Roberts is Head of the Environmental Management Department, eThekwini Municipality (Durban). Croucamp is the Department's Development Assessment and Information Coordinator. Boon and Mander are consultants for the Department.

Citation: This paper may be cited as: [Authors.] 2005. [Article title.] In Ted Trzyna, ed., The Urban Imperative. California Institute of Public Affairs, Sacramento, California.

1. INTRODUCTION

Durban is the largest port and urban area on the East Coast of Africa. The city covers an area of 2,297 km² and has an estimated population of just over 3 million people. Topographically the municipal area is very diverse, ranging from steep escarpments in the West to a relatively flat coastal plain in the East. Given that South Africa is the third most biologically diverse country in the world, it is not surprising that Durban’s diverse landform supports a wide variety of terrestrial, freshwater, and marine natural ecosystems. The high level of biodiversity in the city is primarily due to its location within a broader biogeographic subtraction and transition zone, which consists of three distinct elements:

• A tropical complex entering from the North and becoming less prevalent to the South;
• A warm temperate complex entering from the Southwest and becoming less evident to the North;
• A relatively small transitional complex indigenous to the area (Poynton, 1961).

2. HISTORY OF OPEN-SPACE PLANNING

Over the last three decades, open-space planning in Durban has provided an important vehicle for protecting biodiversity within the city. It has also helped mainstream conservation issues within the planning and decision-making processes of local government. The approach to open-space planning in Durban has evolved from a focus on the protection of conservation-worthy areas in the early 1980s, to a more holistic understanding that emerged in the mid-1990s which focused on the contribution of open space to sustainable urban development. This change in approach was driven by two factors: the democratization of South African society, and the global prioritization of sustainable development (e.g., through the United Nations Conference on Environment and Development held in Johannesburg in 1992). In Durban, the emergence of political leadership that prioritized poverty, economic development, and meeting basic needs over less tangible ecological and conservation needs, was a particularly important driving force in this paradigm shift. As a result, open-space planners began to interrogate the role of the open-space system in contributing towards the new, broader development objectives of the city.

The search for a new understanding of the role of nature in the South African city was particularly influenced by the international research undertaken by Costanza et al. (1997). This focused on the range of goods and services provided “free of charge” by the world’s natural ecosystems, seldom considered in traditional economic accounting. In Durban this concept was used to demonstrate that the open-space system is in fact a significant service provider, and that it provides “goods” (e.g., water for consumption) and “services” (e.g., waste treatment) that are important in meeting people’s basic needs and improving quality of life. This contrasted with previous popular perceptions of the system as an elitist resource focusing on plant and animal requirements rather than human needs. Using the research done by Costanza et al. (1997), seventeen different open-space service types were identified for the Durban area.

Although there is much debate (Scott et al., 1998; Serafy, 1998; Pearce, 1998) regarding the Costanza et al. approach to estimating the value of ecosystem goods and services, it does facilitate an “orders of magnitude” estimate of the financial value of ecosystems. In the urban environment this is useful as it highlights the value of the natural resource base and the potential replacement costs of ecosystem services that are currently enjoyed “for free.” The nature of these benefits includes:

• Direct benefits: Direct consumption or use of goods or services (e.g., use of water in industrial production, wood for fuel, plants for traditional medicines);
• Indirect benefits: Indirect use of services to provide a cost saving to residents (e.g., ability of floodplains to reduce flood damage; trees as windbreaks);
• Option benefits: Reserving resources for future use (e.g. the attractive inshore ocean can be used to promote tourism growth in the future);
• Existence benefits: The existence of a resource (such as a forest, a river, or a beach) may give residents a feeling of well-being simply because it is there.

These environmental services are essential to all communities, but are particularly important in contributing to meeting the basic needs (such as water, firewood, food, etc.) of poorer communities that do not have access to adequate infrastructure and services.

3. SUPPLY OF ENVIRONMENTAL SERVICES IN DURBAN

Given that different ecosystems have varying abilities to supply environmental services, the first step in designing an open-space system for Durban able to secure a sustainable supply of these services, was to identify the main ecosystems and open-space types within the city. Sixteen generic and forty-six specific open-space cover types were used when classifying the natural areas included in open-space system. Terrestrial, vegetated cover types were adapted from Low and Rebelo (1996), Cooper (1985), and Florida Department of Transportation (1985). This relatively simple classification system was used in order to facilitate consistent recognition of cover types on the 1: 5000 aerial photography used for the classification process. The classification exercise was undertaken by members of the Environmental Management Branch who used their field knowledge and ecosystem, habitat, and land use categories to classify all the open spaces within the municipal area.

Because it was not possible to directly relate the global ecosystem values of Costanza et al. to the open-space cover types for Durban, a workshop was held in 1998 to rank the relative ability of the various open-space types in the city to supply environmental services. The workshop was attended by officials from the city’s Environmental Management Branch and Parks Department, who were supported by a team of private consultants assisting with the project. Again this process was based on the field knowledge and experience of those present. This initial assessment of the ability of the various open-space types in Durban to supply environmental services has helped inform all subsequent revisions of the open-space system plan. In designing the system it was assumed that in order to protect a sustainable supply of environmental goods and services it would be necessary to protect an ecologically viable network of open-space types. For this reason obvious priority was assigned to large, biodiverse, and well-connected open-space areas for inclusion within the system.

Certain open-space cover types such as floodplains, wetlands, and forests have a greater potential to supply a wider range of environmental services than other types of open space such as sandy beaches, rocky shores, and alien plant infested areas. The varied ability of open-space types to supply environmental services has implications for open-space protection, development, and management, and suggests that open spaces that supply environmental services in high demand by city residents should be a priority for management and protection. This would mean that wetlands with their broad range of services (e.g., flood attenuation, pollution reduction, water provision) would be prioritized because of their high level of functionality, while sandy beaches (with a lower relative ability to provide services) would be prioritized because of their singular importance in terms of the tourism/recreational sector in the city.

4. DEMAND FOR ENVIRONMENTAL SERVICES

The importance of open space depends not only on the ability to supply environmental services, but also on the demand for environmental services. An urban area with a large number of users of a particular open-space service will have a greater need or demand for the type of open space that supplies the required service. For example, if a catchment contains extensive informal settlements that extract water from local streams, then the rivers and wetlands that supply water and improve its quality would be a priority open-space type. In trying to understand which environmental services, and consequently which open- space cover types, are important to sustainable development in Durban, it is necessary to identify the users of the environmental services in the city. For this purpose, a number of key open-space resource user categories have been identified:

• Low-density formal residential

• High-density formal residential

• Low-density informal residential
• High-density informal residential
• Peri-urban/rural settlement
• Commercial and institutional – retail, tourism, and major public facilities
• Industrial – manufacturing and service industries
• Extractive – mining and quarrying
• Transport – road and rail reserves and major public transport facilities
• Agriculture – sugar cane, market gardening, and mixed farming

These resource user or land-use categories have different needs with respect to environmental services supplied. Environmental services are used directly as an input for consumers (e.g., household water) and for production processes (e.g., water for industry) and also indirectly by land users to ameliorate their impacts on the environment. For example, an industry releasing effluent into the river system will indirectly rely on the water in the river to dilute the effluent and will also rely on the river and estuary ecosystem processes to break down waste products. These ameliorative actions are essential to other service users downstream of the pollution source.

Different resource users have different needs in terms of environmental services. A ranking of these needs was also developed at the 1998 workshop and as such is based on the workshop participants’ knowledge and understanding of the demand generated by different land- use types for environmental services in the Durban area. For example, an urban area with a large number or percentage of high-density informal residential settlements will have a high demand for a number of different environmental services, including flood avoidance, food production, natural products, etc. This highlights the fact that environmental services are important in meeting the basic needs of communities that do not have access to high levels of utility services or infrastructure.

5. ECONOMIC VALUE OF ENVIRONMENTAL SERVICES 

The value of the work done by Costanza et al. is that it quantified, for the first time, the financial value of the goods and services provided by the world’s ecosystems. This is important to open-space planning, as decision-making regarding the use of urban open space or the allocation of resources occurs through economic and political processes which compare the value of open space to the value of alternative land uses (e.g., housing, landfills, and industry).  In most cases, the value of open space (outside of its aesthetic and recreational appeal) is not understood, while the benefits of the alternative land uses appear explicit and quantifiable. In cities, this situation has resulted in open spaces being significantly undervalued because of the general failure of society to recognize the value of a resource when it is not expressed in monetary terms or cannot be owned, or where the services provided are not immediately obvious. Consequently, the identification and economic valuation of environmental services is a critical tool in helping ensure the appropriate planning, management and resourcing of open spaces in urban areas.

The economic valuation of environmental services is, however, still in its infancy and is a complex exercise. Because of the lack of locally specific data, the value estimates for the environmental services provided by the open-space types in Durban were obtained and/or generated from international research such as that of Costanza et al. As this research is not comprehensive, values for some environmental services are not available and, as a result, the overall consolidated value of the open-space asset can only be regarded as conservative. For example, while some of the open-space types in Durban fit neatly into the biomes used in Costanza et.al., e.g. croplands, grasslands, wetland, and freshwater and marine environments, in other cases it was necessary to extrapolate the global figures. As an example, the assumption was made that local forests in Durban are more similar to tropical forests than boreal forest types. On this basis local vegetation types dominated by woody elements were assigned a variable proportion of the tropical forest values given in Costanza et al. based on biomass and diversity. It was assumed that in general the greater the biomass and biodiversity, the greater the value of the open-space type.

Despite these approximations, the values calculated for the open-pace types in Durban are still sufficient to underline the significance and value of environmental services and the magnitude of the costs that would be incurred if they had to be replaced because of short-sighted, unsustainable development.  Key points that emerge from this analysis are as follows:

There is a wide range in the economic value per open-space type, ranging from estuaries, with a value of South African rand (R) 237,453/ha/yr to grasslands, with a value of R 2,413/ha/yr. (As of this writing, the rand is equivalent to about US$0.16.) 

• No data were available for open-space types such as rock outcrops, sand and rock quarries, and urban settlements (the latter having mainly recreational and cultural values not yet quantified).

• Natural open-space types with the greatest replacement cost (highest value) appear to be, in decreasing order, estuaries, floodplains and swamp forest, mangrove forests, water bodies, rocky shores and beaches, forests, near shore ocean, wooded grassland, and grassland.

• Transformed open-space types such as alien vegetation, agriculture, and utility grasslands have a much-reduced value as they are not able to provide the broad range of environmental goods and services provided by the more natural open spaces.

• The near shore ocean contributes 27 percent of the total value of the open-space system.

• Forty-three percent of the value of the terrestrial component of the open-space system is provided by floodplains, which occupy only 7.6 percent of the land surface. The

• The dominant natural land cover type in Durban, dry valley thicket/broad-leafed woodland, occupies 29 percent of the land surface and provides 12 percent of the value of the terrestrial component of the open-space system.

The total replacement value of the environmental services delivered by open space in Durban is conservatively estimated to be R3.1 billion per annum and excludes the value of Durban’s tourism sector. If tourism turnover for Durban is assumed to be largely related to the fact that a majority of tourist visits are because of the sea, sun, beach, and overall sub-tropical environmental quality of Durban, then a significant portion of the annual tourism-related turnover - of around R3.3 billion - can be added to this figure.

6. LESSONS LEARNED IN DURBAN

Reinterpreting Biodiversity

The use of resource economics made it possible to convert the somewhat elusive value of biodiversity into something understandable to the majority of urban stakeholders (i.e., a monetary value). This approach has helped increase political support for biodiversity protection and has impacted on policy development within the city. Despite this, tensions still exist between the short-term time lines, which govern most political decision-making, and the longer-term considerations that influence biodiversity planning. As a result, political expediency continues to pose a potential threat to the implementation of the city’s open-space plan.

Conceptual Flexibility

The mainstreaming of biodiversity issues that has occurred in Durban is largely the result of open-space design remaining responsive to changing development and political pressures. It is likely that the need to ensure an alignment between socioeconomic and biodiversity priorities will be a continuing feature of open-space planning in the city for the foreseeable future. In the early stages of the open-space planning process in Durban the focus of attention was on the protection of conservation-worthy areas and subsequently the creation of an ecologically viable open-space system. This mirrored existing global environmental priorities (e.g., protection of rare and endangered species). A more holistic understanding of the role of biodiversity emerged in the 1990s as a result of the Rio Earth Summit which highlighted the need for development that balanced ecological, social, and economic concerns. This was supported in South Africa by a process of democratization and the increased priority placed on meeting people’s basic needs. The shift from a “conservation” to a “sustainable development” focus has necessitated a change in the tools required for open-space planning, e.g., botanical surveys are now supplemented by the use of resource economics. This process has highlighted the need for biodiversity initiatives to remain responsive to changing political and ideological pressures.

Need for Education

Although the use of resource economics helped provide a realignment between the ecological priorities of environmental planners and the human upliftment priorities of political decision-makers, this approach has not ensured an unchallenged implementation of the Durban’s open-space system framework plan. This suggests that education programs that help develop a deeper understanding of sustainability issues must support the mainstreaming of biodiversity issues in cities. In the long term this will avert situations where a lack of understanding of the interrelated nature of social, ecological, and economic concerns results in ecological (and hence biodiversity) concerns being marginalized when social and economic pressures are high.

The Need for Appropriate Tools

The use of resource economics in open-space planning implies that the non-human world is only of value when it provides goods and services to the human world. Many of the services provided by open spaces are, however, intangible (e.g., aesthetic and cultural values) and are difficult to quantify in economic terms. Many people also consider these services to be irreplaceable or priceless. This means that in the instances where the value of open areas cannot be identified, or where their economic value is not viewed as sufficiently substantial, areas will be treated as valueless. There is clearly a need to develop planning tools that ensure real sustainability and biodiversity protection.

7. REFERENCES

Cooper, K.H. 1985. Indigenous Forest Survey: The Conservation Status of Indigenous Forests in Transvaal, Natal, and O.F.S., South Africa. Wildlife Society of Southern Africa, Durban.

Costanza, R., R. d’Arge, R. de Groot, S. Farber, M. Grasso, B. Hannon, K. Limburg, S. Naeem, R. V. O’Neill, J. Paruelo, R. G. Raskin, P. Sutton, and M. van den Belt.  1997. The value of the world’s ecosystem services and natural capital. Nature 387: 253-260.

Florida Department of Transportation. 1985. Florida Land Use, Cover, and Forms Classification System. Second edition. FDOT, State Topographic Bureau, Thematic Mapping Section, Tallahassee. Procedure No. 550-010-001.

Low, A.B. and A.G. Rebelo (eds.). 1996.  Vegetation of South Africa, Lesotho, and Swaziland.  Department of Environmental Affairs and Tourism, Pretoria.

Pearce, D. 1998. Auditing the Earth: the value of the world’s ecosystem services and natural capital. Environment 40 (2): 23-27. 

Poynton, J.C. 1961. Biogeography of South-East Africa. Nature 189: 801-803.

Scott, M.J., G.R. Bilyard, S.O. Link, C. A. Ulibarri, H.E. Westerdahl, P.O. Ricci, and H. E. Seely. 1998. Valuation of ecological resources and functions. Environmental Management 22 (1): 49-68.

Serafy S.E. 1998. Pricing the invaluable: The value of the world’s ecosystem services and natural capital. Ecological Economics 25: 25-27.

This paper copyright © 2004 International Union for

Conservation of Nature and Natural Resources.

Reproduction of this paper for educational or other noncommercial purposes is authorized without prior written permission from the copyright holder provided the source is fully acknowledged. Reproduction of this paper for resale or other commercial purposes is prohibited without prior written permission from the copyright holder.

Web site hosted by the California Institute of Public Affairs,

an IUCN member since 1980

Home page  /  Site map  /  Copyright & caveats 

The copyright notice applies to the entire contents of this Web site.