Water security has emerged in the 21st century as a powerful construct to frame the water objectives and goals of human society and to support and guide local to global water policy and management. Water security can be described as the fundamental societal goal of water policy and management. This article reviews the concept of water security, explaining the differences between water security and other approaches used to conceptualize the water-related challenges facing society and ecosystems and describing some of the actions needed to achieve water security. Achieving water security requires addressing two fundamental challenges at all scales: enhancing water’s productive contributions to human and ecosystems’ well-being, livelihoods and development, and minimizing water’s destructive impacts on societies, economies, and ecosystems resulting, for example, from too much (flood), too little (drought) or poor quality (polluted) water.
Claudia Sadoff, David Grey, and Edoardo Borgomeo
Water scarcity has long been recognized as a key issue challenging China’s water security and sustainable development. Economically, China’s water scarcity can be characterized by the uneven distribution of limited water resources across space and time in hydrological cycles that are inconsistent with the rising demand for a sufficient, stable water supply from rapid socioeconomic development coupled with a big, growing population. The limited water availability or scarcity has led to trade-offs in water use and management across sectors and space, while negatively affecting economic growth and the environment. Meanwhile, inefficiency and unsustainability prevail in China’s water use, attributable to government failure to account for the socioeconomic nature of water and its scarcity beyond hydrology. China’s water supply comes mainly from surface water and groundwater. The nontraditional sources, wastewater reclamation and reuse in particular, have been increasingly contributing to water supply but are less explored. Modern advancement in solar and nuclear power development may help improve the potential and competitiveness of seawater desalination as an alternative water source. Nonetheless, technological measures to augment water supply can only play a limited role in addressing water scarcity, highlighting the necessity and importance of nontechnological measures and “soft” approaches for managing water. Water conservation, including improving water use efficiency, particularly in the agriculture sector, represents a reasonable strategy that has much potential but requires careful policy design. China’s water management has started to pay greater attention to market-based approaches, such as tradable water rights and water pricing, accompanied by management reforms. In the past, these approaches have largely been treated as command-and-control tools for regulation rather than as economic instruments following economic design principles. While progress has been made in promoting the market-based approaches, the institutional aspect needs to be further improved to create supporting and enabling conditions. For water markets, developing regulations and institutions, combined with clearly defining water use rights, is needed to facilitate market trading of water rights. For water pricing, appropriate design based on the full cost of water supply needs to be strengthened, and policy implementation must be enforced. An integrated approach is particularly relevant and greatly needed for China’s water management. This approach emphasizes integration and holistic consideration of water in relation to other resource management, development opportunities, and other policies across scales and sectors to achieve synergy, cost-effectiveness, multiple benefits, and eventually economic efficiency. Integrated water management has been increasingly applied, as exemplified by a national policy initiative to promote urban water resilience and sustainability. While economics can play a critical role in helping evaluate and compare alternative measures or design scenarios and in identifying multiple benefits, there is a need for economic or social cost–benefit analysis of China’s water policy or management that incorporates nonmarket costs and benefits.
Cathy Rubiños and Maria Bernedo Del Carpio
Adequate water governance is necessary for the world’s sustainability. Because of its importance, a growing literature has studied ways to improve water governance, beginning in the early 2000s. Institutions, which refer to the set of shared rules, codes, and prescriptions that regulate human actions, are a particularly important element of sustainable water governance. Evidence shows that to design institutions that will generate sustainable economic, ecological, and cultural development, it is necessary to consider ecosystems and socioeconomic-cultural systems as social-ecological systems (SESs). In the past, practitioners and international agencies tried to find the government-led panaceas, but this search has been largely unsuccessful. Current views support efforts to move towards addressing complexity (e.g., Integrated Water Resources Management), and search for the fit between the institutional arrangements and SESs’ attributes. The literature on institutional fit in SESs encourages planners to design institutions by carefully considering the defining features of the problems they are meant to address and the SES context in which they are found. This literature has been developing since the 1990s and has identified different types of misfits. A comprehensive fitness typology that includes all the different types of fitness (ecological, social, SES, and intra-institutional fit) helps organize existing and future work on institutional fit and provides a checklist for governments to be used in the problem-solving process for increasing fitness. The water governance and institutional fitness literature provide examples of management practices and mechanisms for increasing institutional fit for each fitness type. Future research should focus on improving the methodologies to measure different types of fit and testing the effect of introducing fit on SES outcomes.
Fidel Ribera Urenda
The importance of groundwater has become particularly evident in the late 20th and early 21st centuries due to its increased use in many human activities. In this time frame, vertical wells have emerged as the most common, effective, and controlled system for obtaining water from aquifers, replacing other techniques such as drains and spring catchments. One negative effect of well abstraction is the generation of an inverted, conically shaped depression around the well, which grows as water is pumped and can negatively affect water quantity and quality in the aquifer. An increase in the abstraction rate of a specific well or, as is more common, an uncontrolled increase of the number of active wells in an area, could lead to overexploitation of the aquifer’s long-term groundwater reserves and, in some specific contexts, impact water quality. Major examples can be observed in arid or semi-arid coastal areas around the world that experience a high volume of tourism, where aquifers hydraulically connected with the sea are overexploited. In most of these areas, an excessive abstraction rate causes seawater to penetrate the inland part of the aquifer. This is known as marine intrusion. Another typical example of undesirable groundwater management can be found in many areas of intensive agricultural production. Excessive use of fertilizer is associated with an increase in the concentration of nitrogen solutions in groundwater and soils. In these farming areas, well design and controlled abstraction rates are critical in preventing penetrative depression cones, which ultimately affect water quality. To prevent any negative effects, several methods for aquifer management can be used. One common method is to set specific abstraction rules according to the hydrogeological characteristics of the aquifer, such as flow and chemical parameters, and its relationship with other water masses. These management plans are usually governed by national water agencies with support from, or in coordination with, private citizens. Transboundary or international aquifers require more complex management strategies, demanding a multidisciplinary approach, including legal, political, economic, and environmental action and, of course, a precise hydrogeological understanding of the effects of current and future usage.
Jazmin Zatarain Salazar, Andrea Castelletti, and Matteo Giuliani
Shared water resource systems spark a number of conflicts related to their multi sectorial, regional, and intergenerational use. They are also vulnerable to a myriad of uncertainties stemming from changes in the hydrology, population demands, and climate change. Planning and management under these conditions are extremely challenging. Fortunately, our capability to approach these problems has evolved dramatically over the last few decades. Increased computational power enables the testing of multiple hypotheses and expedites the results across a range of planning alternatives. Advances in flexible multi-objective optimization tools facilitate the analyses of many competing interests. Further, major shifts in the way uncertainties are treated allow analysts to characterize candidate planning alternatives by their ability to fail or succeed instead of relying on fallible predictions. Embracing the fact that there are indeterminate uncertainties whose probabilistic descriptions are unknown, and acknowledging relationships whose actions and outcomes are not well-characterized in planning problems, have improved our ability to perform diligent analysis. Multi-objective robust planning of water systems emerged in response to the need to support planning and management decisions that are better prepared for unforeseen future conditions and that can be adapted to changes in assumptions. A suite of robustness frameworks has emerged to address planning and management problems in conditions of deep uncertainty. That is, events not readily identified or that we know so little about that their likelihood of occurrence cannot be described. Lingering differences remain within existing frameworks. These differences are manifested in the way in which alternative plans are specified, the views about how the future will unfold, and how the fitness of candidate planning strategies is assessed. Differences in the experimental design can yield diverging conclusions about the robustness and vulnerabilities of a system. Nonetheless, the means to ask a suite of questions and perform a more ambitious analysis is available in the early 21st century. Future challenges will entail untangling different conceptions about uncertainty, defining what aspects of the system are important and to whom, and how these values and assumptions will change over time.