (51% of the total, even above the Spanish average of 42%), means it is imperative to intensify the process of replacing this method with alternatives. It is true that this goal is not easy considering the investment costs required, the difficulty of breaking traditional irrigation habits and the problems of low profitability affecting many crops. Adopting a firm policy to promote the modernization of irrigation systems is vital in this process.
With regard to domestic consumption, it is important to opt for more efficient distribution to avoid significant water losses. A policy of maintaining adequate networks, along with the adoption of realistic plans for investment and improvement of facilities, would contribute to saving and improved quality of the resource. All this combined with campaigns to promote water conservation and the introduction of tariffs that penalize excessive consumption.
Concerning supply, given the known shortage of conventional resources, the so-called unconventional sources gain weight, i.e., reuse and desalination. The latter is a water resource of strategic importance in ensuring urban water supply, provision for tourism and agricultural irrigation in certain areas with serious water shortages, especially on the coast. The use of technologies with lower energy consumption and solution of potential environmental impacts associated with the brine discharge from desalination plants have made desalination a highly viable alternative in many geographic areas. Today, Spain is the fourth country in the world in desalinated water production, while Valencia, with a current capacity of 0.35 cubic hectometres a day (hm3/day) ranks fifth of all Spanish regions.
Reusing reclaimed water has been established as the source with greatest potential to alleviate water imbalance in a geographic area. In fact, given the need for proper treatment of wastewater, common sense tells us that we should use that water once it has been reclaimed. As the largest user of water resources, the agricultural sector would be the major recipient for this treated water source. Notwithstanding, we must not forget the possible uses in the environmental field (wetland restoration, environmental flow…), the urban scenario (flushing streets, watering parks/gardens…) or sports facilities (like golf course irrigation).
Furthermore, conventional water resources could be released through the use of reclaimed water for agriculture and devoted to uses of higher economic value. However, it is clear that farmers will only accept the use of reclaimed water to replace surface water or groundwater if it affords them an advantage. In other words, the economic and financial viability of water reuse projects is mandatory if we are to carry out these changes in water supply source.
In this respect, the role of public authorities is essential both in demonstrating these advantages and supporting the establishment of this type of agreement between water users’ associations and local authorities, for instance. From the standpoint of water policy, there is evidence that it is more effective to reach agreements by means of negotiation than by adopting enforced or regulatory mechanisms. In these cases, the existence of historical rights to water by farmers would make exchange alternatives very complicated.
Therefore, given the water deficit, the reuse of reclaimed water should be one of the priorities in the Comunidad Valenciana (Valencia, Alicante and Castellon). According to the regional water treatment agency (EPSAR), in 2009, 61.4% of treated water was recycled, i.e., 308.8 hm3 of which 73.8 hm3 was done directly. Certainly this figure is well above the Spanish average for 2008 (11.6%). However, agricultural use of these unconventional resources still represents a minority.
|© A. Ponce & I. Rovira
Water is an increasingly scarce resource in the Mediterranean region, partly due to its particular hydrographic and rainfall characteristics, but also to strong population pressure, exacerbated during the summer months through tourism.
«Water has become an increasingly scarce resource and its availability is an essential factor for economic development»
Hernández, F. & J. Sorribes, 2009. «El factor territorial y medioambiental». In Soler, V. (ed.). Economía española y del País Valenciano. Universitat de València. Valencia.
Rico Amorós, A. M., 2007. «Tipologías de consumo de agua en abastecimientos urbano-turísticos de la Comunidad Valenciana». Investigaciones Geográficas, 42: 5-34.
Rico Amorós, A. M. & M. Hernández Hernández, 2007. «Ordenación del territorio, escasez de recursos hídricos, competencia de usos e intensificación de las demandas urbano-turísticas en la Comunidad Valenciana». Documents d’anàlisi geogràfica, 51: 79-109.