Studies and reports in hydrology 2 7

Recent titles in this series

20. Hydrological maps . Co-édition Unesco- WMO. 21 * World catalogue of very large floods/Repertoire mondial des très fortes crues. 22. Floodflow computation. Methods compiled from world experience. 23. Water quality surveys. 24. Effects of urbanization and industrialization on the hydrological regime and on water quality. Proceedings

of the Amsterdam Symposium, October 1977/Effets de l'urbanisation et de l'industrialisation sur le régime hydrologique et sur la qualité de l'eau. Actes du Colloque d'Amsterdam, octobre 1977. Co-edition IAHS-Unesco/Coédition AISH-Unesco.

25. World water balance and water resources of the earth. (English edition). 26. Impact of urbanization and industrialization on water resources planning and management. 27. Socio-economic aspects of urban hydrology.

* Quadrilingual publication : English — French — Spanish — Russian.

Socio-economic aspects of urban hydrology Based on a report on socio-economic aspects of urban hydrology by Gunnar Lindh

Prepared at a workshop, in Lund, Sweden, under the direction of R . M . Berthelot

(unssoo

Published in 1979 by the United Nations Educational, Scientific and Cultural Organization Place de Fontenoy, 75700 Paris

Printed by Offset Aubin, Poitiers

The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the publishers concerning the legal status of any country or territory, or of its authorities, or concerning the frontiers of any country or territory.

ISBN 92-3-101702-0

© Unesco 1979

Printed in France

Preface

The 'Studies and Reports in Hydrology' series, like the related collection of 'Technical Papers in Hydrology', was started in 1965 when the International Hydrological Decade was launched by the General Conference of Unesco at its thirteenth session. The aim of this undertaking was to promote hydrological science through the development of international co-operation and the training of specialists and technicians.

Population growth and industrial and agricultural development are leading to constantly increasing demands for water, hence all countries are endeavouring to improve the evaluation of their water resources and to make more rational use of them. The IHD was instrumental in promoting this general effort. When the Decade ended in 1974, IHD National Committees had been formed in 107 of Unesco's 135 Member States to carry out national activities and participate in regional and international activities within the IHD programme.

Unesco was conscious of the need to continue the efforts initiated during the International Hydrological Decade and, following the recommendations of Member States, the Organization decided at its seventeenth session to launch a new long-term intergovernmental programme, the International Hydrological Programme (IHP), to follow the decade. The basic objectives of the IHP were defined as follows:

(a) To provide a scientific framework for the general development of hydrological activities;

(b) To improve the study of the hydrological cycle and the scientific methodology for the assessment of water resources throughout the world, thus contributing to their rational use;

(c) To evaluate the influence of man's activities on the water cycle, considered in relation to environmental conditions as a whole;

(d) To promote the exchange of information on hydrological research and on new developments in hydrology;

(e) To promote education and training in hydrology;

(f) To assist Member States in the organization and development of their national hydrological activities.

The International Hydrological Programme became operational on 1 January 1976 and is to be executed through successive phases of six years' duration. IHP activities are co-ordinated at the international level by an intergovernmental council composed of thirty Member States. The members are periodically elected by the General Conference and their representatives are chosen by national committees.

The purpose of the continuing series 'Studies and Reports in Hydrology' is to present data collected and the main results of hydrological studies undertaken within the framework of the decade and the new International Hydrological Programme, as well as to provide information on the hydrological research techniques used. The proceedings of symposia will also be included. It is hoped that these volumes will furnish material of both practical and theoretical interest to hydrologists and governments and meet the needs of technicians and scientists concerned with water problems in all countries.

Contents

1. Introduction - purpose and scope

1.1 Background 1 1.2 Importance of urban hydrology 1 1.2.1 Comments on the term urban hydrology 1 1.2.2 Current problems of urban hydrology 2 1.3 Man, culture, physcial environment - aspects of well-being 4 1.4 Socio-economic aspects of urban hydrology versus water management and planning 5 1.5 Concluding remarks 10

2. Urban population trends

2.1 Introduction 11 2.2 Urban growth, migration, density of population, standard of living and demand 13

for water for different purposes

3. Urban systems

3.1 Concepts 14 3.2 The urban system 15 3.3 The urban water management system 15 3.4 The urban hydrological system 17 3.5 The urban social and economic system 21

4. Urban hydrology and well being

4.1 Introduction 24 4.2 The urban ecosystems and the hydrological component 24 4.3 Life conditions: the search for criteria of quality of life 28 4.3.1 Introductory comments 28 4.3.2 Life conditions and the search for social indicators 29 4.4 Man, culture and physical environment 37 4.5 Environmental impact assessment 38 4.5.1 Urban stresses and the environment 39 4.5.2 Purpose of environmental impact assessment 42 4.5.3 Applicability of environmental impact assessment 43

5. Socio-economic considerations in urban water project evaluation

5.1 The need for socio-economic evaluation 45 5.2 Water supply 45 5.2.1 Problems of water allocation 49 5.2.2 Water demand and water use 49 5.2.3 Residential water demand and use 50 5.2.4 Public water demand and use 51 5.2.5 Industrial water demand 52 5.2.6 Water consumption and its implication for planning 53

5.3 5.3. 5.3, 5.4 5.4. 5.4. 5.4. 5.5

.1

.2

1 2 3

Waste water Waste water sewerage Waste water treatment Surface water runoff Introduction Flood protection Storm drainage Other considerations

53 53 54 54 54 55 57 59

6. Conclusions and recommendations

6.1 Conclusions 60 6.2 Urban planning and/or development as a function of water availability 60 6.3 Recommendations 62 6.3.1 Recommendations on well-being and urban hydrology 62 6.3.2 Recommendations on urban water project evaluation 62 6.3.3 Recommendations on liaison/co-operation 63 6.3.3.1 Recommendations on specific research projects 63 6.3.4 Recommendations on data collection 63 6.3.5 Final recommendations 63

7. References including selected bibliography 64

APPENDICES

1. Specimen form for collection of data on water supply use and disposal 71

2. Some case studies of environmental impact assessment 79

3. List of participants in the Workshop 82

1. Introduction—purpose and scope

1.1 BACKGROUND

In 1973 an international Workshop on the Hydrological Effects of Urbanization was convened in Warsaw by Unesco. During this Workshop the preliminary report of the Unesco International Hydrological Decade (IHD) Subgroup on the Effects of Urbanization on the Hydrological Environment formed the basis of discussion. As a result a publication entitled 'Hydrological effects of urbanization' was printed in 1974 as number 18 in the series of Studies and reports •in hydrology. The work of the Subgroup was initiated in order to assist the Working group on the Influence of Man on the Hydrological Cycle. The importance of hydrological effects of urbanization was thereby recognized early in the work of the IHD.

The members of the Subgroup, which had worldwide representation, felt strongly the need for a better understanding of the urban problem and its inter-relationship with urban hydrology. From the foreword of the report emanating from the Warsaw Workshop, it appears that one of the major conclusions was that the field of urban hydrology requires more modern research investment. There has been relatively little study to date of the effect of urban man upon natural hydrological conditions, in spite of the significant economic and environ­mental importance of urban settlements in nearly every nation. It was expected that the report would inspire more extensive research and development in individual countries and would lead to the formulation of improved plans for international cooperation on research subjects of widespread general interest. (McPherson, 1974a).

The results of the work carried out by the Subgroup was reported to the International Conference held in Paris in 1974 (Unesco, 1974a), which discussed the results of the Inter­national Hydrological Decade and future programmes in hydrology. At the first session of the Intergovernmental Council of the International Hydrological Programme (IHP) held in Paris in 1975 it was proposed to prepare a state of the art report or. the known economical, social and environmental relationships of urban hydrology. The intention was that in this report, the growth of urban problems of crowding, water supply, waste disposal and general environmental quality would be emphasized.

At the request of the Intergovernmental Council of the IHP, Professor Gunnar Lindh, University of Lund, Sweden, prepared a draft report which was reviewed during the Workshop on Socio-Economic Aspects of Urban Hydrology held in November 1976 in Lund, Sweden. The draft formed the basis of this publication. A list of participants in the Workshop is given in Appendix 3. They included city planners, economists, sociologists, ecologists, biologists, historians, civil engineers and hydrologists.

The contents and conclusions of this report were used as an input to the Workshop on the Impact of Urbanization on Regional and National Watermanagement and Planning, held in the Netherlands in October, 1977. At this Workshop, technical and planning aspects, as well as the use of planning models were discussed.

The recommendations from both the Lund and Netherlands workshops will be used for the planning of urban water projects and programmes in the next phases of the International Hydrological Programme.

1.2 IMPORTANCE OF URBAN HYDROLOGY

1.2.1 Comments on the term 'urban hydrology'

The title of this report contains the term 'urban hydrology'. In order to understand what is meant by this term, let us recall that there is an internationally accepted definition of hydrology which reads:

'Hydrology is the science that deals with the waters of the Earth, their occurrence, circulation and distribution, their chemical and physical properties, and their reaction with the environment, including their relation to living beings.'

1

Importance of urban hydrology

Logically urban hydrology should be understood as an application of hydrology (as defined above) to phenomena restricted to the urban region. Hydrology provides the scientific basis for explaining and understanding the whole range of water-related activities. However, it was pointed out by many delegates at the First session of the Intergovernmental Council of the Unesco International Hydrological Programme (Unesco, 1975a) that hydrology and water resources formed an inseparable unit and in many countries are merged. The 18th session of the General Conference of Unesco authorized the Director-General 'to stimulate the development of educational activities relating to the water sciences....' (Unesco, 1974b).

Few attempts have been made to define urban hydrology in the literature. However, it is a distinct branch of the broad field of hydrology, because the complex interactions of human activity with air, water and land must be collectively taken into account in concentrated settlements. In other words, the impact of man on the water cycle is greatest per unit area in urban places (McPherson, 1974a).

A possible definition of urban hydrology is:-

"The interdisciplinary science of water and its interrelationship with urban man.'

The broad, intimate man-water concept of urban hydrology has prompted a new look at traditional urban thinking and approaches (Jones, 1971c).

We propose that by urban hydrology shall be understood those processes occurring in the urban hydrological environment. This environment must include the existing metropolitan area, the area for expected future expansion, and the surrounding area which influences the urban water cycle. Included in the concept of urban hydrology are factors such as precipitation, surface runoff, groundwater and water supply affecting inflow to the urban hydrological environment. We have also to take into account évapotranspiration, streamflow, storm drainage, waste water and groundwater as outflow from the urban hydrological environ­ment (McPherson, 1969).

1.2.2 Current problems of urban hydrology

As the title of this report - Socio-economic aspects of urban hydrology - implies, it deals with the relationships between social and economic factors and urban hydrology. Problems encountered in this context originating from the need to provide water supplies for urban areas, affect many people, involve so much water and entail so large an expenditure of money that it is necessary to consider them in detail. The costs of providing metropolitan water services are escalating rapidly. The replacement cost of existing urban systems providing necessary water services in the USA, for example, is in the vicinity of $175 billion and it is estimated that some $15 billion per year will be spent in the next few years for new construction. Combined capital and other current expenditures for water supply, waste collection and disposal in 38 of the USA Standard Metropolitan Statistical Areas were estimated in 1969 at $30.50 per capita and represented 20 per cent of total capital outlays and 4 per cent of other current expenditures. Both the amounts and percentages can be expected to rise dramatically in the future in order to achieve higher standards of water pollution control. (US National Water Commission, 1973).

In order to analyse the role of urban hydrology more closely, it could be broadly stated that water is part of the renewable natural-resource base. Beyond its importance for the support of life, water is essential for the further expansion of urban areas. Its biological function has a parallel in the social and economic metabolism of society.

With regard to urbanization and the role of water, it may be noted that a characteristic feature of urbanization is that it drastically changes the natural conditions where water distribution was governed by climate and the physical character of the land surface. Water is now used both to supply man's need and to carry away his wastes. In that sense, water in the urban environment fulfils the functions of both arteries and veins of urban life (Schneider, Richert and Spieker, 1973).

In analysing the role of water in urban society, water may be regarded not only as

1 American billion: 1,000,000,000

2

Marty culture, physical environment - aspects of well-being

a resource serving the social good but also as a nuisance. The role played by water as a resource is almost self-evident but the role as a nuisance may need some consideration especially since social and economic aspects of urban hydrology are so closely related. It should be underlined that many uses of water may reduce quantity and impair quality. Consequently, the value of water as a natural resource is reduced to the detriment of individuals or the public well-being.

The right to use water is recognized and protected as a property right. Thus if water quality is affected and such is proved, it remains to weigh the merits of the respective rights of all parties involved (Thomas and Schneider, 1970). The right to use water in an urban society is not directly delegated to individuals but the community because individually-held land is generally too small to provide adequate supply, storage, or disposal of water for its occupants. Similarly, each individual may be concerned about water as a nuisance. Apart from creating minor disturbances of well-ordered life such as puddles, mud in unpaved areas, eroding ground, carrying flood-debris and filth, water itself is a repository of urban wastes. Water pollution is only one aspect of a much more complex problem of handling urban wastes. The severity of this pollution problem depends upon the degree of waste treatment and the amount of waste in relation to the amount of water available. This in turn reveals one of the most intricate problems of urban water sciences and engineering of today, namely the lack of an overall approach to the treatment of urban wastes.

Since urban hydrology as a science is responsible for the proper analysis of such problems, it may be emphasized that there exists today no correspondence between the degree of treatment, the treatment plant and the treatment desirable for the protection of the receiving body. This is not the only instance where an ambitious engineering achievement has overlooked the integrated approach. Another important example may be found in the current intensive study of urban-water runoff. The large amounts of money which are allocated for the conveyance of storm water might be better used if the complexity of the problem were better understood.

It is important to be aware of the fact that many urban activities are closely related to the development and use of the land. Such activities may affect the natural water-flow system and all other systems may in time be affected by it. In this sense, one must guard against the violation of the individual's and society's rights, either through land development that adversely affects water processes or through water mismanagement which will affect land resources.

To the problems just mentioned, where urban hydrology has to play an important role, may be added urban runoff. The problem of dealing with these sometimes tremendous amounts of water in addition to heavy pollution loads is exacerbated where rainfall flushes contaminants from urban streets. To these urban water problems can be added the problem of disposal of solid wastes in dumps and sanitary landfills. Such disposals often cause severe pollution of groundwater as well as of surface water due to leaching. Both biological and chemical contamination are liable to occur.

Another water-related problem is associated with the construction of housing and highways which may expose bare soil and thereby accelerate erosion. Such erosion may choke streams with sediment and fill reservoirs. This, in turn, may severely limit the use of water bodies for recreation and aesthetic enjoyment and reduce their capacity to accommodate floods. Another phenomenon which is amplified in urban areas is the flooding process. Roofs, paved surfaces and installation of storm sewers increase the flooding hazards by concentrating the storm runoff. Besides these physical effects on the water resources, urbanization may also alter the recreational and aesthetic values of water bodies. Degradation of the urban environment may destroy aesthetic appeal and decrease recreational potential of areas in or adjacent to the urban region (Schneider, Rickert and Spieker, 1973).

The above illustrates urban water problems to the solution of which hydrological methods may be effectively applied. It would, however, be a mistake to believe that water-related activities in an urban system are limited to the urban area itself. As water supply becomes increasingly inadequate in relation to domestic and industrial demands, it may have to be augmented from other areas. The necessity to import is not restricted to water, imports of fuel, food and other materials are essential for sustaining urban life. This means that hydrological effects caused by the urban population are not limited to the urban area but affect a wider area. This is particularly so in areas of water shortage. In general, water can no longer be taken for granted as a readily available urban commodity.

Man's activities have also brought to light the interrelationship between water and other natural resources. Very often, however, man's measures to solve problems of water

3

Man, culture, physical environment - aspects of well-being

supply and waste removal have been characterized by concentrating on discrete functions and single approaches. The result of such practices has led to rapid eutrophication of lakes, pollution of rivers, and degradation of recreational and aesthetic benefits of water resources. Urban planning and management must therefore be based on sound consideration of interaction and interdependency of all relevant natural resources, among them water.

We assert that urban hydrology has the important function to provide for the rational and efficient use of water in the urban society. It is implicit that this task is subject to the socio-economic constraint of the urban society.

The foreword of the report of the IHP Subgroup on the effects of urbanization on the hydrological environment ends with the statement that 'so many similarities were found in problems and effects that it is concluded that the findings of this report are more univers­ally representative than the small sample of nations involved would suggest.' However, it is important to realize that there may be considerable differences among urban hydrological problems when we look at the different regions in the world. Considering, for instance, man's intervention in the environment, we may expect that the effects thereof will depend on the locally prevalent specific situation. Thus, not only the characteristic features of the urban area but also climatological, geographical, social, economic and political factors may cause a situation which has its specific importance. This means that it may be difficult to find generally applicable solutions to urban hydrological problems, especially as there could prove to be notable differences between urban areas in developed and in developing areas.

It has been demonstrated in a number of countries that urbanization increases the volume of direct runoff locally and that systems of storm drainage conduits create higher direct runoff peaks with a shorter rise time than in pre-urban conditions. A cause of exist­ing generalizations is that, world-wide, the field of urban hydrology is almost devoid of modern research investment and that there has been relatively little study to date of the effect of human settlements upon natural hydrological conditions (McPherson, 1973).

The hydrology of urban areas is exceedingly complex and is not yet completely understood. One reason for this may be that in urban hydrology the peculiar nature of the gauging problem, associated with runoff and other processes, have been seriously neglected. Inade­quate data are available for evaluating the effect of urbanization on many hydrological phenomena. In itself, the urban drainage area is highly variable in such characteristics as slope, size, shape, roughness and degree of imperviousness, and because of this many urban hydrological studies have been limited to small, controlled plots with major emphasis on the rainfall-runoff relationship. Moreover, in urban areas crude estimations are often substituted for reliable data. In a peak-flow-frequency analysis, using historical records, the assumption is often made that all events are random. Moreover, the assumptions may be made that they have occurred under similar water-basin conditions. This is not always true because of changes in land use and improvement in drainage facilities accompanying urban development over a period of time (Robey, 1970).

1.3 MAN, CULTURE, PHYSICAL ENVIRONMENT - ASPECTS OF WELL-BEING

The title of the present report indicates that what has to be analysed are the interactions between socio-economic variables and hydrology within the urban domain. In order to understand such a problem, we have to combine experiences from a variety of disciplines, especially sociology, economics and hydrology, each with its own constraints and possible reactions from the physical environment, directly, or through feed-back loops. The attempted understanding must fulfil an expressed desire for what may be called the harmonious relationship among the three parts that comprise the term total environment, ie man, culture and physical environment. This terminology is taken from Vlachos and Flack (1974) who list a series of problems arising from the expansion of the urban water-resource systems - misuse, abuse, or neglect of the urban water and related land resources :

1. The alteration and even destruction of the natural and hydrological balances in the urban area.

2. The modification of natural runoff patterns by urban development.

3. Environmental degradation, especially through a lack of willingness to design and conduct activity in a manner that may preserve and

4

Socio-economic aspects of urban hydrology versus water management and planning

enhance elements of the natural environment.

4. The basic lack of knowledge and understanding of the inter­relationship between man, his culture and the surrounding physical environment.

5. The difficulty in identifying beneficiaries in the densely-settled urban areas and the concomitant difficulty in allocating accurately costs and benefits.

6. Inadequate financial capacity.

7. Conflicts of interest and conflicting attitudes of groups with special interests and people in general vis-a-vis public officials.

8. The unwillingness of land owners to contribute to a solution of the problem which does not directly affect them.

9. Lack of comprehensive integrated planning as well as administra­tive fragmentation and absence of uniform quality of services.

In an attempt to analyse the dimension of the inter-relationship between man, culture and environment, this report attempts to review research around such concepts as quality of life, well-being, etc. Depending on the type of society and political, geographical and other factors the summarization of, for instance, social well-being and quality of life (SWB/QOL) will be characterized by a set of objective and subjective indicators. Such lists abound in the literature, but they are subject to theoretical debates, definitional discrepancies and often lack empirical data for specific reference. These indicators and their arrangement in order of importance will, in turn, be influenced by the types of society, etc. Consequently the order will reveal the importance played by water for individuals and societies compared with other factors on the list. Whether or not this is a way to take care of the social aspects of water use in the urban life is still open to question. However, it seems to be a logical way to approach the problem. The success of this approach may depend on the future development of sociological studies in characterizing man's conception of his life as a member of an urban society. The concept of well-being (SWB/QOL) will also be important as seen from the point of view that we need some mechanism by which we may register the response of alternative actions taken. These al terna ti-ves are being presented as economic-technical proposals worked out with proper consideration of possible environmental interactions. Using the broad criteria SWB/QOL, we may be able to develop criteria for considering, in a systematic fashion, human factors in water resource projects.

In order to overcome the obviously serious difficulties likely to emerge if we use the notion of SWB/QOL, more direct and simpler methods can be used as substitutes. This implies that as a first approach basic life conditions (such as health, transport, and especially economic factors) can be presented as a first step in outlining elementary objective conditions of well-being. More refined indicators and additional social considerations can then be used as constraints that may modify the hydrological-economic relationships. Such an approach will evidently restrict the degrees of freedom of the complex system being considered, and thereby delimit the possibilities of generalizing the results obtained. Due to the lack of complete knowledge of the impact of social factors on the urban water system, the method proposed may be justified. In addition, basic survival life conditions may be the necessary analytical thrust for developing countries. It is at much later stages of development that more complex indicators of well-being become more meaningful or necessary.

1.4 SOCIO-ECONOMIC ASPECTS OF URBAN HYDROLOGY VERSUS WATER MANAGEMENT AND PLANNING

This state of the art report on socio-economic aspects of urban hydrology can be considered as basic introductory material for the Netherlands' Workshop, in 1977, on the impact of urbanization on regional and national water planning and management. In this sense, the report cannot be made without due regard to this activity. It should be understood that

5

Socio-economie aspeata of urban hydrology versus water management and planning

knowledge of social and economic factors is a prerequisite for successful planning and management. Moreover, we have to explain the constraints of socio-economic factors in technological solutions. Multi-purpose planning - taking into consideration socio-economic aspects of urban hydrology - must establish a wider range of alternatives, since technological solutions also entail changes in life style, level of consumption and similar broader cultural alterations.

The previous considerations have been stressed by many as a vital strategy in urban-water planning. It is a strategy whose main characteristics involve multi-objective, multi-purpose planning. The process itself, through public involvement and successive interactions, is an evolutionary one in both attempted goals and public preferences.

A multi-purpose, multi-objective approach implies taking into account a full range of alternatives, including scientific research as a tool for devising new technologies affecting both demand and supply. For this reason, it would utilize a mixture of public and private administrative instruments, encouraging as much decentralization of choice among individuals and local agencies, as consistent with broad guidelines supported by public consensus. Standards for water quality, hazard reduction, and social valuation would not be rigid, but decisions would be based on criteria for keeping the range of choice as wide as practicable and working toward short-time horizons within frameworks describing longer-term human needs and physical limits. There would be intensive investigation of resources and the theoretical possibilities and social consequences of altering them. In many cases, the dispersal of population along vast metropolitan areas requires that planning should be based on a larger metropolitan organization (White, 1971).

Thus, aspects of multi-purpose planning are intertwined with social, economic, public and institutional factors, with emphasis on the interrelation between planning and environ­mental effects. In turn, multi-purpose planning with regard to the urban-water situation leads to modelling of systems. Planning models require a certain amount of intensive hydrological modelling by which parameters and indicators may be established. Thereby one provides a means of understanding hydrological processes so that simplified expedients are not inadvertently misused (McPherson and Schneider, 1974).

The term water management, widely used only in the last decade, has not yet a specific meaning. Although rational control of water is its objective, there is no common under­standing of policies and institutions required for achieving rational control. Management functions can be roughly divided into a formulative, or strategic, level dealing with goals and policies, and on administrative, or tactical, level concerned with their implementation (McPherson, 1970).

Leaving the precise and strict meaning of water management aside for the moment, it is recognized that a close inter-relationship exists between water management and socio-economic development. As a consequence of the latter, water-demands grow at accelerating rates and properties, increasing in value, must be protected from the damages of water. At the same time, and conversely, advanced water-management is one of the prerequisites for socio-economic evaluation, since the scarcity, abundance, or poor quality of water present potential limits to such an evaluation. (Vincze, 1974).

The determination of urban-water-management requirements, resulting from social trans­formation, economic development, international cooperation and rising standards of living, further the exploration of ways of carrying out the task of long-term water-management planning. As to medium-term water-management plans, they identify the more important water-development objectives envisaged in the long-term plan for a longer period, say five years. For the different urban-water management organizations, the uniform system and quantities of the technical-economic means needed must then be specified. (Bekesi, 1974).

Given all the above, it becomes apparent that urban hydrologists, urban planners and those in other related disciplines have to cooperate in the study of a series of urban problems. Obviously, there also exist apparent obstacles to such a collaboration. We may use as an example urban hydrologists and urban planners. The former are trained in physical sciences, or engineering, whereas urban planners' training is in social sciences or landscape architecture. Per se this should be a good thing since we would then have all aspects of urbanization covered by a broad spectrum of joint experiences. However, in reality, there are substantial difficulties in communication as well as approaches to problems and inter­pretation between these two groups. The solution to such dilemmas must be found in an under­standing of each other's role in the common work. This means that the planner must be aware of the hydrological factors in his planning and the urban hydrologist must acquire knowledge

6

Socio-economic aspects of urban hydrology versus water management and planning

of the rigorous analytic methods nowadays used by urban planners (Schneider, Richert and Spieker, 1973). Together they have to develop an alternative/resource-impact relationship as an essential ingredient for effective decision making. It is necessary that a close team-work has to be established through interdisciplinary dialogue, integrated framework and interrelated field activies. Through continuous exchange of information common checking of the validity of presented alternatives and mutual sensitivity to the integrated nature of urban analysis, a unified approach can become possible. Such an evaluation of an inter­disciplinary effort may be graphically illustrated by Figure 1.1. This figure attempts to delineate a common effort starting with the identification of problems and definition of objectives. The ultimate goal is an improved urban development which can be approached through alternative paths as shown in the diagram. While the upper part in the diagram shows how the urban planner acts, the lower part shows the inputs of the water-resources scientist. Socio-economic aspects as well as technical, institutional, legal and political items are included in the common efforts (Schneider, Richert and Spieker, 1973).

The previous remarks exemplify the central responsibility of the urban hydrologist in judging the merits of alternatives and the need for being informed about urban planning. However, experience has shown that in many instances, communication becomes a one-way process rather than a meaningful dialogue. There is no doubt that there are technical constraints on effective planning (such as inadequate quantitative hydrological data as well as inadequate data on environmental and socio-economic matters). More important, however, is the essential need for an effective and legal framework in which planning can take place (Banks and Williams, 1973).

The importance of teamwork must be repeatedly stressed. One reason, not mentioned so far, is that for the next few decades, we will have to look at urban problems no longer as containing problem areas composed of discrete and essentially closed systems of buildings, utility lines and roads. Instead, we must adopt a broader social system approach. That means that social organization, human needs, and interrelated activities are replacing individual components as the foci of planning inquiry and strategy. This emphasizes the need for an integrated approach beyond specialized disciplines, with particular sensitivity to the social-historical character of technical development. Clearly implied is a problem-oriented approach for investigative and research as opposed to a purely disciplinary approach.

New specialists can claim no loyalties to any one particular discipline and, thus, there is, and will continue to be, an erosion of disciplinary boundaries. This is also due to the accumulation and refinement of integrative theory and the acceptance of once alien concepts that had been the exclusive property of other disciplines. New computer tools and techniques will play a special role in this context, as well as the legal requirements in a number of countries promoting interdisciplinary integration.

For several years now, civil engineers have found themselves increasingly involved with economists and social scientists and have also become members of problem-oriented teams resulting in the erosion of the dualism that has, in the past, maintained boundaries between different professional groups. However, there still exist certain polar distinctions such as analysis versus design, systems and operations research versus more traditional isolated analysis and design, technical isolation versus total involvement etc. The civil engineer must look particularly to new analytical tools, such as a systems approach to changes in human needs as defined by the environmental ecologists. In lieu of further elaboration of this topic, interdisciplinary links - both present and suggested for the future - are diagrammatically shown in Figure 1.2. At present (Figure 1.2a), specialist disciplines tend to integrate their work side-by-side and it is difficult to reach beyond neighbouring fields. The human perspective tends to be subordinated. In the future (Figure 1.2b), the specialist disciplines may work with a common integrating centre I. Inside I are the human sciences and bio-ecology as well as the specialists on integration.

Finally, the new requirements for environmental impact studies, as well as proposed changes to broaden the basis of planning to include land use, may also contribute significantly to a better understanding of disciplinary inputs in a common approach. This may perhaps aid an intellectual synthesis of approach, based upon established working relationships. While there has been much talk of interdisciplinary approaches, too little reality describes the present situation. (Whipple, 1971).

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Concluding remarks

1.5 CONCLUDING REMARKS

Like energy, water has been considered by some people as an inexhaustible resource, available at every place at the right time. Of course a shortage of water in itself reveals a problem but there are other situations which conceal the real problem. It is a well-established fact that a number of urban areas are extremely vulnerable to variations in their water supply, for example, cities located in the upper catchment of river basins - Hyderabad in India, Denver in the USA, Addis Ababa in Ethiopia, Bogota in Colombia, and Caracas in Venezuela - to name a few. A characteristic of these cities is that in dry years they use the total available water by drawing from the watershed, reservoirs and underlying groundwater reservoirs. This may result in an irreversible process of lowering the water table and causing land subsidence. Where cities are located along the ocean shores, depletion of groundwater may result in saline intrusion into the aquifer.

A solution of the water problem of an urban area may be to re-use the water several times. This creates social and economic problems. A variant to this is to use water of different qualities for different demands. This again stresses the social and economic, as well as environmental, aspects of water use. Moreover, we may not be unfamiliar with the idea of the use of brackish water for certain demands, or of the use of desalinated water. This is of course a situation favourable to urban areas near the coast. If fresh water becomes expensive enough, these areas are favourably situated to meet a minor part of their needs with desalinated water which can be produced as a by-product of power plants. This is likely to happen only when the cost of adding extra water supply capacity equals the maximum experienced by a million-size city in the world today. (Meier, 1974).

Many socio-economic problems related to urban hydrology have their origin in the conflicting situation caused by a competing demand for water. To see how such conflicting situations may arise, a starting point may be to define the geographical region that encompasses the water resources used, for instance, by a city. Expansion of the city, or migration into it, may cause an enlargement of the water-resources region. When the region expands in this way, it may interfere with regions which supply agriculture, or other urban areas. Migration should not be regarded as the only reason for such conflicting situations. They are liable to occur in areas of water shortage where a combination of extended activities in industry, agriculture and migration may interact unfavourably. In many areas with a shortgage, water must be transferred from remote districts. This fact does not, however, ensure that no conflicts will arise, as difficulties may arise from competition.

Considering socio-economic aspects of urban hydrology, a possible solution may be to use an increasing amount of water successively for an increasing number of activities within the urban area. The lower limit of the water requirement is the amount of water which is necessary to sustain life. The upper limit may be the amount of water which, if increased would not contribute to further development of social activities. It is assumed that this water would be of suitable quality for the various needs. Social activities would include development of commercial, industrial and other activities, as well as develop­ment of water-based facilities, including recreation, for the urban population. This analysis could be performed assuming a constant population, on the basis of an optimal supply of water of a given quality, and then the effects of an increase could be studied. Such considerations may lead to the notion of a city-balanced water supply showing its relationship to a well-balanced environment. The approaches proposed are straightforward. In order to be used in a meaningful way, a series of important constraints must be taken into account. For instance, the fact that water is not always available. Raising the level of consumption from one or more users may result in severe stresses on the available water resources. Competing use of the resources may aggravate the situation.

10

2. Urban population trends

2.1 INTRODUCTION

This chapter draws attention to expansion and concentration of population. Data on these are regarded as necessary base material for a study of social and economic, as well as political, aspects of urban hydrology to be considered later in this report.

Data about population trends in different parts of the world may be regarded as useful in order to examine the relationship between social and economical factors and urban-water characteristics in the planning for development. More generally, as stated by the United Nations Economic and Social Council (UN, 1973): "The future size, structures and distribution of population are essential for any plan that involves food, housing, employment, education, health or other public services. There is also an area of increasing awareness: of man's unprecedented growth, of the interaction between this growth and the environment, and of the possible implications for the future. Investigations into these complex relationships have aided the demand for population projections'.

It could be added that this is related to urban water management and planning and in turn to urban hydrology as well as to the quality of life. This latter concept must be the guiding one in formulation of the conditions for water demands.

From the figures given in the above mentioned ECOSOC report, it is possible to assemble the data in Table 2.1.

Table 2.1. Urban and rural populations, 1965-2000

Urban population (millions)1

1965 1970 1980 1990 2000

1158 1352 1854 2517 3329

651 717 864 1021 1174

507 635 990 1496 2155

Rural population (millions)

1965 19 70 1980 1990 2000

2131 2283 2614 2939 3186

386 374 347 316 280

1745 1910 2267 2623 2906

Percentage of urban population

1965 1970 1980 1990 2000

World total 35.2 37.2 41.5 46.1 51.1

More developed regions 62.8 65.7 71.4 76.4 80.2

Less developed regions 22.5 25.0 30.4 36.3 42.6

World total

More developed regions

Less developed regions

World total

More developed regions

Less developed regions

11

Introduction

It appears from this table that, in 1970, 37 per cent of the entire world's population were urban; in the year 2000 the urban population is expected to reach 51 per cent of the total. Moreover it is predicted that the combined urban population of the world may increase almost two and a half-fold in the coming thirty years. It is important to note that the urban population growth differs greatly in different parts of the world. If we look at the predicted situation in developed countries we find that the urban population may grow from 717 million in 1970 to 1174 million in the year 2000. This corresponds to an increase of 457 million or 54 per cent. In contrast, the urban population in developing areas may increase from 635 million in 1970 to 2155 million in the year 2000. If we look at the figures for rural population during the same period there is a 26 per cent decrease in developed countries and a 52 per cent increase in developing countries. The table shows that the percentage of total population in urban localities may rise from 66 to 81 per cent in the more developed regions whereas there may be an increase from 2 5 to 43 per cent in the less developed countries.

If we look closer at the predicted development of some areas of the world we note that the ratio between urban population in the year 2O00 and the year 1970 will amount to the approximate values given in Table 2.2.

Table 2.2. Ratio of urban population in the year 20O0 to that in 1970

Europe 1.5 East Asia 2.7

North America 1.7 Latin America 3.1

USSR 1.8 South Asia 3.3

Oceanic 1.9 Africa 4.2

In contrast we observe that Europe, USSR and North America may show a decrease in rural population from 1970 to 2000. In Eastern Asia an increase by 6 per cent is predicted and for Latin America an increase of 26 per cent. In Southern Asia this is equivalent to an increase of 76 per cent and in Africa 86 per cent. We may conclude that the rural population is likely to grow faster in Southern Asia and Africa than the urban population in North America and Europe. The figures are based on what is called the medium variant of population growth in the world. There are also two other variants presented by the ECOSOC analysis, namely a low and a high. What causes the differences between these variants is the point of time when the population expansion is expected to change to zero growth. According to the notion of a medium variant this is supposed to occur by the year 2125 when the total world population is estimated to reach approximately 12.3 billions . The ECOSOC calculations have, however, assumed different points of time for a state of zero growth for developed and less developed countries. For the more developed countries the medium variant assumes that the state of zero growth will be reached by the year 2095 with a total population of 1.9 billion1. For less developed countries it is assumed that there will be a further growth until the year 2130, from which time we may expect a zero growth. At that time the total population in less developed countries may amount to 10.5 billion1. There is at present a gap between the population of developed and less developed regions and we may count on a widening gap in the future. In 1970 the total population of the world was about 3.6 billion of which approximately 75 per cent belonged to the less developed countries. Still referring to the medium variant it is forecast that this percentage will amount to 76 per cent by the year 2000, to 84 per cent by the year 2050 and to 85 per cent by the year 2100. There are other studies of the growth of population and resources which have been under international debate for years.

An interesting model was set up by J^rgensen, in 1975, for the growth of Gross National Product (GNP) and the population. The model shows that there is a relationship between GNP and the population and moreover that GNP is following a logistic growth. The model also shows where the problems are to be found. The author claims that the industrialized countries

1 American billion 1000,000,000

12

Urban growth, migration, density of population, standard of living and demand for water for different purposes

carry their development too far and new countries aim at more industrialization. The result is that the production of countries with a GNP higher than $2000 per inhabitant/year would increase by eight times as much from 1970 to 2030. The developing countries are likely to continue to increase their population beyond that date as it will take longer to obtain a high enough GNP/inhabitant year to enable the birthrate to be reduced.

The way in which development of urban areas progresses is of utmost importance for the following discussion, because different kinds of societies may show different social and economical characteristics. It is a well-known fact that socio-economic development is closely connected with the territorial concentration of productive activity and the population, ie with the agglomeration. We also know socio-economic characteristics are closely interrelated to urban hydrology and urban-water resource development. Thus, there is an apparent connection between urban regional expansion and urban hydrology. We may ask if urbanization will show a tendency to concentrate into a relatively few large urban centres which should then be a continuation of an ongoing process. Or may we expect that the migration to urban areas will be resolved into a distribution among numerous, geographically more widely distributed, urban areas of lower orders and magnitudes?

The ECOSOC report gives some answer to this last question: 'Cities with one million or more inhabitants numbered 162 in 1970 of which 83 in more developed and 79 in less developed regions. By the year 1985, there may be a total of 273 such cities, 126 in more developed and 147 in less developed regions. The population contained in this increasing number of cities may nearly double in fifteen years, from 416 million in 1970 to 805 million in 2000. The million-cities contained 31 per cent of the urban population in the year 2O00; in this respect the urban population will be more or less concentrated in large centres in the less developed, as compared with the more developed regions. By 1985 the million-cities may comprise 27 per cent of the total population in more developed regions, and 13 per cent of the total (rural and urban) populations in the less developed regions'.

2.2 URBAN GROWTH, MIGRATION, DENSITY OF POPULATION, STANDARD OF LIVING AND DEMAND FOR WATER FOR DIFFERENT PURPOSES

In order to sample information from different cities and countries a questionnaire was sent out asking for comments on:

1. Urban growth, migration and density of population (statistical data)

2. Demand for water for different uses (residential, industrial, cooling water, etc)

3. Waste-water disposal

4. Ways of fulfilling water demands.

The enquiry was sent by Unesco to IHP National Committees in:

Australia Netherlands Austria New Zealand Federal Republic of Germany South America Hungary Switzerland India Turkey Italy USA Mexico

The returns were not complete nor were they in a comparable form that would have enabled the Workshop to analyse them and draw conclusions.

During the Workshop, a subgroup drew up a form (Appendix 1) for the data presented in response to the enquiry. The Workshop suggested that this form might serve as a guide for organizing and unifying similar data from other sources in the future in order to promote exchange of information between nations and research in the field of urban hydrology. The form has been used in Appendix 1 to summarize returns for Sekondi in Ghana and Hannover in the Federal Republic of Germany.

13

3. Urban systems

3.1 CONCEPTS

In order to deal with water technology, water policy and management we need a terminology which, among other things, is able to relate the arguments clearly to geographical space. There are two fundamentally different ways of approaching this matter.

The first, is to divide the land area into compact, bounded areal units that cover the whole area and do not overlap. Water basins, or government territories, are examples of such units. As a rule both decision-making competence and statistical information are attached to such units. The second, is to adopt a systems terminology and group functionally-linked elements into systems and subsystems. The elements of such systems are most frequently scattered with respect to location and extension. The intertwining of elements in space makes it impossible to draw clearcut boundaries around systems. They cannot, therefore, be easily made to coincide in a neat way with compact, bounded areal units.

As is well known any system can be viewed as part of a hierarchy of systems, with other systems placed above as well as below. In the case of urbanization it is now increasingly recognized that for purposes of regional economic and social development policies, as well as infrastructure policies (eg transportation), all urban settlements of a nation should be looked upon as forming an interacting system. This level is called 'the national settlement system' or sometimes 'the national urban system'. On the level below, we may recognize the individual urban nucleus with all its linked elements in the closer or more distant surround­ings as an 'individual urban system' or shorter an 'urban system'. This in turn is then made up of subsystems of various nature. In this report the term 'urban system' will be used for the individual subsystem in the national settlement system.

From what has been said above it is clear that we have to face a rather difficult conceptual contradiction. For empirical description, and in discussions of planning and implementation, we will have to rely mainly on the concept of bounded areal units, eg the administrative territories of cities. But, at least from a human and technological point of view, it is increasingly true that the world cannot be divided into neat, territorial compart­ments. Interaction between distant points in space has made the systems terminology preferable as a tool for real-world description and analysis. Systems concepts will therefore dominate in the present report. But it must be kept in mind that it is becoming a major problem, both in theory and in practice, to find acceptable links between the two world-views which these two predominant concepts represent.

It is also important to consider here the concept of urbanisation. Urbanisation is the process of concentration of large numbers of people in a relatively small geographical space enabling and causing a high degree of division of labour, a great variety of activities, as well as intensive and complex interactions. This process created, until recently, compact built-up areas which are virtually man-made environments clearly distinct from the rural areas. Due to improvements in transportation and tele-communication, the urban settlements could grow further, or could be established anew in a much less concentrated way to such an extent perhaps that groups of smaller and larger settlements, with higher or lower densities, interspersed by open spaces, could come into existence, but without a breakdown of the functional relations which characterise the spatial pattern as a system. The larger urban systems are called urban regions because they are no longer a city in the classical (morphological) sense, but, never­theless, they functionally form a socio-spatial unit. Although urban regions are in many countries still growing in area, there are indications that, ultimately, this will lead to a breakdown of the system, because time and cost of transportation remain limiting factors. In several countries, planning policies aim at reconcentration of urban regions in order to regain the qualities which initiated the process of urbanisation in the past.

The gradual transition from urban to rural areas, and further to an adjacent urban area, may cause a number of hydrological as well as socio-economic problems in what is usually called a watershed in transition. Among others, Roberts (1972) has pointed out the complexity of hydrological and socio-economic problems that are to be encountered in watersheds in the rural-urban fringe.

Similarly, the creation of the megalopolis in the future may cause a series of cultural,

14

The urban system

social and environmental problems. De Meló Carvalho (1969) discusses these and remarks: "There is a great need for integration of town and country in order to avoid the artificiality of meglopolis and to bring man as close as possible to his original natural environment1.

3.2 THE URBAN SYSTEM

An urban system may be defined through identification of those entities, or subsystems, which constitute the urban system in question. The nomenclature we use depends upon the way we approach the study of an urban system. One way of naming such entities may be by the aid of those subsystems indicated in Figure 3.1, see MAB report 31 (Unesco, 1975b). Although the literature abounds with both subtly and widely-diverging definitions of an ecosystem, the one which proves most compatible with the inclusion of the urban environment as an ecosystem is, in fact, the original definition. Here an ecosystem is regarded as an open-ended, not necessarily self-sustaining, portion of a larger system with which there may be a constant exchange, or input, of organic and inorganic materials, energy and information as well as, and including, organisms. Figure 3.1 depicts the urban ecosystem as a whole. An urban ecosystem is, of course, a dynamic system, and the preservation of its integrity requires an inward and outward flow of energy, as well as an organic circulation of numerous material, especially water.

In the urban ecosystem, non-biotic components include machines and the built environment, as well as the usual materials and processes such as water, its flow and evaporation, which are included in this category in a natural ecosystem. Also, since in urban ecosystems the human population is the most important biotic element in terms of biomass and influence on the system, the human population is shown separately from the other biotic components. Culture which, for example, includes, beliefs, ideas and laws, can have no impact on the system, nor any of its components except through the intermediary of the human population. In this sense the arrows which pass directly between culture and other components of the system reflect a certain inaccuracy. However, this convention will be retained with the expectation that the involvement of human behaviour in the interactions will be taken for granted. In the content of urban hydrology we can recognise, from Figure 3.1, that the flow of water through an urban ecosystem is effected by, and has an impact on, the non-biotic and biotic components (especially the human population component) as well as the cultural components, which include social, political and economic subsystems.

However, there are many ways of visualising an urban area as a series of subsystems. In fact, various authors have offered classifications and diagrams showing what they consider as a systems concept of the urban region. In order to deal with such intriguing considerations, Vlachos and Flack (1974) maintain that irrespective of what the system and its subsystems are there are two major categories of interrelated parts: the physical subsystem and the non-physical subsystem. They continue: 'Each one of these has its own subsystems, important variables, and inter-relationships. Furthermore, the urban system and its subsystem become much more complex when one introduces such intangibles as environmental amenity, quality of life, social well-being, and similar dimensions'.

The authors just mentioned also give a pictural view of their text. Figure 3.2 shows how a series of independent variables, or constraints, affect, through the particular organization of urban engineering (urban institutions), the quality of life (output) by meeting both needs of survival and needs of fulfilment (the good life). An essential point to have in mind, in discussing how well different systems represent the dynamic processes, is that the model of a system helps in understanding the interconnection of various subsystems in the total environment. (The schematic representation shown in Figure 3.2 does not portray the situation in which there is deliberate planning for a specified future situation). A further major task is to explore how different series of constraints may hinder not only the adoption of appropriate control system for management and operation of, for instance, runoff systems, but also a series of quite different constraints.

3.3 THE URBAN WATER MANAGEMENT SYSTEM

In the discussion at the end of the preceding section we had already entered into the concept of an urban-water management subsystem. The hydrological component of such a system is the

15

energy materials (eg water)

Figure 3.1

energy materials (eg water)

Schematic representation of an urban ecosystem

INDEPENDENT

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The urban hydrological system

urban hydrological subsystem. It may be of some importance to distinguish between these two systems. Let us follow the ideas expressed by Vlachos (1971) that 'a particular water system implies a collection of people, devices and procedures intended to perform some function'. Interpreted in this way we may consider an urban water system as being like an urban-water management system. Such a system aims at exploring all the possible consequences of proposed alternatives. To be able to perform such a task which includes analysis and valuations it is necessary to perceive the system as functioning and operating in an environment with specified inputs. Those inputs consist of a series of variables such as natural resources, population, normative resources, legal constraints etc. The system itself processes these inputs, result­ing in outputs or goals established for the specific function of that system. Such established goals may, according to Hall and Dracup (1970), be largely political and consist rather of a spectrum of goals. Hall and Dracup suggest that such a spectrum of goals might be represented by a certain list. This list, strictly speaking, refers to the goals of water-resource system. This is indeed a wider concept than that represented by an urban water system. In view of the fact that the spectrum of goals for such a larger system may encompass that of the urban system the list may, none the less, still be quoted, viz:

1. 'To control or otherwise manage the freshwater resources of the cognizant geographic or political subdivision so as to provide for protection against injurious consequences of excesses or deficiencies in quality and quantity.

2. To provide or maintain water in such places and times and in adequate quantity and quality for human or animal consumption, wildlife (including native plants), food production (including energy), commerce and for the recreational, aesthetic conservation purposes considered desirable by the body politic.

3. To accomplish all of the above with a minimum expenditure of the physical, economic and human resources available'.

These goals are straightforwardly expressed but their implementation generates a series of complex situations. Some of these are caused by environmental constraints regulated, or not, by man himself. Moreover, there is a series of serious complications originating from feed-back loop effects, negative or positive. Another series of constraints inhibiting improvements are to be found among categories such as technical, economic, political, social and legal. Consequently, improving the system requires that a multidimensional objective function be formulated considering the goal structure of the area. Clearly, the goals of water resource development vary with the decision making level involved (Grigg, 1973).

3.4 THE URBAN HYDROLOGICAL SYSTEM

Before making any detailed analysis of the urban hydrological system let us turn to what is commonly called the 'pre-urban hydrological system', (Cohen, Franke and Foxworthly, 1968). The usefulness of this conception is that it gives a schematic description of the hydrological situation before urbanization takes place in a region, see Figure 3.3. In fact, as may be easily seen, this system represents the natural hydrological system before any agricultural, or urban activity, has started. We may interpret such a system as a blockscheme composed of a series of storages (atmosphere, bodies of surface water, etc) and a series of fluxes (precipi­tation, évapotranspiration, etc). The block system is well-suited as a basis for a mathematical-physical account of the process. Today, the literature on mathematical models of the pre-urban hydrological state is very extensive (see for instance Utah Water Research Laboratory, 1970, IAHS-Unesco-WMO, 1971). We also know that the ruling mechanism of this pre-urban hydrological system is the amount of precipitation and corresponding évapotranspiration, and thus studies of processes by means of this system have to allow for climatologie influence. The geological characteristics of the region in question also play an important role as they determine how much of the 'effective precipitation' will be infiltrated or percolated and re-appear as surface runoff.

An analysis of the pre-urban hydrological system is also equivalent to an analysis of the water balance for a specified time interval. To perform such a study data are needed. If these data are available, we may be able to compare individual sources of water in a system, over different periods of time, and establish the degree of effect of their variations in the water

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regime (Sokolov and Chapman, 1974). With sufficient knowledge of all but one of the components of this water-balance system it is possible to evaluate a previously unknown water-balance com­ponent by means of the water-balance equation. If adequate data are not available we still know about methods of studying and evaluating water resources (Unesco-WMO-IAHS, 1973) .

In the present context, the most important thing about the pre-urban hydrological system is that it allows a study to be made of hydrological condition prevailing before urbanization. In this way we get a reference situation for comparison of results from studies in urbanized areas and so, at least in principle, show the influence of urbanization on the natural pre-urban state. However, it would be more important to reach the position where one could explicitly render an account of the expected consequences of a planned urban activity in the pre-urban hydrological system. Such a prediction has to assume that knowledge of processes in the natural hydrological system are known. The International Hydrological Decade has made an important contribution in this respect by promoting research on virgin areas. However, our capacity for making predictions are limited (see for instance Csallany, McLanghlin and Striffler, 1972), and even if we can make such predictions they are restricted to situations of limited interest. One of the 'classical' problems - namely to predict changes in runoff peaks due to the percentage of land being made impermeable (one measure of the degree of urban­ization) - has been commented upon by Hollis (1975). The problem is, however, much more com­plicated since our interests today focus more and more on qualitative rather than on quantita­tive aspects. Our knowledge of the latter effects are indeed still incomplete and our possibilities of making predictions consequently extremely limited.

Heindl (quoted in Csallany et al, 1972) stresses one more important question noting: 'In general, however, the comments levelled at watershed research in the middle 1960s still hold that their results are unrepresentative and sometimes even invalid, and that their results as yet either have not been extrapolated or transferred, or that they are assumed to be incapable of being extrapolated. It still appears that watershed research has not sufficiently focused its attention on the need to present its scientific interpretations so that they can be used. This is particularly unfortunate since watershed research deals with some of the most pressing problems concerning the nation's land water resources'.

Much work is, and has been, devoted to analyses of the pre-urban hydrological system. In the present report investigation of what is called the urban hydrological system is of course of more importance. This is because it is difficult to find regions of hydrological importance that are not affected by the influence of man. A picture of what an urban system might look like is schematically shown in Figure 3.4 (McPherson, 1976c). We immediately note the complexity of this system in contrast to the preceding one. In Figure 3.4 we have considered only quantities occurring in storages and water fluxes and parts of the previous natural (pre-urban) hydrological system are identified. The special meaning of 'manipulation' in this illustration of the urban hydrological system applies to runoff management, eg in the deliberate provision of local storage in the case of 'urban land surface1. In 'bodies of surface water' the manip­ulation applies to recreation, transportation, flood control measures and also property value enhancement.

Emphasis has been placed on potable water supply, wastewater treatment and stormwater runoff in urban hydrological systems. Nevertheless, there are many other problems of a hydro-logical nature to be solved in urban areas. For example, in association with many urban areas there are agricultural activities which demand water for irrigation, in delta zones fresh water is needed to combat saline intrusions, harbour cities require water bodies for shipping services, mountainous regions may wish to utilise water sources for hydro-electric power generation, and so on.

Climate has an important influence on the urban hydrological system, especially because in urban areas it is subject to significant changes due to man-made processes. For example, recent studies in St Louis, Missouri, under METROMEX (Metropolitan Meteorological Experiment), were concerned with the effects of a large urban complex on the frequency, amount, intensity and duration of clouds, precipitation, and related stormy weather, and the conditions whereby the urban complex modifies the precipitation process. This study showed that inadvertent modifi­cation of precipitation as a result of, among other things, artificial heat generation, emission of particulate matter from human activities, and the altered albedo of the urban surface, has a significant impact on local water resources. In St Louis a 10-30 per cent increase in summer rainfall on the catchment of 2,000 square miles east of the city, produced a 15 per cent increase in streamflow and increased infiltration of groundwater. These results are of primary importance to the water resources of this urban area, because groundwater is used extensively for industrial and agricultural purposes. The beneficial effect was somewhat offset by the pollution of ground-

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The urban social and economic system

water which resulted from pollutants carried off by the heavier rainfall. We may use the urban hydrological system as a means of studying the urban watershed and

we may employ the water-balance method, in a way analogous to that applied in river-basin studies. McPherson (1973), in his paper on the need for metropolitan water balance inventories, used the term 'water balance inventory' and points out that we have to determine the quality and quantity aspects of water from its first appearance in a metropolis as precipitation until its departure as runoff and évapotranspiration. McPherson especially emphasizes that: 'The initial stage of a comprehensive system analysis of the water resources of a metropolitan area is essentially nothing more than the attainment of a suitable metropolitan water balance inventory'.

He like Orlob (1971), examines very thoroughly the overall or integrated view which is taken by system analysts. According to Orlob: 'Systems analysis did offer a great potential for assisting planning, design and operation of urban water systems; but we pointed out that paradoxically comprehensive modelling would likely have to proceed from rather general gross descriptions of the urban water environment whereas we would probably wish to begin at the most detailed operation level, since operating systems with problem are now in service'.

The urban hydrological system as now presented takes into consideration only quantitative aspects of water. If we include qualitative aspects it becomes very difficult to take stock of the situation. Nevertheless, it is important to consider water as an aesthetic component of the environment and as an amenity in addition to the conventional approach to water quality which considers only the biological and chemical content of the water being directed to domestic, industrial or other uses.

A pictorial description of the urban hydrological cycle may be varied in many ways. One interesting variant is that presented by Carlsson and Falk (1976) (Figure 3.5). The right-hand side of the figure gives a water balance model of an urban area. The numerals shown on the figure are approximate values for a region in South Sweden. Water balances for other regions may of course give very different values. It may be more appropriate to give percentage values instead of absolute values. The left-hand side of Figure 3.5 shows the flow of water within an urban region, ie the internal system. On the extreme left of the figure, a water source is shown from which a waterworks imports its water. This water is distributed to various receivers (domestic, industrial, public). After use, the water is conveyed to the sewage treatment plant and thereafter is disposed of in various ways, eg discharged into rivers or reservoirs, or used for spray irrigation. It should be noted that agriculture may be a component of water use in some urban areas.

Since the systems just described have their greatest advantage as a means of structuring ideas of how processes may interact in the pre-urban as well as in the urban hydrological system, it may be of interest to dwell a little longer on the concept of urban watershed. If we concentrate on the urban region it would be appropriate to define the urban watershed as the aggregate of all those urban drainage areas which contribute to the total hydrological effect of the urban area. This may be true but many urban areas use remote sources for their water supply and transfer of water is the rule rather than the exception. What consequences will this fact have on the concept of an urban watershed? If we apply a geographical perspective to such situations we may possibly be led to the conclusion that the (smallest) urban water­shed, at least for developed regions, is of the magnitude of the country itself, or a consider­able part thereof. But this is certainly not true for developing regions where the urban watershed is often the urban region and its immediate hinterland.

3.5 THE URBAN SOCIAL AND ECONOMIC SYSTEM

Although the urban hydrological system is a subsystem of the urban system, it has been described above in its internal relations only. To describe how the system functions, or to indicate how it should function, its relationship with the social and economic system should be taken into account because water management is a human activity based on decisions made by a governing body. These decisions are reached through a process of interaction between individuals, groups and institutions. In this process a large variety of elements play a role - traditions, legal and political systems, power structures, artifacts, property rights, wealth, value-orientations etc. From the specific aspirations of one individual, to the decision to make an investment in a water-management system for a whole urban region, there is a long chain which disappears from sight at a certain point in an extremely complicated network of relations between elements in the different sectors and levels, of which the social and economic system is composed.

Because the urban economic and social system is very complex, in the sense that there are

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opposing interests among groups and institutions, the decision-making process becomes so com­plicated that it is difficult to comprehend. All attempts to understand, manage or predict the process, would be in vain, if human behaviour was not patterned, if there were no stable cultural elements, no consensus in beliefs and values, and no consistency in wishes and needs. There are, however, patterns which allow us to describe urban society as a dynamic system in terms of structure, culture and function. This is the task of the social sciences (including economics).

The urban social and economic system does include the physical environment as it conditions human behaviour and as it is has also been transformed and partly built by human behaviour. In this sense, the urban hydrological system, as far as it is constructed by man, is a structural and a cultural element of the social system. Once it is there it channels and conditions part of human behaviour.

Although an abstract theory of social systems is feasible, the number of elements and relations in such systems is so large, and the rate of change in human behaviour is so high, that mathematical models are hard to make operational. Nevertheless, verbal models can be very useful and should be used if social scientists and hydrologists are to make a combined effort in urban water management.

Because water management is frequently operated on the level of the urban region as a whole, that part of the social sciences which studies the planning process itself is involved and questions arise such as how does planning satisfy people's wishes and how does planning guide people's behaviour in the right direction bearing in mind the intention to maintain or improve the quality of life which is discussed in the following chapter? The failure, so far, of the social sciences to make a substantial contribution to urban hydrology is probably not so much due to deficiencies of the social sciences as to the fact that research policies to direct hydrologists and sociologists to the same track have not been developed.

23

4. Urban hydrology and well being

4.1 INTRODUCTION

Chapters 2 and 3 have dealt with the urban water situation in the world and with systems on human settlements, including urban water systems and social systems. In using these systems for planning purposes an interdisciplinary approach in analysis and assessment of human goals and natural (including hydrological), social and political processes is needed.

The central preoccupation of this chapter is with the urban ecosystem and the social, economic and environmental variables which have to be considered in this respect. The follow­ing will be particularly discussed: features of the urban ecosystem in 4.2; and basic, or minimum, life-conditions related to water which may provide better insight in the search for criteria of well-being in 4.3. Proceeding from these life-conditions, the terms 'well-being' and 'quality of life' are more systematically presented. By living together, people create a culture, but due to a mutual influence, a relationship with the environment should not be disregarded. Against the background of the function between life conditions on one hand and man, culture and environment on the other (4.4), the role of urban hydrology in environmental impact assessment is stressed in 4.5.

4.2 THE URBAN ECOSYSTEMS AND THE HYDROLOGICAL COMPONENT

In Chapter 3 an attempt has been made to describe urban systems and to provide working defini­tions for both natural and urban ecosystems.

A detailed treatment of ecosystem structure and functioning as well as of urban ecosystems was initially elaborated in the framework of Unesco's MAB programme, particularly with MAB Project 11 on ecological aspects of urban systems with emphasis on utilization. This elabora­tion includes conceptual and methodological approaches to integrated ecological studies on human settlements, with detailed analysis of human settlements as ecological systems (Unesco, 1973a, 1975b).

It is recognized that human settlements are both socio-cultural and ecological systems. In comparison with natural ecosystems, socio-cultural variables form a major and dominant feature of human settlements viewed as ecological systems. Furthermore, the socio-economic structure of human populations is an important factor in organizing other aspects of -the settlements system, such as health services and information flows. Since, as systems, human settlements are dynamic and thus changing through time, it is considered important to stress historical processes and historical development.

There are two important features of an ecological approach to human settlements. Firstly, such an approach emphasizes integrated monitoring and modelling studies which include physical, biological, socio-cultural and economic variables and their interactions. Secondly, human well-being is considered to be a fundamental objective in planning human settlements and a central criterion for evaluating the performance of the system.

In this respect, it is important to note that human settlements have been defined to include the full range of settlements, without limitations as to population size of particular functional, cultural or other characteristics.

While definitions vary, a useful line of reasoning is summarized in Figure 4.1. An urban ecosystem has many features in common with a natural ecosystem. Both urban and

natural ecosystems are composed of a complex of subsystems with interacting components with flows of energy, matter and information of various kinds.

In addition it should be recognized that there are socio-cultural variables which influence and are influenced by these flows. Thus an urban system can be understood in relation to the ecosystem. Applying blindly all concepts learnt from natural ecosystems to urban systems would lead to erroneous conclusions.

The different outcomes of the negative feedback mechanism should be borne in mind. In the natural ecosystem there are, as has already been said, a homeostasis effect which exerts a damping on the system functions. This regulating mechanism is supposed to take part within distinct boundaries, defining a certain domain of stability. If these limits are exceeded the system is transformed to another level. When considering a man-made urban system such as the

24

The urban ecosystems and the hydrological component

natural ecosystem urban system

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Figure 4.1. Summary of reasoning followed in Section 4.2

one pictured in Figure 4.2, the premises are somewhat different. These will of course be a positive feedback mechanism which may be difficult to compensate for by a negative feedback process thereby trying to restore the system to a dynamic equilibrium state. But now there exists the unique control mechanism due to man as a social and cultural organism. Thus, man has developed a series of formal and informal social and institutional controls only limited in realization by his own imagination. Man's intervening in the urban system, in order to improve material conditions, has also increased the importance of positive feedback mechanisms. This fact has had the effect of an uncontrolled growth of economy and technology by which man's control of the urban system may be doubted.

Taking into account the different characteristics distinguishing natural and man-made eco­systems, it is obvious that one can not allow a direct transfer of knowledge from the first system to the other. Then, one may ask for the advantages of using the concept of an ecosystem when considering urban processes, especially those which are closely related to urban hydrology or urban-water sciences. One answer is to state that a more thorough understanding and analysis of the real functioning of the total urban system as the complex composition of various sub­systems has led to conviction that urban ecosystems are not solely an environment of human societies with a source of resources and a sink for wastes. As has been said earlier, urban ecosystems are characterized by both natural and social and institutional control mechanisms. The precise nature of those social control mechanisms is however not clearly predetermined. One consequence thereof must be that if urban ecosystem dynamics should be rightly understood then a proper knowledge of human goals and social and political processes reflecting them is necessary (Stearns and Montag, 1974; Linville and Davis, 1976) .

Since water is one of the fundamental resources - perhaps the most important - imported into the urban area and thus an essential input to the urban ecosystem, it is of paramount importance to be able to manage the processes that transform the input resource to an output waste. Thorough knowledge of the ecosystem process will not directly make possible a straight-

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Life conditions: the search for criteria of quality of life

forward design, or precise calculation, of water resources facilities. A sound insight into the ecosystem mechanism will make clear the frames within which urban hydrologists, city planners and others may be allowed to act if severe disturbances are not to be allowed to rupture the ecological balance. The notion of an urban ecosystem will help us to identify those social, economic and environmental parameters which have to be considered in analysing the urban-water processes with the aid of hydrological methods.

What is underlined in the previous remarks is that an overall, integrated, interdisciplinary approach should be adopted to the study of settlements, so that objective scientific information may be provided to planners, decision-makers and managers, to form a basis for sound management oriented to the solution of concrete practical problems. In this respect, then, particular attention should be paid to the usefulness of modelling as a means for facilitating this quest for interdisciplinary approach.

It should be recognized that a model, although less than the reality it depicts, is a map that should be simple enough to be grasped at a glance; a simple representation of more complex forms, processes and functions. Models, organizing our understanding of socio-economic condi­tions, are important as starting points for the systematic analysis and assessment of technolo­gical actions upon social system.

Modelling has proved to be a valuable tool in the syntheses of ecological information, in defining research objectives and in the development of interpretive understanding of ecosystems. Its usefulness lies in the ability of the model to relate information about single components, or a limited number of system variables, to the whole system. Modelling also offers opportun­ities for predicting changes beyond the established data base.

There are currently numerous examples of modelling of socio-economic systems with a vast number of 'critical' variables. No study can include all variables; a selection is necessary to decide which ones are important on any given project and at any given time. We can proceed by offering examples of lists of variables (such as those in Figure 4.3). However, an important point is that the selection of pertinent variables is part of the vision we have about the world around us, the assumptions we make about individuals and nature, and generally part of a con­struction and interpretation of reality.

Indeed, there is no univeral set of variables for the systematic study of the urban eco­system. The urban ecosystem approach is at least a useful means of finding out the measures to be taken concerning the development of the water activities in an urban area. If the water resources are to be used to the optimum the relationship between social changes and changes in a water policy must be known.

Finally, the notion of the urban ecosystem can act as an organizing concept for providing norms with which urban water policy can operate without causing damages to the complex frame­work of social, economic and environmental factors. As can be seen from the next section the means by which the decisive relationship between changes in society and urban water policy may be formulated are not completely known. This is mainly because of a lack of knowledge of the factors which may have an influence on changes in society.

4.3 LIFE CONDITIONS : THE SEARCH FOR CRITERIA OF QUALITY OF LIFE

4.3.1 Introductory comments

It is important, at this point, to turn attention to the central question regarding the search for elements or criteria of well-being. Essentially, we are searching for a reference system that will allow us to explore systematically those life conditions that make possible the development of a coherent scheme summarized under such descriptive terms as 'the good life', 'well-being' etc.

To facilitate the systematic exposition of the argument, we can summarize the essential premises of section 4.3 descriptively in Figure 4.4.

The question that must be raised here is whether we can find any 'social indicators' that can be useful in evaluating different urban hydrological projects. Although no complete schemes are available by which social scientists can offer a means of finding the best alter­natives in water resources planning, this is no excuse for scientific defeatism. We need enhanced social research as a complement to science and technology and especially we need the result of such collaboration as a means of helping the public to make judgements about water resources management. This fact has been emphasized by, among others, White (1971): 'A reliable sounding of preferences requires that the citizen feel himself in a situation where conditions of choice are similar to those he will encounter in dealing with a real stream that he exposeed

28

Life conditions: the search for criteria of quality of life

r

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domains of SWB/QOL

basic dimensions related to water

warnings about formulas of SWB/QOL

parallel efforts for defining 'welfare'

methodological attempts to 'measure' SWB/QOL

v_ applicability of SWB/QOL approaches

Figure 4.4. Summary of premises in Section 4.3

to the full range of information and opinion as to the alternatives open to him and that he have a realistic sense of men's capacity to deal with water and the life it sustains. To do this will call for a close and unprecedented collaboration of natural scientists and engineers with social scientists in designing a new kind of assessment that will inevitably change attitudes as it tests them. This is one of the exciting challenges lying ahead in water management'.

4.3.2 'Life conditions'and the search for social indicators

One way of approaching the social aspects of urban hydrology is to clarify the concepts of 'welfare', 'social well being' and 'quality of life' widely used but seldom clearly defined1. Although difficulties arise when the concepts are translated into different languages, it is, nevertheless, fundamental to distinguish the objective aspects from the subjective or psychological ones.

[ SOCIAL WELL BEING I (predominantly objective \ conditions)

QUALITY OF LIFE ^ ^ (predominantly subjective )

aspects)

1 At the Third Conference on Urban and Regional Research, Warsaw, 5-13 May 1976. Organized by the Committee on Housing, Building and Planning of the United Nations Economic Commission for Europe. Report HBP/SEM.11.4, 15 September 1976, QOL was used as a comprehensive concept comprised of 'welfare' and 'well-being'. The first has been used in a socio-economic sense, while in the second the emphasis was on socio-psychological dimensions.

29

Life conditions: the search for criteria of quality of life

In this scheme, social well being includes predominantly all the structural aspects which determine a person's, or a group of people's, social position in life. Quality of life accounts for some internal satisfaction (positive or negative) that a given position in life provides to the individual and accentuates socio-psychological dimensions. The entire set can be perhaps called 'the good life' or any other descriptive term to encompass the spectrum of the notions introduced above. (For summary reasons we refer to both dimensions collectively as SWB/QOL). Both, the situational, or objective, variables, and the subjective ones (psychological satisfaction or 'happiness' are understood by individuals, or groups in differ­ent ways. The same situation can be understood differently according to the values, and goals of the person, or persons, involved, which of course are derived from the socio-cultural frame in which he is situated and from his individual position in society.

Perception depends not only upon the cultural framework within which perceptions evolve, but also the functional role of given environments (eg as between work environments and resi­dence environments) and the status and orientation of the individual observer. What is seen as appropriate and desirable from the standpoint of the observer need not be the same as that of his or her neighbour, even though they share a common culture (Unesco, 19 73).

One way of visualising the difficult concept of well being is to examine its different meanings around three domains, (Figure 4.5).

Figure 4.5. Components of well-being

By structural, or objective conditions, we emphasize the external, physical and social condi­tions of existence (safety, health, mobility, etc). The perceptual, or value-context, indicates the individual's beliefs, expectations and aspirations. Finally, subjective well-being implies feelings, satisfactions and anxiety of the individual vis-a-vis the other two componen ts.

Such definitions provide essentially a reference frame within which particular studies about life conditions can be undertaken. Certainly such an approach does not constitute an exhaustive list of variables, but a framework for selecting critical variables given different

30

Life conditions: the search for criteria of quality of life

cultures, time, or social groups, within a particular society. Generally, if we are to study well-being, or SWB/QOL, especially in developing countries -

we must bear in mind that there are basic human and social needs that must be satisfied in order to guarantee survival. Thus, with regard to water-related needs, attention should be immediately focused on such basic items as: potable water, health, vegetation/animal life, transportation, disposal of effluents, cleaning of human settlements, protection and prevention from natural hazards and fire protection. At the same time, ideally, water has to be available:

1. At a reasonable walking distance (some hundreds of metres);

2. In a sufficient amount at (nearly) every moment;

3. With a good quality.

Finally, artificial provisions have to be made to prevent natural hazards of diseases due to pollution of surface water, taking into account the criteria of minimal costs and of physical environmental considerations. Such a constraint will have implications for planning of water systems, water resources and human settlements as well as migration to urban areas.

Generally, the fulfilment of these conditions secures what can be called 'minimal living conditions', above which other needs may appear as relevant. This could be the situation in countries in a more advanced stage of development, where the critical variables are not the ones mentioned above, but others such as recreation, institutional stability etc. Their main interest at this stage, is not only the satisfaction of needs, but paying greater attention to the quality of other items. Once a house, as a shelter, is secured, interest shifts to better design, or equipment, for example. Yet, it should be recognized that where living conditions are considered to be below minimal today, actions for guaranteeing survival should not preclude considerations of well being, since in the long run, serious problems may become apparent in future estimations of social well being.

An important point in this distinction rests on recognizing that, depending on the level, phase, or stage of social organisation, different domains of social well-being are considered. Thus, the minimal considerations of well-being involve the basic life conditions outlined above (basic objective conditions). Once the essential needs of survival have been met, one can then consider more refined indicators of well-being through a progressive process of growth emphasizing fulfilment, satisfaction, self-actualisation, etc.

A word of warning: the problem of making comparative assessments of values, goals and preferences is difficult and certainly not easy enough to be resolved here in a few sentences. Obviously, where possible, objective figures should be provided, such as rate of mortality, percentage unemployed, income etc. But there is no completely objective way to use and compare such units. Numbers do not speak for themselves to all groups of people. As a matter of fact, what may be good in one situation may be quite the reverse in another.

The construction of specific indicators for describing social well-being seems to be highly situational, time-specific and culture-relevant. In view of this, one can understand why no adequate formula has yet been devised to measure adequately social well-being.

Summarizing:

1. There is little agreement (and there may never be one) on the definition, or even the minimum desirable levels, of factors describing social well-being.

2. It is extremely difficult to measure social well-being or quality of life beyond basic dimensions (or critical objective conditions).

3. Research for SWB/QOL will require the modelling of a large and variously interacting number of variables on both the objective and subjective levels.

By now, it is becoming apparent, as repeatedly stated elsewhere, that it is not possible to devise a common set of indicators to measure human well-being that would be applicable on a world-wide basis to a wide range of socio-cultural, socio-economic, biosocial and ecological situations. MAB Report No 13, p27 (Unesco, 1973b) reflects on this question as follows:

31

Life conditions: the search for criteria of quality of life

"... it is likely that a large number of different sets will be developed reflecting diverse local, regional and national situations and which recognize the various and often conflicting values and interests of different local, regional and national groups. Moreover, it is likely that any research project, according to its particular purposes and hypotheses, may demand its own particular set of indicators and analytical methods. For some research purposes, it would not be useful to use exactly the same set of indicators for comparisons, for instance, between a large metropolitan area within an advanced industrial country, and a smaller . . . (human settlement) in a developing country.

Nevertheless, as specific sets of indicators are developed for particular ... (human settlements) situations, it is likely that certain common concerns will emerge, reflecting some basic universal human needs and wants, for example, health, income, employment, housing, population, city size, biological indicators, and so on. Wherever this occurs, it is imperative that national (component) studies employ, as far as possible, common classifications and indicators that may be available (eg the health indicators developed by the World Health Organization)'.

Regardless of the difficulties encountered in establishing a given set of indicators for any particular situation, adequate assessment of well-being requires the inclusion of quanti­fiable variables. In this respect, integrated ecological studies of human settlements will therefore include an analysis of correlations, or parallelisms, between measures of human well-being and measures of systems well-being, such as energy and material flows, or environmental health factors, such as air quality, water quality, physical conditions of buildings and the size, diversity and vigour of plant and animal populations. The analysis of these interrelationships is essential if improvements in human well-being are to be achieved through the control of other variables in the settlement system.

In trying to evaluate the socio-economic aspects of urban hydrology we are forced to choose some reference system by which social, as well as economic, aspects may be expressed more exactly. As regards ecomomic aspects we know of methods of judging merits of competing alternatives. This is true as far as tangibles are considered. Though strongly criticized, cost-benefit analysis is still one of the techniques used in finding, among alternative water-resources projects, the one showing maximum economic efficiency. The criteria for this is the maximization of economic net benefits, that is, economic benefits minus costs. We also know that in recent years much research work has been devoted to a study of multiobjective optimization.

Sigvaldason (1975), Major (1969) and Schwartz (1966) have suggested that the different objectives could be displayed graphically along orthogonal axes. The potentially optimal solution to the two-objective optimization problem should then lie along the boundary of a region which contains all possible solutions. By such a way of representing the results, we may put in the graphical illustration a series of indifference curves which in some manner may account for lines of equal social utility. The optimal solution is located at the point of tangency between the boundary of the feasible region and the indifference curve, ie at the point of maximum social utility. However, we must have in mind that it is difficult to deduce the lines of equal social utility.

There have been a series of attempts to deduce a welfare function. Existence of such a social welfare function was first suggested by Bergson (1939) . His welfare function W is a real value function, the arguments of which consist of different aspects of a social state. The function takes the following well-known form:

W = W (u, U„, .. ., U ) (4.1) 1 ¿ n

where U¿ is the level of the utility index of the i th individual. Each of these utility functions is itself a function representing the satisfaction level of an individual as some combination of certain goods, services, and other aspects of each person's environment, that is:

U. = U (0., ... O ) i = 1, ..., n i 1 m

If we substitute this expression in equation 4.1, it appears that:

W = W (0, , . .. O ) X m

32

Life conditions: the search for criteria of quality of life

More generally we may state that the social welfare function is a mathematical means of expressing the inherent idea of the welfare economics which is to develop better procedures for allocating available resources. And as James and Lee (1971) point out, welfare economic is normative, or prescriptive, in character in the sense that it seeks the resource allocation best achieving consensus values, or satisfaction, or needs fulfilled. However, it is not prescriptive in the sense of recommending what these values should be. The social welfare function may in fact be stated in many variants. One used by James and Lee (19 71) is the following:

n I = a, G, + a„ G„ + . . . + a G T. a. = 1 (4.2)

1 1 2 2 n n . , i i=l

Here I represents an index which must be a scalar value to rank alternatives unambiguously. Gj_, G2r Gn symbolize goals and ai, a2, an are weighting factors. The units used to measure progress towards each goal and the weighting factors must be defined so that society will become progressively happier and more contented with increasing value of I. If this ranking function can be used efficiently then each goal must be expressed in such units that it is possible to show quantitatively how progresses have been achieved.

As the social welfare function has to allocate separate parts of human needs, we are faced with the difficulty of finding by optimization the values of W and I which is the best ranking in considering all human goals, or a selected list of such goals. The reason for this difficulty is that it has been questioned how to measure exactly degrees of accomplishment of all social objectives, or assign relative weights to alternative goals. As James and Lee (1971) have indicated, this fact implies that a universal social welfare function can never be developed for general use.

Yet, when all is said and done, people have to make decisions with limited time, resources and information. Thus, a number of criteria (however imperfect) have to be utilized to facilitate such decision-making. Nevertheless, there must be some hope of developing an approximate, or second-order approach. One way of doing this is to find some acceptable mechanism for identifying the substantive contents of the arguments presented in the last of the equations given above. This is done mainly by an attempt to arrive at some consensus on the components of the equation mentioned. By this process we are approaching the idea of social values or identification of social goals, or concerns, which aim at reflecting broad areas of social interest.

Much more work has been done in this field and there is special reason to mention the research results presented by Arrow. According to Arrow, as quoted in a paper by Donovan (1973), among the minimum conditions necessary for collective rationality one can include such items as the notion that:

1. 'Between three alternatives, the social welfare function must give rise to unique social ordering, no matter how individual members of the group choose to order three alternatives.

2. The social ordering must correspond positively, or at least not negatively, to changes in the ordering of any one individual.

3. The elimination of any one alternative shall not affect the ranking of other alternatives in the social welfare function.'

The Bergson and the Arrow concepts have been widely debated. About Bergson, for instance, Rowley and Peacock (1975) say: 'In this sense, a Bergson social welfare function is an ordinate index of society's welfare and is a function of the utility levels of all individuals. It is not unique, and its form depends upon the value judgements of those who deem it desirable since it expresses their view as to the effect upon society of the utility level of the i th individual. In contrast, the Arrow group decision rule is more general in scope in that it specifies the method of deriving the social welfare function. For, in many instances, it may prove impossible to decide upon an acceptable form for the social welfare function by consensus, in which case a group decision rule (dictatorial or otherwise) is clearly required. The Arrow group decision-rule fulfils this important requirement and is a necessary, though not a sufficient condition for the existence of a Bergson social welfare function'.

The important thing to keep in mind when discussing what the social model should be used

33

Life conditions: the search for criteria of quality of life

for is that it should be able to evaluate social processes and social changes. However, we know how difficult it is to set up social models, a difficulty which is related to the fact that social models have to consider a living human system with all the constraints imposed to it. This is per se a much more difficult task than to model processes in the 'dead' world which are so characteristic of natural sciences for instance.

In order to have a measure for social changes, or social reactions, one can use social indicators as mentioned in 4.2. Social well-being/Quality of life can be visualized through a wide range of indicators. By means of these one should be able to account for objective and subjective situations of individuals and groups.

The discussion and differentiation of objective and subjective dimensions presented above should not confuse the issue. What one needs to incorporate in any analysis and assessment are both objective or measurable systems and, at the same time, a recognition of value systems combined in some integrative system of evaluation. In this spirit, the essential difficulties of measurement and of uncertainty should not be viewed as a handicap in the quest of planning for the future. On the contrary, the combination of objective and subjective systems should be considered as an important expansion of imaginative thinking and a necessary ingredient for socially-sensitive responses to a complex, fast changing world.

Wilkinson (1973) points out that 'The concept of social well-being must be distinguished from and related conceptually to a concept of individual well-being on one hand, and one of universal, ecological well-being on the other. These are variant levels of analysis of a singular reality and thus must be conceptualized in ways which are, at least in the most general or abstract sense, consistent with one another .... This is another way of saying that we are looking for general principles of well-being which hold at all levels of analysis and that distinctions among levels are made heuristically so as to provide for testing of whether principles which appear to be valid at one level are also valid at the others, and are thus general' ....

Clearly an individual's personal environment is influenced by the total environment. The relationship between the two is, however, a complicated one, and the individual can be said to be separated from the total environment by a series of filters (which may be cultural (eg food taboos), or economic (eg income). These filters may protect him from potentially harmful components of the total environment, or they may deny him the advantages of certain potentially beneficial components (Unesco, 1975).

This means that a concept of social well-being must encompass concepts of individual and ecological well-being. But again we are still faced with difficulties in identifying the social processes and purposive change strategies which presumably affect it.

We may of course ask how such social indicators, objective or/and subjective may be used when evaluating water-resources projects and how they may influence urban hydrology. A very extensive study on how to use socio-economic indicators, when working out a plan for water-resources development, has been presented by Fitzsimmons and Salama (1973). They started from inter-relationships between man and water:

- statements regarding man's need for water (ie from man to water)

- statements regarding water's positive impact upon man (ie from water to man)

- statements regarding the disutilities which may be generated by water development functions (ie again from water to man)'.

The problem of social indicators is of course a very complicated one especially because of interrelations between them. But, nevertheless, a very interesting and important contri­bution to this matter has been made by Land (1975). As a starting point he uses the notion of social change measured by the concepts of social indicators, expressively not to be confused with the classical economic indicators. If the social indicators are indices of social conditions and arguments of welfare function, then we arrive at indicators known as goal output indicators. But if we impose an external validity criterion then we get the special type known as indicators of social change. These two sets of indicators are not identical. It is virtually impossible for a social welfare function to take into account more than a few aspects of social life. But the contents and relative weights of social welfare functions will undoubtedly change from time to time as the interests of members of a society and of policy-makers change. As this occurs, social scientists will be called upon to provide different indicators as components of the welfare function (Land, 1975) .

34

Life conditions: the search for criteria of quality of life

p = (P r •

R = (Rx, .

X = (x , .

F = (f^ .

• • V

•• v . . X I )

•• v

In fact the crucial point is to delineate a theory which shows the essential factors that characterize a social system. There seems to be one way of starting with the quadruple of sets:

(P, R, X, F)

where

p ) is the set of all N members in the system

is the set of all M socially significant types of binary relations among the members of P

is the set of all I types of socially significant properties of the members of P

is the set of K functional relationships among the elements of X and R

In the above definitions the meaning of 'socially significant' is somewhat obscure. It must be related to the system and study and in some way try to picture the cultural context of the system at a given time and place. Again according to Land (1975), the couple (P,R) may be called the 'social structure1 of the system or the 'role structure'. What it pictures is the network of behavioural, affective and normative relations among the members of the population. For instance, if P is the set of individuals of the system and R indicates a set of kinship relations, the couple (P,R) means the kinship network of the social system.

The couple (X,F) is identified as the operational, or functional, aspect of the system. For example, the set X could represent the variables indicating age and income of the members of the system and F could indicate the function determining income as a function of age. So the two couples (P,R) and (X,F) are the two essential characteristics of the social system, and social changes refer to alteration of the couples; thereby meaning the consequences for one of the couples if changes occur initially in the second. It shows how difficult it is to carry out observations if both the first 'topographical' and the second 'functional' sector of the system are simultaneously changed. Consequently, one tries to let one of the two be unchanged at the start. However, observations may be made easier if some simplifications are based on the fact that some individuals of the social system may be aggregated. This is because there certainly will be some social relationship R according to the institutional structure of the society. We may define a social institution as the set of norms that cohere around relatively distinct values and activities. With this in mind let us collect in special groups, gi# those members of the set of relations R that are oriented to the i th institution I. where i = 1, ..., Q. By this reasoning an equation (4.3) can be written:

(PX, (R / g j , X, F) (4.3)

where P in equation 4.1 has been grouped into classes and P designates a set of structurally equivalent populations.

In order to proceed we need a definition of a society which would allow for a subdivision into aggregates. One definition of a society could be that it is a politically organized, relatively self-sufficient population of human beings which maintains a culture and which is capable of existing longer than the life-span of any individual member; the population being recruited, at least in part, by the sexual reproduction of its members (Aberle, 1950). With this definition we may classify activities in the society into four:

1. Reproduction

2. Sustenance

3. Maintenance of order and safety

4. Socialization and cultural organization

We can now apply the definition of social change given above to any of the four components.

35

Life conditions: the search for criteria of quality of life

As Vlachos and Flack (1974) have pointed out: 'By recognizing these key parts we want to examine how men in creating culture affect both their individual lives and the surrounding physical environment. In turn, the natural environment imposes certain constraints as to what man can do and how a given culture is shaped. There is reciprocal relationship among all of the above. The term "environment" may thus be defined as the system of spatial, and temporal, social regularities which influence the biological and behavioural processes of a given population'.

In another context, Vlachos (1975) points out that the 'key argument of the above remarks is that what is usually called natural environment has meaning and utility only in the context of a social setting in which individuals (and their culture) interact with nature. The individual - centered system is the heart of a total environmental approach and of the society -technology - nature symbiosis'.

To these concepts can be added the notion of the known or understood environment. This is of importance because of the fact that considering the man and biosphere relationship we have to deal not only with a so-called real world which may be the same objective reality for all observers. Moreover we have to recognize a subjectively perceived environment. Thus, perceptual processes present the individual with a picture of the real, objective world: the past experience, concepts, symbols, attitudes, needs and purpose of the perceiver may thus determine, to a large extent, what shall constitute a stimulus and what shall not (Hurst, 1974). It is well known that our descriptions and understanding are communicated through the filters of our sensory organs, minds and experience as well as argument and representation, and political institutions. Perception depends not only upon a cultural framework but also on the functional role of given environments and on the status and orientation of the individual observer. This means that one observer may classify perceptions as appropriate and desirable although a neighbour will not do this even though they share a common culture (Unesco, 1973a).

Dealing with the perception of environment may lead to concern with environmental quality, and there may be a distinct difference between group and individual perceptions and values. As has been pointed out, there has been a tendency to confuse this concept with that of freedom from environmental pollution. This seems to be caused by the fact that pollution is rather simple to evaluate qualitatively as well as quantitatively compared with an overall environ­mental quality. The concepts of quality, as well as the perception of quality, may contain a wide range of considerations and variables which depend largely on the relationship of a given society to its surrounding physical environment. These considerations could, for instance, include the availability of space for recreation, arrangement of man-made structures and so on (Unesco, 1973a).

By introducing the notion of a total environment we are in fact confronted with man as an individual and his community as a whole. As pointed out by Vlachos (1975) two very important parts of this total environment are the geosphere and sociosphere. The first of these includes water as well as air, minerals and land whereas the second contains the common patterns of interaction between all aspects of human resources as well as knowledge and skills. This leads us back again to the importance of urban hydrology stated earlier by McPherson (1974): 'Urban hydrology is a distinct branch of the broad field of hydrology because the complex interactions of human activity in concentrated settlements, with air, water and land must collectively be taken into account '.

Thus, by analysing the total environment according to these two subdivisions we may recognize the close connection between the total environment concept and the quality of life. We may also, by introducing structural and cultural key dimensions of a human community, get an insight into the way people try to organize their lives as regards water-resource activities. By structural and cultural dimensions in analysing interactions between man, culture and environment, Vlachos (1975) says: 'By structural parameters in human community, one may include the basic variables within a spatial/temporal location that describe the essential arena within which social interactions take place. Such important structural variables in water management include first, human ecology (population variables, and spatial arrangements) • second, characteristic institutions (such as family education, religion, political, economic, health, leisure and recreation); and finally, social collectivities (both in terms of formed organizations and informed associations). Cultural features of human community, on the other hand, refer to views and patterns of life shared by a number of interacting individuals. Culture is the system of knowledge, beliefs, practices and artifacts shared by a people and passed on from generations. The culture of a people includes such particulars as lifestyles, historical or legacy features, world views, beliefs, perceptions and definitions of reality, as well as intercultural relations'.

36

Man, culture and physical environment

We may also conclude that it should be possible to measure social change in terms of changes of the properties X, which the respective institutional structures allocate among members of the system. Social indicators in this context may relate to a more general concept of social change. We may also state that social indicators defined in this way may put emphasis on the direct relationship of a social concern to an individual well-being. By this reasoning we will also attain a close relationship to the social well-being function. Moreover, we may then conclude that characteristics which are not directly related to individual well-being should not be measured by social indicators.

Again by introducing indicators in this manner, we may be able to define, more precisely, social goals and aspirations as well as social concerns. This is recognized by the fact that an institutional structure can be considered as a set of social relationships which may be oriented to those norms constituting a social institution. Groups of individuals may then identify certain social concerns that may be regarded as social goals from a sociological point of view. The idea of authority is one of the simplest ways by which we may establish a welfare function (Arrow, 1963).

This section has dealt with the idea of social indicators associated with the social well-being function. The social indicators discussed are not related to a specific political system but applicable to different kinds of such systems. The identification of a social welfare function may differ from the use of this concept of social indicators. However, the proper selection of social indicators may be a troublesome task, and if they are to reach the potential which their originators have envisaged it is obvious that they must be incorporated in models which can mirror the structure of institutional interdependencies of the society (Land, 1975).

The paradox we face at this point is apparent. Without theory, or generalized conception of the problem, it is hard to know which data to collect. Without data it is hard to gain precise knowledge about the overall system or important relationships which may exist among aspects of collective social life. In practice, a rough model can be delineated to act as a guiding scheme for data collection and, through successive processes of repetition, refine, or elaborate, the conceptual approach as well as the required data.

4.4 MAN, CULTURE AND PHYSICAL ENVIRONMENT

Viewed from another perspective quality of life must also reflect man's understanding of his role in the total environment, which is thought to be composed of man himself, culture and the physical environment. Here, as before, it may be useful to outline in a diagramatic form (Figure 4.6) the flow of argument in section 4.4 in order to provide a clearer picture of the major points.

man-culture-environment

objective and subjective reality

1 concern with the total environment

I what the total environment implies (components)

I the centrality of water

1 approaches to the environment maximum economxc

profitability

mixed approach

environmental concern

Figure 4.6. Summary of the outline of argument in Section 4.4

37

Environmental impact assessment

A great deal of current research by sociologists on water problems has been concerned with an attempt to identify those problems which are involved in the interaction between human community and water resources technology. Wilkinson (1972) points out that this conceptual literature focuses on two main categories of issues. The first is concerned with elements of social organization which facilitate and/or impede application of water-resources technology. Illustrative are the studies of the influence of community structure and leadership upon the successful completion of development projects in small watersheds.

In contrast to this problem, studies are also being made, according to Wilkinson, of the effect of such things as the construction of a dam on the social organization and living conditions of people in the surrounding area. From the direction either of an independent variable, or a dependent variable, social organization has been identified repeatedly as a critical factor in water-resources developments and it is at this point of interaction of water resources technology with other aspects of social organization that many of the most perplexing water-resources problems are to be found.

As has been pointed out by many scientists, the main objective of water-resources develop­ment has in the past been economical efficiency and with this goal in mind the use of cost-benefit analysis has been a way of evaluation. But, as Biswas (1973a) mentions, during the last decade a major change has taken place in our perception of the interrelationship between man and his environment. Nowhere is this change more apparent than in our concept of resource utilization and management. No longer is society as a whole willing to accept that economic indices, such as increase in the Gross National Product, increase in pev capita income (both in real terms) and traditional benefit cost analyses, are the sole criteria of progress. On the contrary, it is being increasingly realized that the total benefits that accrue to society from our natural-resource management cannot be totally measured by the market mechanism.

It is quite clear that man's attitude towards the deleterious use of our most important resource has changed remarkedly. This change in attitude is the result of the integrated activities as regards protection or conservation of our environment. We are now well aware of the dualism pointed out by Holy and Riha (1973):

'the input (impulse) into the material system of human living environment is represented by the harmful or useful effects of the economic activity of man; these effects caused to the system are in close functional relation to the output (reaction of this system).

From the point of view of the evaluation of the resulting phenomena in the system of the living environment, there are two main approaches. The first advocates the criteria of maximum economic profitability and the second advocates the criteria of ecology. Criteria of maximum economic profitability is based on the limit values of the exploitation of natural resources, including water. The index of this criteria is economic profit which starts decreasing as soon as the maximum has been attained'.

4.5 ENVIRONMENTAL IMPACT ASSESSMENT

At this point, it is important to shift attention from a broad description of the urban ecosystem and its characteristics to the related question of assessing and evaluating effects resulting from changes with or without any particular intervention. To guide our thinking the sequence of argument as outlined in 4.5 is shown diagrammatically in Figure 4.7.

38

Environmental impact assessment

Stress/intervention/change

(analysis) (Chapter 1.3)

assessment (Chapter 4)

(evaluation) (Chapter 5)

process of assessment

I central concern : methodological attempts for measuring impacts and consequences

I purpose of environmental impact assessment :

generate a 'dynamic' model

1 applicability of environmental impact assessment Figure 4.7. Sequence of argument in section 4.5

4.5.1 Urban stresses and the environment

Environmental impact assessment, diagrammatically expressed in Figure 4.8, generally involves a contrast between present ambient conditions and probable, or desirable, future states and the range of effects and alternatives resulting from implementation of a particular action. In other words, environmental impact assessment can be broadly understood to be an appraisal of short- and long-range consequences of technological change on all surrounding environments.

range of effects

/

/ Future states

\

\

/

analysis -I L

assessment J L

evaluation

Figure 4.8. Diagrammatic expression of environmental impact assessment

In this respect, three different elements bring together the argument throughout this work:

1. Chapters 1-3 (and part of Chapter 4) attempted to provide a basic understanding of the dimensions of the problem {analysis);

39

Environmental impact assessment

2. The present section concentrates on the meaning and significance of the process of assessment; and

3. Following sections will elaborate the process of evaluation, or the passing of judgement and decision-making.

The coming of a new technology, a development, or change affects the complex urban system over a period of time by setting into motion a variety of cause-effect-cause chains and by triggering an interrelated, interacting system of impacts and consequences which through feedback mechanisms may permit among others:

1. The creation of new economic and environmental conditions

2. The demand for new or different services

3. The establishment of required institutional responses to the changing circumstances

4. Changes in the overall quality of life on a given community and in corresponding attitudes and values

5. The generation of a 'multiplier effect, facilitating further growth, expansion and the creation of a new set of socio-economic and environmental conditions.

There are several obstacles to the selection of a list of indicators. Since urban processes may be regarded in the light of the concept of an ecosystem, a study of social and economic changes apparently cannot be undertaken without due consideration of interferences with, for instance, the physical environment. So we have to take into consideration inter­actions in a more widely perceived environment. This is already in practice in those studies that are called 'environmental impact assessment'. Such an approach may, in some way, be regarded as a variant of what is called 'consequence analysis'. This kind of analysis may, in some respect, be regarded as a fourth step in a model development that consists of an input, a throughput and an output. The consequence analysis aims at examining the consequences of the output due to existing constraints of different natures etc. It may be noted that the idea of consequence analysis originally stems from man's experiences from adverse effects due to his environmental activities.

With this approach in mind it would be appropriate to make some definitions. We may state that man's actions cause environmental effects which produce environmental impacts. In such a line of thought, man's actions will encompass legislative proposals, policies, programmes, projects and operational procedures in a manner that has already been commented on. An environmental effect is generally defined as a process that will put in motion, or will be accelerated, by man's actions. Such an effect could for instance be the erosion of soil, the dispersion of pollutant, or the displacement of persons; all due to urban activities. By the environmental impact could be meant the net changes which may be regarded as good or bad for man's health and well-being. With the above text in mind, it is important to include the well-being of the ecosystem on which man's survival depends (Munn, 1975). Those net changes are the expected results from an environmental effect and they are related to changes in the quality of the environment, if we regard it as unaffected by man or under the influence of man's activity.

An environmental impact assessment should include four items relating to general environmental effects, namely:

1. Determination of the initial reference state (ambient conditions)

2. An estimate of the future state 'without action'

3. An estimate of the future state 'with action'

4. Criteria for assessment and evaluation.

40

Environmental impact assessment

Since one of the most important goals of this report on socio-economic aspects of urban hydrology is to pay special attention to the impacts of water-related urban activities on the (physical) environment, it is important to elucidate how to look upon the quality of the environment. One way of approaching this quality problem would be to formulate the conditions for making this quality of the environment as large as possible. This could be expressed by stating that the objection function could be of the following type:

d (QOE) = I a. dG. - I a dB •+ max (4.4) . 1 1 s s i s

In this expression QOE represents an index of environmental quality which may be composed of the difference of weighted positive (good) and negative (bad) components represented by dGj_ (i = 1, ... 1) and dBs (s = 1, . . . S) respectively. The parameters a^ and as are relative weight coefficients. The bad components are those which are of special concern in this case. They are connected to human action as well as to the biosphere by a set of S balance equations of the following type (Unesco, 1973).

dB = E - P + H - R (4.5) s s s s s

where

E = amount of 'bad' s emitted s

P = amount destroyed by human action

H = amount created by biosphere

R = amount destroyed by biosphere It is now possible to relate the variables included in equation 4.5 to two other social, economic and ecological variables by a relationship of the following kind, say

E = Z e . G. s si i

i where

e . = amount of bad s produced when one unit of good i is produced

We may also form a set of equations which take account of the cleaning activities Pm

(m = 1, ... M) responsible for destroying at least part of the negation impulses of economic actions P . This relationship may be expressed in the following way:

P = I c P (4.6) s sm m

m The coefficients c s m as well as the relationship shown in equation 4.6 may be implemented from engineering information. Research results could be introduced into the model presented by the variables Hs and Rs, by linking the net influence of the environment to a function of certain natural features W k (k = 1, ..., K) of the biosphere. This gives the relationship

(4.7) H •

s - R = E d , W

s sk k K

where d are some 'weight' factors.

Besides these relationships we may postulate some critferion of environmental quality standards. This criterion could then limit the amount of good activities and maximize the amount of bad activities. Those conditions could be expressed as

dG. £ Q. (4.8a)

dBs £ Q (4.8b)

In addition we need to consider the physical resources available, a condition which could be expressed as

41

Environmental impact assessment

Z b P + Z b . d G . < M (4.9) rm m ri i v r

m i where

M = amount of resources available during the period under consideration

b = relative amounts of the resource necessary for activities m at the unit level

b . = relative amounts of the resource necessary for activities i ri

at the unit level

The crucial point in the above analysis is of course the fact that effects of water activities alone may be very difficult to separate from secondary effects (chain reactions).

4.5.2 Purpose of environmental impact assessment

While environmental impact assessment has become a formalized procedure in only a few countries, the basic principles are useful as a methodological approach to a systematic analysis of the consequences of technological change.

The purpose of an environmental impact assessment must be clarified as far as possible. Short time as well as long time consequences should be thoroughly contemplated. As a starting point it could be asked if the greatest long-term benefits of well-being are possible only if the natural environment is maintained in a condition as close as possible to that existent before the world population explosion and industrial revolution.

However, not all interventions in the environment are necessarily adverse or have negative spillovers. A number of actions must be taken to guarantee survival and common welfare. Also, our appreciation of effects is limited by our present state of knowledge.

As Munn (1975) and others explain in the context of the requirements provided by the National Environmental Protection Act of 1970 in the USA, an environmental impact assessment should contain:

1. A description of proposed actions together with alternatives. These alternatives may include one to the effect that no action at all will be undertaken;

2. Predict the nature and magnitude of the environmental effects;

3. Identify the relevant human concerns;

4. List the impact indicators to be used. For each of these we have to define its magnitude and for the total set we have to define the weights to be assigned to each indicators as obtained from the de ci s i on-maker or national goals;

5. From the predicted values of the environmental effects deduced above under (2), determine the values of each of the impact indicators and moreover the total environmental impact;

6. Then it is necessary to make recommendations for one of the following:

(a) acceptance of the project (b) remedial action (c) acceptance of one or more alternatives (d) rejection

7. Finally, recommendations should be made for inspection procedures to be followed after the action has been completed.

42

Environmental impact assessment

It may be advisable to have a general model of the process by which plans lead to socio­economic impacts. This model should be considered in order to take into account the complexity of a series of otherwise unforeseen interactions which may occur before the ultimate implementation of a plan.

A simple example may suffice to show how chain reactions, or cause-effect-cause chains, make a system dynamic (Fitzsimmons, Stuart and Wolff, 1975):

1. The project alters water availability.

2. New economic and environmental conditions are developed.

3. Change in economic opportunities affects existing population groups differently and attracts new residents.

4. New residents bring new values which may conflict with those of the existing population.

5. New people demand more and perhaps different services.

6. Institutions must respond in new ways.

7. Changes occur in the quality of life and in community and values.

8. Changed conditions, in turn, may attract new outside investments, and so forth.

Moreover, the so-called 'dynamic systems model1 which is of great use in impact assessment studies may have the following properties:

1. Such a model allows for consideration of various influences acting upon a system. Plans for alternative water development projects are examples.

2. This approach also allows one to consider other sources of influence upon the system (exogenous variables), such as changes in the resources and values of the larger society, which may interact with the implementation of the plan.

3. The approach allows one to form ideas about the system - its communities and residents - in terms of a complex of present-day characteristics. This implies that, in part, the effects of a plan are contingent upon the nature of the community being affected.

4. Changes taking place in the system are viewed in terms of distribution over space, over time, among many groups, and of being valued differently by different people.

5. Changes are viewed as both a direct and an indirect result of the implementation of the plan. This occurs as a result of interactions set into motion among persons, groups, organizations, and new demands placed upon institutions. These are complex and involve many cause-effect-cause chains over time.

6. Changes which occur will, in fact, encompass a variety of beneficial and adverse effects, and the ultimate recommendation of a given plan will involve judgements about the value of a variety of trade-offs of good and bad effects.

4.5.3 Applicability of environmental impact assessment

As stated above, the purpose of environmental impact assessment is to appraise the effects of technological action on the surrounding environments as part of integrated, long-range planning.

43

Environmental impact assessment

In its broadest terms, assessment becomes a procedure for analysing and predicting effects of purposive action and, thereby, forestalling, or reversing, adverse consequences to which a particular project may give rise.

The final task of environmental impact assessment must include someone's evaluation of perceived effects and, thus, provide the basis for informed decision-making. This point of evaluation is discussed in the next chapter. We conclude here, with some general remarks as to the potential applicability and ultimate utility of environmental impact assessment. It can help the decision-maker to:

1. Examine community changes through comparisons of alternative versions of a project;

2. Consider various impacts in terms of benefits and liabilities for different community groups;

3. Provide a means for organizing, comparing and delineating lots of criteria in a variety of urban hydrological situations;

4. Establish a basis for examining the relationship between short-term impacts and long-range consequences;

5. Balance the results of environmental considerations against technical, economic and social costs and benefits;

6. Integrate technological considerations and physical solutions with non-structural alternatives in social sciences;

7. Create a background for informed decision-making compatible with the aspirations of the people.

In essence, such selective considerations reinforce a general approach that attempts to provide an objective framework for analysing urban processes so that the underlying logic and process can be followed by all parties concerned.

The process of environmental impact assessment is currently evolving rapidly. Currently, a number of basic works exist on the general topic, with special emphasis on conceptual premises and methodological strategies. A selected list of studies and commentaries is given in Appendix 2. It should be noted that in the field ofvurban hydrology little work has been published, although a number of publications on impact of water projects are useful for their approach to the subject.

44

5. Socio-economic considerations in urban water project evaluation

5.1 THE NEED FOR SOCIO-ECONOMIC EVALUATION

The planning and design of urban water projects are frequently determined by budgets rather than by considerations of optimal design (Green, King and Bowden, 1975). Expenditure on water supply, sewerage, sewage treatment, etc. is fixed by a higher authoritative body, and the engineer proceeds withintheprescribed limits. Such a scheme has the advantage of simplicity, and it may well be asked whether or not socio-economic evaluation should be allowed to disturb this well-established pattern.

Three factors of increasing importance, probably in all countries of the world, indicate the demand for socio-economic evaluation: (a) the scarcity of resources, (b) the increasing size of urban areas and urban investment, and (c) the accountability of urban designers and managers to those both above and below them in the responsibility chain.

Scarcity of resources here refers not to water resources as such, which will be considered subsequently, but to resources for investment, both material and human. Nearly all communities find that they cannot achieve all they would like, due to insufficient resources of finance, material or human skill. The optimal allocation of scarce resources is the traditional ground for economic appraisal and comparison of potential projects.

As already discussed in section 2.1, an increasing proportion of the world's population lives in urban areas. Investment in urban water projects is consequently affecting an increasing number of people, and the investment itself is accounting for very large sums. Efficient use of these sums is clearly desirable, and the emergence of common urban problems throughout the world gives some hope that broadly similar methods of solution, adjusted as necessary to local social, economic and political conditions, will be found.

The resource crisis has in many places created a sense of concern in the use and development of water. The urban manager is responsible to the general public, or to his higher officers, or to both, and looks for objective methods of clarifying his choices.

The emergence of evaluation procedures may also be traced through three phases, which may be described as financial, economic and socio-economic. The first deals only with monetary units, and may also be called budgeting or accounting. The second takes account of wider issues, but attempts to reduce them to the common base of monetary units. The problems of the value of intangibles has been generally recognised, but decision-making has frequently been based on those factors for which values have been estimated. Socio-economic evaluation, the third phase, extends this technique further into the intangible area, to the extent that social non-monetary evaluation may dominate the decision-making process.

The complex interactions of a systematized urban water system are shown in Figure 5.1 in which the symbols of Forrester (1971) have been used. The figure gives some indication of the number of evaluations which are required in a typical system. The independent inputs include the quantity and quality of the water source, storm runoff, the population and the available capital. Within these constraints the system performance is determined by a set of values indicated by the'valves'in Figure 5.1. These values are dependent on the resources demanded, and could be derived from the price-demand relationship.

Four water uses are indicated: agricultural, municipal, industrial and a residual category which includes intangible and ecological purposes. As mentioned earlier the water used in an urban area is often brought from remote districts and this may lead to competition between agricultural and urban water use. A similar competition between urban water users is illustrated in Figure 5.1.

The remainder of this chapter will review the possibilities for socio-economic evaluation of various types of urban water project. Most attention will be given to water supply (section 5.2) which is of fundamental world-wide importance and concerning which most socio-economic data are available. However, similar investigations are possible for other types of urban water project, as discussed more briefly in sections 5.3 to 5.5.

5.2 WATER SUPPLY

The progress of technology has made it possible to supply urban regions with sufficient

45

WATER QIíaT.TTV

WATER SOURCE

r

i

— — PRICE L

LvOLUME^J

^^^^

í — AGRICULTURAL

USE

REMAINING QUANTITY OF WATER NECESSARY FOR OTHER SOCIAL, ECONOMICAL AND ECOLOGICAL REASONS

Figure 5.1 Urban water use system

Water supply

amounts of water, even if it has to be transferred over long distances. Moreover, today refined methods of treating water are used so that water which could not be used in the past because of low quality can now be used. Technological progress is also partly responsible for the increased water demand of modern society. Immigration to urban areas may necessitate a more rapid development of the water distribution system than is permitted by the supply available.

In this situation, water costs will increase and water management planning will have to consider a range of factors - social, political, environmental and hydrologlcal. This may in some instances, result in a decision to stop further suburbanisation.

The negative effects of the scattering of new human settlements in a country have to be pointed out because countries not yet at this stage can learn from the past mistakes in urban planning of other countries.

Urban growth has already been briefly discussed in an earlier chapter. The increase in urban population taken in conjunction with an increase in the amount of water used per capita has not only caused problems for water authorities but also brought about a competitive situation in the demand of water from rural areas. Hall (1974) questions if all the social and economic costs are greater or less than the cost of providing more water in lieu of reallocation. Moreover, are the marginal uses of water in the urban environment really higher in value for the national goals than their use in agriculture? What is the relationship between the amounts of water used in urban and agricultural sectors? How much urban water use is equivalent to the use of a given volume of water on the farm? Current decisions on water allocation could be reversed by the answers to questions such as these.

Water for urban use is obtained principally from surface sources such as lakes or rivers and from groundwater sources such as springs or wells. An urban region is usually supplied from one or more water-works operated by a water authority. However, industries with a great demand for water very often draw upon their own water sources and they try to locate the plants where water is easily available.

Some of the socio-economic aspects that could be considered in the use of different kinds of water sources are that groundwater is generally of better quality than surface water and that the risk of disturbance in a water supply system based on groundwater sources is probably smaller than for one using surface water. For instance, pollution of surface water may rapidly reduce the quality of water, whereas groundwater reservoirs are not always so vulnerable. On the other hand, the effects of groundwater pollution may be much worse than that of surface water; the pollution of groundwater may not be known before long periods of time elapse between cause and effect, and the process of purification may be similarly prolonged.

It is important to remember the possibility of combined use of surface and groundwater. Such an integrated use assumes an allocation process based on concise planning of activities (Kuiper, 1971). Such planning necessitates proper knowledge of hydrological processes.

Another possible source of water for urban regions is desalinated water which is already being used, especially in North Africa and the Middle East. However, the desalting costs have been significantly increased in recent years (to more than US$1 per m3) as the cost of energy has increased. The use of conventional sources will for a long time remain less costly. It is only when the demand exceeds the possible supply from optimally allocated conventional sources and when this water is used in the most efficient way that the use of unconventional (desalted) waters will be economically justified (de Marl, 1976). Also, known laws of physics seem to limit the possibility of a major break-through in costs (Koelzer and Bigler (1975)). All desalting techniques use large amounts of energy. With the exception of solar processes (which are not highly promising for installations of appreciable size), this energy must be supplied by steam or generating plants. Even with an efficient energy system, the absolute minimum amount of energy needed, to perform the work of separation of water molecules from the ions in the saline water in order to convert saline water to fresh water, remains high.

Several other aspects of the possible use of desalinated sea water should be considered. Nikitopoulos (1962) discussed the costs of transporting water from the coast, but because of the cost, he considered desalination would probably be unrealistic at long distances from the coast and only possible in areas where no conventional water resources are available. Therefore urban areas at the centre of continents are not likely to be supplied by desalinated sea water. Notable here is the Sahel area in Northern Africa. Another aspect is the environmental effect caused by the disposal problem. According to Koelzer and Bigler (1975)

47

Water supply

the volume of effluent from a 10 mgd plant will contain about 2O0O tons of salt residue daily. This amount is not unrealistic as the largest plant in operation in 1971 had a capacity of 7.65 mgd.

A further problem is that an urban area solving its water demand problem by desalination will remain dependent on the continuous operation of such a desalination plant. An interruption caused by technical breakdown, or for other reasons, may give rise to catastrophic consequences for the urban area.

According to present water-demand tendencies, water distribution systems will probably call for an increased investment per capita for the following reasons (Grima, 1973):

1. higher per capita consumption

2. the need to develop less accessible sources of supply

3. urban sprawl (for instance longer distribution conduits, larger lawns etc)

4. peak demand increases more rapid than average demand. In addition to these reasons for increased investment per capita it should be noted

that an augmented use of water in urban districts causes water treatment costs to rise. Water supply problems in industrialized countries may considerably affect the nation's

economy. In developing countries, especially in arid parts of the world, the provision of a safe supply of fresh water could have an enormous impact on social and economic development. But according to Feachem (1975), for the great majority of the world's population who live in rural communities, or low-income urban slums, with grossly inadequate access to safe water, there is no possibility that available financial and human resources will provide them with the high level of water provision to which the people of many developed countries have been accustomed. Because there is no immediate prospect of providing a significant proportion of low-income communities with high-grade water facilities, it is necessary to examine closely the goals of water supply in order that scarce resources may be allocated as efficiently and rationally as possible.

Feachem (1975) , also makes the important remark that during the last two decades, many studies concerning water supply schemes for developing countries have been carried out and that nearly all of these have indicated that water supply may be a necessary condition, but is never a sufficient condition, for development. Thus, water-supply development must be accompanied by a carefully designed package of complementary inputs if it is to achieve the goals stated.

In the planning and development of water distribution systems, complex processes are involved. Sometimes these may be well-handled by modelling. For instance, some kind of system dynamics may be used as in studies of the behaviour of complex social and physical systems. Grigg and Bryson (1975) have recently used simulation methods in a study of the Fort Collins system. The general programme proceeds according to the following steps:

1. Definition of goals (level of water service need in quantity, quality and location)

2. Collection of data (existing systems, population projections etc)

3. Study and formulation of the alternatives, eg

(a) alternative of objective (b) engineering alternatives (c) management alternatives (d) institutional alternatives (e) times and scale alternatives (f) location alternatives

4. Evaluation of alternatives

5. Selection of a plan

48

Water supply

An example concerned with a developing economy is the model of the need for water-supply development in Puerto Rico discussed by Attanasi (1975). His model is especially interesting as it relates development and industrial patterns to water-resource investments. This relationship is shown mathematically by regression analysis. Attanasi found a significant relationship, over the nine year period considered, between changes in the income distribution and the pattern of water resources development.

In such a planning process, several different models may be used, eg, models for population growth and models for water use. Such models are, as a rule, adapted to a specific situation that exists in a particular region or nation.

The planning of a water-supply system necessitates that some essential basic data are properly known. First of all the available water resources have to be known, a knowledge that is acquired by thorough hydrological analysis. Secondly, a cost-supply relationship and the price-dependent water-demand should be determined.

McPherson (1976a) has suggested that these relationships are not clear:

'Investigations of relationships between price and demand, and metering and demand, have been handicapped by the limited amount of representative detailed demand data available in a usable form. For example, it is still not clear to what extent metering constrains demand in response to price.'

5.2.1 Problems of water allocation

The allocation of water resources may cause problems because the water can no longer be regarded as a free commodity. According to Goddard (1975) continued population and economic growth have caused the resources that once were free, or at least relatively so, to become scarcer and, consequently, more valuable. Thus, in allocating water for urban use the manager is faced with a situation of competition between different uses.

The problems and solutions of an efficient or optimal allocation of scarce resources should be analysed on the basis of economic efficiency and its associated concepts, such as opportunity costs, net benefits, externality analysis and consumer sovereignty, which are fundamental to valid analysis as long as economic efficiency is a social goal with respect to resource utilization (Goddard, 1971). Most economists advocate that the economic efficiency concept should be used in analysing allocation problems see, for example, Mishan (1972) and Baumol (1972), who also state that the net benefit concept should be the measure of performance.

The cost of water as well as its value play an important role among the social factors. The cost of water may be defined as the cost per unit volume to make it available at a given flow, at a given time, and a given place. Likewise, the value of water can be defined as the maximum price per unit volume which we would be willing and able to pay, to obtain a given flow, at a given time, and at a given place; or the minimum price per unit volume which we would be willing to accept if someone proposed to take away from us a given flow, at a given time at a given place. It follows from this definition that if we quote a value of water we must also state precisely the circumstances under which this quotation is made. (Kuiper, 1971).

Accordingly what should be determined and firially maximized is the net benefit or revenue less costs, in providing water to the users. The appropriate cost concept is the opportunity cost which, in most cases, is the same as, or approximately the same as, the production cost. More problematic is the revenue concept, the definition and measurement of which is the main theme of this report. This is so because the revenues cannot be measured solely in monetary terms. Social factors are very important and these can be both positive and negative.

5.2.2 Water demand and water use

The costs of water-distribution systems are comparatively easy to determine if the quantity to be withdrawn is known. Difficulties arise in the prediction of the water demand. In the industrialized countries demand is, to a limited extent, governed by the price. The industrial demand, however, is more dependent on processing technologies. Technological break-throughs cause considerable changes in the withdrawal demands and also in the actual water use.

49

Water supply

The water demand of urban areas may be divided into three types, industrial, municipal and agricultural. Municipal demand may be subdivided into four types showing different price-demand relationships (see Figure 5.2):

1. residential demand 2. public demand

3. industrial demand (industries connected to the municipal distribution system)

4. leakage

TOTAL WATER DEMAND

_

AGRICULTURAL DEMAND

MUNICIPAL DEMAND

RESIDENTIAL DEMAND

PUBLIC DEMAND

T T

INDUSTRIAL DEMAND

LEAKAGE

INDUSTRIAL DEMAND

Figure 5.2 Schematic view of urban water demand

This subdivision is based on that of Berry and Bonem (1974). In a study for New Mexico they found that the per capita municipal water use was linearly related to the per capita income. Price, temperature, etc. had no significant influence on the water use. This result is not in conformity with the results obtained by Howe and Linaweaver (1967) . The main reason for this is that the Howe and Linaweaver study was concerned only with residential water use whereas the Berry and Bonem study considered municipal water use as a whole.

5.2.3 Residential water demand and use

Residential water demand and use refer to water used for various activities mainly in dwelling houses. The residential water use in developing countries is much less than that in industrialized countries. Dieterich and Henderson (1963) found in a WHO study of problems in 75 developing countries that only one-third of the urban population and less than one-tenth of the total population were supplied with piped water in or near their homes.

A study financed by the US Agency for International Development, in 1967, in a large provincial area of a developing country with about 6.8 million urban population showed similar results:

1. About 35 percent of the urban population had some form of municipal water service: 23 percent of these were provided with private connections, although inadequate (not sufficiently treated, low pressure, marginal storage, etc.) and 12 percent were served by public taps. The remaining 65 percent derived their water from waterways, irrigation canals and private wells. None of the population received an adequate service, of continuous supply, properly treated and disinfected.

Only 7 percent were directly connected to sewers. 65 percent were served

50

Water supply

by open drains, and 23 percent had no known sewerage service.

The studies mentioned show that in developing countries the residential water supply is far from adequate, suggesting that an improved supply (quantitatively as well as qualitatively) would undoubtedly bring about important social and economic progress.

In industrialized countries there is generally enough water of the present standard to provide for the present demand. Thus how much is needed seems to depend on existing or desirable standards and the stage of economic development. In a study recently made in Sweden, VAV (1975) calls attention to the fact that residential need most probably will be unchanged. The reason for this is that water closets requiring less water will be installed. Moreover, individual metering will be introduced in residential areas. The study also shows domestic water use in various countries. According to the authors, the differences between various countries are explained by differences in living standards, climate and general availability of water. The need for watering of lawns, for example, may vary much from region to region.

For the prediction of residential water needs, several models have been developed. The method applied to most of the earlier urban water studies has been ordinary least squares multiple regression analysis usually with the quantity consumed being a function of price, income and environmental determinants such as temperature and precipitation (Schelhorse et al. 1974). Primeaux and Hollman (1973) in a study of North Mississippi Municipalities obtained their best results by using eleven determinants:

xl = number of persons per residence x2 = number of bathrooms per residence x3 = number of dishwashers per residence x4 = number of clotheswashers per residence x5 = existence of a swimming pool x6 = irrigable lawn space of residence x7 = market value of residence x8 = average maximum temperature x9 = annual precipitation xlO = education index xll = price of water at mean level of consumption

The study revealed that the price of water was least significant compared with the results of other studies. One explanation of this is that individual household data were used in this study. In using average household data for the community all variation is obscured. The most significant determinant seemed to be the number of persons per residence which means that an adequate forecast of the population growth will bring about a good estimate of the future residential demand. However, none of the remaining determinants could be excluded without reducing the fit.

Other studies have shown approximately the same results, ie, the number of persons per household and household income (or sales value of residence) being the most significant determinants, see for example Darr et al. (1975) and Schelhorse et al. (1974).

5.2.4 Public water demand and use

The public demand for water in an urban area is dependent on the structure of the area. This is due to the fact that the public demand may come from schools, hospitals, shops, restaurants, offices, parks, street cleaning, etc. Since large cities contain more official administration buildings, schools etc. than small cities, it may be expected that the public demand per person will rise with increasing size of the city.

According to Schelhorse et al. (1974), the public water demand should depend primarily on the level of expected services which in its turn is a function of per capita income. Other determinants would include the proportion of the city area devoted to public parks, and climatic factors such as temperature and precipitation. Unfortunately, however, few attempts have been made to examine statistically this water-use responsiveness.

51

Water supply

5.2.5 Industrial water demand

Contrary to the residential and public water demand, which is a direct demand reflecting individual or governmental needs and desires, the industrial demand is a derived demand. Water is used as input to the production processes. Hence, the demand for water relies on an analysis of the water-using processes and on the demand for the products. (Schelhorse et al. , 1974) .

The authors mention five factors that should be considered in a water-use analysis of industries connected to the municipal supply:

Input side: 1. Existing state of technology, Output side: 2. Per capita income of the city,

3. The extent to which the city provides services to other than its own population,

4. Market access, 5. The general level of economic activity.

Kellar and Brewer (1975) give the following classification of industrial water use in the USA:

Percent Process water 28.3 Air conditioning 3.2 Steam, electrical, cooling 12.1 Other cooling and condensing 51.6 Boiler feedwater, sanitary and other 4.8

In conditions of water shortage, industries have tried to overcome this difficulty by recycling and making changes in processing techniques. As an example, Kollar and Brewer (1975) mention that in the water-abundant Great Lakes Region of America, the water intake per ton of steel may be 50,000 gallons (US) or more, while in the water-short regions of the West, the requirement is as small as 2,500 gallons (US) per ton of steel.

Schelhorse et al. (1974) mention that the statistics for California, for 1957-1959, indicate that water was on average recycled 1.08 times. The values ranged from 0.01 times for printing, publishing and allied industries to 5.61 times for rubber and plastic products. This shows evidence that manufacturers have found it economical to recycle water in the production process.

As the price of water increases, the economic incentive to recycle water, or to reclaim waste water, increases as well. The price at which recycling becomes economical, shows considerable variations among industries, but the re-cycling rate may be influenced by the following factors:

1. Availability and cost of water delivered to the plant

2. Raw-water quality characteristics, favourable or unfavourable

3. Plant processes and plant technology

4. Recovery of materials, products, by-products and energy

5. Consumptive losses

6. Air- and water-pollution-control regulations

7. Cost avoidance

8. Age of plant and plant technology.

52

Waste water

5.2.6 Water consumption and its implication for planning

Many authors stress that water is 'our most valuable resource'. This is because water is necessary for life and because it is a necessary ingredient for reaching so many goals. It is equally true that man does not act as though water had a value 'equal to life itself. The reason for this may be that water exists in excess of the amount needed to sustain life. In many parts of the world, water has no price in the market which means that water is a free commodity. However, it may be posible to estimate economic values even if no real market prices exist.

Water users show considerably willingness to pay for small amounts of water for some selected uses (for example, household supplies for drinking and cooking). But willingness to pay for additional water declines when the most essential uses are satisfied. If the quantity of water available is large enough, willingness to pay, and value, may decline to zero, or even become negative. Beyond some quantity, extra water has no value. (US National Water Commission, 1973).

White, Bradley and White (1972) have approached the costs and value of water from another direction. They have studied the domestic water use in West Africa. They discuss, among other things, the volume of water use and health benefits. They ask what improvement in health will result if the pollution of a source is halved, or the quality of water per person is doubled. 'We can be confident that increasing supply by half a liter for those consuming 3 liters a day will have some effects, and we can also be sure that allowing another 100 liters of bath water for the rich man who already wallows in ICO liters will change health but little. There is a sector - we would guess somewhere in the 20 to 30 liters per person range - where health benefits of increasing water begin to level out. It is essential to find more precisely where this point lies, since it greatly affects social costing of water, and this can best be determined by field studies of the effects of varying levels of water improvement. It is remarkable that such studies have not yet been carried out.'

There have been some recent studies about the water consumption per capita, country of origin and number of persons per dwelling, see for instance Darr, Feldman and Kaman (1975). This study deals essentially with the situation in cities in Israel, but some comparison with cities in Asia - Africa and Europe - America is also made. They found that, in the group with low incomes and small families, households of Asian-African extraction and those from Europe -America show little difference in per capita consumption. However, Israeli-born families in the same category use substantially less. Among families of this size (one - three persons) in the higher-income category, little difference in consumption exists between those born in Israel and those of Asian-Africa extraction, but those from Europe-America consume more.

What do these examples and figures teach us? Firstly, that water, which is scarce in many parts of the world, is affected by a price-mechanism. Secondly, as stated by Lee (1969) 'variations in the level of water consumption is not just a random process and it can be shown that different classes of consumers place consistently differing demands on the water supply system'. Thirdly, further exploration of existing water-consumption patterns will be of great importance for water management planning. 'If a relationship between water demand and socio-economic differences could be established, it would greatly simplify the planning of supply systems in developing countries. The provision of water supply would be tied to other elements in the development process.' (Lee, 1969).

In this respect, the need for sufficient hydrological data has to be underlined. These are necessary for the balance of water resources and needs, as well as for the planning and implementation of measures to avoid negative consequences for the population and the regional economy. Such measures are now being used as an effective tool in many EEC countries (Probedimsky, 1973; Bassler, 1975).

5.3 WASTE WATER

5.3.1 Waste water sewerage

The main benefits from sewerage schemes, such as the alleviation of health hazards, reduced inconvenience and improved aesthetic conditions, are mostly intangible. Fundamentally, it is the service itself that is desirable. This service does have a value, but the value cannot be determined by using the traditional benefit-cost analysis and is usually set arbitrarily by, or on behalf of, the community in the form of normative criteria.

53

Surface water runoff

Waste water in sewers consists of water which has been supplied and passed through a polluting process. Thus, where a cost-recovery basis is adopted for financing the works, the pricing structure for a sewer service often imitates that for water service. On the other hand, in many countries sewer services are not separately levied. Moreover, the number of water users without access to public sewer systems is very large in certain urban regions. In order to reduce potential health hazards, it is necessary that the provision, or extension, of sewer services to high density-low income urban areas should have a substantially high social priority.

There is a two-directional linkage between urban fringe growth and availability of sewers. For example, in some North American cities, wastewater sewers (and water mains) are not approved for construction when they do not satisfy growth policy. On the other hand, availability of such services is recognised as a stimulus to growth.

5.3.2 Waste water treatment

Treatment plants are the interface between the urban infrastructure (sewers in this case) and the river basin. The purpose of treatment plants is to avoid some prescribed level of pollution in receiving waters. The benefits to be derived from the installation of sewage-treatment plants are both tangible and intangible. The tangible economic benefits arise from the prevention of degradation of the receiving water-body quality so as not to affect adversely its subsequent economic use in the development of water supplies, tourism and commercial fishing. The intangible benefits are primarily improved aesthetics and maintenance of ecosystem balances. Thus, the removal capacities, or efficiencies, of treatment plants are closely associated, in a socio-economic sense, with river basin goals and objectives.

The degree of treatment being accorded to wastewater varies from zero at many places to almost potable levels in a few instances. The cost of wastewater treatment is usually high, especially if the plant has also to treat industrial wastes. It would be desirable to make industries treat certain of their wastes to prescribed levels of pollution before discharging them into the city sewers or receiving water bodies.

Eventually, all urban sewage will require some degree of treatment if for no other reason than the protection of public health. There are economic issues involved in the use of a few large plants versus a larger number of smaller plants. For example, economies of scale for consolidated plants may be offset by costs of more elaborate centralised sewers. The locating, or siting, of plants is almost always a social issue and is often an economic issue.

5.4 SURFACE WATER RUNOFF

5.4.1 Introduction

The total water inflow to an urban area may consist of river flows, water withdrawn from an external source and used for different purposes in the urban society and the precipitation which falls on the watershed. Some of this precipitation is taken advantage of in urban areas such as for watering lawns and cleaning roofs and streets, and for domestic uses, thus reducing the withdrawal needs. But more often this water is disadvantageous and measures have to be taken to reduce these disadvantages to attain certain social goals. The measures may be defined as urban drainage and flood control projects.

Urbanisation is a gradual process and somewhere in this process the drainage and floods create problems. A description by Vlachos and Flack (1974) is a setting for the subsequent discussions:

'Traditionally the rural or low-density suburban area outside the city initially develops its water supply and sewage disposal facilities on a private house-by-house basis. As the area becomes more developed and density increases, small water systems emerge. Finally, as the urban constellation emerges and population increases rapidly the limited water, sewer, and disposal systems prove inadequate and communities are forced to consider much larger permanent facilities. It is with this last stage that water management becomes a crucial element in bringing together planning and construction on a larger scale.

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Surface water runoff

On top of this, another problem is that urbanizing areas tend to develop in flood plains.'

Urbanisation thus creates a demand for all types of services, some of which are viewed as infrastructures, which should be provided by the public sector. Urban drainage and flood control projects provide a service to urban areas in three ways:

1. Flood control

2. Convenience drainage

3. Environmental sanitation

As pointed out by Jones (1967) the urban drainage system has two subsystems: a major one which accommodates the rarer more severe events, and a minor one which provides for the drainage of frequent runoff events.

5.4.2 Flood protection

The need for flood protection measures has been apparent for a long time as flood damages occur when man makes use of lands liable to inundation. Flood damages, therefore, result from the forces that encourage people to use or locate property on flood plains, (James et al. 1975). The reasons for using flood plains are well described by the same authors:

'Historically, development on the flood plains along major rivers has held locational advantages for many types of industry and commerce, and the constraints of low incomes and slow transportation have caused people to live near their jobs. Agriculturalists were attracted to the soils made fertile by flood-deposited sediments and have in turn attracted agriculturally-oriented cities. A more important factor in attracting urban developing to the flood plain, however, has been the use of rivers for transportation and power and their attractiveness to industry and commerce as sources of water and as depositories for wastes. These factors made industrial and commercial development least expensive near rivers, job opportunities migrated toward river-front cities, and residential development followed on nearby flood plains.

Today technological advance has reduced the dependence of industry on rivers. The commercially important water wheel has long since gone. Few industries rely heavily on waterborne commerce. Water can be brought from great distances, and wastes can no longer be freely dumped into rivers and forgotten. Nevertheless, these historical factors have led to large sections of many older cities being located on flood plains and made flood plain management an important consideration in many urban redevelopment programs.

Technological advance has also made possible unbroken urban development covering hundreds and sometimes thousands of square miles. No matter where such a complex is located in relation to major rivers, local runoff will periodically collect in its internal drainage system and create significant flooding. The only way for a metropolitan area to be free of flood damages is to keep every low-lying area along every stream free from buildings, to create a trellis work of open space throughout the metropolis.

Homesites are one example of an urban land use that may enter a flood plain or any other open space in the urban community. A person seeks some set of site characteristics in selecting a location for

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Surface water runoff

his home. Proximity to employment was the dominant factor in the days of slow transportation, long hours, and low incomes; however, today faster transportation, more leisure time, and higher incomes lead many people to view these economic factors as no more than constraints bounding the general location and characteristics of the home site they select. Selection of a specific lot relates more to the attractiveness a location has in terms of the activities a family enjoys at home, aesthetic values, and opportunities for social relationships with compatible neighbours.

A particular flood-plain resident may or may not be aware of the hazard. Some living groups recognize the hazard at the time they move on to the flood plain. They choose the site because they believe the advantages to exceed the cost and are willing to pay a flood damage bill to achieve something they want. Others enter ignorant of the hazard. After each major flood, some from both groups still see too many advantages in a site to want to leave, but others from both groups re-evaluate the advantages and costs and seek another location.'

Thus, in earlier years, attention was paid mainly to remedial works, ie structural and non-structural measures to reduce the inconveniences of settling in a hazard area. Structural measures included such projects as reservoirs, channelization, and levees, and non-structural measures included flood warning and flood insurance.

In recent years, there has been a shift to preventive activities, the objective of which is to reduce, or minimize, the occurrence of situations requiring remedial works. The tools may be proper land use planning, regulations, information, education, etc.

As pointed out earlier, every flood-control project provides a service for the improve­ment of living conditions in the urban area. As a service it provides for specific needs; in this case, the need for flood damage mitigation and protection. But, urban flood-control projects must compete with other urban projects for funding from the limited public purse. Thus it is important to be able to describe and enunciate all the benefits that these projects provide so that they can compete for funding. (Grigg et al. 1975).

The benefits from a flood control project may be classified according to the following, see also Grigg (1975):

1. Tangible (a) Direct

Reduced flood damage to public and private facilities Reduced probability of loss of life Land value enhancement

2. Intangible (b) Reduced inconvenience

Increased sense of security Improved aesthetic conditions

Methods for evaluating the benefits mentioned are not far advanced. Attention has been focused mainly on the potential reduction in direct flood damages. This is probably due to the visibility of flood damages after severe floods and to the availability of data for quantifying direct benefits. However, according to Grigg et al. (1975), the damages fall into five categories:

1. Direct damages, which affect structures and their contents, public facilities such as roads and utilities, and vehicles. These damages are experienced mostly by flood plain occupants.

2. Indirect damages, which include the value of lost business and services, the cost of alleviating hardship, safeguarding health, re-routing traffic, delays, etc. Indirect damages are usually taken as percentages of the direct damages.

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Surface water runoff

3. Secondary damages, which may occur when the economic loss caused by flooding extends further than the immediate area of flooding. Secondary benefits are now generally considered to be outside the scope of flood-control project evaluation because of their complex nature (or considered offset by secondary costs).

4. Intangible damages, which include the reduction in environmental quality and aesthetic values. It is not at present feasible to estimate the monetary values of intangible damages and the corrresponding benefits, but they should be considered as an important part of the analysis for project selection as many of the social goals, which are served by flood protection measures, fall under this heading.

5. Uncertainty damages, which consist mainly of the hardship suffered by occupants of flood hazard areas because of the ever-present uncertainty of when the next flood will occur and how serious it will be.

According to James, Benke and Ragsdale (1975), the selection of an appropriate combination of measures to deal with a particular urban riverine flooding situation requires :

1. Hydrological information to characterize the hazard.

2. Engineering and economic information to quantify the flood damages and to design and estimate the costs of various remedial measures.

3. Information on the character and severity of the ecological and other environmental consequences.

4. Information on affected public institutions and agencies to assess support for the structural alternatives and receptivity to the non-structural possibilities.

5. Information on how flood plain land use relates to the well-being of nearby residents and to the overall objectives of the community.

It may be worthwhile to consider some of the above points, especially those dealing with socio-economic aspects. A benefit-cost appraisal of major flood prevention proposals may well be beneficial, and techniques have been illustrated by Jones (1971a, 1971b) and Local Government Operational Research Unit (1972, 1973) .

Important information includes community factors such as the recognition of flooding as a community problem, environmental concern within a community, and the community's philosophy of public versus private responsibility. The information needed also includes individual factors such as sympathy for programme goals, willingness to conform to regulation, individuals' philosophy of public versus, private responsibility, and perceived personal benefits and losses.

Basic information about flood-plain land-use is a factor in the total land-use pattern of the community and the well-being of the residents is affected by this land-use pattern.

5.4.3 Storm drainage

The minor urban drainage system can be seen as an environmental management service provided by the community. The main benefits of this service may be classified as follows:

1. Tangible Reduced damage to property Reduction in traffic delays

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Surface water runoff

Reduced costs of cleaning and maintenance

2. Intangible Reduced inconvenience Alleviation of health hazards Improved aesthetic conditions.

According to Grigg (1975), the benefits of minor drainage projects cannot, as a rule, be evaluated by using (traditional) benefit-cost analysis because benefits for minor systems are normally those associated with convenience, aesthetics, etc. For the time being, minor projects must be designed by setting standards and criteria and then finding acceptable minimum cost solutions for meeting the standards. This approach is currently relied on in most environmental fields.

The same conclusion is reached by Green, King and Bowden (1975) who emphasize that a service is provided for the public by the drainage system. Fundamentally, it is the service itself that is desirable. This service does have a value, but the value is set arbitrarily by value judgements made by, or on behalf of, the community. These judgements are defined by prescribed standards and criteria.

Also, according to Grigg et al (1975) one of the difficulties inherent in considering intangible costs and benefits in evaluation of small drainage projects is that the cost of analysis may be excessive.

Green, King and Bowden (1975) suggest that preferences could be expressed for or against storm-sewer services that are better or worse than a defined norm. In the presentation of a drainage plan, various levels of effectiveness could be considered instead of considering only one choice (the norm) and one price.

The objectives and design of urban drainage systems have been challenged in recent years. McPherson (1974) writes:

'Historically, urban settlements have been drained by underground systems of sewers that were intentionally designed to remove storm water as rapidly as possible from occupied areas. Substantial departures from that tradition are required by new national priorities : enhancement of urban environments; conservation of water resources; and reduction in water pollution.

The greatest public concern will increasingly be on the quality of water. This concern is intimately related to acknowledged imperatives of aesthetic enhancement, expansion of recreational opportunities and more extensive availability of waterfronts for public uses. Runoff is a carrier of wastes, either as harvested for water supplies and converted to water-borne sewage or as an urban ground-surface wash. Thus, public health considerations can transcend or temper economic considerations. In addition, comprehensive approaches for managing water pollution problems that require that other water uses, planning, and guiding sound development, also be considered. For example, utilization of the 'blue-green' development concept, which employs ponds with open space, for stormwater detention and recreation, can enhance urban property values and decrease property depreciation rates, thereby increasing long-term local government revenues. On the other hand, peak drainage runoff rates can be reduced by means of proper land-development design. The guiding principle is to reduce the liabilities and increase the assets of urban runoff.'

Thus, to obtain the benefits listed above, and also in order to reduce the costs, there seems to be a need to depart from the traditional approaches. It has been shown that it is possible to use storage reservoirs, both surface ponds and underground reservoirs built into the piped system, to reduce the peak flows and thus obtain a more efficient drainage system, see for example, Rice (1971) and Lager (1974).

An example of the use of ponds in the drainage system is in the new town of Melun-Senart in France. As well as the advantages of smaller peak runoff it is claimed that the ponds

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Other considerations

serve as sanitation sites as the ponds fit into the original ecological system, (Melun-Senart 1974). In Australia, Bonham (1975) has described a drainage system in the suburb of Beagle Bay. The system performs completely without piping. Instead grass zones are established along streets and other impervious areas where the stormwater is dispersed as widely as possible through the grass. Bonham also claims that the grass filtration will remove most of the suspended sediments and also the nutrient enrichment of the storm water. Bonham believes that the use of roads and paved areas at grade with the surrounding grassy lawns is greatly to be preferred to the conventional systems in order to increase the environmental benefits and reduce the system costs of new suburban drainage systems.

According to Field and Lager (1975) storm runoff is a significant source of pollution, 'typically' having large solids concentrations, large BOD concentrations, and bacterial contamination greater than the concentrations considered safe for water contact activities. Further health hazards, such as nutrients, heavy metals, and pesticides, may also be present.

The conclusion of this section is that the evaluation of minor urban drainage systems is laborious and it seems to be impossible to price the benefits of urban drainage projects. Therefore the practice today is to use standards and design the system to this standard at minimum cost. The evaluation problems are then moved to the organization that has to set the standards: the problem of relating the social factors to the service provided still remains.

5.5 OTHER CONSIDERATIONS

Socio-economic evaluation of water supply, sewerage and flood drainage should not neglect some problems which are not apparent at first sight but which concern directly the maintenance of the eco- and bio-systems.

It is important to point out that some of the water-related engineering activities in a growing city can become very harmful and cause problems. Some of the effects may become almost non-reversible. Therefore, it is necessary to keep in mind the possibility that they may create an adverse socio-economic situation.

Excessive and long-term pumping from an aquifer and the simultaneous paving of the ground surface can for instance produce subsidence. In other places, near the coast, there are instances where the lowering of the water table has caused salt water intrusion. The cost of repairing the damage and of recovering a quasi-equilibrium could be immense. Other examples have demonstrated that the urban runoff, or rainfall affected by industrial fumes, are polluting the aquifer. These pollutants are very frequently under-estimated.

It is encouraging that planners and decision makers are now attributing higher values to environmental and aesthetic benefits than were once assumed. This is in line with a statement by McKean and Ericson (1975) that the quality of life, as currently envisaged by many Americans, is related to scenic and recreational opportunities and to the desire to replace the negative externalities of urban living with a more secluded and natural environment. This pre-supposes, however, that the basic (high-priority) socio-economic objectives have already been achieved.

Simultaneously with the diminishing economic advantage of flood plain locations for industrial development, recreational and aesthetic values have become increasingly important. In an era when urban economy is able to prosper at sites remote from major rivers, lakes, or the ocean, recreational and aesthetic attractions have become a primary cause of residential and resort development near large bodies of water. These bodies of water may also be storm basins or reservoirs of water for the city (like the reservoir of Troyes, in France). Natural flood plains in residential areas may be the principal contact with nature for many city-dwelling children. As such, the flood plains provide important unstructured educational benefits as well as recreational opportunities.

Inside the urban area, the banks and rivers, like any other historical asset, should be maintained or restored. For instance, the Roman aqueduct of Sens (France) is being used again to supply water to the city after an interval of 1,500 years. In metropolitan areas, peak-hour demand or dry-weather water consumption could be very efficiently decreased by re-using old tanks or wells.

The requirements of urbanisation oblige the planner to protect the environment from pollution and damage. However, the well-being of the population (discussed in more detail in Chapter 4) would be even further enhanced if the planner decided to maintain and re-use the cultural heritage.

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6. Conclusions and recommendations

6.1 CONCLUSIONS

As a general conclusion of this report, it may be stated that the relationship between socio­economic conditions and processes and urban hydrology is not yet sufficiently understood. There is need for a comprehensive analysis of the more important factors in the interplay between society and urban hydrology. Urban water management and planning as well as decision-making processes are evidently social in nature and result from the complex interactions of:

1. water resources needs

2. The types of development proposed

3. The kinds and organizational qualities of institutions existing, or required, to implement the development

4. The types of communities being considered and the structure of the urban society

5. The matrices of values, attitudes, and goals of all those involved - including planners, construction workers, administrators, decision makers, and community residents.

The characteristics of these categories of variables mentioned above might affect the viability of any urban water management and planning system (Johnson, 1974).

To these five points a series of objectives must be added for instance, the following (Vlachos, 1975):

1. National economic development and development of particular regions or communities within the country - through increased employment and improvements of the economic base.

2. The preservation of the nation's resources, including protection and rehabilitation insuring availability for the future.

3. Enhancement of the quality of the environment by improvement of certain natural and cultural resources and ecological systems.

4. Promotion of the well-being of people and concern with the social welfare of all, by contributing to the security of life and health; by providing educational and cultural opportunities; and, guaranteeing balanced growth among various affected persons or groups.

To this should be added concern for the surrounding natural and man-modified environment.

6.2 URBAN PLANNING AND/OR DEVELOPMENT AS A FUNCTION OF WATER AVAILABILITY

The world is becoming more and more urbanized and this seems to be a constraining trend. As a result the effective control of urban water resources becomes critical. This situation prevails not only in developed countries but also in developing countries. The magnitude and physical scale of the urbanization process shows that urban water resources should be carefully and wisely allocated if the environment of man is to be improved. We also note that this increased demand for urban water is attributed not only to increased urban population but has to do with changes also in social and cultural habits, changes in transportation and communication systems. Moreover, we observe an evolution in the needs of production processes, as well as in the requirements for leisure.

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Urban planning and/or development as a function of water availability

As the urban infrastructure becomes more costly and inefficient and institutions and facilities fail to provide adequate services to the population, it may be expected that urban, social and economic inbalances and injustices will be intensified. As a consequence, the quality of the total urban environment erodes and it becomes difficult to harmonize man's activities with the natural environment. This brings into focus the social values as determined by the goals and needs of urban society and the economic value of the urban land.

Considering the activities which depend on water resources, the growth of urban cities is faced with some important problems. There is in fact a risk that a narrowly-based engineering-technological view of urban water-resource management and planning will be also applied to solve the water problems of the megalopolis, implying that the complex water system of a big city could be solved by means of a separate study of all its different parts. Not only the engineering approach has to be changed but also the design of the institutions capable of satisfying the constraints of the urban water environment have to be altered. These institutions may grow well beyond the relatively simple enlargement of the geographical domain of the water authority, and very often they may touch upon the socially sensitive subjects of differential water and waste water pricing, as well as land and water zoning, intake and outfall locations, intra-regional economic development and city-suburban relations (Zobler, 1972) .

Whether we consider urbanized areas in developed or developing countries, we are faced with the central problem due to the use of water resources with a conflict between the two categories of supply and disposal, especially as the urbanization expands and user groups adopt self-interest. This leads to a strategy, including:

1. Acquisition of new sources, more distant locations, or deeper drilling of old sources,

2. Raising treatment levels of raw water,

3. Supporting regulatory or preventive measures against disposers;

or in a different sphere:

1. Encouraging the water users to acquire new sources of water or non-conventional sources of water,

2. Seeking to postpone the imposition of penalties or requirements for effluent pre-treatment,

3. Relocating outfalls. Both categories of user have concurrent needs for clean water just because they use the same waterways for supply as well as disposal. Resolving the urban water problem presupposes the analysis of the subsystems of the urban water systems. The urban water system consists of subsystems for water supply, water demand, sewage disposal etc. Interactions of these subsystems should be considered as a whole. This is a fundamental idea which is not yet generally accepted. Consequently, today we witness some sort of suboptimization based for instance on factors which result in a sanitary sewer system being unrelated to the water supply system, or a storm sewer system not related to possible pollution loads. However, to adopt an overall view of urban water problems, we have to analyse the functioning of relevant subsystems. According to Hufschmidt and Elfers (1971) there are three basic functions which underline all systems: the controls of water in time, space and quality. The urban water supply system, the water demand system and thereafter a combination of these two are studied. This last system is a system of stochastic nature of hydrology and of values and objectives in relation to the use of water. There is an interaction between supply and demand which is controlled by the functions for control of water. However, besides this control mechanism there must exist a monitoring scheme with a feedback to control the use of the three functions: control in time, space and quality. There are three levels of correction which may develop an imbalance, or discrepancy, between the supply and demand of water:

1. Altering the control of the three functions,

2. Changing the specific uses of water.

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Reaommenda tiens

3. Reappraising basic values and objectives.

The three levels of feedback can operate in the system at the time but 'the lower the level, the more likely it is to occur and the shorter the time lag for implementation. However, the higher the level of feedback and change, the more significant its long term effect is likely to be.'

6.3 RECOMMENDATIONS

6.3.1 Recommendations on well-being and urban hydrology

1. Informed planning, decision-making and management in urban hydrology should include considerations of welfare, social well-being and quality of life.

2. Researchers and decision-makers involved in solving problems in survival areas where conditions are below minimal, should ensure that their actions to solve immediate problems do not create serious problems which may jeopardize the well-being of the people at some future date.

3. It should be recognised that there are no universal formulae for determining well-being. Criteria to be used for its measurement should take into account time, place, culture and specific situations.

4. The environmental impact assessment can be used as an important means of evaluating human activities in relation to hydrological processes, in the context of an integrated, interdisciplinary understanding of the urban ecosystem.

5. The environmental impact assessment should pay particular attention to a balance between short-term gains and long-term enhancement in order to ensure equitable consideration of economic development, on one hand, and the protection, conservation, and improvement of natural resources, on the other.

6. The choice of alternatives should take into account the fact that problem-solving should be compatible with the needs and aspirations of the people benefiting from a particular project and with the available technological possibilities.

6.3.2 Recommendations on urban water project evaluation

1. Different techniques for project evaluation are in use by some national and local agencies. The techniques are not necessarily incompatible, but they do approach socio-economic considerations from different directions. There is a trend towards the blending of river basin planning with urban planning, one result of which has been confusion over evaluation methodology and interpretation. National and local authorities are urged to reconcile this dichotomy and researchers in the social sciences are requested to offer improved concepts for more orderly evaluation.

2. The basic water requirement to maintain a minimum acceptable standard of health should be investigated.

3. Measures for reconciling competing uses for water, such as domestic versus agricultural supplies, should be investigated.

4. Maintenance of water quality requires overall management of the catchment, embracing supply sources (including aquifers) and disposal.

5. Water and sewer services to high-density low-income urban areas should have a high social priority.

6. Some degree of sewage treatment should be provided, particularly for the protection of public health.

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Recommendations

7. Large drainage and sewerage schemes should be the object of socio-economic evaluation. Small schemes probably do not justify the effort of such an evaluation, but should be designed as minimum cost solutions to meet prescribed standards. The authorities responsible for setting drainage standards should re-examine those standards in the light of recent socio-economic changes.

6.3.3 Recommendations on liaison/cooperation

1. Means should be adopted, nationally, for coordination between researchers and decision makers in the field of urban hydrology.

2. Unesco should establish the necessary machinery for periodic meetings on a regional and world-wide basis.

3. The IHP should take into account the conceptual and methodological framework of the MAB program, especially those projects related to human settlements, ecosystems analysis and monitoring research.

6 3.3.1 Recommendations on specific research projects

With respect to specific research projects, it is recommended that the following procedure be accepted :

1. develop a mechanism for consultation on the identification of specific problems,

2. outline the contributions to the design of research projects, to be expected from various groups of decision makers,

3. establish an agreement between decision-makers and researchers on the most appropriate formats such as non-technical description, technical manuals, and other devices for communication, for presenting the research results,

4. encourage direct participation in the research by the decision makers' technical staffs (such as local and regional planners, land developers, water-resource engineers, etc.),

5. organize meetings, as appropriate, at which research progress at national, regional and international level may be presented to interested individuals and future plans for action discussed,

6. encourage and reinforce dialogue and collaboration between social, natural scientists and engineers for the solution of common, complex problems,

7. develop appropriate methodological approaches to facilitate interdisciplinary techniques, gathering of pertinent data and relevant field work.

6.3.4 Recommendation on data collection

The Workshop recommends that information should be collected from various cities on urban growth, irrigation, crowding, water supply, water use, waste-water systems, and socio-economic parameters, according to the format given in Appendix 1. This will be especially useful for the preparation of information manuals, in accordance with IHP Project 7.1.

6.3.5 Final recommendation

The Symposium and Workshop to be held in Amsterdam in October 1977 should take cognisance of the recommendations of this Workshop on socio-economic considerations in urban water-project evaluation, and this report should be distributed to all countries concerned.

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7. References including selected bibliography

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COHEN, P; FRANKE, O.L; FOXWORTHY, B., 1968. An atlas of Long Island's water resources. New York Water Resources Commission, Bull.62, Albany, New York.

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P-

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70

Appendix 1. Specimen form for collection of data on water supply use and disposal

Specimen form for collection of data on water supply use and disposal (with summaries of data for Sekondi-Takoradi in Ghana and Hannover in the Federal Republic of Germany)

1. General notes

1.1 Country

1.2 City (urban area):

1.3 Land area:

1.4 Population: (rate of change):

1.5 Population density:

1.6 Infant mortality:

1.7 Services, industry:

2. Water supply and water use

2.1 Water production:

2.2 Nature of source and origin: Inside jurisdiction:

2.3 Water supply 2.3.1 Public supply: 2.3.2 Private supply :

2.4 Water used: 2.4.1 Domestic: 2.4.2 Commercial: 2.4.3 Industrial: 2.4.4 Municipal and other:

2.5 Water losses, unmetered and own water use, in percentage of water used:

2.6 Water quality criteria: 2.6.1 Raw water: 2.6.2 Potable water:

2.7 Treatment:

2.8 Population served:

2.9 Per capita use daily: (rate of change)

2.10 Metering of use (system):

71

2.11 Water rate criteria:

2.12 Total network (pipe length, reservoirs, pumping station etc)

3. Waste water system

3.1 Sewage system 3.1.1 Number of population served: 3.1.2 Percentage of total population:

3.2 Type of sewers: combined; separate; combined+separate:

3.3 Number of outlets and location of outfall:

3.4 Organization of service:

3.5 Treatment facilities: 3.5.1 Number of population served

Percentage of total population Percentage of served population:

3.5.2 Type of treatment: Io; 2°; 3°; physical/chemical advanced

3.5.3 Treatment and final disposal of sludge:

3.6 Re-use of the municipal waste water: purposes, hygienic control criteria:

3.7 Final disposal of the effluents criteria and standards:

3.8 Principle for water pollution control (water quality criteria for the receiving body, standards for the effluents, combined principles)

3.9 Waste-water rate criteria:

4. Explanation notes of socio-economic nature:

General notes

1.1 Country:

1.2 City (Urban area):

1.3 Land area:

1.4 Population: (rate of change):

1.5 Population density:

1.6 Infant mortality:

1.7 Services, industry:

Ghana

Sekondi-Takoradi

91,874; 3.6 percent, per annum

Number of industrial set-ups is second only to ACCRA-TEMA metropolitan area in Ghana.

Water supply and water use

2.1 Water production:

2.2 Nature of source and origin :

Surface water

2.3 Water supply: 2.3.1 Public supply: 2.3.2 Private supply :

2.4

2.5

Water used: 2.4.1 Domesctic: ) 2.4.2 Commercial: ) 2.4.3 Industrial: ) 2.4.4 Municipal and other : )

Water losses and unmetered water use, in percentage of water production:

2.6 Water quality criteria: 2.6.1 Raw water:

2.6.2 Potable water:

2.7 Treatment:

2.8 Population served:

2.9 Per capita use daily:

2.10 Metering of use (system):

10O0.9 million gallons per annum

Inside jurisdiction:

Not inside City Council jurisdiction

Public authority supplied No private supply

692 million gallons per annum

The quality is fair, colour and turbidity are moderate and the organism content is generally high Treated to meet WHO criteria

Aluminium sulphate, chlorination, ammonium sulphate, lime.

20 gallons

No metering for domestic use, but metered for non-domestic use.

73

2.11 Water rate criteria: Water rate is set nationally by government legislative instrument and is meant to cover cost of the service

2.12 Total network: (pipe length, reservoirs, pumping stations, etc): Two service reservoirs plus secondary

service reseroirs. Booster pump on the trunk distribution main

3. Waste-water system

3.1 Sewage system 3.1.1 Number of population

served: 3.1.2 Percentage of total

population:

3.2 Types of sewers: combined; separate; combined +separate

3.3 Number of outlets and location of outfall:

3.4 Organization of service: municipal; private; mixed with other water services

3.5 Treatment facilities: 3.5.1 Number of population

served Percentage of total population Percentage of served population

3.5.2 Type of treatment: 1°; 20; 30; physical/ chemical advanced

3.5.3 Treatment and final disposal of sludge:

3.6 Re-use of the municipal waste water : purposes, hygienic control criteria:

3.7 Final disposal of the effluents criteria and standards

3.8 Principle for water pollution control (water quality criteria for the receiving body, standards for the effluents, combined principles)

74

3.9 Waste-water rate criteria:

4. Explanation notes of socio-economic nature:

Pressures, especially during peak draw-off periods, are in many parts of the city very low -so low in fact that whole areas are sometimes starved of water.

75

General notes

1.1 Country:

1.2 City (urban area):

1.3 Land area:

1.4 Population: (rate of change):

1.5 Population density:

1.6 Infant mortality:

1.7 Services, industry:

Federal Republic of Germany

Hannover

204,09 km2

566,175 (1974) -0.9 percent per annum

2724 inhabitants/km2 (1974)

55 percent labour force: Adminlstr., Educ, Services.

44 percent labour force: Industry

Water supply and water use

2.1 Water production:

2.2 Nature of source and origin: Groundwater

2.3 Water supply 2.3.1 Public supply : 2.3.2 Private supply :

2.4 Water used: 2.4.1 Domestic: 2.4.2 Commercial: 2.4.3 Industrial: 2.4.4 Municipal and other:

2.5 Water losses and unmetered water use, in percentage of water production:

2.6 Water quality criteria: 2.5.1 Raw water : 2.5.2 Potable water:

2.7 Treatment:

2.8 Population served:

2.9 Per capita use daily: (rate of change)

85 million m3/year in 1974 (for 690,000 inhabitants of the town and area)

Inside jurisdiction: 31 percent

61 million m3/year 24 million m3/year

)

30 percent 70 percent

)

About 8 percent

Water Protection Zones, no criteria WHO standards; National standards

Aeration and filtration (sand, activated carbon)

690,000 inhabitants (about lOO percent)

220 litres + 1.5 percent per year

2.10 Metering of use (system) Every house

76

2.11 Water rate criteria: Price very near to costs, public tariff

2.12 Total network: (pipe length, reservoirs, pumping station etc): 1,853 km net; 4 Waterworks.

3. Waste water system

3.1 Sewage system: 3.1.1 Number of population served:555,000 3.1.2 Percentage of total

population: 98 percent

3.2 Type of sewers : combined; separate; combined +separate:

3.3 Number of outlets and location of outfall:

Combined

River Leine

3.4 Organization of service: municipal; private; mixed with other water services: Municipal

3.5 Treatment facilities: 3.5.1 Number of population served:555,000

Percentage of total population: 98 percent

Percentage of served population: 98 percent

3.5.2 Type of treatment: Io; 2°; 3°; physical/ chemical advanced 3°

3.5.3 Treatment and final disposal of sludge: Deposited in polder areas

3.6 Re-use of the municipal waste water: purposes, hygienic control criteria: No

3.7 Final disposal of the effluents criteria and standards :

River authority Standard accord. 3rd Treat.

3.8 Principle for water pollution control (water quality criteria River standard for the receiving body, standards Class II-III for the effluents, combined (moderate to heavy polluted) principles):

3.9 Waste water criteria: Price according to costs

4. Explanation notes of socio-economic nature :

Highly industrialised town with a big part of services and educational activity;

Fair-place for industry and other fairs;

Centre of North-German transportation lines;

- Formerly old town; very highly renewed buildings after the war.

78

Appendix 2. Some case studies of environ­mental impact assessment

A survey of the literature on environmental impact assessment studies reveals that several have been made in various parts of the world. However, as far as it can be seen, practially no studies have been made of the total environmental impact of urban water-related activities. Among the studies made, the following are mentioned because they are useful from a method­ological point of view.

1. Fitzsimmons, Stuart and Wolff (1975). According to the summary given in the report, the social well-being account (SWB) is divided into five groups, each containing various evaluation categories with specified data:

(a) Individual, personal effepts (life, protection and safety, health, family and individual attitudes and environment);

(b) Community, institutional effects (demographic, education, government operations and services, housing and neighbourhood, law and justice, social service, religion, culture, recreation, informal organizations and institutional viability);

(c) Area, social-economic effects (employment and income, welfare and financial compensation, communications, transportation economic base, planning and construction);

(d) National, emergency preparedness effects (water supply, food production, power supply, water transportation, scarce fuels, population dispersion, industrial dispersion, military, and international treaties); and

(e) Aggregate, social effects (quality of life, relative social position, and social well-being).

Completion of the SWB account requires five steps:

(a) Description of the history of water resources of the area, and of the functions, activities, impact area, and schedule of alternative water plans;

(b) Description of the planning area to be affected in terms of its history, present-day social profile, and life-style;

(c) Identification of the future social impacts attributable to each alternative plan for each of the components and their evaluation categories;

(d) Comparison of the future beneficial and adverse social effects of the alternative plans; and,

(e) Recommendations of the plan with optimal future social well-being effects on the plan area.

Ultimately, the optimal water development decision will be a function of the combined social, economic, regional, environmental, and regional effects.

2. Leopold, Clarke, Hanshaw and Balsley (1971). This study presents an extensive matrix which can be used for evaluation of environmental impacts. It is a simple system designed with the premise that there is, at present, according to the authors.

79

no uniformity in approach or agreement on objectives in an impact analysis. The generalized matrix presented is a step in that direction.

James, Benke, and Ragsdale (1975). An abstract of the report gives the following condensed version of the paper:

'A well-planned flood control program requires coordinated implementation of a number of structural and nonstructural measures selected through the evaluation of a variety of hydrologie, economic, écologie, social preference, and community well-being information. This study employed regional hydrologie analysis, a computer program for maximizing net benefits, field surveys of the flood plain environment, a questionnaire to learn the perceptions and the preferences of the concerned public, and an analysis of the relationship between flood plain land use and the well-being of the community and integrated all five types of information into the formulation of flood control programs for four small urban watersheds in Metropolitan Atlanta. The needed information of all five types is outlined in detail, and procedures for collecting and analyzing it are explained. The study strategy was to present the framework of information needs and procedures for collection and analysis to a class of graduate students containing several experienced planners, select four case study flood plains, divide the class into five teams (one for each information category), have the students collect the data, and formulate a course of action through group discussion. Plans combining channelization, flood proofing existing homes and businesses, building codes to require flood proofing of new construction, land use restrictions on new flood plain development, and preservation of identified valuable ecological areas are proposed. A 17-step procedure for use in formulating flood control programs for urban or urbanizing areas is outlined.'

Fitzsimons, and Salama (1973). A summary of the study reads as follows:

"The scope of this study essentially dealt with man's need for water and water's impact upon man. The investigation was broad but, at the same time, clearly delimited. It was concerned with the social-psychological aspects of man's need for water, in contrast to the more traditional economic and technical aspects of man's use of water. Moreover, the study also differed from earlier research in that most previous research has been limited to water's impact upon man, excluding the needs of man, per se. The present effort studies this relationship as a two-way matter, proceeding first from man's needs for water and then from water's impact upon man. Once the social aspects are better understood, they must then be considered in relation to economic, environmental and technical engineering assessments, since the simultaneous consequences of man's social, economic and environmental needs interact with one another in a series of complex cause-effect-cause chains. Initial separation of social concerns from environmental, economic, technological and budgetary concerns is necessary to develop the conceptual and theoretical strength of such concerns in preparation for a later merging with these other, more developed data areas currently used in water planning.'

Contributions on the following topics were reviewed in this study:

social science theory and research

- water development history and policy

research on natural resources in general

multiple-objectives planning

research on social impact assessment in various sectors (eg housing, transportation, and water development)

social indicators and economic indicators procedures

The literature review revealed that only recently has the public demonstrated real concern over socially-oriented, man-environment interaction questions. In addition, social science and water-resources theory and applied research regarding man's social interaction with the environment are limited. Moreover, at the programme level little is known about how to conduct social impact assessment.

Based upon the above findings, four conclusions were drawn which shaped the procedures as applied to this study.

(a) Social impact assessment can only occur in the presence of more developed theory, research, and programme experience. Neither the passage of legislation, nor continuing public concern, make such assessment possible.

(b) To overcome the lack of theory, two approaches were possible: (i) create new theory out of "whole cloth' (that is, begin from scratch); or (ii) examine existing social and water theory and construct an interface between the two (that is, build a new theory out of the two 'parent' theories). The second alternative was chosen for two reasons. Firstly, one gains important advantage by utilizing existing theories, and the work of other scholars, as these may offer a basis for understanding man and his relationship with water. Secondly, by working with the existing theories, one gains access to considerable data (theories built without a body of data can lead in many false directions), and good theory seems to emerge from a variety of data.

(c) Given the absence of directly relevant research, and the impossibility of simply obtaining data, a form of 'matrix logic' was used to generate findings about the interrelationship of man and water. That is, a matrix was constructed to enable a systematic examination of the ways in which man and water interact with one another.

(d) To compensate for lack of programme experience, two alternative sources of guidance to preliminary measurement specification were used. Firstly, water related policy documents were used to help guide selection. Both the Water Resources Council's proposed principles and standards for planning water and related land resources (Federal Register, 1971) and the Bureau of Reclamation's guidelines (Bureau of Reclamation, 1972) commonly referred to as the 'yellow book', helped to clarify policy concerns. Secondly, a variety of techniques of multiple-objectives planning were applied to guide the measurement selection process.

To meet the needs of public opinion and legislative mandates, and in the absence of directly related theory, research and programme experience, this study was built upon existing knowledge of the social sciences and water development theories. A matrix was constructed to identify various interactions between man and water in order to derive a set of preliminary measures which were relevant to existing water development policy and programme concerns. Moreover, various considerations were carefully organized. Both social sciences and water development theory were examined in order to develop a matrix wherein the interaction of these two theories could be systematically studied. In turn, policy and programme consid­erations were examined and a set of preliminary measurements selected. Finally, specifications for the collection and analysis of data were set out and a series of recommendations made for further research toward development of an actual social assessment procedure. Each of these was discussed in turn.

Other studies include the works by Napier (1975a, 1975b), Napier and Wright (1975), Whitlatch (1976) and Hendricks, Scott Tucker, Vlachos and Kellogg (1975).

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Appendix 3. List of participants in the workshop

ACQUAH, T. Ghana Water & Sewage Corporation, PO Box M 194, Accra, Ghana

AKINTOLA, F Dept. of Geography, University of Ibadan, Ibadan Nigeria

ALMEIDA, J Director of Sanitation, National Dept. of Sanitation Works, Av. Presidente Vargas 62, 8th floor, Rio Janeiro, Brasil

BASSLER, FRIEDRICH. Professor, Dr. Technical University, 6100 Darmstadt, Germany

-Ing. BERTHELOT, ROGER M., Senior Technical Adviser, UNDP, One United Nations Plaza New York, N.Y., 10017, USA

BUCHAN, STEVENSON, Consultant Hydrogeologist 14 Monks Road, Banstead, Surrey SM7 2EP England

CELECIA, JOHN F., First Officer, Division of Ecological Sciences, Unesco, Place de Fontenoy, Paris 7e, France

COLYER, PETER J., Hydraulics Research Station, Wallingford, Oxon 0X10 8BA, England

82

CONSTANDSE, ADRIAAN K., Head Socio-Economie Research Dept., Ysselmeerpolders Development Authority, Zuiderwagenplein 2, Lelystad, Netherlands

DOHERTY, JOSEPHINE, Programme Manager, National Science Foundation, Division of Advanced Environmental Research and Technology,

Washington, D.C., 20550, USA

FALKENMARK, MALIN, Executive Secretary Committee for Hydrology, Natural Science Research Council, Sveavagen 166, 15 tr, S-113 46 Stockholm, Sweden

FERREIRA, F., Superintendente CAESB, S.C.S. Q13/67 Code 70O00 Brasilia, Brasil

FILIP, A., Senior Engineer, Energoproject Co., 18 Zeleni Venae, 11.OO Beograd, Yugoslavia

GIROULT, E., Regional Officer for Basic Environmental Senior,

World Health Organization, Regional Office for Europe, Scherfigsvej 8, Copenhagen, Denmark

GUILLERME, ANDRE, URBAN Civil Eng., Historian, Eede Nationale des Travaux Publics d'Erar, 69 Vaux.en-Velin, Route de la Tourelle, Paris, France

HENRIQUEZ, HUGO, Chief Hydrogeology Section, Instituto de Investigaciones Geológicas, Agustinas 785 6o Piso, Santiago de Chile, Chile

HJALTE, K., Fil kand, Nationalekonomiska inst. University of Lund, Allhelgona Kyrkog 14, 220 05 Lund, Sweden

HXGERSTRAND, T., Professor,

Inst. f. kulturgeografi, University of Lund, Solvegatan 13, 223 62 Lund, Sweden

83

KNALLINSKY, M., Sociologist Mining Secretariate of State, Sante Fe 1548, Buenos Aires, Argentina

KORDIC M., Head of Sanitary Eng. Energoprojekt co., Z. Venae 18 Beograd Yugoslavia

Div.

LECLERCQ, PAUL J., Hydrologist, Agricultural Engineer, Université Catholique de Louvain, Service Hydrogéologique , B.1348, Louvain - La Neuve, Belgium

LINDH, G., Professor, Dept. of Water Resources Engineering, Lund Institute of Technology, Fack, S-220 07 Lund, Sweden

MCPHERSON, MURRAY, Program director, American Society of Civil Eng

MANSU-ASMAH, GILBERT FORSTER, Asst. Research Officer, Water Resources Research Unit, Box M 32, Accra, Ghana

de MARE, LENNART, Research assistant, Dept. of Water Resources Engineering, Lund Institute of Technology, Fack, S-220 07 Lund, SWEDEN

MASSING, H., Head of Division I of the Landesanstalt, Landesanstalt für Wasser und Abfall, Bornestr. lO, 4000 Dusseldorf, Germany

MENDIA, L., Professor of Engineering, University of Naples, Via Claudio 21, Naples, Italy

NEWCOMBE, K., Centre for Resources and Environmental Studies PO Box 4, Canberra, AC1., Australia

OBRADOVIC, D., Chief systems analyst, Energoprojekt - Energodata, 18, Zeleni Venae, llOOO Beograd, Yugoslavia

ROMIJN, E., Hydrologist, Provincial Waterboard Gelderland, Marktstraat 1, Arnhenm, The Netherlands

ROY, NIRHILESH, Professor of Civil Engineering, Bañaras Hindu University, Varanasi, 221006, India

84

SEIJAS, HAYDEE, Investigador Associado, JeFe, Laboratorie de Etnologia, Instituto Venezolano de Investigaciones Científicas,

Apartado 1827, Caracas ÍOI, Venezuela

SNEL, M., General Manager Société Nationale Distribution d 21 Rue de Treves, 1040 Bruxelles, Belgium

eau,

VERHOOG, FREDERIK H., First Officer, Division of Water Sciences, Unesco, Place de Fontenoy, Paris 7 e, France

VLACHOS, EVAN, Professor of Sociology and Civil Engineering, Colorado State university, Fort Collins, Colorado 80523, USA

ZUIDEMA, FLORIS. C , Head Watermanagement and Hydrological Research, Ysselmeerpolders Development Authority, Zuiderwagenpiein 2, Lelystad, The Netherlands

85

Titles in this series

1. T h e use of analog and digital computers in hydrology. Proceedings of the Tucson Sympos ium, June 1966 / L'utilisation des calculatrices analogiques et des ordinateurs en hydrologie: Actes du colloque de Tucson, juin 1966. Vol. 1 & 2. Co-edition IASH-Unesco / Coédition AIHS-Unesco.

2. Water in the unsaturated zone. Proceedings of the Wageningen Sympos ium, August 1967 / L ' eau dans la zone non saturée: Actes du symposium de Wageningen, août 1967. Edited by/Édité par P . E . Rijtema & H . Wassink. Vol. 1 & 2 . Co-edition IASH-Unesco I Coédition AIHS-Unesco.

3. Floods and their computation. Proceedings of the Leningrad Sympos ium, August 1967 / Les crues et leur évaluation: Actes du colloque de Leningrad, août 1967. Vol. 1 & 2 . Co-edition IASH-Unesco-WMO / Coédition AIHS-Unesco-OMM.

4 . Representative and experimental basins. A n international guide for research and practice. Edited by C . Toebes and V . Ouryvaev. Published by Unesco. (Will also appear in Russian and Spanish.)

4 . Les bassins représentatifs et expérimentaux: Guide international des pratiques en matière de recherche. Publié sous la direction de C . Toebes et V . Ouryvaev. Publié par ¡'Unesco. (A paraître également en espagnol et en russe.)

5. Discharge of selected rivers of the world / Débit de certains cours d'eau du m o n d e / Caudal de algunos ríos del m u n d o / Pacxoflbi B O A H n36paHHbix peK Miipa. Published by Unesco / Publié par ¡'Unesco.

Vol. I: General and régime characteristics of stations selected / Vol . I: Caractéristiques générales et caractéristiques du régime des stations choisies / Vol. I: Características generales y características del régimen de las estaciones seleccionadas/ T O M I: 0 6 m , n e H - p e m H M H b i e xapaKTepucTHKii n36panHbix CTaminíí.

Vol. II: Monthly and annual discharges recorded at various selected stations (from start of observations up to 1964)/ Vol. II: Débits mensuels et annuels enregistrés en diverses stations sélectionnées (de l'origine des observations à l'année 1964) / Vol . II: Caudales mensuales y anuales registrados en diversas estaciones seleccionadas (desde el comienzo de las observaciones hasta el año 1964) / T O M II: MeCHHHtie H roflOBbie pacxoflbi B O A L I , aaperHCTpnpoBaHHbie pa3JiH<t-H w M H H 3 6 p a H H H M H CTaHiTHHMH (c naqa.ua Ha6jiioa;eHHH Ao 1964 rojra).

Vol. Ill: M e a n monthly and extreme discharges (1965-1969) / Vol . Ill: Débits mensuels moyens et débits extrêmes (1965-1969) / Vol. III: Caudales mensuales medianos y caudales extremos (1965-1969) / T O M III: CpeAHe-MeCHMHbie H

BKCTpeMajibHbie pacxosbi (1965—1969 rr.).

Vol. III (part II): M e a n monthly and extreme discharges (1969-1972) / Vol. Ill (partie II): Débits mensuels moyens et débits extrêmes (1969-1972) / Vol. III (parte II): Caudales mensuales medianos y caudales extremos (1969-1972) / T O M III

(qacTb II); CpeAHe-MecHHHbie H sKCTpeManbubie pacxo^bi (1969—1972 rr.).

Vol. Ill (part III): M e a n monthly and extreme discharges (1972-1975) (English, French, Spanish, Russian). 6. List of International Hydrological Decade Stations of the world / Liste des stations de la Décennie hydrologique internationale

existant dans le m o n d e / Lista de las estaciones del Decenio Hidrológico Internacional del m u n d o / C n n c o K CTamnift Mewfly-HapoíiHoro rn«pojiornHecKoro jrecflTHJieTHH 3eMHoro m a p a . / Published by Unesco I Publié par ¡'Unesco.

1. Ground-water studies. A n international guide for practice. Edited by R . B r o w n , J. Ineson, V . Konoplyantzev and V . Kovalevski. (Will also appear in French, Russian and Spanish / Paraîtra également en espagnol, en français et en russe.)

8. Land subsidence. Proceedings of the T o k y o Sympos ium, September 1969 / Affaissement du sol: Actes du colloque de T o k y o , septembre 1969. Vol. 1 & 2 . Co-edition IASH-Unesco / Coédition AIHS-Unesco.

9. Hydrology of deltas. Proceedings of the Bucharest Sympos ium, M a y 1969 / Hydrologie des deltas: Actes du colloque de Bucarest, mai 1969. Vol. 1 & 2 . Co-edition IASH-Unesco / Coédition AIHS-Unesco.

10. Status and trends of research in hydrology / Bilan et tendances de la recherche en hydrologie. Published by Unesco / Publié par V Unesco.

11. World water balance. Proceedings of the Reading Sympos ium, July 1970/Bilan hydrique mondial : Actes du colloque de Reading, juillet 1970. Vol . 1-3. Co-edition IAHS-Unesco-WMO / Coédition AIHS-Unesco-OMM.

12. Research on representative and experimental basins. Proceedings of the Wellington ( N e w Zealand) Sympos ium, December 1970 / Recherches sur les bassins représentatifs et expérimentaux: Actes du colloque de Wellington ( N . Z . ) , décembre 1970. Co-edition IASH-Unesco / Coédition AIHS-Unesco.

13. Hydrometry: Proceedings of the Koblenz Symposium, September 1970 / Hydrométrie : Actes du colloque de Coblence, September 1970. Co-edition IAHS-Unesco-WMO.

14. Hydrologie information systems. Co-edition Unesco-WNO,

15. Mathematical models in hydrology: Proceedings of the Warsaw Sympos ium, July 1971 / Les modèies mathématiques en hydro­logie: Actes du colloque de Varsovie, juillet 1971. Vol. 1-3. Co-edition IAHS-Unesco-WMO.

16. Design of water resources projects with inadequate data: Proceedings of the Madrid Sympos ium, June 1973 / Elaboration des projets d'utilisation des resources en eau sans données suffisantes: Actes du colloque de Madrid, juin 1973. Vol. 1-3. Co-edition Unesco-WMO-IAHS.

17. Methods for water balance computations. A n international guide for research and practice. 18. Hydrological effects of urbanization. Report of the Sub-group on the Effects of Urbanization on the Hydrological Environment. 19. Hydrology of marsh-ridden areas. Proceedings of the Minsk Sympos ium, June 1972. 20. Hydrological maps. Co-edition Unesco-WMO.

21. World catalogue of very large floods/Répertoire mondial des très fortes crues/Catalogo mundial de grandes crecidas/ BceMHpHbiñ Karajior 6ojibiuHX HaBOAKOB.

22. Floodflow computation. Methods compiled from world experience. 23. Guidebook on water quality surveys. (In press.) 24. Effects of urbanization and industrialization on the hydrological regime and on water quality. Proceedings of the Amsterdam

Symposium, October 1977, convened by Unesco and organized by Unesco and the Netherlands National Committee for the IHP in co-operation with I A H S / Effets de l'urbanisation et de l'industrialisation sur le régime hydrologique et sur la qualité de l'eau. Actes du Colloque d'Amsterdam, Octobre 1977, convoqué par l'Unesco et organisé par l'Unesco et le Comité national des Pays-Bas pour le P H I en coopération avec l'AISH. (In press / Sous presse).

25. World water balance and water resources of the earth. 26. Impact of urbanization and industrialization on water resources planning and m a n a g e m e n t . 27. Socio-economic aspects of urban hydrology.

/ A . 2 2 / SC.78/XX-27/A