That cities will continue to grow into the future is not open for debate. People migrate towards population centers for jobs, for services, for opportunity, for a perceived better future. Whether their expectations are met is part personal initiative, part luck, and part leadership. Leaders in these centers impact the urban economy, the politics, the social contracts, the educational opportunities, the health, and in sum the life of new arrivals.
In the developing world, the history of urban populations is checkered at best. The WHO sees much of the infrastructure upon which services are based as less than adequate. Half the urban population is challenged with poor water or inadequate sanitation with resultant disease burden. 17% of the childhood population is dead before the age of five. In spite of this, cities continue to grow, and if managed well, provide advantages beyond those available in many rural settings.
By 2030, 5 billion of the more than 8 billion global citizens will be urban dwellers. (Table 7.1) In 1990, cities contained only 15% of our population. By 2002, the number was 48% and in 2030 it will be 60%. Not only are overall numbers growing but city size on average is expanding. The largest 100 cities in 1800 averaged a population of 200,000. One hundred years later, it was 700,000. But by 2000, 388 cities averaged 1 million plus inhabitants and 16% had more than 10 million accounting for remarkable centralization of 4% of our entire global population. These cities are centered and fueled by Earth’s largest regional economies. And they are also positioned in some of our most water stressed geographic locations.
If you look at predicted movements of populations between 2000 and 2015, trends for both developed and developing nations show movement from rural to urban environments. For developed countries, urban residents will grow from 71% to 79% of the population as rural populations decline from 25% to 21%. In developing nations, city residents will increase from 40% to 49% of the total population, and rural populations will decline from 60% to 51% of citizens. (Table 7.2)
The perceived benefits of this centralization of human capital in terms of opportunity rests heavily on both communal and domestic development which translates quite directly into expanding demands for water. Not surprisingly then most cities are progressively digging deeper for groundwater and traveling farther to access surface water than ever before. Of the 2.9 billion current urbanites, some 60% are dependent on surface source water and 40% on ground source water. And they are not alone, but must compete with agricultural, industrial, energy, and urban sprawl domestic consumers for an increasingly expensive resource. Yet those that have it are the lucky ones. For those who do not (some 6%), they generally must purchase vendor water at higher prices.
The world’s 389 largest cities range from Tokyo, Japan with 26 million to Volgograd, Russia with 1 million citizens (Table 7.3). The history of urban water management is one of crisis and mismanagement, with leaders who seek the least expensive way to access and dispose of water. But over the course of years, the cost of failure, in dollars and political fallout, the rise of knowledge and expertise, and the establishment of standards of measurement and stable regulatory authorities have moved us at least in the right direction. But the truth remains, that urban water and waste management, at best, is enormously complex. Water systems, waste systems, flood prevention, pollution management, sustainable resourcing while maintaining growth – all of this and more requires funding, planning, execution, monitoring, and integration. It also requires standard setting, in that water supplied must be safe and affordable, and sanitation systems should be reliable, well-maintained and convenient.
Standards often must consider pragmatic realities. In more developed countries a standard that “all urban households have safe, regular piped water to their home, internal plumbing and their own sanitary toilet” is achievable. In a developing nation urban setting, pursuing this same standard might assure ideal access to the richest 20% and no access at all to the poorest 80%. For such a circumstance, safe access to a tap within 50 meters of one’s home that can provide a person with 20 liters of safe water per person per day may, more realistically, impact most of the population. Finally, one can build toward standards, but maintaining the infrastructure requires continued investment and improvements reliably over time. Middle income countries increasingly build toward higher standards but often under fund maintenance of the system. For lower income countries, efficiency, maintenance, pricing, supervision and regulation are the challenges. Their infrastructure is often incomplete and management of what does exist remains highly variable. The populations come for better jobs and opportunities, but often inherit water that is heavily compromised by bacteria and pollutants.
On the other hand, cities have advantages when it comes to water. There exist economies of scale with larger enterprises that more easily support infrastructure investment. Average incomes are higher than for rural counterparts. People are concentrated, and therefore more easily within reach of mapped delivery systems for both water and sanitation. Done well and properly funded, urban migrators can expect major improvements in access to water and safe sanitation. Done poorly, they can become entrapped in an explosive, disease laden environment that can be life threatening.
The presence of piped water, sanitation, and garbage removal in a city directly impacts basic health. In well developed cities, child mortality rates are commonly 10 per 100,000 live births. Where infrastructure is inadequate, child death rates are frequently increased by a factor of ten. And within the sub segments of these cities, there exists great variability in a single city. A study of seven communities in Karachi, Pakistan, for example, revealed infant mortality rates from 33 to 209 per 100,000 live births. They die from water born cholera, typhoid, hepatitis B, and even malaria which has normally been a factor primarily in rural environments. They have worms and scabies and trachoma. They are malnourished, immune depleted, and in general vulnerable and at-risk.
The extent of the urban challenges varies by geography. Of the 2.9 billion urban dwellers in 2002, 49% lived in Asia, 18% in Europe, 14% in Latin America and the Caribbean, 10% in Africa, and 8% in North America. (Table 7.4) Worldwide, approximately 6% of urban citizens are at risk from inadequate water and 17% from poor sanitation. Africa is most at risk with 14% lacking adequate water and 20% having inadequate sanitation. Asian cities are in a similar position with 7% suffering from poor water and 26% from poor sanitation. Latin American and Caribbean numbers are slightly better at 6% and 14% for poor water and sanitation. And Europe and North America populations are with some minor and intermittent exceptions relatively secure (Table 7.5). Overall, these numbers are likely to understate the problem as a result of under reporting, differing definitions of “safe” and “adequate” and considerable variability from nation to nation, city to city, and community to community. If one looks at the ideal, that is piped water and sanitation, it is clear that the challenge, especially in the developing world, is considerable. (Table 7.6)
Sanitation tends to be worse in smaller cities than in large urban settings. A study of 43 cities in Africa showed that only 18% had toilets connected to sewers. In many of the settings shared toilets or pit latrines were the rule. Shared toilets have a wide range of problems including cross-contamination, accessibility to flies and other disease carrying insects, overuse, poor maintenance, travel distance (especially for young children), privacy (especially for women and girls), and expense to utilize public latrines. A study in Ghana in 2000 demonstrated that regular use of public latrines by family members could consume up to 15% of family revenue. Not surprising then that open defecation, and paper wrapping of fecal material is not uncommon. A study of children under 5 in India revealed only 1% use latrines. 5% of parents dispose children’s feces into a latrine. The remaining 95% throw them into ditches, streets or yards. In poor settlements, lack of solid waste collection further complicates these practices.
Inadequate drainage and disposal of contaminated waste accumulates and translates into higher direct disease burden and secondary contamination of water sources. Open ditch disposable has to wait only for the next storm to flood surrounding areas with disease, and standing, soggy, polluted materials provide excellent breeding grounds for insect disease vectors.
As cities grow and prosper, water consumption predictably increases. This water then is returned almost always in a lower quality state to lakes, rivers and seas. The water coming from the sanitary systems is joined by waste water. With backup, the streams of sewage connect and travel. Containment under such circumstance is highly unlikely. Poor segments of the population, from Mamba to Seoul to Delhi, are gradually segregated to smaller districts, usually selected because they are the worst location, least valuable, and most compromised. The cost of extending water, sewage and drainage to these areas is prohibitive and low on the priority list considering the fact that many of these settlements are unplanned and unstable.
Urban centers, in concentrating their populations close to coastal waters, are vulnerable as well to water related disasters. Floods cause the major loss of life. Studies reveal that most deaths and injuries could have been prevented with better predictive warnings, preparation, and response capability. Drainage infrastructure, good water shed management and well planned construction and housing offer protection. In contrast, population concentrations in flood paths, flammable shelters and fuel based cooking and heating assure higher death and injury tolls.
The water challenges encountered around the world are uniquely different one from another. What they share in common is the need for local governance and site-specific solutions. Good water governance is built around human needs, with institutions tailored to servicing those needs. Good water governance takes a long term integrated view, supporting industries and developers for economic growth, but setting limits on where and when and how, so that the overall impact on the regional water basin can be managed. Good urban water governance is accountable to the citizens, properly funded, and views basic provision of water and sanitation within these growing urban enterprises as not only equitable and just, but essential to accomplishing the full economic and human potential of the enterprise.