Water infrastructure is the system of physical (both built and environmental), social (e.g., governance), and technological elements that move water into, throughout, and out of human communities. It includes, but is not limited to, water supply infrastructure (e.g., pipe systems, water treatment facilities), drainage and flood infrastructure (e.g., storm sewers, green infrastructure systems, levees), and wastewater treatment infrastructure (e.g., pipe systems, wastewater treatment plants, reclaimed water facilities). Smart city approaches to water infrastructure emphasize integration of information and communication technologies with urban water infrastructure and services, usually with the goal of increasing efficiency and human well-being. Smart water meters, smart water grids, and other water-related information and communication technologies have the potential to improve overall infrastructure efficiency, to reduce water use, to match new water supplies with appropriate water uses, to innovate wastewater treatment, and to protect residents from floods and other water-related climate events. However, without stronger attention to issues of equity, social systems, governance, ecology, and place, a smart city approach to water infrastructure may achieve efficiencies but fail to generate broader socioecological values or to contribute toward climate adaptation.
Smart Cities and Water Infrastructure
Infiltration of Water Into Soil
John Nimmo and Rose Shillito
The infiltration of water into soil has profound importance as a central component of the hydrologic cycle and as the means of replenishing soil water that sustains terrestrial life. Systematic quantitative study of infiltration began in the 19th century and has continued through to the present as a central topic of soils, soil physics, and hydrology. Two forces drive infiltration: gravity, and capillarity, which results from the interaction of air-water surface tension with the solid components of soil. There are also two primary ways water moves into and within the soil. One is diffuse flow, through the pores between individual soil grains, moving from one to the next and so on. The other is preferential flow, through elongated channels such as those left by worms and roots. Diffuse flow is slow and continues as long as there is a net driving force. Preferential flow is fast and occurs only when water is supplied at high intensity, as during irrigation, major rainstorms, or floods. Both types are important in infiltration. Especially considering that preferential flow does not yet have a fully accepted theory, this means that infiltration entails multiple processes, some of them poorly understood. The soil at a given location has a limit to how much water it can absorb—the infiltration capacity. The interplay between the mode and rate of water supply, infiltration capacity, and characteristics of the soil and surrounding terrain determines infiltration into the soil. Much effort has gone into developing means of measuring and predicting both infiltration capacity and the actual infiltration rate. Various methods are available, and research is needed to improve their accuracy and ease of use.
What Is Public and What Is Private in Water Provision: Insights from 19th-Century Philadelphia, Boston, and New York
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.
Politics of Water Flows: Water Supply, Sanitation, and Drainage
Tatiana Acevedo Guerrero
Since the late 20th century, water and sanitation management has been deeply influenced by ideas from economics, specifically by the doctrine of neoliberalism. The resulting set of policy trends are usually referred to as market environmentalism, which in broad terms encourages specific types of water reforms aiming to employ markets as allocation mechanisms, establish private-property rights and full-cost pricing, reduce (or remove) subsidies, and promote private sector management to reduce government interference and avoid the politicization of water and sanitation management. Market environmentalism sees water as a resource that should be efficiently managed through economic reforms. Instead of seeing water as an external resource to be managed, alternative approaches like political ecology see water as a socio-nature. This means that water is studied as a historical-geographical process in which society and nature are inseparable, mutually produced, and transformable. Political ecological analyses understand processes of environmental change as deeply interrelated to socioeconomic dynamics. They also emphasize the impact of environmental dynamics on social relations and take seriously the question of how the physical properties of water may be sources of unpredictability, unruliness, and resistance from human intentions. As an alternative to the hydrologic cycle, political ecology proposes the concept of hydrosocial cycle, which emphasizes that water is deeply political and social. An analysis of the politics of water flows, drawing from political ecology explores the different relationships and histories reflected in access to (and exclusion from) water supply, sanitation, and drainage. It portrays how power inequalities are at the heart of differentiated levels of access to infrastructure.
Wastewater Reclamation and Recycling
Soyoon Kum and Lewis S. Rowles
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.
The Mirage of Supply-Side Development: The Hydraulic Mission and the Politics of Agriculture and Water in the Nile Basin
In an era of calamitous climate change, entrenched malnutrition, and the chronic exclusion of hundreds of millions of people from access to affordable energy, food, and water, evaluating the policy options of African states to address these challenges matters more than ever. In the Nile Basin especially, a region notorious for its poverty, violent instability and lack of industrialisation, states have invested their scarce resources and political capital in a “hydraulic mission” in the belief that they can engineer their way out of international marginalization. Incumbents have bet on large-scale hydro-infrastructure and capital-intensive agriculture to boost food production, strengthen energy security, and deal with water scarcity, despite the woeful track-record of such a supply-side approach to development. While ruling elites in the Nile Basin have portrayed the hydraulic mission as the natural way of developing the region’s resources—supposedly validated by the historical achievements of Pharaonic civilization and its mastery over its tough environment—this is a modern fiction, spun to justify politically expedient projects and the exclusion of broad layers of the population. In the last two hundred years, the hydraulic mission has made three major political contributions that underline its strategic usefulness to centralizing elites: it has enabled the building of modern states and a growing bureaucratic apparatus around a riverain political economy; it has generated new national narratives that have allowed unpopular regimes to rebrand themselves as protectors of the nation; and it has facilitated the forging of external alliances, linking the resources and elites of Egypt, Ethiopia, and Sudan to global markets and centers of influence. Mega-dams, huge canals and irrigation for export are fundamentally about power and the powerful—and the privileging of some interests and social formations over others. The one-sided focus on increasing supply—based on the false premise that this will allow ordinary people to access more food and water—transfers control over livelihoods from one (broad) group of people to (a much narrower) other one by legitimizing top-down interventionism and dislocation. What presents itself as a strategy of water resources and agricultural development is really about (re)constructing hierarchies between people. The mirage of supply-side development continues to seduce elites at the helm of the state because it keeps them in power and others out of it.
Water Supply, Sanitation, and the Environment
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.
Input–Output Models Applied to Environmental Analysis
Joaquim J.M. Guilhoto
Input–Output (I–O) models and analysis were originally conceived by the Nobel Prize winner Wassily Leontief in the 1930s as a tool that can be used by economists and economic policy makers to help in their decision process. The I–O models provide a “picture” of how the economy works, that is, what are the necessities to produce goods and services, how this production generates income, profits and taxes, and how this income is spent. In a simplified way the I–O models can be seen as the model implementation of the economy circular-flow diagrams usually shown in economics introductory courses. Associated with the theory behind I–O models and analysis, I–O tables contain the empirical information necessary to implement these models and theory. Taking, for example, the production of computer screens: • On the production side, the I–O models have information on: (a) how much is spent on the inputs, goods and services necessary to produce the screens; (b) whether these inputs have their origin in the domestic market or are imported; (c) how much was paid in tax to the government; (d) what was the total amount paid in wages and salaries; (e) what were the profits of the producing firms; (f) how many computer screens are sold on the domestic market or on the international market (exported); and (g) whether they are sold directly to the final consumer or are used as a production input, that is, incorporated into other goods, for example, a refrigerator with a computer screen; • On the demand side, the I–O models, taking into consideration the total income received by the different players in the economy, that is, households, firms, and government, have information on: (a) how the income of these players is spent on goods and services, and whether it is used for consumption or investment; (b) whether these goods and services were produced domestically or abroad (imported); and (c) how much consumer tax was paid. From the aforementioned structure of I–O models, and using economic mathematical models, it is possible to measure the direct and indirect inputs needed to produce goods and services in the economy, for example, to produce a car there is no need for agricultural goods as a direct input for production, but the fabric used in the car seats or on the car carpets could have come from cotton, which is an agricultural good, so, cotton is an indirect input used in car production. I–O models, by their capability to show a complete picture of the economic system, and tracing of the origin of direct and indirect inputs used in the production process, can be used in environmental studies by linking economic and environmental variables, on the production and consumption sides. From the production side it is possible to measure, by considering the direct and indirect inputs used, how many natural resources were used and how much pollution was generated in producing the goods and services. On the demand side it is possible to measure the environmental variables, natural resources, and pollution, embodied in the goods and services consumed in the economy. Expanding I–O models to a global scale, that is, using inter-country I–O models, it is possible to measure the environmental impacts, and contents, of the goods and services by country of origin of production and by countries of consumption.