- Urban Infrastructure and Services
- How can urban utilities be provided sufficiently, efficiently, economically and equitably to all in a city?
Urban infrastructure and services are an important differentiator between cities and rural areas. A range of universal services that we now take for granted in large and wealthy cities like piped water, sewage, underground drainage, electric power supply, public transportation, telecommunications and more recently the Internet; were only available to the elites, merely a century ago. In many cities of the global South, the daily struggle for a large proportion of citizens, is about access to basic services.
Universal basic urban services, are critical drivers of increased productivity, quality of life and access to education and healthcare that permit people to live in cities at much higher densities, than in most villages. All of these factors, enable cities to become vibrant and productive places with high volumes of economic output, social interaction, innovation and learning.
The counterfactual is that many cities that do not have universal access to these basic services experience, not only lower productivity, incomes and job opportunities; but poor health and sometimes lower life expectancy; poorer education levels and hence weaker economic and social opportunities. In fact, dense concentrations of people, in slums and informal settlements who are poorly served by water, sanitation, drainage and solid waste services are often at higher risk of infectious diseases and natural hazards because of the locations and conditions in which they live.
In effect, urban infrastructure like many of the key systems in the human body, enables the metabolism of cities to function effectively, efficiently and sometimes sustainably.
What do we mean by urban infrastructure?
Today we will look at water supply, sanitation, drainage and solid waste management or what we call urban environmental services; also the energy infrastructure, mobility and transport systems, and information and communications systems.
Let us start with our first cluster of critical environmental services (water supply, sanitation,drainage and solid waste management) that manage flows of potable water, waste water and storm run-off.
They also manage the flow of different types of solid waste that all of our cities create (for example, organic compostables through bone, paper, glass, metals and plastics, toxic chemicals and bio hazards). Environmental services are primarily provided by natural ecosystems (for example rivers and groundwater aquifers, forests and wetlands) and by constructed systems like water filtration and treatment plants and sewage and septage treatment facilities.
Water supply systems are a good example of the full cycle of these services, as shown in this diagram: they begin with withdrawal from surface and groundwater sources, moving to treatment to appropriate standards in filtration plants, transmission and distribution through large pressurised water networks, use, recycling, reuse and finally waste water treatment before returning that water to the environment from which it came from.
In the past, such environmental services, like water supply were conceived as linear source to sink systems where unlimited withdrawal of the natural resource was common, as was untreated discharge back into the environment. As cities have grown, pollution loads exceed the Carrying capacity of the surrounding ecosystems to absorb them. This is what we saw happen to the Thames in London in the 19th century and what is currently happening to rivers in China and India like the Yangtze and the Ganga.Learning from this experience, planners are now visualising urban systems as closed-loop systems where we try to conserve the use of a precious resource like freshwater, recycling and reusing it is many times as possible, as Singapore and Beijing do, so effectively, and then treat it to return it into the environment at the same level of quality at which it was withdrawn.
Only 1% of global water resources are available as freshwater for human use. Irrigated agriculture consumes the bulk of this freshwater while urban and industrial use is less than 10 to 15% of the total demand in a typical region. Urban water can come from different sources depending on the location of the city: from glacial melt, lakes, tanks, rivers, and groundwater.
Its quality varies considerably depending on the quality of the source, and the amount of pollution (such as faeces, solid waste, chemicals and even antibiotics) that cities and citizens unthinkingly release into the water. In most locations, source water needs to be filtered, treated for pathogens and then distributed through pipes and sometimes tankers and informal water vendors.
Only the more affluent cities and households in much of the world have the luxury of access to 24×7 piped water. Increasingly, groundwater is being used in many parts of the world, either because surface water is becoming less available or is polluted or because citywide piped water infrastructure is not in place, especially as cities grow in unplanned ways. In its absence, it’s easier to drill a bore well within one’s property than wait endlessly for water to come from a partially-functioning water system.
As water scarcity rises, some cities like Singapore have taken the lead in recycling and reuse. Others, like New York, have set aside large catchment areas in the Catskill mountains to protect natural aquifers and provide water security to the city. In others, such as Perth which faces severe drought due to Climate Change, wind turbines power desalination plants that augment the city’s water systems.
On top of the challenge of water supply, comes the global crisis of sanitation as human populations in poorly-served cities and neighbourhoods now crosses into the billions. Dealing with human faeces has been a perennial public health challenge ever since cities were first created.
Indus Valley civilisation towns were planned over 5,000 years ago, with toilets and cesspools just outside houses, separated from underground storm water drainage and water harvesting and storage structures, creating barriers to the spread of waterborne diseases. Many cities and towns, even today do not have the levels of services that we see in these ancient settlements.
One of the great public health innovations of the 19th century, was the Victorian popularisation of the water closet and the water carriage flush systems. This was a significant public health innovation that over the course of a few decades, reduced the incidence of waterborne epidemics like cholera and typhoid in cities like London, Calcutta and Bombay.Such systems have become the aspirational norm for cities across the world, but require over 100 litres per capita per day, and because of the significant cost are becoming increasingly impractical in a world of water scarcity. In reality, large numbers of slum dwellers are forced to practice open defecation, that puts them and their communities at considerable risk, especially in countries like India. In India, over 50 million people defecate in the open in urban areas each day.
Contrary to popular perception, the most common form of urban sanitation in the world is not sewerage but on-site sanitation, such as pit latrines and septic tanks that require an elaborate human and service infrastructure to safely remove human waste from them. Improving these systems, especially in areas that still exploit people who handle human waste are a critical frontier of urban innovation.
Drainage is an often-neglected infrastructure with dire consequences, including flooding and the widespread incidence of vector-borne diseases like malaria and dengue, in areas and cities that are poorly drained. Underground drainage is often expensive to provide and difficult to retrofit into unplanned areas. Hence, in many parts of the world, storm water (often mixed with household waste and sewage) drains off to roads and channels. Drainage systems are often clogged with silt and solid waste if they are not managed adequately and regularly.
Adequate planning, design and the maintenance of drainage infrastructure, is critical, especially in low-lying, coastal and riverine areas and this makes a difference between healthy and liveable neighbourhoods and those at risk. Mumbai went through a horrific flood in 2005 , that shut down the metropolis for more than a week because of poor drainage planning and management.
Solid waste management has become the bane of many cities, because of growing populations, rising consumerism and the associated increase in industrial packaging materials which are difficult to recycle and segregate. The long-term solution is to consume less, recycle more, shift to biodegradable packaging materials and segregate it at source so that downstream recycling is more efficient and less damaging to the environment.
For a long period, landfills were seen to be the modern solution to the problem of the mountains of waste that were produced by large metropolitan cities. Landfills don’t work as well, in low and middle-income countries as they do in high income countries because land is scarce, and municipalities are unable to invest in safe, sanitary facilities. As a consequence, landfills tend to leach into groundwater and soil, give out methane; incineration at landfills releases noxious gases and communities protest and reject plans to locate landfills near where they live.
The collection, transport, treatment and storage of solid waste, has become a serious challenge in most countries. Some types of waste contain toxic chemicals and bio-hazards that need to be treated specially by using incineration to be able to render them safe which are often too expensive in low and middle-income countries. The solid waste disposal chain employs a large numbers of waste pickers and recyclers in cities of the global south, where they provide a critical service to the city’s residents, but are often excluded and discriminated against.
All aspects of sustainability, economic, social and environmental need to be addressed in dealing with the waste economy, as urban’s forward looking waste management systems seek to demonstrate.
The metabolism of the modern city is effectively driven by its energy infrastructure. Most preindustrial towns and many contemporary cities are still driven by the biomass economy, using materials like wood and agricultural residues, to enable cooking and artisanal production. During the Industrial Revolution, the primary energy source for cities and industrial production shifted first from wood to coal and later to oil and gas and nuclear energy. Urban energy services, especially in advanced economies are slowly shifting from the use of fossil fuels such as coal, oil and even gas to renewable sources such as wind energy, solar photovoltaics and in some locations, biofuels.
Highly energy efficient devices like LED lighting are dramatically reducing energy demand. Smart grids and dynamic tariff systems are encouraging energy efficiency in cities. Yet, large population of households in cities of the global South do not have access to reliable, affordable and uninterrupted power that will permit their children to study at night or even refrigerate food.
This is clearly a priority for the SDGs. But exciting innovations are afoot, for example, to reduce energy uses in building and house construction, technologies to decarbonise the production and transportation systems of our cities. Taking these innovations to scale in our cities are essential, if we are to achieve the goals of the Paris Climate Accord and restrain global mean temperature rise to 1.5 degrees C above pre-industrial levels.
While the energy infrastructure can help move the wheels of industry, commerce and household energy use, it is the mobility and transport systems that enable the city and its citizens to move people and their things from one location to the other, whether it’s from home to work, school to market or to gardens and recreational spaces.
Dramatic technological changes have taken place in transportation systems over the last century, but the apparent contradiction is that the faster and more sophisticated that our vehicles become, the slower transportation speeds become, because of congestion and poor planning. In many cities, the mean velocity of vehicular traffic is often not faster than a bicycle, accompanied by an epidemic of traffic accidents and severe air pollution.
A distinguishing feature of the modern city is urban sprawl, driven by the expansion of transport networks, starting with trams and rail and now taken over by the motor car, in most parts of the world to create massive suburbs and growth corridors. This is a serious challenge not only to sustainability, but to the livelihoods and economic security of the working poor, who either choose to live in poor conditions close to work in the decaying heart of many cities or are pushed to the periphery.
The most appropriate mix of mobility modes (walking, cycling, driving motorcycles, cars, buses and trains) and the role of active and public transport have been a deeply contested set of questions over the last few decades. It is now largely agreed that denser, more walkable cities are not only more secure but also more efficient, productive and make for more liveable spaces.
Cities like Vancouver, Perth and Copenhagen have demonstrated to the world that moving to more active and public transport linked to sustainable land use and mixed land use can improve the liveability and attractiveness of a city. Commuter rail, mass transit and metro systems have become an important symbol of million plus city life even though they are considerably more expensive than other options, and their environmental and climate impacts are relatively low.
Finally, the movement of goods and materials in cities, is probably as important as that of citizens. The effective functioning of cities depends on the flux of materials, fuels, finished goods and products through it and its linkage with regional and long distance transportation networks like shipping, air-freight and rail.
The most recent but almost ubiquitous urban service, is the telecommunications and information infrastructure that we built over the last century or so, that started with the telegraph and fixed wire telephone lines, but now is rapidly graduating to wireless voice, data and Internet connectivity.
Even in some of the poorest parts of the world, the expansion of optical and wireless communication systems across cities and urban areas has marked a most remarkable innovation over the last two decades dramatically increasing the importance and value of community and economic interaction and networks. The conception of basic services has now been extended in some cities to include universal free Wi-Fi , such as Helsinki which provides free municipal wifi zones throughout the city.
Irrespective of of the mix of the service providers that challenges of integrated planning of universal urban services; their effective development, operations and maintenance; and their apparition and replacement at the right point of time are all processes that need to be regulated appropriately and governed effectively, if we want our cities to be safe, productive, inclusive, resilient and sustainable.
What have we learnt today?
Infrastructure and services are a key differentiator between urban and rural areas and help create the economies of scale that draw people and enterprises to urban areas.
There are large differences in access to basic services like water supply, sanitation and solid waste management in and between cities, leading to risks of disease, disasters and inefficiencies. Environmental services like water supply, sanitation, drainage and solid waste management are critical to the effective functioning of the city but are linked to the ecosystem services of the region.
Most cities struggle with water scarcity and pollution, sanitation access and affordability, leading to health risks and lower quality of life for their residents. Urban energy infrastructure, based largely on fossil power is critical to maintain the metabolism of industry, commerce and household activities in the city. Universal access to quality modern energy sources, a renewables and energy efficiency transition across buildings, transportation, production and household energy needs to be effected very rapidly.
The city’s mobility and transport infrastructure helps determine its spatial form, expansion and the economic and livelihood opportunities that it offers to its citizens.
Active and public transport systems in cities that are compact and walkable are possible, effective, cheap and dramatically improve liveability and city attractiveness.
ICT infrastructure has revolutionised the interaction between people, enterprises and public institutions in the city. Nevertheless, a digital divide does exist that needs to be closed, through universal access to these services.
This will help in the integration and improvement in service delivery, cost effectiveness and the resilience of other urban services.
OpenEdition sugere que esta publicação seja citada da seguinte forma:
Pedro Pereira Leite (12 de Março de 2017). Museologia social e urbanismo IX. Global Heritages. Recuperado em 2 de Dezembro de 2024 de https://doi.org/10.58079/p380