INTERNATIONAL HYDROLOGICAL PROGRAMME PROGRAMME HYDROLOGIQUE INTERNATIONAL
PROCEEDINGS / ACTES
Frontiers in urban water management:
Deadlock or hope?
Frontières de la gestion de l’eau urbaine:
Impasse ou espoir?
SYMPOSIUM 18-20 June / juin 2001 Marseille, France
Edited by / Sous la direction de:
José Alberto Tejada-Guibert and Čedo Maksimović
IHP-V Technical Documents in Hydrology / Documents Techniques en Hydrologie No. 45 UNESCO, Paris, 2001
Water Academy Académie de l’Eau
World Water Council Conseil Mondial de l’Eau
City of Marseille Ville de Marseille (SC-2001/WS/10)
The designations employed and the presentation of material throughout the publication do not imply the expression of any opinion whatsoever on the part of UNESCO concerning the legal status of any country, territory, city or of its authorities, or concerning the delimitation of its frontiers or boundaries.
The ideas and opinions expressed in this book are those of the individual authors and do not necessarily represent the views of UNESCO.
Les appellations employées dans cette publication et la présentation des données qui y figurent n’impliquent de la part de l’UNESCO aucune prise de position quant au statut juridique des pays, territoires, villes ou zones, ou de leurs autorités, ni quant au tracé de leurs frontières ou limites.
Les idées et les opinions exprimées dans cet ouvrage sont celles des authors et ne refletent pas nécessairement le point de vue de l’UNESCO.
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Preface
The International Symposium “Frontiers of urban water management: Deadlock or hope?” (Marseille, 18-20 June 2001) represents a unique opportunity to assess the current status of urban water systems in various settings around the world and to explore various approaches, proposals and technologies that hold promise in facing the shortcomings. The nature and gravity of the urban water problems in the developing countries is such that they warrant our immediate attention. The aim is not only finding ways to cope and to hold off an impending collapse, but to provide sustainability and improve the quality of life of the urban population, while safeguarding the well-being of all members of society.
This Symposium, organised by UNESCO and the Académie de l’Eau de France, with the support of the City of Marseille and of the Secretariat of the World Water Council, represents the culmination of the activities related to the theme Integrated Urban Water Management of the Fifth Phase (1996-2001) of the International Hydrological Programme (IHP) of UNESCO. A number of other important partners and sponsors who provided an essential support to the Symposium are identified in a separate page. Their support in preparation and running the Symposium is highly appreciated.
This volume holds the papers selected to be presented orally at the six workshops of the Symposium, and the abstracts of the papers accepted for poster presentations.
In evaluating the papers submitted to the Symposium, the Scientific Advisory Committee assessed the quality of the papers, coverage of topics and geographical distribution of authors. Some of the keynote papers and workshop papers were not available when this volume had to be submitted to the printer, so have they not been included here. Nevertheless, the companion CD-ROM contains the full set of papers, including those of the posters.
We would like to express our deep thanks to all the authors whose valuable contributions appear here. Likewise, we would like to thank all its members of the Scientific Advisory Committee of the symposium, whose work provided an admirable base for the selection of the papers.
We also thank Mr. Yoslan Nur who materially put together this volume.
We hope that the readings contained here will provide food for thought and action.
Preface
Le symposium international “Les Frontières de la Gestion de l’Eau Urbaine”: Impasse ou Espoir?” (Marseille, 18-20 Juin 2001) constitue une chance unique d’évaluer l’état actuel des systèmes d’eau urbaine existant dans un certain nombre de milieux autour du monde, et de passer en revue les différentes approches, propositions et technologies disponibles pour faire face aux situation défectueuses existantes. La nature et la gravité des problèmes d’eau urbaine dans les pays en développement sont telles qu’ils nécessitent notre attention immédiate. Le but recherché n’est pas seulement la découvert de moyens de résister aux situations menaçantes de destruction et de les néutraliser, mais aussi de fournir et d’améliorer une qualité de vie durable aux populations urbaines tout en sauvegardant le bien être de la société.
Ce symposium organisé par l’UNESCO et l’Académie de l’Eau de France, avec le soutien de la ville de Marseille et du Conseil Mondial de l’Eau, représente le point culminant des activités entreprises dans le thème de la Gestion intégrée de l’eau urbaine de la Cinquième Phase (1996-2001) du Programme Hydrologique International (PHI) de l’UNESCO. Un certain nombre d’autres importants partenaires et parrains ayant apporté un support essentiel au Symposium sont présentés dans une page spéciale. Leur aide dans la préparation et l’organisation du symposium a été déterminante et est hautement appréciée.
Ce volume contient les contributions qui seront oralement présentées au symposium et les résumés d’articles acceptées pour être présentées par affiches. En évaluant les documents soumis au symposium, le Comité Scientifique a jugé de la qualité des présentations, de leur couverture des thèmes retenus et de la distribution géographique des auteurs. Certaines articles de discours introductifs et de ateliers n’étaient pas encore disponibles quand le volume a été soumis à l’imprimeur, donc elles n’ont pu être inclues dans ces actes. Néanmoins, l’accompagnant CD-ROM contiendra tout les articles, y compris ceux présentés sur les affiches.
Nous aimerions exprimer notre profonde gratitude aux auteurs dont les contributions sont presentées ici. Nous aimerions egalement remercier tous les membre du Commité Scientifique du Symposium dont le travail a permis de fonder sur d’excelentes bases la selection des documents. Nous remercier également Mr. Yoslan Nur qu’a materialement préparé ce volume.
Nous espererons que son contenu nourrira les pensées come les actions.
CUW-UK
Čedo Maksimović Urban Water Research Group Dept. of Civil and Environmental Engineering Imperial College of Science,Technology and Medicine & Centre for Urban Water (CUW-UK) London, UK
José Alberto Tejada-Guibert
International Hydrological Programme (IHP) Division of Water Sciences
UN Educational, Scientific and Cultural Organization UNESCO
Paris, FRANCE
vii
SYMPOSIUM CHAIRPERSONS
PRESIDENTS DU SYMPOSIUM
J. A. Tejada-Guibert (UNESCO) C. Maksimovic (CUW-UK)
INTERNATIONAL ORGANIZING COMMITTEE
COMITE INTERNATIONAL D’ORGANISATION M. Abu-Zeid (World Water Council/Conseil Mondial de l’Eau) J. Bartram (World Health Organization)
B. Braga (International Water Resources Association)
C. George (International Association of Hydraulic Engineering and Research) P. Hubert (International Hydrological Programme)
T. Milburn (International Water Association)
J. L. Oliver (Ministère de l’équipement, des transports et du logement) K. Ray (UNCHS - Habitat)
P.A. Roche (Agence de l’Eau Seine-Normandie)
L. Roussel (Agence de l’Eau Rhône-Méditerrané- Corce) D. Savic (International Association of Hydrological Sciences) A. Szöllösi-Nagy (UNESCO)
P. F. Tenière-Buchot (United Nation Environment Programme) F. Valiron (Académie de l’Eau)
SCIENTIFIC ADVISORY COMMITTEE
COMITE SCIENTIFIQUE
J. A. Abrishamchi (Iran) J. Marsalek (Canada) M. P. Boudouresque (France) J. Niemczynowicz (Sweden)
D. Butler (UK) K. M. Nouh (UAE)
L. Casanova (Japan) M. Saad (Egypt) B. Chocat (France) S. Saegrov (Norway) M. Desbordes (France) J. P. Sotty (France)
P. Harremoes (Denmark) D. Stephenson (South Africa)
T. Lee (Chile) C. Tucci (Brazil)
J. Lundqvist (Sweden) E. Vlachos (USA)
S. Matsui (Japan)
LOCAL ORGANIZING COMMITTEE
COMITE LOCAL D’ORGANISATION L. Fauchon, Chairperson (Groupe des Eaux de Marseille) J. Al-Alawi (Secretariat du Conseil Mondial de l’Eau) V. Burroni (Conseil Régional Provence-Alpes-Côte d’Azur) J-P. Chirouze (Agence de l’Eau Rhône-Méditerranée-Corse) J-N. Guerini (Conseil Général des Bouches-du-Rhône) G. Pipien (Préfecture des Bouches-du-Rhône)
P. Martel-Reison (Chambre de Commerce et d’Industrie Marseille Provence) J. Mancel (Office International de l’Eau)
D. Vlasto (Ville de Marseille)
Table of Contents / Table des Matières
Preface
Workshop 1: Demand management practice, policy, data and technologies 1
GPA Strategic Action Plan on Municipal Wastewater with Recommendation for Decision-Making . . . .
De Vrees, L (Keynote) 3
A Case Study of Integrated Water Resource Management in Windhoek, Namibia. . . Biggs, D. & R. Williams
10
Reduction des Pertes: Cas de la Ville de Fès (Maroc) . . .
Coulange, F. 19
Heigthening Urban Water Supply Capacity and Reliability Trough Reconstructing Integrated Regional Water Resources Systems
Feng,G. & Y. Feng
22
Society and Water Quality: Self-Organized Critical Water System. . . Geldof, G.D.
30
Water Quality in Networks in the Condition of Substantial Decrease of Water Consumption . . . Koppel,T., N. Kandler, K. Tiiter and A.Vassiljev
38
Community-Based Urban Water Management under Scarcity in Dar Es Salaam, Tanzania . . .
Kyessi, A.G. 46
Water Crisis in Iran, Codification and Strategies in Urban Water. . .
Motiee, H., Monouchehri and M.R.M. Tabatabai 55
GIS “Hydro-Manager” for Urban Areas Water Control. . .
Tskhay, A.A. & Y.S. Morozova 63
Abstracts of Poster Presentations: . . . 70
The Tuul River Water Resources Changes and Water Use in Ulaanbaatar City, Mongolia . . .
Batnasan, N. 70
Impact des Eaux Urbaines sur la Qualite des eaux de l’Oued Seybouse. . .
Djabri, L., A. Hani, J. Mania, and J. Mudry 70
Masterplan Tools for Water Supply Network . . .
Odeh, K., F. Fotoohi and P. Feron 72
Implementation of International Technologies and Know-How for Improvement of Water Supply in Alytus, Lithuania
Paukstys, B. and E.A. Hansen
72
Urban Thermal Climate Affects on Stormwater in Cold Regions? . . . Semadeni-Davies, A.F., L. Bengtsson, A. Lundberg and W. Schilling
73
European Side Water Resources Management in Istanbul. . .
Sen, Z. and V . Eroglu 73
x
Workshop 2: Recycling and Reuse at Different Scale. . . 75 Protecting Urban Water Supplies in South-Central Kansas by Integrated Groundwater-Surface Water Management to Meet Municipal, Agricultural and Ecosystem Water Needs
Buddemeier, R.W., H. Rubin and D. P. Young
77
Xenobiotic Organic Compounds in Grey Wastewater: a Matter of Concern? . . .
Eriksson, E., M. Henzen and A. Ledin 84
Wastewater Reuse – Integration of Urban and Rural Water Resources Management . . .
Friedler, E. 92
Wastewater as a Source: Perspectives and Challenges. . .
Hamdy, A. 99
Recycled Water: Technical Economic Challenges for Its Integration as Sustainable Alternative. . . Resources
Lazarova, V.
108
La réorganisation du cycle de l'eau en milieu oasien: une nécessité. L'exemple du Sud-Tunisien . . . Moguedet, G., R. Bouckchina, A. Romdhane, D. Dubost, A. Houas, A. Jadas-Hecart, C. Kergaravat and A.M. Pourcher
117
Removal of Nutrients and Heavy Metals from Urban Wastewater Using Aeration, Alum and Kaolin Ore
Rashed, M.N. and M.E. Soltan
127
Abstracts of Poster Presentations: . . . 136 La reutilisation des eaux usées traitées dans le secteur agricole defies et controverses . . . Ben Brahim, H. et L. Duckstein
136
Early Australian Regulatory Models for Water Reuse to Ensure that it is a Major Contributor to . . . Sustainable Urban Development
McKay, J.
137
Water Reclamation in South Africa: the Answer for the Increasing Water Demand in the Gauteng . . . . Region?
Vandaele, S., C. Thoeye and K. Snyman
138
Water Quality Investigation and Management in Bangkok Metropolitan Region, Thailand. . .
Weeteeprasit, W. 138
Workshop 3: Water and Health. . . . 141 Health Impacts of Water . . .
Giroult, E. (Keynote) 143
Needed Innovative Urban Water Management for Developing Countries, Case of Egypt . . .
Amer, A.M. 147
Water, Health and Development . . .
Baral, H. 154
Towards a Recycling Society – A Case Study on the Successful Implementation of the Pilot Project in in Dalu Village, China
Mi Hua
161
Rethinking Urban Wastewater Re-use : Opportunities and Challenges . . . Raschid-Sally, L., C. Scott, M.U. Hassan, J. Ensink, Y. Matsuno, and W. Van der Hoek 168
Abstracts of Poster Presentations: . . . 177 La Reustilisation des Eaux Usées Traitées dans le Secteur Agricole Defis et Controverses . . . Ben Brahim, H. and L. Duckstein
177
Managing the Water Quality Effects from Densely Populated Settlement in South Africa. . .
Boyd, L.A., M. Hinsch and G. Quibell 178
Monitoring and Comparing the Levels of 20 Trace Metals in the Reservoirs of Water Supply and Sewerage Corporation of Athens using the ICP-MS Technique
Lytras, E., F. Tzoumerkas and D. Xenos
178
Catchment Restoration and Sustainable Urban Water Management: A New Paradigm
Powell, A.M. and L. Jones 179
Water Quality in Three Reservoir at Citarum River Basin, Indonesia . . . Sembiring, S.
180
Workshop 4: Technological outlook for the future. . . 181 Sustainable Management of Municipal Wastewater and Stormwater: UNEP-IETC's Information and Capacity Building Resources
Casanova, L.
183
Rooftop Rain Water Harvesting - An Alternative Technology for Fresh Water Augmentation in Chronically Deficient Urban Agglomerates of India
Dhar Chakrabarti, P.G.
191
State of the Art and New Opportunities for Membranes in Municipal Water Treatment . . .
Durand Bourlier, L. K., Glucina, I. Baudinand P. Aptel 200
Energy Related to Sustainable Waste Handling Technology . . .
Eilersen, A.M. and M. Henze 209
Waste Design Paves the Way for Sustainable Urban Wastewater Management . . . Larsen, T. A., W. Rauch and W. Gujer
219
Prévention et Diminution des Inondations Urbaines; Emergence de Solutions Intégrées . . .
Lavallée, P., M. Pleau, R. Martin, D. Guthrie and M. Link 230
"Slum Networking" - Using Slums to Save Cities . . .
Parikh, H. H. 238
Abstracts of Poster Presentations: . . . 246
Urbanisation Process and Urban Hydrology Problems in Developing Countries: The Case of Argentine
Bertoni, J.C. and P. Chevallier 246
xii
Integrating urban water management in the Higher Education Curriculum, Hungarian case study . . .
Csobod, E. 247
The evolution of stromwater management in New South Wales, Australia . . .
McManus, P. Smith, R.R. Brown and R. Ryan 247
Workshop 5: Integrated urban water management for the future . . . . 249
An Australian Case study: Why a Transdisciplinary Framework is Essential for a Successful Integrated Water Management Policy
Brown, R.R., R. Ryan and R. McManus
251
Water Management in the Mexico City Metropolitan Area: The Hard Way to Learn . . .
Castelan, E 260
Sustainable Management of Water Supplies for Developed Urban Areas: Issues, Perspectives and a Vision
Kallis, G. and H. Coccosis
269
Development of Sustainable Water Management in Beijing, China . . . Nie. L. & W. Schilling
279
Vers un Service Universel : Nouveaux Concepts pour l’Approvisionnement en Eau et l’Assainissement des Zones Urbaines à Faible Revenus
Mathys, A.
285
Overcoming Macro/Micro Gridlock: the Implications for Regulatory Reform of a Local Urban Water Conflict
M’Gonigle, R.M.
292
L'Assainissement Urbain dans les Pays en Voie de Développement. Le Besoin d'une Stratégie . . . Alternative
Roumagnac, A & M. Benedetti
301
Abstracts of Poster Presentations: . . . 307 Tashkent Irrigation Net in Tashkent City - Problems and Decisions . . . Makhmudov, E.J. & A.D. Ganiev
307
The Challenges for Urban Water Management in Tropical Coastal Megacities: Bangkok, Jakarta and Manila
Nur, Y
308
La Ville Nouvelle de Sidi Abdellah et le Développement Durable un Example d’Amenagement à Partir de la Gestion des Eaux Urbaines
Souag, M. and S. Dorbhan
308
Urban River Catchment Management Association - A Long Term Experience as a Model for the Future
Sperling, F 309
Urban Water Problems: the Case of the Metropolitan Area of Mexico City . . . Tortajada, C.
310
Workshop 6: Private participation in the provision of urban water services 311
Partnership for the Sustainable Urban Water Utilisation and Management in South-West Nigeria: . . . Issues and Prospects
Akegbejo-Samsons, Y.
313
The Importance of Public Attitudes and Behaviour for Management of Urban Water Systems . . .
Ashley, R.M., N. Souter and S. Hendry 318
Is Privatisation of Urban Water Supply Services in Developing Countries a Sustainable Alternative?
Experiences from Argentines Recent Privatisation Strategy Bundschuh, J. & A. Fuertes
327
Water Provisioning in Dar es Salaam, Tanzania: The Publilc - Private Interface . . .
Kjellén, M. 337
The Participation of the Private Sector in Urban Water Services Provision. . .
Moss, J. 344
A New approach for the Delivery of Sustainable Services in Poor Peri-Urban Areas: Business Partners for Development. Kwazulu-Natal Project
Rousseau, P. & E. Tranchant
352
The Challenge of Urban Water Management in Africa. . .
Thuo, S. 358
Abstracts of Poster Presentations: . . . 362 Urbanization and Water Industry Growth in Malaysia: Issues and Challenges in the New Millenium . . .
Hashim, N.M. 362
Social and Economic Aspects of Urban Water Management. The City of Thessaloniki Case. . .
Kolokytha, E.G., Y.A. Mylopoulos and A.K. Mentes 363
Water Supply Options in Urban India – Institutional Challenges and Opportunities . . . Saravanan, V.S.
363
Workshop 1
DEMAND MANAGEMENT PRACTICE, POLICY, DATA AND TECHNOLOGIES
Convenors:
United Nations Environment Programme
UNCHS - Habitat
GPA STRATEGIC ACTION PLAN ON MUNICIPAL WASTEWATER WITH RECOMMENDATIONS FOR DECISION-MAKING
L.P.M. de Vrees*
* UNEP/GPA Coordination Office, P.O. Box 16227 2500 BE The Hague, The Netherlands.
Email: l.dvrees@unep.nl or gpa@unep.nl ; Web-site: www.gpa.unep.org ABSTRACT
This paper outlines the Strategic Action Plan on Municipal Wastewater of the Global Programme of Action for the Protection of the Marine Environment. The GPA/Coordination Office developed this Action Plan, in cooperation with other organisations, to support nations to address the problem of sewage adequately. One element of this action plan is the development of Recommendations for Decision-making on Municipal Wastewater. The aim of this paper and its presentation is to stimulate an exchange of views on the usefulness, adequacy, applicability, or appropriateness of these proposed Recommendations for Decision-making on Municipal Wastewater.
KEYWORDS
Clearing-house, Global Programme of Action (GPA), Marine Environment, Recommendations for Decision-making, Wastewater management
BACKGROUND
Coastal and marine pollution have become world-wide phenomena and triggered international action. In 1995, the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities (GPA, 1995) was adopted by 108 countries and the EC. The GPA recognises that the environmental effects associated with domestic wastewater are generally local, though with transboundary implications in certain geographic areas. The GPA notes that the commonality of sewage-related problems through coastal areas of the world is significant.
Therefore, urban wastewater discharges are considered one of the most significant threats to sustainable coastal developments world-wide.
The priority for action on “sewage” was also identified by:
• Seven regional workshops of Government-designated experts held in the period 1996-1998 in the framework of the United Nations Environment Programme/UNEP’s Regional Seas Programme and involving more than 60, mostly developing, countries;
• UNEP Governing Council (decision 20/19B.1.d) who requested the Executive Director in cooperation with other relevant organisations to explore the possibility to convene a global conference to address sewage as a major land-based source of pollution, affecting human and ecosystem health.
The slowly growing awareness, the technical complexity and high cost of wastewater management, are main reasons why it has taken several decades before the rich industrialised nations managed to take effective action. The burden on the developing countries is the heavier as they are less wealthy and have weaker institutions. Therefore, the GPA Strategic Action Plan on Municipal Wastewater (GPA, 2000a) aims at supporting the efforts of States to address the serious public health problems and the degradation of coastal ecosystems that result from the disposal in coastal areas of inadequately treated municipal wastewater. It does so through, amongst others, the development of Recommendations for Decision-Making on Municipal Wastewater (GPA, 2000b) and associated Knowledge Base; and the holding of regional meetings - including partnership meetings - and global consultations. The Recommendations for Decision- making are a guide for local and national decision-makers and professionals on appropriate and environmentally sound wastewater management systems, including treatment. It contains key principles and annotated checklists of recommended practices and procedures.
The Action Plan builds upon, develops and enhances the relevant sections on sewage of the GPA.
This Action Plan is the reflection of concerted actions by the United Nations Environment Programme (UNEP), the World Health Organisation (WHO), Habitat (UNCHS) and the Water Supply and Sanitation Collaborative Council (WSSCC).
COMPONENTS OF THE GPA STRATEGIC ACTION PLAN ON MUNICIPAL WASTEWATER
Assessment
• Global review of the State of Affairs, including the extent of the problem, hotspots and root- causes;
• Four regional reports on socio-economic opportunities and potential partners (i.e. East Asia, South Asia, Eastern Africa and South East Pacific);
• Case studies, illustrating the social, environmental, and economic benefits of action (and no- action);
• An analytical paper on challenges, opportunities and benefits. Especially the effects of improper sewage management on health, and the difficulties of sewage management in large urban centres will be analysed.
Management
The envisaged outputs are:
• Global Knowledge Base, describing the range of management options for addressing the sewage problem. Best practices, experiences and cases studies will illustrate these options.
The GPA information and data clearing-house on sewage and sanitation will be used as a vehicle for access, dissemination and further development of the Knowledge base. This so- called “Sanitation Connection” is a partnership of UNEP/GPA, World Heath Organization (WHO), International Water Association (IWA), Water and Sanitation Programme (WSP), and the Water Supply and Sanitation Collaborative Council (WSSCC) and is accessible via www.sanicon.net.
• Recommendations for Decision-making on appropriate and environmentally sound wastewater management. It contains key principles and annotated checklists of recommended
practices and procedures. It details ranges of approaches, infrastructures and tools available to practitioners and policy makers. The full document is available at:
www.gpa.unep.org/documents.
• Regional Cooperation for Innovative Actions: Four regional meetings (i.e. in the Caribbean, Eastern Africa, West Asia and East Asia region) are planned in the period February – July 2001, bringing together national and local experts, private sector, international financial institutions, potential donors and other stakeholders to:
• Review the Recommendations for Decision-Making
• Share technical, administrative and financial experience
• Identify demonstration projects
• Provide a forum for partnership creation
• Identify regional resource centres
• Global Consultation Process, consisting of
(i) High level segment at the GPA Intergovernmental Review in 2001. To this high level segment the results of the regional meetings will be presented and the Recommendations for Decision-Making submitted for endorsement. The meeting will be requested to assess if the process and outputs of the implementation of the Municipal Wastewater Action Plan as described above could be used to guide the development of similar activities for the other source categories, identified in the Global Programme of Action (such as nutrients, heavy metals, and habitat modification);
(ii) Sessions for professionals during planned global conferences, organised by professional associations, such as the 10th Stockholm Water Symposium (August 2000), Canada 2000 (September 2000), the fifth Global Forum of the WSSCC in Brazil (November 2000), the Symposium “Frontiers of Urban Water Management:
deadlock or hope?” in Marseilles (June 2001), etc;
(iii) Regional partnership meetings, as mentioned above.
AIM OF THE RECOMMENDATIONS FOR DECISION-MAKING
The development, consultation with experts from the different stakeholders and finally seeking political endorsement of the Recommendations for Decision-making fits within the normative function of UNEP. Seeking involvement of key stakeholders is another focus of UNEP. There is an important role of central and local authorities, citizens, non-governmental groups, private sector, in their role as water polluter (industries), water user (certain sectors such as tourism, fisheries) and water service operator (water supply and treatment industry). New partnerships between all these stakeholders, also involving regional organisations and finance institute is the new paradigm along which solutions for the future need to be sought.
There are several prerequisites for addressing the management of wastewater in order to safeguard human and ecosystem health, and to avoid the degradation of water quality and other coastal and marine resources. These include:
• Stakeholder involvement, which will foster the political will to assign a high priority to wastewater management among other pressing public investment needs
• Financial affordability.
These recommendations aim to provide guidance how to gain this political will and to increase financial affordability by describing sustainable systems for wastewater management, including less expensive technical options and ways of attracting support.
The key principles for managing wastewater sustainable are to conserve water resources, by eliminating pollution at the source, using water efficiently, and maintaining water quality, and to respond effectively to demands from society.
RECOMMENDATIONS FOR DECISION-MAKING: KEY-ISSUES
This paper gives all the (draft) key-issues and recommendations, which will be reviewed at the regional meetings mentioned above, amended, and possibly, to be endorsed at the GPA Intergovernmental Review of November 2001.
Issue 1
A comprehensive and integrated approach to urban wastewater management is needed to maintain the environmental integrity and the economic functions of aquatic ecosystems, including ground water, rivers, lakes, and coastal areas.
Recommendations
1.a Promote studies to quantify the socioeconomic impact of environmental pollution in case of inaction and action, and use such information to determine the priorities for investment and clean-up programs.
1.b Prioritise actions to minimise current and future environmental damage with carefully selected policies, programmes, and investments; invest stage-wise in infrastructure for wastewater management while maintaining a long-term horizon for planning and operations.
1.c Impose appropriate effluent standards that are feasible for local conditions.
1.d Integrate planning for wastewater with the planning for other sectors, such as water supply, solid waste, and land use.
1.e Use a mix of technological options and managerial approaches, including community- based development approaches, that are appropriate and optimal for different zones in the city.
1.f Incorporate wastewater management within integrated approaches for the management of river basins and coastal zones.
STAKEHOLDER INVOLVEMENT Issue 2
Successful wastewater management requires a high level of public commitment.
Recommendations
2.a Invest in creating and maintaining awareness among citizens regarding their dual role as polluters and beneficiaries of wastewater management.
2.b Develop commitment to a clean environment and “river basin solidarity,” and demonstrate that “win-win” situations exist when all polluters cooperate in wastewater management.
2.c Devolve decision-making to the lowest appropriate administrative level, and ensure that local communities receive financial power to participate in local or regional initiatives to operate, manage, and maintain their part of the infrastructure.
2.d Ensure that citizens receive an adequate wastewater management service relative to their financial contributions.
Issue 3
Wastewater management is pre-eminently an effort that involves many actors who must be willing to cooperate and contribute to the overall result.
Recommendations
3.a Apply both restrictive and enabling regulations. To make this approach more palatable and effective, add positive incentives, such as load-based licensing fees.
3.b Introduce market-based instruments, such as tradable effluent permits, in conjunction with administrative regulation to give polluters more flexibility to invest and operate in the management of wastewater.
3.c Develop mechanisms that allow civil society and its representatives (such as consumer associations) to hold polluting entities accountable, whether they are owned and operated privately or publicly.
3.d Ensure that the investment and operational mechanisms and instruments enable the equitable distribution of costs and benefits among all stakeholders.
FINANCING Issue 4
The financial sustainability of the wastewater management system must be assured.
Recommendations
4.a Strive to apply the principles of “the water user pays” and “the polluter pays” in the wastewater management systems.
4.b Design the financial system to balance the quality of the service, the investment costs, and the tariffs that households are willing and able to pay (demand-driven approach).
4.c Involve the stakeholders who are to gain from the water quality improvement, including those benefiting from enhanced land values, and ensure that they contribute financially (opportunity-driven approach).
4.d Use charges or pollution fees to establish funds for the cofinancing of wastewater treatment facilities, instead of considering these revenues as taxes that enter the national budget.
4.e Establish systems to ensure that tax revenues are allocated to the appropriate service provider.
4.f Examine the potential to use cross-subsidies.
INSTITUTIONAL ARRANGEMENTS Issue 5
A country’s central government can play a significant role as a facilitator and initiator of appropriate wastewater management.
Recommendations
5.a Develop systems to ensure good and sustainable governance and protect the performance of investments and operations, whether performed by the public sector or the private.
5.b Recognise the responsibility and authority of the central government to set the institutional environment to encourage local governments, the private sector, regional and river basin agencies, and other partners to initiate and implement programmes. This can include:
• Developing and maintaining national policies and strategies in cooperation with local governments and other stakeholders
• Enacting legal and regulatory instruments
• Encouraging the development of appropriate organisations to complement local government initiatives.
5.c Consider cofinancing schemes and infrastructure that are highly cost-effective and that have a high priority, as appropriate.
5.d Make local governments and environmental agencies accountable to central governments for implementing, operating, and maintaining sustainable wastewater management systems.
5.e Establish criteria for central governments to assess the performance of local governments and environmental agencies in reducing pollution.
Issue 6
In many countries, institutional restructuring and strengthening is required to ensure the good performance of the wastewater management system.
Recommendations
6.a Develop a long-term strategy for institutional reform and capacity building where existing structures, legal and regulatory frameworks, and organisations inside and outside of the government are weak or inadequate.
6.b Recognise that weak capacities pertain to the capacities of individuals (such as wastewater engineers) and to capacities embodied in managerial procedures, regulations, administrative rules, and career and salary incentives.
6.c Make use of or develop dedicated networks of multidisciplinary sector experts in academia, government, industry, and civil society.
6.d Ensure that these networks and information exchange systems, such as web-based clearing-houses, help to identify or articulate the problems to be solved and draw upon experiences from other countries in the region and globally.
Issue 7
Partnerships between the public sector and the private sector are important options and useful tools to assist local governments in financing and operating the infrastructure for wastewater management.
Recommendations
7.a Review the regulatory and legal frameworks that might impede public–private partnership arrangements; appropriate frameworks can facilitate local governments and the private sector to investigate partnership opportunities.
7.b Devise carefully the requirements and options for such regulation, which should be compatible with the country’s economic, social, and political situation and should discourage monopolistic behaviour.
7.c Structure the contract and its implementation to maximise the long-term effectiveness of collaborative partnerships between the contracting authority and the operator by building in systems for dialogue.
7.d Implement pilot public–private partnership initiatives and learn from the experiences.
7.e Evaluate fairly and objectively the performance of such partnerships against international benchmarks and consumer satisfaction surveys, regardless of whether the utility is managed by a private firm or a public entity.
TECHNOLOGY Issue 8
The high cost of wastewater management warrants a very careful search for low-cost and thus more sustainable technologies and approaches.
Recommendations
8.a Introduce appropriate strategies and incentives that target waste prevention and minimisation, water conservation, and the efficient use of water.
8.b Apply more cost effective technologies such as lagoons, natural systems, anaerobic treatment, and reuse schemes.
8.c Adapt land use policies and financial and other regulation to promote the segregation of industrial effluents unsuitable for municipal wastewater treatment by relocating industries, recycling waste streams, and using the best available technologies.
8.d Promote the exchange of experience with the implementation and operation of different technologies.
REFERENCES (available at http://www.gpa.unep.org/documents)
- GPA (1995). Global Programme of Action for the Protection of the Marine Environment from Land-based Activities. UNEP(OCA)LBA/IG.2/7. Washington D.C. [USA]: UNEP.
- GPA (2000a). GPA Strategic Action Plan on Municipal Wastewater. The Hague [The Netherlands]: UNEP/GPA
- GPA (2000b). Recommendations for Decision-making on Municipal Wastewater. The Hague
A CASE STUDY OF INTEGRATED WATER RESOURCE MANAGEMENT IN WINDHOEK, NAMIBIA
By Dudley Biggs* and Rick Williams*
*Department of Water Affairs, Private Bag 13193, Windhoek, Namibia.
E-mail: biggsd@mawrd.gov.na and williamsr@mawrd.gov.na.
ABSTRACT
Integrated water resource management is crucial in meeting and managing the increasing water demand in Namibia. Recent studies have shown that as part of that process both water demand management measures and non-conventional water supply augmentation schemes are considerably cheaper than developing more traditional pipeline schemes. This paper presents a case study of Windhoek, describing the different initiatives adopted by the municipality in conjunction with the bulk water supplier, NamWater and the Department of Water Affairs in the Government to integrate traditional supply systems, WDM and non-conventional supply initiatives to manage and meet this demand. The case study provides an indication of what can be achieved and what are feasible and practical interventions. The case study shows that lessons that have been and continued to be learnt in Windhoek can apply to many other areas in Namibia as a way to promote sustainable water resource use yet meet increased demand.
KEYWORDS:
Integrated water resource management, supply augmentation, conjunctive use, water demand management
BACKGROUND
Namibia is Southern Africa’s most arid country. Its rainfall and consequently its surface and ground water sources in the interior are extremely limited and variable. Potential evaporation exceeds precipitation by a factor of between two and five. There are no natural resources of perennial surface water other than rivers on the borders of Namibia. It is estimated that 56% of water consumption is derived from groundwater, 20% from ephemeral rivers and 24% from perennial border rivers. Of the low total rainfall of between 20 and 700mm, 83% evaporates, only 1% contributes to groundwater recharge and 2% can be harvested in surface storage facilities.
With a population growth of over 3% and a growing economy, water supply is becoming an increasing constraint for Namibia. Until the beginning of the 1990s emphasis has been placed on supply augmentation. Over the last 40 years surface water dams have been built to collect run off from ephemeral rivers. However, further supply augmentation is becoming increasingly expensive as the country has to look further afield for water. Water demand management (WDM), implemented to reduce demand rather than continue to augment supply, and non- conventional supply schemes have become important components in Namibia’s integrated water resources management (IWRM) programme. The recently approved Water Sector White Paper reflects this and concentrates more on managing water resources.
As more research is conducted there is an increasing number of feasible and potentially feasible projects to conserve water and augment supply cost effectively. Windhoek has been the forerunner in IWRM in Namibia. This paper describes IWRM supply and demand side initiatives that have been adopted and which are being investigated for Windhoek and how these have been developed by a partnership of Windhoek Municipality, NamWater and the Department of Water Affairs. It then discusses the implications of current and future IWRM for Windhoek and the progress made in some aspects of IWRM in the rest of the country.
A CASE STUDY: WINDHOEK Introduction
Urban growth in the capital city, Windhoek is high. Due to urbanisation pressures it has a population growth rate of approximately 6% per annum. Economically, politically, culturally and socially it is the most important city in Namibia. The country’s parliament is located there and it is the capital for trade, industry, commerce, culture and education. At the beginning of the 1980s average water consumption was 600-700litres/person/day (l/p/d) in the affluent areas of Windhoek. IWRM was introduced in the early 1990s as a concerted effort to both reduce the level of consumption and increase the safe yield of Windhoek’s water resources to meet increased demand. Considerable progress has been made to date, the current average water consumption having reduced to 180l/p/d, although this is still above average for African cities.
Areas of intervention
The areas of intervention for Windhoek’s water supply concentrates on both supply and demand side measures. The different approaches for Windhoek now and in the future are presented below.
Supply side
Current sources of supply for Windhoek
Traditional water supply to Windhoek has come from groundwater in the Windhoek locality.
Whilst Windhoek still gets some of its yearly supply from groundwater its main source is from the 3 dam system north of Windhoek. Table 1 summarises Windhoek’s supply sources.
Table 1. The Supply of Water to Windhoek (1999).
Operator Water Source Capacity (Mm³/a) Safe Yield
(Mm³/a) Amount supplied (Mm³/a)
Omatako Dam 43 5
Swakopoort Dam 63.5 Ephemeral
Rivers
Von Bach Dam 48.6
} 20
13.180 NAMWATER
Groundwater Berg Auchas Mine - 3* 2.177
Avis Dam 2 4 1 2
Ephemeral
Goreangab Dam 3.6
Groundwater Municipal Boreholes - 2.3 MUNICIPALITY
Reclamation Goreangab Works - 3.6 2.424
TOTAL 161.6 30.1 17
Source: Ben van der Merwe and Ben Groom (1999)
• Integrated three dam system
The 3 dam system was developed between 1970 and 1982. Of the three dams, the Von Bach is the nearest to Windhoek and the most efficient1. Water from Swakoppoort Dam bypasses Von Bach Dam and is pumped straight to the water treatment plant and used directly for Windhoek.
The Omatako Dam, the smallest of the 3 dams and also the least efficient, is intended to store only a minimum amount of water and is used primarily for surface water catchment2 and replenishing the Von Bach Dam. By operating the dams on such an integrated basis the 95%
assurance of supply is increased from 13.7Mm³/a to approximately 20Mm³/a, a 42% increase in efficiency.
• Groundwater
Groundwater is Windhoek’s traditional source of water. When settlers first moved into what is now Windhoek, there were springs in a number of places. However the Windhoek Aquifer has been depleted to the point where there are no longer springs. Over the long term the aquifer can sustainably supply 2Mm³/a of Windhoek’s total water consumption. However in the short term and with conjunctive use it can supply as much as 6Mm³/a.
• Reclaimed and reused water
Windhoek was the first city in the world to reclaim its water back to potable water quality for use in the reticulation system. The first pilot plant, commissioned in the 1959, was followed by a full scale plant in 1960. The treatment process includes flocculation, sedimentation, flotation, filtration, ozonation and treatment with activated carbon. As a cost effective way of augmenting supply, Windhoek Municipality is currently constructing a new reclamation plant to increase the capacity from 3.6Mm³ to 7.5Mm³ of water per annum. In addition to reclaiming water back to potable standards, approximately 1Mm³ of semi-purified water is distributed from Gamanns sewerage works in a separate reticulation system for use in parks, sports fields and a golf course.
• Kavango River/Karst Aquifer Pipeline schemes
Investigations into conventional groundwater and surface water supply augmentation has been done and focus on two main schemes, water transfer from the Karst Aquifer, north east of Windhoek and from the Kavango River. The Karst Aquifer is divided by a natural ridge. The south eastern section is already in production with water drawn from Kombat and Berg Aukas mines and transported along the Eastern National Water Carrier (ENWC) into the Windhoek supply system via the Omatako Dam. The north western section is currently under investigation and would follow the same route with little extra infrastructure required. The Kavango scheme would involve the construction of a 250km pipeline also feeding into the ENWC. Because of their geographical situation these two supply augmentation schemes complement each other.
However both are seen as expensive options3 in comparison to other IWRM options, involving water transfers over 350km and 600km respectively.
1 Efficiency is measured as a ratio between depth and surface area. The amount of evaporation relative to capacity is subject to this ratio.
2 With the addition of the Omatako Dam, the 3 dams cover two river basins with a total
catchment area of 16 800km². Planners anticipated that this should increase the surety of supply by splitting the risks of drought in different river basins. The success of this strategy has been disappointingly limited since drought patterns in southern Africa stretch over very large areas, minimising the advantage.
3See table 6
• Congo River Transfer scheme
Due to sensitivities regarding the use of water from the Kavango River and the potential environmental impact on the Okavango Delta, alternatives that avoid influencing water flow to the Delta are being investigated as well. Many Southern African Development Community (SADC) countries experience or at least anticipate a shortage of water. For this reason a desk study is underway to determine the feasibility to transfer water from the headwaters of the southernmost tributaries of the Congo River such as the Kasai or Lualaba to the headwaters of the Zambezi or Kwando Rivers, possibly in cooperation with hydropower projects e.g. Nzilo.
• Artificial recharge
Artificial groundwater recharge is considered a potentially important part of IWRM for Windhoek. To cancel the effects of evaporation, groundwater can be an efficient way of storing water. As an estimated 35Mm³ evaporates every year from the 3 dam system there could be great benefit in preventing evaporation of even some of the water that is stored. At present, research is being conducted into the financial feasibility of artificial recharge in the Windhoek locality and the suitability of certain aquifers for water storage. Initial results suggest that artificial recharge of the Windhoek Aquifer is a feasible alternative to storing water above ground. Further studies are due to start this year on aquifers in the 3 dam system area and to the south of Windhoek. Table 3 shows the estimated amount of water saved over three years through artificial recharge, depending on the amount of water stored. This alternative for water storage could certainly postpone alternative, more expensive supply augmentation schemes, some perhaps indefinitely.
Table 2. Artificial Recharge and Total Saving in Evaporation Loss
Artificial Injection in First Year only (Mm³)
Saving in Evaporation Loss over 3 years (Mm³)
Total Saving* in Surface Water over Three Years (Mm³)
10.00 3.95 11.95
15.00 5.70 17.70 An allowance of 20% was made for losses in the aquifer during storage
Source: Ben van der Merwe and Ben Groom (1999)
• Reduction in unaccounted for water levels
An additional water conservation measure on the supply side is to reduce unaccounted for water levels that have traditionally accounted for a disproportionately high level of the total water supply in Namibia. At present, Windhoek loses an estimated 10%, a loss of 1.7Mm³/a4, of its total water supply through leakages and poor maintenance of its reticulation system. This is relatively low in comparison to other municipalities in Namibia but is still a cause for concern. A study is currently underway to look at implementing WDM related maintenance programmes in municipalities throughout Namibia to try to reduce the extent of this problem.
Conjunctive use of water
The very low safe yield of the individual surface water sources is a direct result of the low efficiency of storage due to evaporation and the variability of rainfall. By augmenting or ‘backing up’ these sources of supply with other sources that are more reliable like a perennial resource, or at least not as affected by drought, existing sources can be utilised at a much higher risk,
increasing their effective and safe yield dramatically. Table 3 illustrates how the safe yield of the dams increase from 12Mm³ to 20Mm³ by operating them on an integrated basis, which increases to 30Mm³ when the Karstland groundwater is fully utilized, and finally 40Mm³ once water is supplied from the perennial Kavango River. Groundwater is also important. In times of good rain, surface water can be used before the water evaporates as the predominant water source whilst saving groundwater for years of low inflow into the dams due to low rainfall. The table also shows the effects of non-conventional water conservation and supply initiatives such as artificial recharge and the increase of capacity at the Goreangab reclamation facility. Conjunctive use of Windhoek’s water supply system is one of the key components of IWRM for Windhoek.
Table 3: Conjunctive Use of Windhoek’s supply side schemes
SOURCE SUPPLY POTENTIAL Mm3/a
Windhoek Boreholes 2 2 2 2 2
Artificial recharge 1.5 1.5 1.5
Windhoek Reclamation 4 4 4 4 4
Additional reclamation plant capacity 3.5 3.5 3.5
Individual Dams (95% assured yield) 13.7
Dams on Integrated Basis 20 20
Dams with Karstland Water 30
Access to Okavango River 40
TOTAL 19.7 26 31 41 51
Source: Piet Heyns
Demand side
Water Demand Management
One of the main components of IWRM and an important consideration in terms of conjunctive use, is WDM. A WDM policy was introduced in Windhoek in July 1994. Windhoek has seen a growth in total water consumption of 1.28Mm³, an increase of just 7.7% over 9 years against a population growth of approximately 60% since 1991. WDM measures can be broadly split into two areas:
• Market mechanisms and
• Direct interventions.
Table 4: Water consumption in Windhoek
Financial
Year Total Water Consumption (Mm³)
Growth in water
consumption (%) Daily/capita residential
consumption (l/p/d)
Total daily/capita water consumption (l/p/d)
1990/91 16.72 - 201 322
1991/92 15.59 -6.8 201 283
1992/93 14.58 -6.5 167 251
1994/95 17.50 201 161 271
1995/96 14.41 -17.7 136 211
1996/97 12.36 -14.2 117 179
1997/98 15.24 23.3 130 201
1998/99 17.69 16.1
1999/2000 18.00 1.8
1. This is over the previous two years Source: Windhoek Municipality
• Market mechanisms: block tariff structure
A block tariff structure based on a system of volumetric charges has been implemented in at least four municipalities throughout Namibia. Windhoek was the first to approve a block tariff structure in 1991. In conjunction with other WDM measures this has met with considerable success in promoting conversation and more efficient use of water. Table 5 shows Windhoek’s block tariff structure.
Table 5. The Block Water Tariffs in Windhoek
Water Consumption (m³/month) Tariff (N$/m³) (June 1998) Tariff (N$/m³) (Dec 2000)
0-6 2.65 3.51
7-15 3.70 4.89
16-36 4.75 6.28
37-45 6.25 8.26
45+ 8.15 10.77
Source: Windhoek Municipality
There are two main benefits of a block tariff structure can have. Firstly a block tariff structure can achieve full cost recovery of the water supply yet still keep the cost of water affordable5 for low income groups. It achieves this through the cross subsidisation of water from rich to poor. The wealthier part of the population are characterised more by those who have large gardens to water, swimming pools to maintain and more cars to keep clean. Therefore these will be people who demand more water. Secondly this pricing structure, as it increasingly punishes higher water consumption, encourages more efficient, careful use of water by consumers because the less water they use the less the average cost of each unit.
The structure of the block water tariff has a significant impact on water conservation. The more a unit of water costs, the less a rational customer will consume. The degree to which this is the case is dependant on the Price Elasticity of Demand6 (PED) In terms of water conservation in conjunction with keeping the lowest block affordable but still achieve full cost recovery, this is very important. Block water tariffs have proven to be an important component of WDM. It is also a relatively flexible tool and works towards three policy objectives of WDM, namely full cost recovery, affordability, and water conservation. In addition the more efficient the use of water, the larger the population that Windhoek’s water supply system can support, thus contributing to the conjunctive use of the supply system.
5 Affordability is defined as the minimum amount of water required for human consumption not costing more than 5% of a person’s income.
6 PED = % change in quantity
• Direct interventions
The main components of these measures are summarised in Box 1.
Box 1: Water Demand Management Direct Interventions
POLICY-policies approved and implemented in Windhoek
Maximum reuse of water: including semi-purified effluent for irrigating municipal areas and recycling of water to potable standards
Plot sizes: reduced for new developments and higher density housing encouraged for existing developments
Urbanisation: guidelines have been developed to efficiently supply water to growing population.
Reduction of municipal water use: for public gardens etc. reduced by 50%.
Wet industries: guidelines given to promote efficient water use in wet industries and re-use of water by new wet industries
LEGISLATION
Compulsory water efficient equipment: metering taps in hotels, taps outside non-residential building to be self closing or lockable, toilet cisterns must be dual flush units, automatic flushing devises prohibited; replacement of inefficient devices within 3 years.
Groundwater: monitoring of abstraction and groundwater levels controlled.
Gardens: watering prohibited between 10.00 and 16.00 Swimming pools: must be covered when not in use
Prevention of pollution: regular testing of underwater tanks mandatory and all tanks to be registered TECHNICAL MEASURES
Lowering of unaccounted for water: leakage detection carried out, repair programmes in place, water audits undertaken, proper management of meters, and systematic pipe replacement programme.
Efficient watering methods: proper irrigation systems for municipal gardens, advice given on efficient watering methods
PUBLIC CAMPAIGNS AND AWARENESS
Education programmes: lectures in schools and other educational institutions, use of radio, television and local media, pamphlets on water saving ideas distributed with water bills.
Consumer advisory service: advice on water related issues an information on leak detection.
Advice of efficient gardening methods: including suitable flora and efficient watering techniques Community empowerment in formerly neglected areas: training of community based plumbers and gardeners
Source: Ben van der Merwe and Ben Groom (1999)
Comparison of financial implications of IWRM measures for Windhoek
Table 5 shows the difference in unit cost between some the schemes presented above. As can be clearly seen, traditional supply schemes and conventional supply augmentation are generally more expensive that alternatives supply sources and non-conventional supply augmentation. This provides the financial impetus for introducing IWRM in Windhoek and potentially the rest of Namibia.
The progress of WDM in other areas of Namibia
Block water tariffs have been implemented in other areas in Namibia. Table 7 shows the municipalities that had introduced a block water tariff system by 1998.
