Assessing Water Shortage through a Balance Model among Transfers, Groundwater, Desalination, Wastewater Reuse, and Water Demands (SE Spain)

Currently, water demands are increasing notoriously, spreading the pressure on available water resources around the world in both quantity and quality. Similarly, the expected reduction of natural water inputs, due to climate change, depicts a new level of uncertainty. Specifically, Southeast Spain presents water scarcity due to its aridity—irregular and scarce precipitation and high evapotranspiration rates—combined with the competition between several water demands: environment, agricultural dynamics, urban-tourist activities, and industry. The study area of this work is the most relevant functional urban area of Alicante province (SE Spain), where the administration of water management is carried out by a range of authorities at different levels as the consequence of a complex historical development of water governance schemes: at the national, regional, and local levels. This study analyzes 21 municipalities and proposes a conceptual model which was developed by including different origins of water inputs—surface resources, groundwater, desalination, wastewater reuse, or interbasin transfers—and water demands with information obtained from 16 different sources. Our main results denote a relevant water deficit of 72.6 hm3/year even when one of the greatest rates of desalinated water and reused wastewater in Europe are identified here. This negative balance entails restrictions in urban development and agricultural growth. Thus, presented results are noteworthy for the water policy makers and planning authorities, by balancing the demand for water among various end users and providing a way for understanding water distribution in a context of scarcity and increasing demand, which will become one of the most challenging tasks in the 21st century.

Water Management

Nature did China few favors in its allocation of water, either spatially or seasonally. The South has abundant water but little land that is easy to cultivate, while the much drier North and Northwest have extensive plains but limited rainfall, which when it comes is concentrated strongly in the summer months, followed by long dry winters. Under these circumstances, water management in China is a holding company of wicked problems, including floods, droughts, pollution, climate impacts, hydropower development, environmental degradation, urbanization on an unprecedented scale, and, recently, international waters. It is fair to conclude that the nature and fate of the Chinese state has been linked in large degree to extensive and continuous intervention in the hydraulic cycle, both to prevent harm (shuihai水害) and to make beneficial use of water (shuili水利). Methods adopted for that intervention, discussed in separate entries in this chapter, have included dikes, irrigation, dams, interbasin transfers from water-abundant to water-scarce areas, and institutional reform. Attempts at institutional reform can themselves confront wicked problems of implementation in a polity of the size and complexity of China, with a governing system that, while changing in many ways under the People’s Republic, and especially in the recent reform period, remains one that is perhaps best characterized as one of “fragmented authoritarianism.” In the 21st century, the water needs of a globalized market economy and the growth of megacities, the exploitation of international waters (notably for hydropower), gigantic interbasin transfers, and water pollution have added to the complexity of water management, and to a fragmentation of scholarship on what falls under the expanding rubric of water management. An entrée to this expanding literature may be found in the individual sections of this bibliography.

Percentage of municipal water coming from interbasin transfers

This layer shows the percentage of water sourced from watershed(s) outside the watershed within which a given city resides. On average, cities secure 43% of their water supply via intebasin transfers. Note that if a city gets a small fraction of its water from surface water, there will be calculated values for this metric, but it is not particularly meaningful for a city's water risk or opportunity profile. For more information, access the Urban Water Blueprint report here: http://www.iwa-network.org/wp-content/uploads/2016/06/Urban-Water-Blueprint-Report.pdf You can also visit the Urban Water Blueprint website here: http://water.nature.org/waterblueprint/#/intro=true Abstraction Drinking water Supply