Across the globe, freshwater scarcity is increasing due to overuse, climate change, and population growth. Increasing water security requires sufficient water from diverse water resources. Wastewater can be used as a valuable water resource to improve water security because it is ever-present and usually available throughout the year. However, wastewater is a convoluted solution because the sources of wastewater can vary greatly (e.g., domestic sewage, agricultural runoff, waste from livestock activity, and industrial effluent). Different sources of wastewater can have vastly different pollutants, and mainly times, it is a complex mixture. Therefore, wastewater treatment, unlike drinking water treatment, requires a different treatment strategy. Various wastewater sources can be reused through wastewater reclamation and recycling, and the required water quality varies depending on the targeted purpose (e.g., groundwater recharge, potable water usage, irrigation). One potential solution is employing tailored treatment schemes to fit the purpose. Assorted physical, chemical, and biological treatment technologies have been established or developed for wastewater reclamation and recycle. The advancement of wastewater reclamation technologies has focused on the reduction of energy consumption and the targeted removal of emerging contaminants. Beyond technological challenges, context can be important to consider for reuse due to public perception and local water rights. Since the early 1990s, several global wastewater reclamation examples have overcome challenges and proved the applicability of wastewater reclamation systems. These examples showed that wastewater reclamation can be a promising solution to alleviate water shortages. As water scarcity becomes more widespread, strong global initiatives are needed to make substantial progress for water reclamation and reuse.
301-312 of 312 Results
Article
Yoshika S. Crider and Isha Ray
The large and multidisciplinary literature on water for domestic use and gender has two primary foci: (1) the negative health and well-being impacts of inadequate access to safe water, and (2) the effects of women’s participation in water allocation and management decisions. These foci are reflected in both the research and policy literatures. Smaller bodies of work exist on water and social power, and on nonmaterial values and meanings of water. The term “gender” refers to the socially constructed roles and identities of girls, women, boys, men, and nonbinary people, but the literature on water and gender to date is mainly concerned with women and girls, on whom inadequate water access places a disproportionate burden.
The water and health literature during the Millennium Development Goals era focused overwhelmingly on the consequences of unsafe drinking water for child health, while paying less attention to the health of the water carriers and managers. Studies on women’s participation in water-related decisions in the household or community were (and to some extent remain) mixed with respect to their effects on equity, access, and empowerment. Both the health and participation strands often assumed, implicitly or explicitly, that water work was women’s work. Yet data on access was mainly collected and presented by household or community, with little effort to disaggregate access and use by gender.
In keeping with the spirit of the Sustainable Development Goals, the post-2015 literature has gone beyond a focus on infectious diseases to include the psychosocial stresses of coping with unreliable or inadequate water supplies. These stresses are acknowledged to fall disproportionately on women. A relatively small literature exists on the health impacts of carrying heavy loads of water and on the hard choices to be made when safe water is scarce. The negative impacts of inadequate domestic water access on girls’ education opportunities, on the safety of those who walk long distances to collect water, and on family conflicts have also been studied. Access is being defined beyond the household to prioritize safe water availability in schools and in healthcare facilities, both of which serve vulnerable populations. Both are institutional settings with a majority-female workforce. The definition of domestic water post-2015 has also broadened beyond drinking water to include water for cooking, sanitation, and basic hygiene, all of which particularly concern women’s well-being.
Intersectionality with respect to gender, class, ability, and ethnicity has started to inform research, in particular research influenced by feminist political ecology and/or indigenous values of water. Political ecology has drawn attention to structural inequalities and their consequences for water access, a perspective that is upstream of public health’s concerns with health impacts. Research on participation is being augmented with studies of leadership and decision-making, both within communities as well as within the water sector. Critical studies of gender, water, and participation have argued that development agencies can limit modes of participation to those that “fit” their larger goals, e.g., efficiency and cost-recovery in drinking water systems. Studies have also analyzed the gendered burden of paying for safe water, especially as the pressure for cost recovery has grown within urban water policy.
These are significant and growing new directions that acknowledge the breadth and complexities of the gender and water world; they do not simply call for gender-disaggregated data but attempt, albeit imperfectly, to take water research towards the recognition of gender justice as a foundation for water justice for all.
Article
William D. A. Bryant
General equilibrium theory thinks of the economy as a collection of interconnected markets, each of which, in isolation and in combination, is driven toward some sort of equilibrium. Computable general equilibrium (CGE) models add to this abstract point of view by calibrating models of the economy using actual economic data. The aim is to empirically solve for equilibrium demand, supply, and price levels across the markets in the economy. Many areas of economic analysis, reform, and policymaking have benefitted from scrutiny in a CGE context. This is particularly true of issues to do with tax and tariff reform, where CGE models first gained prominence. More recently, the areas of environmental economics and regulation has attracted the attention of CGE modelers. Considerations of environment and environmental regulation, inevitably involve a consideration of issues to do with water. Such issues range from aquaculture through pricing of water to virtual water—and many points in between. In the analysis of each of these issues—and the role water plays in the overall economy, CGE models have made an important contribution to understanding and informed policymaking.
Article
Riddhi Singh
Public investments in water infrastructure continue to grow where developed countries prioritize investments in operation and maintenance while developing countries focus on infrastructure expansion. The returns from these investments are contingent on carefully assessed designs and operating strategies that consider the complexities inherent in water management problems. These complexities arise due to several factors, including, but not limited to, the presence of multiple stakeholders with potentially conflicting preferences, lack of knowledge about appropriate systems models or parameterizations, and large uncertainties regarding the evolution of future conditions that will confront these projects. The water resources planning literature has therefore developed a variety of approaches for a quantitative treatment of planning problems. Beginning in the mid-20th century, quantitative design evaluations were based on a stochastic treatment of uncertainty using probability distributions to determine expected costs or risk of failure. Several simulation–optimization frameworks were developed to identify optimal designs with techniques such as linear programming, dynamic programming, stochastic dynamic programming, and evolutionary algorithms. Uncertainty was incorporated within existing frameworks using probability theory, using fuzzy theory to represent ambiguity, or via scenario analysis to represent discrete possibilities for the future.
As the effects of climate change became palpable and rapid socioeconomic transformations emerged as the norm, it became evident that existing techniques were not likely to yield reliable designs. The conditions under which an optimal design is developed and tested may differ significantly from those that it will face during its lifetime. These uncertainties, wherein the analyst cannot identify the distributional forms of parameters or the models and forcing variables, are termed “deep uncertainties.” The concept of “robustness” was introduced around the 1980s to identify designs that trade off optimality with reduced sensitivity to such assumptions. However, it was not until the 21st century that robustness analysis became mainstream in water resource planning literature and robustness definitions were expanded to include preferences of multiple actors and sectors as well as their risk attitudes. Decision analytical frameworks that focused on robustness evaluations included robust decision-making, decision scaling, multi-objective robust decision-making, info-gap theory, and so forth. A complementary set of approaches focused on dynamic planning that allowed designs to respond to new information over time. Examples included adaptive policymaking, dynamic adaptive policy pathways, and engineering options analysis, among others. These novel frameworks provide a posteriori decision support to planners aiding in the design of water resources projects under deep uncertainties.
Article
Rebecca F.A. Bernat and Sharon B. Megdal
Water governance in the United States has followed a water federalism system, in which government functions are shared between federal and state authorities. Water federalism is the sharing of governance across different levels of government over freshwater quantity (water quantity federalism) and quality (water quality federalism). These terms have evolved throughout different eras of U.S. history. Initially, water federalism involved water quantity federalism only, and both state and federal governments had management prerogatives. The 1922 Colorado River Compact and the 1944 U.S. and Mexico Treaty are examples of a combination of horizontal and vertical federalisms. Then, the 1970s marked significant changes in water federalism. First, states regained control over water resources management. Second, water quality federalism arose as a subset of, and at the same time as, environmental federalism. The 1972 Clean Water Act is an example of cooperative federalism, which was commonly used to refer to environmental federalism. In the 21st century, a variety of environmental federalism frameworks have been offered to address the negative effects of climate change on water resources as well as other environmental issues. The contemporary literature on environmental federalism encompasses water quantity and water quality federalism. Throughout history, the role of American Indian tribal primacy has been overlooked in the water federalism literature. Another layer of government, the American Indian tribal government, should be included in discussing states versus federal water management prerogatives. Overall, new water quality and water quantity federalisms must be developed using institutional, sociocultural, and economic principles of good governance that foster a more inclusive, participatory, democratic, and engaged form of federalism.
Article
Maite M. Aldaya, M. Ramón Llamas, and Arjen Y. Hoekstra
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
The water footprint concept broadens the scope of traditional national and corporate water accounting as it has been previously known. It highlights the ways in which water consuming and polluting activities relate to the structure of the global economy, opening a window of opportunity to increase transparency and improve water management along whole-production and supply chains. This concept adds a new dimension to integrated water resources management in a globalized world.
The water footprint is a relatively recent indicator. Created in 2002, it aims to quantify the effect of consumption and trade on the use of water resources. Specifically, the water footprint is an indicator of freshwater use that considers both direct and indirect water use of a consumer or producer. For instance, the water footprint of a product refers to the volume of freshwater used to produce the product, tracing the origin of raw material and ingredients along their respective supply chains. This novel indirect component of water use in supply chains is, in many cases, the greatest share of water use, for example, in the food and beverage sector and the apparel industry. Water footprint assessment shows the full water balance, with water consumption and pollution components specified geographically and temporally and with water consumption specified by type of source (e.g., rainwater, groundwater, or surface water). It introduces three components:
1. The blue water footprint refers to the consumption of blue water resources (i.e., surface and groundwater including natural freshwater lakes, manmade reservoirs, rivers, and aquifers) along the supply chain of a product, versus the traditional and restricted water withdrawal measure.
2. The green water footprint refers to consumption through transpiration or evaporation of green water resources (i.e., soilwater originating from rainwater). Green water maintains natural vegetation (e.g., forests, meadows, scrubland, tundra) and rain-fed agriculture, yet plays an important role in most irrigated agriculture as well. Importantly, this kind of water is not quantified in most traditional agricultural water use analyses.
3. The grey water footprint refers to pollution and is defined as the volume of freshwater that is required to assimilate the load of pollutants given natural concentrations for naturally occurring substances and existing ambient water-quality standards.
The water footprint concept has been incorporated into public policies and international standards. In 2011, the Water Footprint Network adopted the Water Footprint Assessment Manual, which provides a standardized method and guidelines. In 2014, the International Organization for Standardization adopted a life cycle-based ISO 14046 standard for the water footprint; it offers guidelines to integrate water footprint analysis in life-cycle assessment for products. In practice, water footprint assessment generally results in increased awareness of critical elements in a supply chain, such as hotspots that deserve most attention, and what can be done to improve water management in those hotspots.
Water footprint assessment, including the estimation of virtual water trade, applied in different countries and contexts, is producing new data and bringing larger perspectives that, in many cases, lead to a better understanding of the drivers behind water scarcity.
Article
Claudia Sadoff, David Grey, and Edoardo Borgomeo
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.
Article
N. Vijay Jagannathan
Sustainable Development Goal No. 6 (SDG 6) has committed all nations of the world to achieving ambitious water supply and sanitation targets by 2030 to meet the universal basic needs of humans and the environment. Many lower-middle-income countries and all low-income countries face an uphill challenge in achieving these ambitious targets. The cause of poor performance is explored, some possible ways to accelerate progress toward achieving SDG 6 are suggested.
The analysis will be of interest to a three-part audience: (a) readers with a general interest on how SDG 6 can be achieved; (b) actors with policy interest on improving water supply and safe sanitation (WSS) service issues; and (c) activists skeptical of conventional WSS policy prescriptions who advocate out-of-the-box solutions to improve WSS delivery.
Article
If there is too little or too much water, farmers may be able to work together to control water and grow more food. Even before the rise of cities and states, people living in ancient settlements cooperated to create better growing conditions for useful plants and animals by diverting, retaining, or draining water. Local collective action by farmers continued to play a major role in managing water for agriculture, including in later times and places when rulers sometimes also organized construction of dams, dikes, and canals.
Comparative research on long-lasting irrigation communities and local governance of natural resources has found immense diversity in management rules tailored to the variety of local conditions. Within this diversity, Elinor Ostrom identified shared principles of institutional design: clear social and physical boundaries; fit between rules and local conditions, including proportionality in sharing costs and benefits; user participation in modifying rules; monitoring by users or those accountable to them; graduated sanctions to enforce rules; low-cost conflict resolution; government tolerance or support for self-governance; and nested organizations.
During the 19th and 20th centuries, centralized bureaucracies constructed many large irrigation schemes. Farmers were typically expected to handle local operation and maintenance and comply with centralized management. Postcolonial international development finance for irrigation and drainage systems usually flowed through national bureaucracies, strengthening top-down control of infrastructure and water management.
Pilot projects in the 1970s in the Philippines and Sri Lanka inspired internationally funded efforts to promote participatory irrigation management in many countries. More ambitious reforms for transfer of irrigation management to water user associations (WUAs) drew on examples in Colombia, Mexico, Turkey, and elsewhere. These reforms have shown the feasibility in some cases of changing policies and practices to involve irrigators more closely in decisions about design, construction, and some aspects of operation and maintenance, including cooperation in scheme-level co-management. However, WUAs and associated institutional reforms are clearly not panaceas and have diverse results depending on context and on contingencies of implementation. Areas of mixed or limited impact and for potential improvement include performance in delivering water; maintaining infrastructure; mobilizing local resources; sustaining organizations after project interventions; and enhancing social inclusion and equity in terms of multiple uses of water, gender, age, ethnicity, poverty, land tenure, and other social differences.
Cooperation in managing water for agriculture can contribute to coping with present and future challenges, including growing more food to meet rising demand; competition for water between agriculture, industry, cities, and the environment; increasing drought, flood, and temperatures due to climate change; social and economic shifts in rural areas, including outmigration and diversification of livelihoods; and the pursuit of environmental sustainability.
Article
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.
Article
Gwynneth C. Malin
Water became the first public utility in the United States. Before public transportation and public regulation of utilities like electricity and gas, North American cities adopted public water, but this transition is a relatively recent phenomenon. Until the 1830s, both water supply and sewerage were seen as private entities to be managed by private companies and private individuals with nominal assistance from local governments. Water provision was often a blend of public and private efforts, and if residents wanted a well or a sewer built in their neighborhood, they had to help pay for it. Until the mid-19th century, residents of Northeast U.S. cities drew water for domestic uses from local ponds, rivers, and groundwater sources. At this time, procuring water was a daily activity for residents that was linked to economic class.
The 19th century was a key period in the redefinition of water as a public-sector responsibility in the United States. The cities of Philadelphia, Boston, and New York illustrate this change. City officials made the gradual transition from relying on private water companies to implementing public management of the water supply. As increasing urbanization and growing immigrant populations rendered local and privately managed water sources undersupplied, elected officials began to search for new sources of water located beyond city limits. Philadelphia was the first to transition to public water management in 1801, followed by New York in 1842, and Boston in 1848. While each city’s history is unique, city officials took similar approaches to defining public and private with regard to water provision by gradually eliminating private water companies and by increasing funding for public works. Common themes included water pollution, the need to tap new water supplies further from the city centers, disease prevention, fire protection, and financial corruption, within both private water companies and municipal efforts to supply water. While most cities of the Northeast United States transitioned to municipal operation of water supply during the 19th century, the shift was not without its challenges and complexities. Funding shortages often prevented change, but crises, such as fire, drought, and infectious disease outbreaks, forced the hands of municipal officials. Timelines to public water varied. While Boston and Philadelphia achieved permanent public water in the early 19th century, New York experienced a longer trajectory. In each case, public management of water definitively triumphed over private. By the early 20th century, urban Americans conceptualized public and private differently than they had during the 19th century. Water management was at the center of this profound shift.
Article
The challenges of integrated approaches and equity in water resources management have been well researched. However, a clear division exists between scholars working on equity and those working on integration, and there is remarkably little systematic analysis available that addresses their interlinkages. The divide between these two fields of inquiry has increased over time, and equity is assumed rather than explicitly considered in integrated approaches for water resources management. Historically, global debates on water resources management have focused on questions of distributional equity in canal irrigation systems and access to water. This limited focus on distributional equity was side-lined by neoliberal approaches and subsequent integrated approaches around water resources management tend to emphasize the synergistic aspects and ignore the political trade-offs between equity and efficiency. The interlinkages among equity, sustainability, and integration need deeper and broader interdisciplinary analysis and understanding, as well as new concepts, approaches, and agendas that are better suited to the intertwined complexity of resource degradation.
