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close this bookUnited Nations University - Work in Progress Newsletter - Volume 15, Number 2, 1998 (UNU, 1998, 12 pages)
View the document(introductory text...)
View the documentWater for sustainable growth: "Nor any drop to drink"
View the documentThe work of UNU/INWEH: Improving water management
View the documentStanding in line for water: Cooperation on the Ganges and Brahmaputra
View the documentHydropolitics along the Danube
View the documentCity water: 21st century challenge
View the documentNew ways to govern the seas
Open this folder and view contentsRavaged seas in Central Asia
View the documentHistory's plagued seas: The Mediterranean
View the documentClimate, history and water
View the documentWater: The 21st century's oil?
View the documentA chemical eye on water
View the documentWhen oil troubles waters

City water: 21st century challenge

By Juha I. Uitto, Asit K. Biswas and Cecilia Tortajada-Quiroz

Farmers around Beijing are losing irrigation water to satisfy the thirsty demands of Beijing. Groundwater levels are dropping in many places in the Third World to meet the demands of nearby mega-cities. Rising urban affluence intensifies competition for agricultural water.

The burgeoning urban populations of the world are generating some of the severest environmental challenges of the coming century - most notably in providing safe and clean water to the five billion people who will live in cities (double the present number) by the year 2025. In 1997, the UNU organized a Forum in Tokyo on the topic "Water for Urban Areas in the 21st Century," which brought together eight leading world experts from Asia, Europe, North America, Latin America and the World Bank. This article summarizes and highlights the main issues raised in the Forum. Dr. Juha I. Uitto is a Senior Academic Programme Officer at the UNU Headquarters. Prof. Asit K. Biswas, who acted as the convenor of the Forum, is the Chairman of the Committee on International Collaboration of the International Water Resources Association (IWRA). Cecilia Tortajada is the Vice-President of the Third World Centre for Water Management in Mexico. The UNU Press is planning to publish a book, edited by Drs. Uitto and Biswas, on the urban water forum. - Editor

The number of urban dwellers on the globe is expected to double to more than five billion people by the year 2025. Between 1950 and 1990, the number of cities having more than one million people increased almost four-fold, from 78 to 290. By 2025, the number of such cities is likely to double to more than six hundred.

Asia and Africa are now experiencing explosive urban growth at around 4 per cent per year. The provision of clean water and sanitation facilities in the mega-cities of the developing world -places like Lagos, Shanghai, Jakarta and Mexico City - is going to be one of the most challenging tasks faced by development strategists in the 21st century.

Already, there are very disquieting signs of inadequate water supply and sanitation in the developing countries. Some of the signs:

· Unsafe water is responsible for 80 per cent of all diseases and 30 per cent of deaths in the developing world;

· Annually 1.2 billion people suffer from diseases caused by unsafe drinking water or poor sanitation;

· Annually more than four million children die from waterborne diseases;

· Fifteen per cent of children will die before reaching the age of five years due to diarrhea - deaths that might be avoided with reasonable water and sanitation services.

Both quality and quantity are serious urban water concerns. The cities of the world produce huge amounts of sewage - both from households and industries - which causes health problems both for humans and for ecosystems. Water-related diseases are prevalent, especially in the poorer parts of developing country cities. Similarly, providing sufficient amounts of water to the growing urban centres is in itself a challenge.

Solutions obviously need to be found on multiple fronts involving a range of stakeholders. Thus far the main emphasis has been on managing water supplies. As new sources of water all over the world become scarce and more expensive to develop, emphasis needs to shift from supply to demand management. One of the tools will be increasing reliance on water pricing. Appropriate water pricing could significantly reduce water wasted in all sectors.

The public sector has often failed to deliver sustainable water supply and sewage systems. The World Bank estimates that the current investment needs in this sector in developing countries and the countries with economies in transition are in the order of $50 billion per year. Such huge investments can only be harnessed through public and private sector partnerships. Private sector will have to play an increasingly important role in the future.

The efficiency of water supply systems is frequently appallingly poor. Water distribution systems all over the world lose between 15 and close to 70 per cent of water through leakage. Poor operation and maintenance is a significant problem, for example, in the Indian mega-cities of Bombay, Madras, Calcutta and Delhi. More emphasis needs to be placed on water conservation to reduce such major losses.

The example of Japan can serve to demonstrate what careful management can contribute to the efficiency of urban water supply. Tokyo has experienced remarkable growth during this century and is now arguably the largest urban conglomeration in the world (with some 31 million people in the eight adjacent cities). Nevertheless, the losses (systemic leakages before water reaches the end-users) in the urban water supply system of Tokyo have been reduced from 80 per cent in 1945 to the current remarkably low 9 per cent.

Considering the escalating conflicts in water resources development and the increasing water demand in the developing countries, wastewater reclamation and reuse will need to be seen as increasingly important options for sustainable development of urban water resources. As environmental requirements become more stringent, wastewater reclamation is becoming more important. Reused wastewater can be used for purposes where the quality requirements are not that high: flushing toilets, washing cars, gardening, etc.

Another Japanese case can highlight the need to balance the requirements of water for urban areas with other ecosystem demands in the region surrounding the cities. Lake Biwa, the largest lake in Japan, is important for the water supply for the second largest urban conglomeration in the country, the Kansai area consisting of the cities of Osaka, Kyoto, Nagoya and Kobe. The Lake Biwa-Yodo river system shows how individual municipal water systems have evolved for many different local reasons based on the agendas of the various municipalities in the basin. A holistic approach to integrated watershed management has been lacking. Consequently, policy has been segmented and the implementation approach has been incremental, causing problems with the economics of water use.

Now environmental considerations and restoration are becoming increasingly important with regard to, for example, water resources management and quality. In Japan, the development of water resources has traditionally been seen in the context of overall economic development, with emphasis on river development, dam construction, diversion channels, etc. In the future, however, it is important to incorporate environmental considerations and conservation into the water resources development plans.


The role of engineered treatment, reclamation, and reuse facilities in the cycling of water through the hydrologic cycle. (Source: Asano, T. and A.D. Levine, "Wastewater reuse: A valuable link in water resources management," Water Quality International, 1995, No. 4)

The Lake Biwa Comprehensive Development Project took twenty-five years to complete. This was achieved during a time of very rapid economic growth in Japan when environmental concerns were not considered front-burner issues. Similar projects today and in less wealthy countries would take much longer to realize.

A case in point may be Mexico City, a sprawling metropolitan area of 25 million people. Population growth remains high and the water demand is increasing rapidly. To cater to the growing demands, Mexico has embarked on projects that involve long-distance water transfers from basins located far from the city. As a consequence, the costs are escalating rapidly. Similarly, supplying water to the urban giant is taking a toll on the environment in the surrounding areas. The situation will not be sustainable in the longer term.

Water management during disasters needs special attention. For example, human suffering and property damages due to fires could have been significantly reduced after the Great Hanshin Earthquake that devastated the city of Kobe in 1995 with more efficient planning and operation of the water supply systems. Many of the world's urban centres are concentrated in locations susceptible to hazards. Coasts where most of the large cities are concentrated are generally exposed to climatic hazards, such as typhoons and hurricanes that can disrupt water supply and sewage systems. Incidents of flooding can have devastating effects in urban areas.

The solutions to the pressing problems of urban water supply and sanitation must combine both technological as well as managerial and policy issues. There is also need for enhanced cooperation between the industrialized and developing countries. The industrialized countries need to rethink the focus and priorities of their official development assistance programmes in the water sector. What is needed now is a long-term vision for broad-based cooperation in the water sector that places more emphasis on the "software" aspects, such as capacity building and institutional strengthening. It will also be important to change the national policy environments to facilitate efficient water management in a holistic manner. Public awareness needs to be raised to support these processes.

The world is now facing an urgent water crisis of dimensions that no earlier generation has had to face. These problems must be solved lest there will be a major human tragedy facing mankind, especially in the developing countries. However, the problems can be solved with correctly focused investment, technology, and management. What is needed to achieve this is political will and active collaboration between the North and South, and East and West. If countries can initiate urgent actions, there is reason to be cautiously optimistic about the future.