Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA Roland White Jane Turpie Gwyneth Letley All queries on rights and licenses should be addressed to the Publishing and Knowledge Division, The World Bank, 1818 H Street NW, Washington, DC 20433, USA; fax: 202-522-2625; e-mail: pubrights@worldbank.org. © 2017 International Bank for Reconstruction and Development / The World Bank, 1818 H Street NW, Washington DC 20433 Telephone: 202-473-1000 Internet: www.worldbank.org Some rights reserved. This work is a product of the staff of The World Bank with external contributions. Note that The World Bank does not necessarily own each component of the content included in the work. The World Bank therefore does not warrant that the use of the content contained in the work will not infringe on the rights of third parties. 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Design and production by Zephyr www.wearezephyr.com Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA Roland White Jane Turpie Gwyneth Letley PREFACE AND ACKNOWLEDGEMENTS This report is based on a suite of eight research exercises undertaken over the period 2015-2017, all of which – together with accompanying datasets – are available on-line: ·· A regional desk-study which examines and synthesizes available material, providing an overview of the key situational dynamics and trends in the natural environment in Africa’s main cities; ·· Detailed urban environmental profiles of three case study cities of Durban, Kampala and Dar es Salaam developed Many people contributed to the overall study: using the “Rapid Urban Environmental Assessment” (RUEA) Dr Timm Kroeger, Dr Raffaele de Risi, methodology; Dr Francesco de Paola, Chris Roed, Dr Dambala Gelo, Dr Liz Day, Dr Robynne Chrystal, Prof. ·· Ecosystem Services Valuation (ESV) studies which provide Derek Stretch, Dr Stef Corbella, Kat Forsythe, a valuation of urban natural capital and ecosystem services Chyi-Yun Huang, John Bachmann, Diane and the identification, quantification and valuation of the Dale, Brian Goldberg, Jennifer Black, Petrina costs and benefits associated with specific development Rowcroft and Maritza Pechin all made valuable interventions in the three cities of Durban, Kampala contributions to the production of the regional and Dar es Salaam. Drawing on TEEB (The Economics of desk study, the detailed urban environmental Ecosystems and Biodiversity) methodologies, these studies profiles, the three city case studies and the were conducted through a number of key steps involving urban environmental toolkit. both extensive technical work and intensive stakeholder dialogue; We are grateful to Dr Jeffrey Wielgus, Mike Toman, Sanjay Strivastava, Urvashi Narain, ·· A toolkit of policy measures, instruments, and planning and Glen-Marie Lange, Elizabeth Tellman, Rob management strategies taken largely from both developed McDonald, Stephane Hallegatte, Steve and developing country experience which can be adapted Hammer, Kavita Sharma and Daniel Auerbach and utilized by city and national governments to address who contributed invaluable technical insights, the sorts of environmental externalities and ecosystem critical review, and guidance. services impacts identified in the environmental profiles and ESV studies. Thanks to Jonathan Schroeder, Robert Pretorius, Chivashni Bachen, Dr David Kyamboto, Amy Faust, Nancy Lorenzo Garcia, Mary Bitekerezo, Herbert Oule, Najib Lukooya Bateganya, Susan Namaalwa and Stephen Tumwebaze who provided data, assisted with data collation, and provided other useful inputs and city-specific advice. We are also grateful to the relevant municipal staff in eThekwini (Durban), Dar es Salaam and Kampala for their interest and support of the research projects conducted in their cities over the two year period. 4 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Preface and Acknowledgements A. INTRODUCTION: BACKGROUND AND OBJECTIVES 2 B. THE RELATIONSHIP BETWEEN CITY GROWTH AND THE NATURAL ENVIRONMENT 4 How urban activities affect the environment 4 Why this matters 5 Trends are self-reinforcing 5 Cities may be on negative or positive trajectories 6 Influencing the trajectory requires understanding the nature of urbanization 7 C. THE KEY CHARACTERISTICS OF AFRICA’S URBANIZATION 10 Late but rapid urbanization 11 Low levels of industrialization, motorization and technology 12 Low levels of wealth, fiscal resource and service delivery 12 Institutions and systems are weak 14 D. ENVIRONMENTAL TRENDS IN AFRICAN CITIES 16 Urban encroachment on natural ecosystems 17 Consumption of natural resources 22 Pollution 23 Hydrological changes 25 Introduction and proliferation of invasive species 26 Biodiversity loss 27 Increasing vulnerability to climate change 29 E. COSTS AND CONSEQUENCES 30 Economic consequences 30 Fiscal consequences 34 Social consequences 35 F. CHANGING THE TRAJECTORY: GREEN URBAN DEVELOPMENT IN AFRICA 36 Crystallizing the challenge 36 The elements and benefits of green urban development 37 Actualizing green urban development in Africa: an agenda for action 39 G. UNLOCKING THE BARRIERS TO GREEN URBAN DEVELOPMENT 46 Strengthen institutions to manage green urban development 46 Targeted finance 47 H. REFERENCES 48 URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 1 A INTRODUCTION: BACKGROUND AND OBJECTIVES Africa is urbanizing late but fast. This brings many benefits but, as this report shows: Thus far, urbanization in Africa, unique in a number of respects, is having deleterious and largely unchecked impacts on the natural URBANIZATION, environment; THE ENVIRONMENT The degradation of natural assets AND GREEN URBAN and ecosystems within African DEVELOPMENT IN cities carries tangible economic, AFRICA fiscal and social costs; There are important opportunities to change the current environmental trajectory of African cities so that they move towards a more harmonious relationship between their natural and built environments. For this to happen, focused action is necessary. 2 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Introduction: Background and Objectives In this context, the lack of an adequate understanding of the natural environment and the extent of urban environmental degradation in Africa, its economic and human costs, and the complex interplay between urban development, natural asset decline, and the value of ecosystem services provision is becoming increasingly problematic. National and city governments are unable to make well-informed, cost-effective urban planning, land-use, budgetary and investment decisions regarding the development of urban areas, and lack the tools to mitigate negative environmental externalities. Moreover, there is a significant risk that African cities may become locked into a “grow dirty now, clean up later” development path which is potentially costly, inefficient and welfare-reducing (World Bank 2012). Thus far, with one or two exceptions (de Wit et al., 2011) very little systematic analytic work has been done on these issues in Africa and little attention has been paid to the development of instruments, strategies and approaches which can improve cities’ capacities to improve their decision-making capabilities and enable them to respond effectively to the erosion of the value of their environmental assets. This report, and the suite of eight research studies which underlie it (see Preface), is directed at addressing part of this knowledge deficit. An improved understanding of urbanization’s impacts on the environment, and the proper valuation of the costs and benefits associated with interventions that alter the natural capital base and ecosystem services provision, can allow public agencies to make more cost-effective and responsible urban development decisions, balance the trade-offs between natural capital conservation and other land-uses, and inform approaches to developing urban land and the nature of the associated investments (TEEB 2010). It is particularly important that knowledge and technical capacity gaps in this area are addressed sooner rather than later: once ecosystems are severely degraded or destroyed it becomes very difficult, or impossible, to restore them and the value of the services they provide may be irreversibly lost. There is a significant risk that African cities may become locked into a “grow dirty now, clean up later” development path. __ URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 3 B THE RELATIONSHIP BETWEEN CITY GROWTH AND THE NATURAL ENVIRONMENT How urban activities affect the environment Urbanization entails the growth and spatial concentration of population, economic production, and consumption. This involves three types of activity which affect the natural environment: The expanded use and consumption of natural resources; The transformation of the natural environment into the built environment as residences, economic enterprises, and infrastructure are established; The generation of waste including atmospheric emissions, wastewater and solid waste. 4 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services The relationship between City Growth and the Natural Environment In any urban space, these activities exist in complex are also beneficial. Natural resource consumption, for interaction with one another and have mutually compounding example, is a precondition of economic production, hence effects. Broadly speaking, however, they impact the natural of improvements in human welfare. But it is important environment in three ways: to recognize that deterioration in environmental quality also invariably has negative economic, fiscal and welfare i. They affect the natural asset base of the city, e.g. consequences for cities. Such consequences may be felt at they may reduce the amount of freshwater available the level of the household or firm; they are more or less and diminish its quality. The rate of natural resource measurable; they may be more or less severe; and they consumption is determined by a combination of may be experienced in a variety of ways: increasing costs demographic and economic drivers: population growth, of water production; deteriorating human health (and the increases in wealth and living standards, and growth in costs of addressing this); damage to infrastructure (and the economic output. costs of addressing this); reduced property values; loss of ii. They affect the ecosystems of the city and the volume recreation and tourism value; and so on. and value of the services these systems generate. For instance, the conversion of wetlands to agriculture or Trends are self-reinforcing hard surfaces reduces the value of the water cleansing Thus, while urbanization impacts the natural environment, services that wetlands often provide; the natural environment impacts cities. Environmental assets can enhance city resilience to disasters such as floods, and iii. They affect the biodiversity of the cities in that species ecosystems can reduce the costs of service-delivery. In other may be eliminated. words, there is a feedback loop between urban development and the quality of the natural environment which may be Why this matters either positively or negatively reinforcing. To a significant extent, such impacts are intrinsic to the urbanization process and insofar as urbanization In any city, the way in which urban growth affects the is inevitable, these impacts are also inevitable. They natural environment, and the nature of the feedback loop, Figure 1: Urbanization-natural environment impact chain Urbanization Impacts on Natural Economic, Fiscal & Activities Environment Welfare Consequences Cost of production Natural asset and Natural resource resource base Human health, consumption healthcare costs Damage to grey Natural to built Ecosystems and related environment infrastructure, services infrastructure costs Property value Generation of waste Biodiversity Recreational and tourism values City Character Negative/positive feedback loop City Agency Actions URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 5 B are determined by both the character of the city (economic, Cities may be on negative or positive trajectories demographic and spatial) and any measures affecting For any given city, or group of cities within a country or environmental quality taken by city institutions. Such region, a range of different scenarios from A to C is possible: measures range from those which target environmental ·· Under A, a city is able to arrest and reverse the impact assets directly to those which do not focus on the of urbanization-activities on its natural asset base, environment specifically but which may have significant ecosystems and species (see Box 1). A1 presents a scenario positive environmental impacts. It should be noted that in which a positive feedback cycle has emerged and non-targeted measures may often be more important in an improvement in environmental quality is becoming their environmental consequences than targeted measures. increasingly rapid; For example, city-wide sanitation programmes undertaken primarily to enhance liveability may improve water resource ·· Under B, the city slows but does not stop environmental quality more than liquid waste control programmes directed deterioration; at industrial and commercial enterprises. ·· Under C, deterioration continues largely unchecked. Figure 1 illustrates the basic relationships in the “general A negative feedback cycle emerges under C1, and impact chain” outlined above. Typically, as urbanization the deterioration in environmental quality becomes progresses and cities grow, urbanization activities have increasingly rapid. large, negative environmental impacts and few measures to It should be stressed that, as with many other aspects of city address these impacts are taken, either directly or indirectly. development, natural environment impacts can be highly As illustrated in Figure 2 below, the city thus progresses path-dependent and may be more or less difficult to reverse. rapidly from top to bottom along the vertical axis, and is For example, ecosystems that have been built on are lost, characterized by a rapid deterioration in environmental but deforested areas and degraded wetlands can be restored. condition. As the consequences and costs of this deterioration The problem is that this restoration can be very difficult and become evident, direct and indirect measures may be too costly to be feasible. Once ecosystems such as wetlands undertaken and the city may begin to move increasingly in urban areas have become severely impacted, they are up the vertical axis. At a certain point, at least as regards often effectively eradicated, as is the stream of services they some natural assets and ecosystems, a positively reinforcing can provide to support economic production and human well- feedback cycle between environmental quality and being (Box 2; Turpie et al., 2016). However, with appropriate environmental interventions may set in (the better the base policy and sufficient resources it is possible to significantly condition of the environment gets, the greater the positive improve the quality of a deteriorated urban river system, or impacts of any set of environmentally targeted actions), city atmosphere, within a reasonable period of time. Choices and the city may begin to reverse its direction of travel like these can have important consequences for a city’s (environmental conditions may actually improve). economic and fiscal future. Figure 2: Relationship between urban growth and natural environment quality over time High A1 Environmental A quality B C Low C 1 Small City growth Large 6 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services The relationship between City Growth and the Natural Environment Box 1: Cities can intervene to improve the environment and its benefits to people Mexico City and London provide examples of how cities can utilize different measures to reduce their impact on the environment, and at the same time, benefit their citizens with improved environmental quality. In the early 1990s, the United Nations monoxide and other pollutants have declared Mexico City’s air quality as also been reduced. the lowest in the world. Through a Meanwhile, London has been able series of actions that have included to reverse the city’s impact on the replacing old cars, removing lead from watershed of the Thames River. In the gasoline, adopting the use of natural 1950s, pollution from the city caused gas in transportation, and expanding oxygen levels in the river to be so low public transportation, the city has been that the river was declared biologically able to reduce the health impacts dead. With the implementation of air pollution drastically. Although of strict regulations that prevent the city still has a long way to go the dumping of pollutants, better in improving its air quality (such as treatment and diversion of sewage dealing with high levels of ozone and from the city, and the rebuilding fine suspended particles), the average of mud banks and other habitat, concentration of lead (which can the river has made an impressive cause neurological effects in children) comeback. The combined effect of has dropped by approximately 90% these interventions has resulted in a (from 1.30 μg/m3 to 0.13 μg/m3), swift resurgence of riverine fauna, and and the concentration of sulphur today, more than 100 species of fish dioxide (which can cause respiratory inhabit the river and wading birds have problems) by approximately 91% become a common sight. (from 58 ppb to 5 ppb). Carbon In an urban context, the core insight of the “sustainable features of Africa’s urbanization will affect the character development” thesis is that while in the short term human of the cities that emerge, and hence their environmental welfare gains may be compatible with paths B and C, in impacts. It is thus important to understand the nature the long term these paths will erode the natural assets and of the urbanization process in Africa; how this process ecosystems on which economic production and human is shaping SSA cities; how city development is, in turn, life rest. It is thus important that, directly and indirectly, affecting the natural environment and the feedback measures are consistently undertaken to bend the trajectory loop between the environment, urban character and of urban development from B or C to A, or cities will become environmental measures. It also needs to be recognized increasingly costly, less productive and less liveable. that the dynamics of political economy (such as immediate demands for housing; the influence of powerful developers Influencing the trajectory requires understanding the nature over environmental decisions) and fiscal and institutional of urbanization constraints determine and circumscribe the priorities and Sub-Saharan Africa (SSA) is no different than any other limits to action. A consideration of such factors in any given region in that its urban and environmental futures are context is necessary to inform what measures may or may interlocked and will ultimately either be virtuously or not be possible at any time, and the design of feasible viciously correlated. And, like other regions, the specific environmental instruments. URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 7 B Box 2: Lessons from Kampala’s Nakivubo wetland (Source: Turpie et al., 2016a) The Nakivubo wetland, one of several large wetland systems that are found within and around the city of Kampala, is severely degraded. Polluted water from the city passes through the wetland before entering Inner Murchison Bay. In the late 1990s, it was ascertained In this study, a sequential set of Recreational that the water treatment service performed by the wetland yielded a interventions was identified to restore the wetland to a level where economic benefits would significant cost saving for the nearby Ggaba Water Treatment Works. benefits could be realized. This “treatment train” included improved exceed US$22 However, as the city has continued to sanitation infrastructure and measures, grow, pollution flows into the wetland extending and upgrading the waste million per year. have increased significantly, while the water treatment works, wetland size and assimilative capacity of the wetland has decreased. As a result the rehabilitation, conservation measures, and investment in recreational facilities. __ nearby water treatment works has been Excluding some of the required upgraded twice and new treatment sanitation work which is already works have been sited far from the underway, the proposed fix would incur above. Now it is too costly and, from city. Fisheries in Inner Murchison Bay an initial cost of US$53 million, with a political point of view, impractical to have also all but collapsed, and the ongoing maintenance and operating restore the wetland to a state where wetland itself has become the site of costs of US$3.6 million per year. these benefits can be achieved. This slum development. These concerns, as lesson holds for the many additional Benefits of the project would include well as the increasing shortage of public wetland areas that could become water treatment cost savings of US$1 open space areas in the city that are engulfed as Kampala continues to grow. million (limited because of sunk costs) available for recreation, have led to the Most wetlands within the existing urban and recreational benefits exceeding city’s consideration of the rehabilitation area have already been effectively lost. US$22 million per year. The net present of the Nakivubo wetland, both to Without proactive interventions, the value of the project over 15 years restore its functioning and to create the wetlands outside of the present urban would be in the order of US$80 million opportunity for a recreational area with core will also be destroyed and the (-US$24 to US$220 million), and the associated possibilities for economic cumulative impacts on Murchison Bay internal rate of return would be in the development. and any economic activities around the range of 20% (4% to 34%), depending bay, including the viability of a future on assumptions. The restoration would waterfront development, could be also enhance the feasibility of creating significant. a waterfront development next to the wetland. Nevertheless, the initial capital One of the main challenges in achieving costs are high, and such a project may such interventions will be institutional. well not be undertaken due to financial Greater Kampala extends well beyond constraints and political intractability. the boundaries of the Kampala Capital City Authority (KCCA), which originally There are important lessons to be encompassed the entire city. Unless the learned from this study. Considerable KCCA area is adjusted accordingly (as environmental, economic and fiscal has been done in other countries), the costs have been incurred by allowing problems that will arise in a growing the built environment to encroach on city will be in areas under multiple and largely eradicate a crucial part of other jurisdictions. the city’s natural capital endowment. A green urban planning paradigm (see Section F) would have yielded the sustained flow of benefits outlined 8 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services The relationship between City Growth and the Natural Environment URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 9 C THE KEY CHARACTERISTICS OF AFRICA’S URBANIZATION Four key features of the urbanization process in Africa appear to have significant impacts on the way in which city growth is affecting the natural environment. Late but rapid Low levels of wealth, urbanization fiscal resource and service delivery Low levels of Institutions and industrialization, systems are weak motorization and technology 10 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services The Key Characteristics of Africa’s Urbanization annual urban population growth rate is projected to be between 1.44% and 1.84% from 2015 to 2030 (WHO 2015). From an environmental perspective, this has two important Late but rapid urbanization implications. On the one hand, most of Africa’s urban space Africa is urbanizing late but fast. Urbanization in Africa began has yet to emerge. Much of the area which will eventually later than in any other global region and, at a level of about be covered by the built environment has not yet been approximately 40%, Africa remains the least urbanized constructed and populated. Crucial natural assets – and region in the world. However, as indicated in Figure 3, this is significant biodiversity – thus remain intact in areas to which rapidly changing: SSA’s cities have grown at an average rate cities will eventually spread. On the other hand, this is of close to 4.0% per year over the past twenty years, and changing quickly: pressures on the natural environment in are projected to grow between 2.5% and 3.5% annually from and around cities are escalating steadily and these assets are 2015 to 2055 (Figure 3). By contrast, globally the average increasingly under serious threat. Figure 3: Rural and urban population growth in Africa and the average rate of urban population growth (1950 – 2055) (Source: WHO 2015) 1,200 6.0 1,000 5.0 800 4.0 Population (million) Percentage (%) 600 3.0 400 2.0 200 1.0 0 0 55 55 60 60 65 65 70 70 75 75 80 80 85 85 90 90 95 95 00 00 05 05 10 10 15 15 20 20 25 25 30 30 35 35 40 40 45 45 50 50 5 05 20 -20 20 -20 20 -20 19 -19 20 -20 19 -19 20 -20 20 -20 20 -20 20 -20 19 -19 19 -19 19 -19 20 -20 19 -19 20 -20 19 -19 19 -19 19 -19 20 -20 -2 50 19 Rural population Urban population Africa’s urban population growth rate URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 11 C Low levels of industrialization, motorization Low levels of wealth, fiscal resource and service delivery and technology Africa is urbanizing at substantially lower levels of wealth Africa is urbanizing at relatively low levels of industrialization than other regions (Figure 5). This is aggravated by low (Lall et al., 2017), motorization and technology. For example, proportions of overall capital investment (infrastructure, at levels of 42, 25 and 39 per 1,000 population, respectively, housing and office building) which remains at around 20% of motorization levels in Nairobi, Dar es Salaam and Dakar are GDP. In contrast, capital investment in China rose from 35% low by international standards (Behrens et al, 2016; CETUD, to 48% of GDP at the time that its urbanization level rose 2015). This has varying effects on the urban environment. from 18% to 52% of the population (1978-2012), and capital For example, while atmospheric emissions related to investment in East Asia as a whole remained above 40% transportation and manufacturing are relatively low, heavy over this period (Lall et al., 2017). reliance on biomass fuels in African cities tends to generate high levels of fine and small particulate matter (PM2.5 and PM10)1 relative to other regions (Figure 4). Figure 4: Average annual small particulate matter (PM10) concentrations for cities in SSA and other regions (Source: WHO 2016) 600 550 500 Annual mean PM10 (µg/m3) 450 400 350 300 250 200 150 100 50 0 zh ai B g ng ng ng es r On rg ha te ba m o Ka da ya a itt nj g a ed i w ad i An ar Lo es w n rk ris m elh Pe pind nn ka ra pal tn Ba air n on Ne o ijia gh Ch nga Lo haw Yo bu l Pa ea A en Ra ab its ua Ho eiji Ko nd ge ha Da Pa Ah D rC ag Na m Sh an al s Sh s Gr Jo China Africa South-East Asia America & Europe WHO guideline, annual mean PM10 1 Small and fine particulate matter (PM10 and PM2.5) include pollutants such as sulphates, nitrates, black carbon, and dust which penetrate deep into the lungs and cardiovascular 12 system, posing the greatest risks to human health (WHO 2016) Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services The Key Characteristics of Africa’s Urbanization Figure 5: GFP per capita of different regions, at Sub-Saharan Africa’s current urbanization level (Source: Lall et al., 2017) US$3,617 Urbanization 41% 41% rate 37% 37% (percent) US$1,860 US$1,806 GDP per capita US$1,018 (2005 US$) Latin America Middle East East Asia Sub-Saharan and the and North and the Africa Caribbean Africa Pacific (2013) (1950) (1968) (1994) In the context of rapid urbanization, and in combination is characterized by poor levels of infrastructure and service with other factors (such as weak planning and institutional delivery. Third, in the context of social and political pressures capacity), this has had three important and interrelated which tend to emphasize the delivery of services focused impacts. First, relative to city size, fiscal resources are on access and immediate human consumption (water, roads extremely limited. This is reflected in exceedingly low public and so on), infrastructure and services which deal with waste expenditures on urban infrastructure which (outside of are deprioritized and receive little of the scarce resources South Africa) are normally in a range of less than US$1 per that are available. Thus, the urban population without access capita per year to around US$15 per capita per year.2 Second, to improved sanitation has grown steadily over the past 2-3 household resources for investment in housing and payment decades from 89 million in 1990 to 189 million in 2010 (Figure of service charges are also very limited, one reason for the 6; AMCOW 2012). For the entire region the proportion of very high proportion (at 70% by far the highest in the world) urban residents with access to sanitation was estimated to be of the urban population living in informal settlement, which only 37% in 2010.3 Figure 6: Urban population without access to improved sanitation in Sub-Saharan Africa (1990-2010) 200 access to improved sanitation 180 Urban population without 160 (millions) 140 120 100 80 60 1990 2000 2010 2 World Bank staff calculations drawing on various data sources 3 World Bank staff calculations URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA drawing on various data sources 13 C Solid waste coverage also remains very limited with poorly capacitated. Most metropoles traverse numerous collection rates for many African cities at below 50% (Table jurisdictions, managed by different elected bodies, local 1). The upshot is that African cities appear to be doing less government structures and agencies, many of which have to manage the waste that their urban populations and fragmented and/or overlapping planning and regulatory enterprises generate than most other cities in the world. authority which restricts effective urban environmental management. Even in cities widely regarded as amongst the urban management leaders on the continent (such as Durban), tectonic faults impose severe effectiveness constraints (see Box 3 below). Second, institutional systems pertaining to the administration of assets which are critical to the nature Institutions and systems are weak of urban development suffer from severe deficiencies. As Institutions and systems which are cardinal to effective regards land, for example, cities struggle with overlapping urban development and management are weak. There are and contradictory property systems, in which rights are two respects in which this has important implications for the often unclear and administrative systems function poorly. natural environment. First, it is clear – for example – from In West Africa, for example, only 2-3% of land is held evidence assembled by the World Bank in the course of with a government registered title. In addition, across the undertaking Urbanization Reviews in ten African countries in continent, planning regulations are often anachronistic, recent years,3 that the organizations which are responsible restrictive and impracticable from an enforcement point of for planning, managing and governing African cities tend view (Lall et al., 2017). to be jurisdictionally fractured, weakly empowered and Table 1: Percent of municipal solid waste collected in selected cities of Sub-Saharan Africa (SSA), East Asia and South Asia (Source: Hoornweg & Bhada-Tata 2012) Urban Solid waste collection Country (Data source) City Year Population coverage (%) Benin (UNSD 2009) Paralou 2002 148,450 10 Burkino Faso (UNSD 2009) Ouagadougou 1995 876,200 51 Cameroon (Parrot et al., 2009) Yaounde 2005 1,720,000 43 Chad (Parrot et al., 2009) Ndjamena 2003 800,000 15-20 Cote d’Ivoire (Parrot et al., 2009) Abidjan 2002 2,777,000 30-40 Guinea (UNSD 2009) Conakry 2007 3,000,000 76 Kenya (Parrot et al., 2009) Nairobi 2006 2,312,000 30-45 Mauritania (Parrot et al., 2009) Noualchott N/A 611,883 20-30 Senegal (Parrot et al., 2009) Dakar 2003 1,708,000 30-40 Tanzania (Parrot et al., 2009) Dar es Salaam N/A 2,500,000 48 Togo (Parrot et al., 2009) Lome 2002 1,000,000 42 Zambia (UNSD 2009) Lusaka 2005 1,300,000 18 Zimbabwe (UNSD 2009) Harare 2007 2,500,000 99 China, Hong Kong SAR (UNSD 2009) Hong Kong 2007 6,926,000 100 China, Macao SAR (UNSD 2009) Macao 2007 525,760 100 Indonesia (UNSD 2009) Jakarta 2004 8,962,000 86 Philippines (UNSD 2009) Manila 2007 1,660,714 95 Nepal (Asian Development Bank 2013) Kathmandu 2003 738,173 86 Sri Lanka (UNSD 2009) Dehiwala-Mount Lavinia 2007 206,787 96 Moratuwa 2007 189,790 90 3 These countries include Ethiopia, Kenya, Ghana, Senegal, Malawi, Cote d’Ivoire, Nigeria and 14 (forthcoming) Tanzania, South Africa and Mozambique Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services The Key Characteristics of Africa’s Urbanization Box 3: Challenges of managing environmental assets under overlapping jurisdictions Durban, South Africa, faces challenges in environmental management due to two parallel structures that govern land within the eThekwini Le Mercy municipality’s boundaries. Cato Ridge Approximately 36% of the municipality is controlled by the eThekwini Municipal Authority, while 37% falls within traditional authority areas administered by the Ingonyama Trust Board, which is under the Hammersdale national-level administration by the Minister for Rural Development and Land Reform. While the Durban eThekwini government has developed an ecosystem management and protection program for green open spaces throughout the city, a large part of this land Urban development line lies within traditional authority areas, limiting the Umbumbulu eThekwini Metro eThekwini government’s authority to administer green Tribal name open spaces. Cele/Vumengazi Dassenhoek Dar es Salaam, Tanzania, has a complex and Embo/Kwakhabazela fragmented institutional structure comprised of three Embo/Nkasa Isimahla municipalities: Ilala, Kinondoni and Temeki, in addition Fredville Ilanga to a central coordinating entity called the Dar es Ingqungqulu/Thembu Salaam City Council. Each municipality is governed Luthuli/Umnini Trust by its own mayor and municipal council and has Umgababa Makhanya/Sobonakhona Manganeni/Vumazonke its own individual departments, often lacking staff Maphumulo dedicated to environmental management. Both of the Umkomaas Ngcolosi Phephetha municipalities as well as ministries and agencies of Qadi the national government manage key environmental Qiniselani Manyuswa functions including water supply and sewerage, Shangase Toyana transport and traffic management and urban planning. Ximba This fragmented structure inhibits comprehensive and effective environmental management of the city’s Traditional Authority Areas within eThekwini Municipality aquatic and terrestrial assets. (Source: Corporate GIS, eThekwini Municipality) From an environmental perspective, these institutional directed actions. With the possible exception of some South realities have two key impacts. First, with very few African cities, the research undertaken for this report was exceptions, cities are unable to grow in a manner which unable to discover any effective or sustained programmes conserves and enhances key environmental assets. While or actions currently being undertaken by African cities to African cities are not necessarily more fragmented than cities protect or restore ecosystems. In short, African cities lack the in other regions, their development takes place in an ad hoc, institutional capacity and resources to initiate actions which unplanned manner with little regard for the importance of could arrest the development of an increasingly negative environmental assets and ecosystems and the benefits that feedback loop and begin shifting their development from derive therefrom. Second, urban management institutions in path C and B towards path A. Africa are largely unable to take effective environmentally URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 15 D ENVIRONMENTAL TRENDS IN AFRICAN CITIES Although urban areas cover a relatively small proportion of the Earth’s surface, their expansion drives global environmental change (Seto et al., 2012). Rapid urbanization, coupled with low levels of wealth and technology and weak institutions, have had a combined effect on the environment that has been particularly severe in Africa. Poor and ineffective planning has led to the transformation of valuable ecosystems and other open space areas in and around cities, while a growing backlog in infrastructure investment and service delivery has led to major problems of pollution, flooding and overconsumption of resources. All of these problems, along with a lack of protection from invasive alien species, have had major impacts on ecosystems and biodiversity. These problems, discussed in more detail below, will be exacerbated by the effects of global climate change while also contributing to the problem. 16 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities Urban encroachment on natural ecosystems The transformation of open space areas within African There is often very little green open space remaining within cities has come about through both formal and informal African cities, particularly the poorer cities. The amount development. Due to the strong demand for housing close of all public parks, recreation areas, greenways, water to the city centre for access to employment and transport, ways and other protected areas accessible to the public is suitable open space areas tend to be developed in these estimated to be below 1 m2 per inhabitant in some African areas first, leaving only wetlands and river floodplains. As cities, such as Luanda, Cairo and Alexandria (African Green the alternatives for informal settlement become increasingly City Index 2011). This is well below the 9 and 30 m2 per distant from the city centre, so the demand for these central capita recommended by the World Health Organization and floodplain areas increases, in spite of the high risks of United Nations, respectively. flooding. Examples of this are seen in most African cities, including relatively high income cities such as Durban. This In Dakar, Senegal, the amount of green open space within pattern can be expected to radiate outwards over time. the city decreased by approximately 34% over a twenty year Indeed, there are many African cities in which high risk areas period between 1988 and 2008 (World Bank 2009). In Addis are under informal settlement even at some distance from Ababa, Ethiopia, most of the urban trees have been cleared the city centre. for housing purposes and it is estimated that vegetation coverage, including trees in private yards, cover 7,900 ha In Dar es Salaam, for example, thousands of informal or just less than 15% of the total city land area (Dubbale et dwellings are situated along river banks and floodplains al., 2010). Rapid urbanization has also been identified as the of the Msimbazi River system, with densities increasing major cause of the depletion of green space in the city of downstream towards the city centre (Figure 7, Turpie et al., Kumasi in Ghana, once known as the “Garden City of West 2016b). While there is provision for a 60 m protected River Africa” (Mensah 2014a, b). Many of the parks and garden Reserve on either side of all rivers in the city (as outlined in spaces within the city that were once in a good condition the Environmental Management Act of 2004), this post-dates have been degraded or encroached, and green open space much of the settlement and has been difficult to enforce. As now covers only 10% of the total land area (Mensah 2014a, a result, there are frequent episodes of flooding and loss of b). In South Africa, the Durban Bay estuary has been reduced human life. by about 57% and only 14% of the original tidal flats, 3% of the mangrove forest and 4% of the natural shoreline habitat remain (ERM & MER 2011). Other estuaries in Durban have lost more than 70% of their original fish habitat (Forbes & Demetriades 2010). Figure 7: Msimbazi River flowing through dense residential area in Dar es Salaam showing informal structures erected in the floodplain (Source: Google Earth) < 1m2 per capita Access to public parks, recreation areas, greenways, water ways and other protected areas is below 1m2 per capita in some African cities. URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 17 D Wetlands are also attractive for settlement as they provide the unscrupulous creation of title deeds as well as lack of opportunities for alternative income sources such as enforcement. The functional area of Nakivubo Wetland, harvesting resources, farming and brick making (Vermeiren centrally located between the city centre and Lake Victoria, et al., 2012). In Kampala, where over 60% of the population shrunk from its original extent of 500 ha to 400 ha by 1955, live in informal settlements, encroachment into the city’s 280 ha by 1990 and 90 ha in 2015; an 82% reduction in wetlands has been extensive, and only about 8% of the wetland area (Turpie et al., 2016a). Each year the numbers of remaining wetland area within the city boundaries is still rural poor living in slums within or adjacent to wetland areas highly functional (Figure 8, Isunju et al., 2013, KCCA 2014). The increases, resulting in the subsequent degradation or loss wetlands have been encroached by transport infrastructure, of wetland habitat surrounding the city along the northern industry and informal settlements as well as being drained shores of Lake Victoria. This has had major impacts on water for small-scale agriculture. Despite legislation preventing quality, fisheries and human health as well as biodiversity development of these areas, this has been facilitated by (see Box 2). Figure 8: Informal households situated in four wetlands (Nakivubo, Kinawataka, Kansanga and Kyetinda/Ggaba) that drain into Murchison Bay of Lake Victoria (Source: Isunju et al., 2016) Surveyed households Wetland boundaries Kilometers 0 1 2 3 18 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities Figure 9: Probability of urban expansion in 39 high fertility African countries, 2030 (Source: Seto et al., 2012) Likelihood to become urban by 2030 100% National boundaries Kilometers 39 High fertility African countries 0 250 500 1,000 Urban extent circa 2000 1% As well as the transformation of habitats within cities, all 9). This growth is estimated to be concentrated in five main cities expand over time and invariably adjacent lands become regions: the Nile River in Egypt; the coast of West Africa on incorporated into the urban fabric. Seto et al., (2012) have the Gulf of Guinea; the northern shores of Lake Victoria in predicted that by 2030 more than 5.87 million km2 of land will Kenya and Uganda and extending into Rwanda and Burundi; be converted to urban areas globally. Based on present and the Kano region in northern Nigeria; and greater Addis Ababa, projected regional urban populations, population densities Ethiopia (Seto et al., 2012, Figure 9). The results show that and GDP values, they also predicted that the rate of increase there is, in fact, a high probability that the northern shores of in urban land cover will be highest in Africa, increasing to Lake Victoria, from Kampala, Uganda to Kisumu, Kenya, will almost six times the 2,000 urban land cover levels (Figure become one contiguous built-up area (Seto et al., 2012). URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 19 D Whereas neither the rate of growth nor the horizontal exponentially from 71 km² to 386 km² (Vermeiren et al., extent of this growth is unusual in African cities, it is the 2012). This is expected to increase to 653 km² in 2020 and unplanned nature of this growth that is of particular concern. up to almost 1,000 km² by 2030 (Figure 18, Vermeiren et al., While well-planned growth might minimize the costs of 2012), and if uncontrolled could result in significant losses expansion and capitalize on the potential services offered by in surrounding forest and wetland habitats and associated maintaining selected natural systems, uncontrolled growth ecosystem goods and services. can incur disproportionately high costs through indiscriminate Most of the population growth in Dar es Salaam over the last degradation and loss of natural systems. Uncontrolled few decades has been in informally-developed settlements, expansion leaves peripheral city areas without the benefits with new settlements swelling at the urban periphery. of green open space areas. This is particularly pertinent Between 1982 and 2002, more than 15,500 ha of open space in African cities, where the majority of urban poor live in or agricultural land was transformed into urban land uses informal settlements and may be more dependent on natural with more than 75% of these new developments being systems to meet their basic needs, particularly in peri-urban classified as informal. While much of the influx of people is to areas (Boon et al., 2016). informal settlements near the city centre, population growth The city of Kampala is one of the fastest-growing African is also rapid at the periphery, with peripheral municipal wards cities (Vermeiren et al., 2012). During the last two decades accounting for 42% of the total population increase between the city has expanded in all directions beyond the 2002 and 2012 (World Bank 2015a). While continued influx administrative city boundary, incorporating satellite towns into the city centre leads to increasing densities, the densities and transforming surrounding agricultural and natural land. tend to decrease outwards from the city centre (Congedo & Between 1989 and 2010 the total urban area increased Munafo 2013), with the peripheral areas grading into rural Figure 10: Growth of Lagos city over the last 50 years. Green open space areas in the city cover less than 3% of the total land area (Source: Sawyer 2013) 20 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities agricultural homesteads. Pressure on the remaining natural (Figure 11). Increasingly, however, these are under threat and resources in these areas is intense, and these peri-urban a combination of proactive planning measures to secure a inhabitants mostly exist in highly degraded landscapes. potentially green city structure and assertive management steps to preserve and enhance the quality of natural assets In 2008/09, 49% of the eThekwini (Durban) municipal within this structure will need to be taken to avoid the fate of area was classified as “transformed” (i.e. converted for Dakar, Senegal (urbanization level 45%), where the pattern development), and by 2014/15, this had risen to 53% of growth of the city has effectively eradicated almost all (EPCPD 2015). The municipality encompasses a significant natural assets up to a distance of 15 km from the CBD. amount of rural and peri-urban land as well as the city of Durban. Much of this area falls under traditional authorities Figure 11: which lack formal planning schemes to Urban land cover in Addis Ababa, Nairobi and Dakar ca. 2010 (work done for regulate land use activities (see Box 3). study based on satellite image analysis) Land here falls under traditional tenure and (World Bank 2015c) allocation systems and the relative ease of acquisition by in-migrants appears to have had a spatially distortionary impact 100% Addis Ababa on the development of the city. Despite their relatively remote location, these 80% areas have seen significant increases in Land cover population, resulting in loss of important 60% biodiversity areas (Boon et al., 2016). Rapid urbanization has caused substantial 40% loss of habitat in a number of West African cities (e.g. Lagos, Ibadan, Kano, Kaduna, 20% Sokoto, Dakar, Freetown, Abidjan, Accra, Kumasi and Tema) (see Figure 10), with 0% open space and peri-urban forests being 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 transformed for housing or converted into Nairobi dumping sites (Fuwape & Onyekwelu 2010, 100% Mensah 2014). 80% Examination of land use patterns in three African cities illustrates both the challenges Land cover 60% and the opportunities surrounding the relationship between the natural and built 40% environments within these settlements. In Addis Ababa, Ethiopia (urbanization 20% level around 18%), significant areas of well-located open space remain close to 0% the city centre, but these have largely been 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 denuded of vegetation and the quality of terrestrial assets has declined (Figure Dakar 11). In other words, the structure of the 100% city still permits for the development of a more harmonious relationship between 80% natural and built environments, but much Land cover more active steps will need to be taken to 60% manage the remaining natural assets well if they are to contribute effectively to the 40% health of the city. 20% In Nairobi, Kenya (urbanization level approximately 25%), key vegetated and 0% relatively high-quality natural assets (such 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 as the Nairobi National Park, located about Distance to CBD (kilometers) 7 km from the Central Business District (CBD) remain close to the city centre Built-up Vegetation Bare soil Road URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 21 D Supply and consumption of natural resources has resulted in urban consumers relying on biomass fuel, When people move to cities, their resource demands may which degrades forests, produces high particulate matter change to some extent. For some, the direct dependence concentrations and high carbon emissions. In Sub-Saharan on natural resources may decrease as a result of increased Africa, 73% of the urban population uses biomass fuels income opportunities. Many, however, remain reliant on (wood, charcoal, manure, crop residues) as the main source agriculture and natural resources, leading to the conversion of energy for cooking and heating (Ezzati 2010), with of open space areas described above, as well as the charcoal being the most common choice in most cities (Zulu depletion of local forestry and fishery resources. In general, & Richardson 2013, Sedano et al., 2016). Charcoal production however, the growth of city populations and incomes leads to for urban energy consumption is a main driver of forest increased rates of consumption which increase the footprint degradation in Sub-Saharan Africa (Sedano et al., 2016). of cities, or the amount of resources that have to be provided For example, there have been three distinct waves of forest from other areas. The combined effect of a growing urban degradation emanating from Dar es Salaam (Ahrends et al., population and a higher per capita demand for resources, has 2010, Figure 12), for high-value timber, medium-value timber resulted in a significant increase in the amount of pressure and then charcoal. Between 1991 and 2005 the zone of being placed on ecological resources both in and around cities impact of these activities extended significantly (Figure 12). (Giljum et al., 2009, WWF 2016). These include fuelwood, In 2005 charcoal production had become the dominant use up charcoal and water, the excessive use of which is harmful to 50 km from the city and extended as far as 170 km from to surrounding environments from which they are sourced, Dar es Salaam, with the outer boundary of the area where as well as leading to localised problems of environmental charcoal production was the dominant use having moved 30 degradation. km (i.e. 2 km per year). The forest reserves close to Dar es In African cities, constrained access to, and relatively Salaam have also been impacted, with a loss of more than high costs of electricity and Liquid Petroleum Gas (LPG) 30% of forest cover (World Bank 2015a). Figure 12: Map of the degradation waves of dominant forest use in the study area in 1991 and 2005 (Source: Ahrends et al., 2010) 1991 2005 Charcoal wave 1 2 DES DES 4 5 6 3 Low/medium-value Charcoal wave timber wave 7 High-value timber wave Low/medium-value timber wave 8 Dominant forest use charcoal burning 9 Dominant forest use logging 10 of low/medium-value timber Dominant forest use logging of high-value timber High-value Kilometers 11 timber wave 0 10 20 30 40 12 1 Ruvu North FR; 2 Pande GR; 3 Ruvu South FR; 4 Pugu FR; 5 Kazimzumbwi FR; 6 Vikindu FR; 7 Kisiju; 8 Mchungu FR; 9 Ngulakula 22 FR; 10 Ngumburuni FR; 11 Namakutwa; 12 Kiwengoma Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities In Durban, the influx of poor households into its peripheral Because of the rapid growth of informal settlements, fiscal traditional authority areas has increased the demand constraints, and weak institutions, Africa has made limited for natural resources in these areas. With increased progress in providing residents with access to basic sanitation development, unauthorized activities such as sand mining (see section C). For example, in Kampala it is estimated have become more prominent causing habitat degradation, that only 5% of the population is connected to the sewer infilling, bank erosion and the subsequent loss of sand to the network, with 95% of the population having access to basic coastal environment. The eThekwini Municipality systematic on-site, mostly shared, sanitation (NWSC 2014). This has conservation assessment has shown that by 2012, about resulted in significant degradation of surrounding wetland half of the natural vegetation in the eThekwini Municipality areas. The volumes of flows entering wetland channels have (Durban) was degraded (Mclean et al., 2016). A significant increased significantly with increased contaminated runoff proportion of the remaining open space area in Durban is from informal areas and the generation of large volumes located on tribal land, requiring proactive management and of partially-treated wastewater from the overburdened coordination between local government and tribal authorities sewage works. Current levels of pollution in the Nakivubo to prevent further environmental degradation. Wetland are hazardous to human health, with high levels of human excreta, patristic nematodes and faecal bacteria being Much of the urbanization in Africa has occurred in coastal recorded (Turpie et al., 2016a). This has significant negative areas (Small & Nicholls 2003, Seto et al., 2011, Neumann impacts on wetland and lake ecological function and impacts et al., 2015). Given the dependence on natural resources on the cost of water supply to the city from Lake Victoria’s as a low-input option for many poor households, this has Inner Murchison Bay (see Box 2). In Kinshasa, Democratic led to concentrated pressures on coastal mangrove and Republic of the Congo, the expansion of informal settlements fishery resources. Due to poor management and lack of has also been found to contribute to the costs of water enforcement, this has had heavy effects on resource stocks. supply (UNEP 2011). Without action, these pressures will only get worse, as the highest rates of population growth and urbanization are also While it has many benefits, urban agriculture also contributes expected to be in the coastal zone, particularly in Egypt, and to pollution. Fertilizer use in crop fields can be a major in Sub-Saharan countries in western and eastern Africa (Seto contributor to ammonia emissions which react with other et al., 2011, Neumann et al., 2015). chemicals in the atmosphere, increasing PM2.5 levels (World Bank 2016). Moreover, as illustrated by the Nakivubo Urbanization also leads to increasing per capita demands for example (see Box 2), conversion of green assets delivering water, and provision of adequate, safe water supplies is a public benefits - such as wetlands which filter water runoff or major concern in most cities. This is creating challenges in mangroves which protect against flood-surge – to agricultural many cities since much of the continent is arid or semi-arid, uses in which benefits accrue to private interests can and 41% of African countries are water-stressed (WWF 2016). accumulate significant problems for cities. Many African cities have relied on large-scale inter-basin water transfers to meet demand thus far. Water supply The combination of sewage and poorly managed industrial problems are exacerbated by the increasing anthropogenic effluents and agricultural return-flows has led to critical inputs of nutrients and eroded sediments from catchment levels of pollution in many urban river systems, to the point areas that increase the cost of water treatment, coupled of being hazardous to human health. For example, the Little with the loss of loss of natural capital assets such as riparian and Great Akaki rivers in Addis Ababa, Ethiopia suffer from forests and wetlands that play a role in the amelioration of multiple pollution stresses and their water is badly polluted these effects. In coastal cities, excessive pumping of aquifers with trace metals and high concentrations of E. coli bacteria has resulted in the contamination of groundwater resources. (Gebre & Van Rooijen 2009). Similar conditions occur in the In Dar es Salaam, water samples from Mikocheni, Oyster Msimbazi River and its tributaries, which course through Bay, Msasani, Masaki, and the central areas of the city show highly urbanized areas of Dar es Salaam. Coliform bacteria elevated chloride, sulphate and sodium concentrations, and counts at the mouth of the river in the Indian Ocean are over 50% of the samples were brackish (Mitoni 2010). These approximately 1000 times greater than the levels considered problems will be further exacerbated by climate change. safe for swimming (UNEP-NEMC 2014). The Msimbazi also has high concentrations of heavy metals, such as lead, Pollution that exceed WHO drinking water standards (Mwegoha & Most African cities are characterized by high levels of Kihampa 2010). In Dakar, Senegal, biological contamination of pollution. Air pollution is linked to the large proportion of groundwater is a major concern, as 87% of sites within one households that rely on wood fuels for energy, as well as area of the city were found to contain water that is below industrial emissions, fertilizer use in urban and peri-urban WHO standards for human use (Niang et al., 2007 as cited in agriculture, transportation and congestion. Water pollution is UNEP 2014). In Lagos, Nigeria, the Lagos Lagoon is heavily linked to inadequate sanitation as well as industrial effluents impacted by solid waste, sewage and industrial effluents that and agro-chemicals. Solid waste problems are linked to low flow untreated into the lagoon (Amaeze et al., 2012). The fish investments in waste collection services. Most of these fauna has changed in favour of species that are tolerant of problems are exacerbated by a lack of enforcement of polluted and low oxygen waters, such as tilapia and catfish, existing regulations. and the reduction in fish diversity and numbers has been URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 23 D widely observed by local Lagos fishing communities (Amaeze The situation is particularly bad in Nigeria where four of the et al., 2012). In Durban, South Africa, seven of the sixteen worst cities in the world for air pollution are located (Figure estuaries within the municipality are highly degraded, with 13). According to WHO, Onitsha in Nigeria is the world’s overall estuarine functionality reduced to 35% of the natural most polluted city when measuring small particulate matter condition (Turpie et al., 2017a). Contaminated runoff from (PM10) concentrations, with concentrations being 30 times informal settlements, poorly treated sewage effluent and higher than the WHO recommended levels (WHO 2016). The dams that restrict freshwater flows are some of the drivers of poorest segments of society are affected disproportionately Durban’s declining estuarine health. by air pollution impacts, with the poor more likely to work and live in polluted environments (World Bank 2016). The In 2013 air pollution was ranked as the fourth leading fatal disproportionate health burden felt by the poor is due to health risk, with an estimated 5.5 million premature deaths higher exposure to air pollution, low resistance to illness, and attributable to air pollution worldwide (World Bank 2016). a lack of basic services such as sanitation (World Bank 2016). Air quality in most African countries has deteriorated, with few cities having formal air pollution regulations or adequate Given the high percentages of urban populations that are capacity to monitor and enforce emissions. Increasing reliant on charcoal for cooking and heating (e.g. 75% in industrialisation, growing ownership of private motor Kampala), the high air pollution levels in African cities are vehicles, burning of household waste, and the continued probably driven more by household burning of biofuels use of charcoal and wood as a primary household energy than by industry and motor vehicles. This is the main cause sources has raised air pollution levels significantly across of respiratory illness in women and children in informal the continent, with the latter being the main feature of air settlements in Sub-Saharan Africa (UN-HABITAT 2008). In pollution in African cities. According to the latest urban air Africa as a whole, the death toll from indoor air pollution has quality database released by the World Health Organization, grown concurrently with the growth in the size of the urban 98% of the cities in low- and middle-income countries with population (Roy 2016). Among the risk factors to human more than 100,000 inhabitants do not meet WHO air quality health in Africa, air pollution (household and ambient) is guidelines (see Figure 4 and Figure 13). the only factor whose contribution to premature deaths has continued to increase over the past two decades (Table 2). Figure 13: Annual mean concentration of particulate matter in 13 African cities (Source: WHO 2016) Nairobi PM2.5 PM10 Morogoro Vereeniging South Africa Tshwane Johannesburg Hartbeespoort Bamenda Dakar Kampala Umuahia Aba Nigeria Kaduna Onitsha 0 100 200 300 400 500 600 Annual mean concentration (µg/m ) 3 24 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities Table 2: Premature deaths from selected major risk factors in Africa (Source: Roy 2016) Risk Factors 1990 1995 2000 2005 2010 2013 Unsafe water 837,702 780,095 751,892 644,136 561,342 542,855 Unsafe sanitation 615,540 573,084 551,948 468,815 407,092 391,656 Childhood underweight 474,819 467,921 420,606 309,945 273,294 275,813 Household air pollution 396,094 422,895 436,463 429,199 450,969 466,079 Ambient PM pollution 181,291 190,933 200,854 213,429 227,428 246,403 Traffic congestion also plays an important role. The number in size and frequency and exposing inhabitants to increasing of vehicles in Dar es Salaam increased from 24,600 in 1979 flood hazards (ActionAid 2006, Satterthwaite 2008). This is to 705,000 in 2011 and it is projected that there will be made all the more problematic by the increasing numbers of about one million vehicles by 2030 (World Bank 2015a). The people exposed to flood risk as a result of development of numbers of motorcycles and tricycles have also increased, informal settlements in floodplain areas. In Dar es Salaam, contributing to significant increases in emissions. flooding is a major problem which frequently brings the city to a standstill. This is caused by increased development in the Solid waste problems arise from a lack of policy and service catchment leading to higher runoff, inadequate drainage, and provision. Waste policies, such as overall waste management a lack of solid waste management which leads to blocked strategies and environmental standards for waste landfills, waterways. Frequent floods not only result in damages to are seriously lacking in most African cities (African Green City property and direct loss of life, but also disrupt traffic and Index 2011). From a group of 28 cities of over 300,000 people expose people to health risks as a result of exposure to for which there is solid waste management information, none sewage, industrial wastes and waterborne disease (World had guidelines for the management of sanitary landfills, and Bank 2015a). These risks will increase over time as a result of only Ouagadougou, in Burkino Faso, has regulations that further urbanization (Figure 14), and will also be exacerbated mandate the segregation of waste. Solid waste collection by climate change. is also low in Sub-Saharan cities (Table 1), particularly in informal settlements where garbage piles up along walkways and roads, and in gutters, drains and waterways. In Dar es Salaam 18% (767 tons per day) of uncollected waste is controlled on-site by burning. Much of the rest ends up in stormwater drains, contributing to runoff pollution into rivers and coastal waters and exacerbating annual flooding events and health problems (World Bank 2015a). Buildings, roads, roofs, Hydrological changes Buildings, roads, roofs, paved areas, and other hard surfaces paved areas, and other hard surfaces in the built in the built environment prevent rainfall from infiltrating into the soil, increasing the rate and volume of run-off during any given rainfall event. This has two main impacts. First, existing river channels become eroded downwards or laterally, which impacts habitat integrity and creates problems for property environment prevent rainfall owners and city managers. Second, flood inundation areas increase, putting more people at risk. from infiltrating into the These effects are magnified as cities expand and densify. soil, increasing the rate and In Kampala, the construction of unregulated structures in informal settlements has reduced infiltration of rainfall volume of run-off during significantly, increasing runoff to six times more than what would occur on natural terrain (ActionAid 2006). While some of the increase is likely due to climate change, this is largely any given rainfall event. the direct result of land cover change. As a result even moderate storms produce high flows, with floods increasing __ URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 25 D Figure 14: Exposed population in Dar es Salaam to a 1 in 100 year flood event, 2005-2070 (Source: Watkiss et al., 2011) 250 Population exposed (thousands) 200 150 100 50 250 2005 2030 2050 2070 Ilala Temeke Kinondoni Total (Dar es Salaam) In addition, the importation of water from surrounding fragmented urban ecosystems (Zari 2014). These species catchments to meet urban water demands adds to the have a range of impacts, including loss of biodiversity and problem of increased flows within cities. Much of this water disruption of ecosystem functioning, interfering with water is channelled through sewage works, which pump a continual supply and increasing the risk of fire and floods. stream of treated effluent into rivers. In Cape Town, South Durban, located within a global biodiversity hotspot, Africa, the additional water brought into the city has led to has been invaded by at least 130 alien plant species. For the transformation of naturally ephemeral wetlands and example, Spanish Reed (Arundo donax) introduced from rivers into permanent reed-choked systems, as well as the Mediterranean has had a major impact on rivers and the radical modification of most of its estuaries (Brown & streams. These reeds are easily dislodged during floods Magoba, 2009). and as a result cause severe blockages of waterways and culverts, increasing flood damage. In Harare, Zimbabwe, Introduction and proliferation of invasive species the reservoir that supplies 77% of the city’s potable water Invasive alien species are animals, pathogens and plants is clogged with the invasive water hyacinth (Eichhornia that are intentionally or unintentionally introduced from crassipes) and spaghetti weed (Hydrocotyle ranunculoide), other areas, and which are able to spread and multiply increasing evapotranspiration and threatening water supply in the absence of their natural predators or other limiting (Nhapi 2007). In Cape Town, situated within the Cape Floristic factors, causing damage to the environment, economy and Region, invasive Australian acacias not only threaten the human health. They pose a serious threat to biodiversity unique floral diversity, they also impact on water supply and are a growing driver of species extinction (EPCPD and dramatically increase the severity of fires in the city 2015). In particular, they cause the declines or elimination (Richardson & van Wilgen 2004). of indigenous species through competition, predation, transmission of pathogens, and the disruption of ecosystem Biodiversity loss functioning. Biodiversity, a precondition for life on Earth, plays a major Global trade and travel have reduced geographical barriers, role in maintaining ecosystem integrity and resilience. facilitating ease of movement of species around the world. Biodiversity includes ecosystem, genetic and cultural Urban areas, and in particular port cities, are extremely diversity, and the connections between these and all species, vulnerable to the introduction of alien invasive species (van including humans (EPCPD 2015). Global biodiversity losses Ham et al., 2013, Zari 2014). In addition, the planting of exotic have reached unprecedented levels. Monitored species plants in urban parks and private gardens contributes to the population abundance declined by 58% between 1970 and release and spread of alien invasive species into the already 2012 (WWF 2016). The continued degradation of ecosystems 26 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities and loss of biodiversity can have significant impacts on Cities can harbor a surprising amount of biodiversity. With human well-being and economic productivity (TEEB 2010). the transformation of both rural and urban environments, When ecosystems are degraded and biodiversity is lost, the cities can even provide important refugia for some species. biocapacity of the planet to support species populations and Many cities are situated within global biodiversity hotspots, to regenerate natural resources is considerably reduced, including Durban, Cape Town, and several cities along leading to the loss of vital ecosystem services (Zari 2014, the Indian Ocean and West African coasts (Figure 15). In WWF 2016). these cities urbanization’s effect on biodiversity has global consequences. Irrespective of its global significance, the loss Human activities are accelerating ecosystem degradation of biodiversity within cities also has particular relevance for and biodiversity loss at unprecedented rates as a result its inhabitants, since urban biodiversity has considerable of habitat transformation, overexploitation of resources, amenity and tourism value (Turpie et al., 2017a). hydrological alteration, introductions of invasive alien species and pollution. These pressures are particularly severe in African urban environments, as discussed above, and will be further exacerbated by climate change. Biodiversity is also affected by the approach taken to greening cities. In Addis Ababa, Ethiopia, only 10 – 40% of trees planted have been indigenous tree species (Shikur 2011), compared to Durban where 97% were indigenous, 2.7% were fruit trees and only 0.3% were exotic (EPCPD 2015). Figure 15: Global biodiversity hotspots (Source: SCBD 2012) URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 27 D In Durban, only about 10% of the open space area is under in numbers of waterbirds in Durban Bay harbor (Figure formal protection, and much of the remaining biodiversity is 16). Similarly, in Cape Town, also located within a global in private hands or in communal lands on the city’s periphery. biodiversity hotspot, 13 plant species have become extinct With more than 2% loss per year, Durban’s terrestrial and 319 species are threatened by extinction as a result of vegetation faces significant extinction threat. Loss of urbanization; this represents 18% of the threatened Red List biodiversity is also evident in Durban’s estuaries, due to loss species in South Africa (Rebelo et al., 2011). The losses in of habitat and changes in hydrodynamics and water quality. other African cities may be comparable but have not been These impacts, along with international declines in migratory quantified. bird numbers, have contributed to the dramatic decline Figure 16: Total numbers of waterbirds counted in Durban Harbor during counts from 1974 to 2012. (Source: Allan 2012) 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 0 January June December June November May November May 1974 1979 1984 1990 1995 2001 2006 2012 All waterbirds (1974-2013) 28 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Environmental Trends in African Cities Increasing vulnerability to climate change Salaam, Tanzania, and Doula, Cameroon, the degradation and Global climate change is manifest in increasing temperatures, loss of mangrove forests has increased the vulnerability of changes in rainfall pattern, rising sea levels, and increased coastal areas to damages from coastal storm surges (Ellison incidence of storms. These changes, which are already & Zouh 2012). observed, are expected to lead to changes in biodiversity In a sample of 30 African countries, it was found that two- and ecosystem functioning, changes in water availability, thirds are warming faster than the world as a whole (AGI increased severity of droughts and floods, increases in 2017). This trend is expected to continue, placing challenges heat-related illness, and impacts on agriculture and energy on both current and future development progress in African production (IPCC 2007). This will affect economies and human cities, especially given that Africa contains seven of the ten well-being on a global scale, but more so in developing countries that are considered the most threatened by climate countries that are more reliant on land and natural resources change globally: Sierra Leone, South Sudan, Nigeria, Chad, (Tol 2012). Ethiopia, the Central African Republic, and Eritrea (AGI 2017). Cities are particularly vulnerable to many of these effects The cities most at risk are those where extreme events are because of the large number of people, buildings and already common and have already caused serious damage infrastructure potentially exposed to natural disasters such and disruption (Satterthwaite 2008), and where levels of as floods and more intense coastal storms in combination environmental degradation are high and institutions and with higher sea levels, the potential exacerbation of existing policies are weak. heat-island effects, and the fact that their biodiversity Superimposing the climate trajectory on Figure 2 begs the is fragmented, leaving little room for natural adaptation. question as to whether the impacts of climate change will Supplying urban water demands will also become outstrip the ability of city or regional authorities in Africa increasingly difficult under climate change. to take action, keeping success (path A or A1) consistently The degradation of environmental assets, such as forests, out of reach. Increasing frequency of disaster events will rivers, coastal habitats, and wetlands, reduces a city’s potentially put even greater pressures on fiscal resources. It is resilience to climate change, undermining the well-being of not so much that climate change will increase environmental residents and future economic prospects. Climate change degradation (it will, to some extent, through direct pressures exacerbates resource scarcity and places vulnerable on ecosystems for example), but that ecosystems will communities at risk from sea level rise and more frequent become more critical to buffer the impacts of more extreme and intense storms, under which the likelihood of extreme temperatures and storm events. This ramps up the urgency flooding events is expected to increase. Developing countries with which cities need to ensure the protection of these already tend to be less resilient to natural disasters because critical natural areas in catchments, along rivers and along the of fragile economies, poverty, lack of risk awareness, and a coast to protect from flooding, and maintaining tree canopies lack of coping capacity in urban communities (De Risi et al., within city centres to protect from temperature rise (as well 2013, Jalayer et al., 2015). Loss of forest areas and wetlands as pollution). in urban catchments increase the risk of flooding. In Dar es 66% warming faster The degradation of environmental assets, such In a sample of 30 African as forests, rivers, coastal countries, it was found that habitats, and wetlands, two-thirds are warming faster than the world as a reduces a city’s resilience whole (AGI 2017). to climate change. __ URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 29 E COSTS AND CONSEQUENCES Economic consequences Untangling the economic costs of environmental degradation in urban areas is complex, as they usually go hand in hand with poorly-maintained buildings and infrastructure, poorly-organized street-trading and transport activities and high levels of crime. Neglect of city environments also means that they lack the enhancements one sees in developed cities, such as roadside verges, trees and gardens. While the environmental quality of cities may be treated as a low priority by financially-strapped local governments, it has an important bearing on urban, and hence national, economies. Greener and cleaner cities are likely to have healthier and more productive citizens, as well as being more attractive to property developers and buyers, international business and tourism. 30 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Costs and Consequences Deterioration of environmental quality arising from Durban, which has a well-developed network of green urbanization is adversely affecting health, income, open space, shows that the premiums paid for proximity to productivity, and the quality of life in African economies good quality natural and man-made open space areas are and cities. Global welfare losses resulting from exposure significant (see Box 4). These premiums don’t exist where to household and ambient air pollution were estimated open space areas are lacking and house prices are discounted amount to some US$5.11 trillion in 2013, with welfare losses when surrounding natural environments are degraded. in Sub-Saharan Africa equivalent to 3.8% (2.41%-5.54%) of Turnover in property markets is thus significantly affected by the regional gross domestic product (GDP; Figure 17; World environmental quality, and this in turn, has implications for Bank 2016). Urban residents, in particular poor households, the property and financial sectors. are exposed on a regular basis to elevated concentrations of fine particle air pollution, with potentially serious long-term Urban tourism opportunities are being squandered. Although implications for health and well-being. The total foregone Africa is known for its nature-based and largely rural cultural labor output totalled more than US$16 billion in 2013 in tourism opportunities, a high proportion of tourism activity, Sub-Saharan Africa, or 0.8% of GDP (World Bank 2016). The which includes business tourism, is in cities. In South Africa, overall economic loss resulting from lack of access to safe where cities have a relatively high level of well-kept natural water and basic sanitation is estimated at US$28.4 billion open space areas, even a large proportion of leisure tourism a year, or around 5% of GDP in Sub-Saharan Africa (UN is associated with urban areas (Turpie et al., in review). In 2009). The healthcare cost and loss in labor productivity Cape Town, total tourism expenditure including business from mortality and morbidity due to contaminated water is tourism and visiting friends and relatives (VFR) is about estimated to cost the Ugandan economy between US$22-35 US$720 million, and based on visitor data collected locally million every year. and photographic data, nature-based attractions account for an estimated US$127 million of this (Turpie unpublished Property values are affected by environmental degradation. data). In Durban, where total tourism expenditure is about Research undertaken in the relatively developed city of US$520 million, non-agricultural urban open space areas in Box 4: Impacts of green open space areas on property prices (Source: Turpie et al., 2017a) city centre, whereas they are lower in Durban, South Africa, is a garden city located the lower-income inland suburbs such in a lush subtropical coastal environment. It is as Cato Ridge (US$2,900 per ha) and well endowed with both natural and man-made Pinetown (US$32,600 per ha). green open space areas that make up the Durban The total premium associated with public parks was approximately 6.4% Metropolitan Open Space System (D’MOSS). of overall property value, amounting to a total of US$1.06 billion with an A statistical analysis of house sales was 2% of overall property value, average value of US$1.13 million per data showed that prices paid for which amount to US$339 million with hectare. Park are most valuable in and properties in Durban are strongly linked an average value of US$8,377 per ha around the city centre as well as in to environmental factors. Natural of natural space. This is only part of other densely populated areas such open space areas in a good condition the asset value of these areas, which as Chatsworth (5,500 people per km2) attracted significant and positive price also provide other ecosystem services. and Phoenix (6,400 people per km2), premiums while those in a degraded The highest values are within the where residents may value public condition led to discounted prices. main urban core (US$108,000 per ha) open space more than residents living Degraded open space patches are not and along the coastline where high more affluent suburbs with private only unattractive but are also often quality natural coastal forests are still gardens. The high value of parks associated with crime. Man-made intact (e.g. Umhlanga – US$262,000 compared to natural spaces is due to green open space, such as golf courses per ha). The values are also higher in their greater accessibility, perceived and park areas both had a significant and around the suburbs of Hillcrest and safety (being more busy and open positive effect on house prices. Kloof (about US$77,000 per ha), both rather than forested or bushy) and The total premium associated with being affluent areas, much like the more multifunctional uses especially for natural open space in a good condition coastal suburbs of Umhlanga and the families with children. URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 31 E Figure 17: Welfare losses due to air pollution in selected Sub-Saharan African (SSA) countries in 2013, as a percentage of GDP equivalent (Source: World Bank, 2016) air pollution (% of GDP) 6 Welfare losses due to 5 4 3 2 1 0 .) er C R Cô ra L had d’ ne re Ca ud i m an Gu on M G ea ng M aga na (D ri r . R ia hi .) N pia Za eria N ia Be er Bu L nin a a Bu Faso n i an l To a So Ug go h da nz a Zi al a ba i oz Ke e A b a ve u e ) al Se nd m aw Rw ega o au sca ge in ri d Ta fric M ni SS am ny bw CA ep Et ep em tan b oi ig in M ut an ad ha (a iq te eo rk ibe o m o a ra ru ig er Iv (R A S o ng Co Si M Co Durban also coincidentally generate an estimated US$127 far more likely to be able to develop a strong tourism sector million per annum in expenditure (see Box 5). Thus in two within their economies (Runfola & Hughes 2014), and may relatively well-managed African cities, urban open space also be more attractive for business and staging of events. areas contribute 18-43% of tourism revenues. These figures There are also important feedback loops to consider. While represent an important contribution to national exports, maintaining green spaces, trees and gardens and clean river particularly in the case of Cape Town. systems and beaches in cities can bring important economic Nature-based tourism is also important in other coastal and benefits, the revenues derived from tourism can also help to non-coastal African cities. For example, beach-based tourism finance their green features and environmental management. is one of the main attractions in Dar es Salaam, which is In Durban, the tourism value generated from green open evident from the large number of hotels and conference space is higher than the value of developing these areas venues along the city’s coastline. This is also true of lakeside (Turpie et al., 2017b). cities such as Kampala and its satellite town of Entebbe. A lack of environmental management in African cities However, Kampala now faces limitations in the possibilities has also increased the economic impacts of extreme for development of a waterfront area that could generate weather events. As cities grow, the magnitude of flood significant revenue for the city. The management of effluents flows arising from any given rainfall event also grows. This and storm water quality is therefore also crucial to the means that the natural floodplain areas in low-lying parts economic development of cities. of the city also increase. Tolerance of people settling in The full potential of many African cities is undoubtedly these floodplains, and lack of recognition of the increasing limited by their environmental condition as well as other floodplain area or need to increase the capacity of negative factors such as traffic congestion. Green cities are conveyance infrastructure has led to growing numbers of people at risk. It is no surprise therefore, that the numbers of flood-related disasters have increased exponentially. This is in line with the exponential, uncontrolled growth of cities Figure 18: and probably not entirely to be blamed on climate change, Breakdown of tourism expenditure in Cape Town which further exacerbates this problem. In Dar es Salaam, the expected annual losses from damage US$35m US$127m US$157m US$400m to structures in the Msimbazi floodplain alone amount to an estimated US$47.3 million per year. This does not include the loss of productivity as a result of disrupted work by directly- affected households and businesses. Nor does it include the impacts of traffic frequently being brought to a standstill after relatively normal rains. This cost has not been calculated but is likely to be very significant. Wine tasting Nature-based Cultural Business, VFR The excessive hardening of catchments without maintaining attractions and other and other natural areas has meant that the flood attenuation capacity attractions expenditure 32 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Costs and Consequences Box 5: The importance of environment for urban tourism (Source: Turpie et al., 2017a) The city of Durban is a leading tourism destination in South Africa. The year- round warm weather conditions encourage leisure tourists to enjoy the many outdoor tourist attractions, but the beach and marine environment is known to be the core leisure tourism experience on offer. Tourism expenditure by type of attraction This was the main attraction for 50% of international tourists and 83% of domestic tourists to KwaZulu-Natal (SAT 2014). Nature-based US$12m US$20m US$49m US$57m US$155m activities such as walking, trail-running and bird watching are also important in certain areas, such as on estuaries and wetlands and in the 27 nature reserves and botanical gardens which feature scenic river gorges, indigenous coastal forest and grassland and an abundance of bird life. In 2012, some 15.5 million people visited the city, Rural Parks Nature Beaches Built resulting in a total expenditure of about US$438 areas and marine environment million and a total GDP contribution of US$750 environment million. Of the latter, leisure tourists were estimated to contribute some US$294,000 in expenditure and US$428 million of the GDP contribution. Determining the tourism value of particular areas such as parks or nature reserves usually involves labor-intensive surveys and studies at the scale of a whole city are rare. However, the recent emergence of various social media tools, specifically involving uploading of geotagged photographs, provides an opportunity to assess the spatial behavior of tourists in relation to green space areas. Using data on over 10,000 photographs uploaded to Panoramio.com, which hosts outdoor images of landscapes, natural features and architecture, Turpie et al. (2017a) mapped the value of leisure tourism in Durban. The spatial patterns and photo content analysis suggests that open space areas within the municipal area account for almost half of the tourism attractions in Durban, with coastal attractions, nature areas, parks and rural farmland accounting for 20%, 17%, 7% and 4% of leisure tourism value, respectively. The tourism value associated with the coast is very high, with the most popular coastal areas contributing up to US$5.1 million per kilometer to GDP. Man-made open space such as parks and golf courses contribute US$18,000 per hectare. The combined tourism value of natural and man-made open space is approximately US$180 million. URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 33 E of these areas has been lost, raising the cost of the forfeited, it is clear that environmental degradation can have stormwater conveyance infrastructure such as culverts, pipes a significant impact on city revenues, both from property and drains required to minimize flood risk. In Durban, the taxes and more broadly. This is an important consideration flood attenuation service provided by its remaining natural for achieving self-sufficiency and improving the resilience systems translates to a 0.7%-3.5% capital cost saving in of cities, especially since own source-revenues are likely stormwater infrastructure, which amounts to about US$26 to become more important over time as cities expand and million in net present value terms (equivalent to US$2.3 revenue systems strengthen. million per year; Turpie et al., 2017a). Environmental degradation in urban areas also has a bearing on the cost of provision of services by national institutions. In Fiscal consequences Kampala, the city has always channelled its storm water and Local authorities in African cities are confronted with a treated sewage into the Nakivubo wetland on the edge of widening gap between the availability of financial resources Lake Victoria’s Murchison Bay. The capacity for the wetland to and municipal spending needs. Rapid urbanization in the assimilate these wastes has long since been overwhelmed, context of low levels of household wealth has generated with the result that the bay has become hypertrophic, large informal settlements that need to be provided with harboring frequent algal blooms. This preventable outcome basic services. The funds to provide these and other services has increased the National Water and Sewerage Corporation’s are obtained from the central fiscus as well as from own- source finance, which is mainly from property taxes and service charges. Property taxes form a substantial proportion of city income in most cities, and are directly related to the value of property. In Durban, which still maintains substantial areas of green open space, property owners pay a premium for being close to natural and semi-natural open space areas that are in a good condition. This additional property value translates to additional tax revenues amounting to about US$27 million per year which is at least 5% of total property tax income to the municipality. This amount does not include similar The first health challenge is benefits that could be attributed to the city’s well-maintained beaches. More importantly, it does not include the premium the lack of development and that people are prepared to pay to live in Durban rather than other cities, that could be ascribed to the overall inadequate services, including environmental qualities of this attractive city. While it is safe drinking water and difficult to determine exactly what income a city might have acceptable sanitation. 34 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Costs and Consequences (NWSC) costs of supplying water to Kampala city. The city’s water-borne diseases such as cholera, which resulted in water treatment works, located just 3 km south of the outbreaks in the city in 1997, 1999, 2004, 2006, and 2008. Nakivubo wetland, has been upgraded twice in order to cope In Dar es Salaam households use polluted water from the with the deteriorating water quality, including improvements Msimbazi River to water their vegetable gardens and wash to the facilities and extending the intake pipe deeper into produce, causing the spread of diarrheal disease. The rate of the lake. In spite of this, the cost of water treatment is still diarrhea among children under three years in the informal over US$1 million per year more than it would be if the settlements in Nairobi, Kenya is estimated to be about 8%, water quality were restored (Turpie et al., 2016a). However, which is more than eight times the rate of the city as a whole the sunk costs of the upgrades and the planning of the next (African Population and Health Research Centre 2014). In facility at some distance from the city to obtain cleaner water 1994, 61,960 cases of cholera were recorded, resulting in are probably far more significant. At an estimated US$53 4,389 deaths in Angola, the Democratic Republic of Congo, million, the cost required to undo this damage and restore the Malawi, Mozambique and Tanzania (WHO as cited by Boadi wetland may now be prohibitive. et al., 2005). In that same year, 171,000 cases of dysentery were recorded, with at least 600 deaths reported in Malawi, Social consequences Mozambique and Zimbabwe. In addition, asthma, chronic Environmental quality has a bearing on health and well- pulmonary disease, lead and beryllium poisoning are all being, livelihoods, and household food security through associated with increasing air pollution in African cities opportunities for agriculture and resource harvesting as (Moore et al., 2003). well as recreation. The main ways in which nature or green In other regions, urban green open space areas have been open space contribute to health and well-being in urban shown to have a positive impact on health and well-being. environments include improved air quality, enhanced physical In Spain, Triguero-Mas et al. (2015) found that an increased activity, greater social cohesion, relaxation and stress exposure to green space was linked to both improved reduction (WHO 2016). Rapid and unplanned urban expansion physical and mental health, independent of socioeconomic in Africa has caused severe environmental degradation, status or gender. Evidence suggests that living closer to which has resulted in significant health burdens, rising health urban green space, such as parks, and having higher levels costs, and increased incidences in illness and premature of neighbourhood greenery is associated with lower levels deaths. These impacts affect the poorest households as they of mental illness, depression, anxiety and stress (White et are more exposed to air and water pollution, lack adequate al., 2013, Beyer et al., 2014). In Canada green open space in services and are unable to protect themselves. cities has been associated with a reduction in mortality, in Most urban residents in Africa face numerous health particular, mortality from respiratory disease (Villeneuve et challenges. The first challenge relates to the lack of al., 2012), and in Spain greenness of neighbourhoods was development and inadequate services, including safe associated with lower mortality risk during heat waves (Xu drinking water and acceptable sanitation, affecting poverty et al., 2013). In the United Kingdom an association between levels, malnutrition, and the spread of infectious and small amounts of green open space and elevated risk of parasitic diseases such dysentery, diarrhoea, and cholera circulatory disease was found (Mitchell & Popham 2008) (Moore et al., 2003, Boadi et al., 2005). These problems and in Lithuania, higher usage of green open space reduced are exacerbated by flooding. The second challenge relates cardiovascular disease and walking in parks had a greater to health conditions arising from newly modernizing effect on reducing heart rate and blood pressure than walking societies and changes in lifestyle, such as cancers, obesity, in busy urban streets (Tamosiunas et al., 2014, Grazuleviciene cardiovascular disease, diabetes and chronic respiratory et al., 2015). diseases caused by unhealthy diets, physical inactivity, air The condition of green open space areas is also important. pollution and exposure to toxins and wastes (WHO 2016). Degraded open space areas are often linked to crime, which Poorly planned urban environments tend to discourage has massive ramifications for the economy and human physical activity and promote unhealthy food consumption. welfare. In Cape Town, small neighborhood parks are still Overcrowding, high volume traffic, poor air quality and lack abundant, but many are not well maintained and harbor of safe public open space/recreational areas contribute to vagrants and criminals. These parks are effectively not overall low activity levels in African cities. The third challenge available for use, and people avoid using them. To address relates to emerging diseases such as mental health and this problem, the City of Cape Town is changing from many psychiatric disorders associated with poor living conditions, small parks to fewer, large multi-use “smart” parks, which overcrowding and socio-cultural changes (Boadi et al., 2005). will not only contain a variety of amenities, but will also be In many African cities subsistence agriculture is widespread the location of small businesses such as restaurants. The and often situated within floodplains and wetland areas idea is to encourage a high level of use in a well maintained where the water is severely contaminated with pathogens environment, which would deter criminals and allow people that carry a risk to human health. Residents farming in the to come out and enjoy their public open space areas. Nakivubo Wetland in Kampala, for example, are exposed to large loads of parasitic nematodes and faecal bacteria which, when coupled with flooding, cause frequent outbreaks of URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 35 F CHANGING THE TRAJECTORY: GREEN URBAN DEVELOPMENT IN AFRICA Crystallizing the challenge The research presented above indicates that most African cities are on a trajectory of environmental degradation that has become self-reinforcing though negative feedbacks. This is the path C1 described earlier in Figure 2. This situation is not sustainable: cities urgently need to change their trajectory by slowing and ultimately reversing environmental decline. An investment in environmental assets and quality would yield positive economic, social and fiscal returns and rejuvenated cities would be able to make a positive and vitally-needed contribution to national development. 36 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Changing the trajectory: Green Urban Development in Africa As things stand, much of the already-built urban space in An estimated US$7.3 million a year in sea dike maintenance African cities may be too far deteriorated for immediate was saved because of an investment of US$1.1 million on revitalisation to be feasible. However, Africa’s cities are set to restoration of natural mangrove forests. The project areas increase dramatically in extent in the coming years, and this suffered significantly less damage than neighboring provinces is where the opportunity lies. If this growth can be guided during typhoon Wukong in 2000. Such restoration programs appropriately, these newly-developed areas will not only be are also possible in Africa, but will be significantly more more liveable and productive themselves, but will ultimately challenging, given the under-resourced nature of the cities. be able to pay for some of the costs of restoring already- While African cities will have the potential benefit of learning degraded urban areas later. In sum, the key initial priority from other country experiences, a green development is to set African cities on a greener development path; path will still pose particularly acute challenges for the secondly, attention can turn to reversing some of the damage donor community. Much of the damage that has been done that has already been done. is irreversible or prohibitively costly to fix. Swift action While restoration is typically more costly than avoiding needs to be taken to avoid further such losses and wasted degradation in the first place – one reason why a course- opportunities. Given the rapidity with which degradation adjustment for future African city growth is so important takes place under conditions of uncontrolled urbanization, it – there are cases in which investments in the restoration is imperative that cities prioritize taking firm steps to ensure of natural capital will be worthwhile, lowering operating a green approach to city growth before embarking on a costs and supporting local economic development. Massive comprehensive plan towards the remedial actions required to environmental rejuvenation of cities has happened in address existing environmental problems. other parts of the world, such as Singapore, Vancouver, San Francisco, Bogotá, and Curitiba. Cities elsewhere have The elements and benefits of green urban development also started to invest in the ecological infrastructure at From the preceding discussions, it is clear what cities should and beyond their urban limits. For example, New York not do (Box 6). Based on this it is possible to formulate the has secured its source of drinking water by purchasing types of actions that will be required to embark on a green and restoring the Catskill watershed for US$2 billion. A urban development path. The environmental challenges comparable pre-treatment plant would have cost US$7 described above can be alleviated through a comprehensive billion. In northern coastal regions of Vietnam, where more green urban development strategy which tackles problems than 70% of the population is threatened by natural hazards, in multiple and mutually-reinforcing ways. Green urban local communities have planted and protected mangroves. development is an approach that aims to minimize the Figure 19: The main elements of a green urban development policy protected measures to reduce natural assets (Source: Turpie et al., 2017b) water consumption, for biodiversity biofuel use and conservation, carbon emissions ecosystem services & amenity Green Urban Development active structural sanitation and “green engineering” regulations to measures to retard minimise air, water storm flows and and solid waste address water pollution quality well kept parks, street trees and gardens for amenity and pollution control URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 37 F Box 6: What cities should not do Research undertaken for this report indicates that there are important things that cities should avoid doing if they are to attempt a shift to a positive environmental trajectory. These essentially fall into three broad areas – waste and stormwater, city structure and the use of natural resources – and are also strongly linked to service delivery. In dealing with waste and stormwater, leads to increased flooding problems, ·· Allowing the introduction of alien cities should avoid excessive reliance pollution of amenity areas and species e.g. via ships and other on either natural systems or traditional destruction of animal life. transportation might impact local conveyance infrastructure: resource stocks, habitats and In managing urban growth and biodiversity. ·· Passive engineering structures city structure, cities should avoid for the conveyance of floodwater indiscriminate loss of natural and semi- It is also important that cities do not become inefficient in the face of natural open space areas: neglect their poorest citizens. To do urban growth and are damaging to so leads to some of the biggest and ·· These areas will be increasingly the environment, as they involve the costliest environmental problems valuable to the city as it grows, and modification of river channels and in urban areas. Poor populations’ a strategically-determined amount disconnection of rivers from their continued reliance on charcoal for of open space should be allowed to floodplains, as well as the alteration energy, disposing of their sewage remain in each part of the city; of flow dynamics into receiving waste into rivers and wetlands, along aquatic ecosystems such as estuaries; ·· Natural areas, parks, gardens and with quantities of solid waste that are trees within cities provide aesthetic not managed or disposed of effectively, ·· Using rivers and estuaries as a and recreational value, and can have is bad for their wellbeing and conduit for treated sewage should be a significantly positive impact on air deleterious to the health of cities. avoided, as the combination of higher quality and temperatures; flows and pollution alters the health and value of these systems. This ·· Preventing settlements in areas set impacts on recreational users, people aside as green open space, especially who grow vegetables using polluted along rivers and in floodplains will water, as well as those who consume be far less costly than the potential this produce. Rather pipe the costs of disaster management effluents far out to sea, or preferably services, damages to the households Waste and recycle the effluents to supply water; themselves, and the inevitable costs Stormwater of resettlement. ·· Natural ecosystems in urban areas cannot realistically be expected Cities should not neglect looking after to take the place of engineering their natural resources: infrastructure. The capacity of natural ·· The indiscriminate sourcing of raw wetlands is limited and this will City Structure materials such as building sand, poles result in their degradation and loss of and timber from ecosystems in and biodiversity and values. Rather use around the city can compromise a technology or constructed wetlands number of increasingly-valuable that will be more efficient for the services that are delivered by those purpose; ecosystems; ·· Using river systems, wetlands or Use of Natural ·· Leakages and inadequate pricing Resources other open space areas as a short- or payment collection can lead to term solution for the dumping of wastage and increase the costs of waste (by citizens or waste services) water supply; 38 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Changing the trajectory: Green Urban Development in Africa impacts of urbanization on the environment and enhance ·· I nvesting in greening measures. These include creating and environmental values. The approach is advocated to increase, maintaining recreational green open space areas such as rather than limit, the development potential of cities. It is also parks, and investing in the planting of trees and gardens vital for global welfare. along city streets. These will not only provide aesthetic enhancement but will contribute to the reduction of air The main general elements of green urban development are pollution (Beckett et al., 1998, Jim & Chen 2008) and outlined in Figure 19. Suitably adapted, these can address mitigate against urban heat island effects (Akbari et al., the environmental problems that have arisen in African 2001, EPA 2014). cities as a result of rapid urbanization and policies that have prioritized growth with little regard for the environment. In ·· Securing the protection, restoration or rehabilitation of a nutshell, green urban development involves tackling the selected natural areas in order to maintain biodiversity and core problems of pollution and waste, the consumption of valuable ecosystem services. Natural systems within cities natural resources and eradication of ecosystems, and the contribute to livelihoods through the provisioning of natural diminution of biodiversity in the context of urban growth. resources, contribute to human health and wellbeing, In addition to a range of policy interventions, this involves property value and tourism through the provision of investing in natural capital as well as use of green structural aesthetic and recreational amenity value, and contribute engineering and conventional grey infrastructure. “Green” is ecosystem services such as flood control, sediment synonymous with “environmentally friendly,” and does not retention, air and water quality amelioration, carbon just refer to vegetated areas. It should also be emphasized storage, pollination of crops and provision of nursery that natural, green and conventional grey infrastructure are areas for marine fisheries. As cities grow the remaining complementary and likely to achieve the best results when natural areas within them become increasingly important applied in combination. Grey and green infrastructure can as refugia for biodiversity. All of these functions are lost play a critical role in the protection of natural infrastructure, however, if they are excessively degraded and fragmented. while the latter can reduce the costs of grey infrastructure. Thus cities need to plan and manage a system of natural open space areas. The elements of green urban development include: Planning also needs to consider the potential effects of city ·· Tackling the problems of air, water and solid waste growth on valuable aquatic and terrestrial ecosystems and put pollution through the provision of solid and liquid waste pre-emptive mechanisms in place to avoid their degradation management services and enforcement of appropriate and loss, or to avoid insurmountable costs in trying. regulations to control effluents and emissions from a wide variety of sources. This is not only a necessity from a social Kampala provides a very clear illustration of the costs a city and human health perspective, but is also a prerequisite incurs if it does not develop its structure with due sensitivity to the success of all other green urban development to the natural environment and the services ecosystems interventions; provide. As urban areas grow, the natural areas that they retain are likely to increase in value as the demand for ·· Replacing natural with built surfaces in a more their services increases, and as they take on new uses such environmentally friendly manner. This entails as recreation and tourism. These areas will also become implementation of sustainable stormwater management increasingly important as refugia for biodiversity. Economic systems that include neutralising the impacts of hardened development plans should recognize the economic and social surfaces on stormwater flows using attenuation measures values of natural systems, particularly in sectors such as such as detention ponds, infiltration trenches, porous tourism, include these assets as part of their core strategies, paving and green roofs (Box 7). and allocate resources accordingly. In the case of Durban, it ·· Tackling water and energy consumption. The former is has been shown that the inclusion of substantial green open primarily to ensure the sustainable supply of water from space areas was key to having a cost-effective strategy surrounding surface and groundwater source areas as for maintaining high levels of environmental quality and well as the impacts of water use within cities (see Box ecosystem services (Box 9), while in Dar es Salaam natural 8). Dealing with this problem also helps with the problem systems provide one of few options available to solve the of waste water management, particularly if waste-water problems of flooding in the city centre (Box 11). recycling is used as part of the solution. Tackling energy consumption has multiple advantages. It addresses the Actualizing green urban development in Africa: necessity of reducing carbon emissions to reduce the an agenda for action risks of climate change both globally and locally. Given Green urban development will need to be implemented the high reliance by urban households on wood fuel in through a combination of local and national government Africa, it would also address local air pollution, as well action, and with strategic input from development partners, as deforestation in the areas beyond cities, which occurs investors and other stakeholders. The actions required at great cost to biodiversity and society, and which also comprise a combination of indirect and direct interventions exacerbates environmental problems such as flooding. that will serve synergistically to develop vibrant, resilient cities that are greener in appearance, greener in terms of URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 39 F Box 7: Sustainable urban stormwater management systems (Source: Turpie et al., 2017b) Because urbanisation leads to the “end-of-pipe” interventions to convey mechanisms to deal with urban hardening of surfaces, the importation these problems away, these measures stormwater problems. These active of water to supply urban inhabitants have often not been able to keep structural and non-structural measures and the production of wastewater ahead of the problems, and have address flooding, water quality and sewage, managing the quantity also contributed to the pollution and problems, or both, and complement the and quality of surface water flows is degradation of aquatic systems within traditional, passive structural measures one of the most important challenges and downstream of urban areas. Great used to channel storm flows away from of city planners and engineers. While strides have been made in the design flood prone areas (see figure). conventional measures have involved of more sustainable engineering Types of measures to address urban stormwater problems Passive structural measures for conveyance Non-structural measures • Drains, swales • Policies, laws and • Modify river channel – widen/deepen/levees enforcement (sanitation, • Hydraulic bypass effluents, litter) • Solid waste management, river cleaning Active structural measures (“Green engineering”) programmes Source controls Local controls Regional controls • Riparian buffers • Permeable pavement • Vegetated swales • Detention basins • Catchment conservation • Infiltration trenches • Filter strips • Treatment wetlands areas • Sub-surface soakaways • Sand filters • Green roofs • Bio-retention areas • Rainwater harvesting Active structural measures aim to behavioral changes, in particular insurance and relocations also belong to modify the hydrograph (i.e. reduce through policies, public awareness this typology of measures. flood peak and volume) and address raising, training and education. These These approaches are increasingly water quality by retarding water include flood warning systems, land being applied in development planning movement, by increasing infiltration use regulations such as development in South Africa, and their inclusion or storage in the catchment area. setbacks which identify where (in any form) has recently become These can be referred to as “green” development can and cannot occur, mandatory for new developments in (sustainable/environmentally-friendly) or to what elevation structures should the City of Cape Town and in Durban engineering measures. locate their lowest habitable floor to; with the aim that the potential impacts regulations that require flood proofing Non-structural measures do not of new developments on stormwater and retrofitting of buildings may involve physical construction but use are effectively “neutralized”. increase the strength against flood knowledge, practice or agreements actions; elevation of buildings may to reduce risks and impacts through avoid completely the inundation. Flood 40 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Changing the trajectory: Green Urban Development in Africa their local, regional and global environmental impacts, and while also ensuring the supply of potable water to their in which natural systems provide meaningful refugia for growing numbers of households. These policies should biodiversity and are used to advantage in supplying valuable include maintenance of infrastructure to limit leakage, and ecosystem services and tourism assets. consideration of measures, such as stepped water pricing, to recover costs and limit overconsumption by wealthier Some actions are urgent as prerequisites for other actions, households, ensuring the provision of water at high standards others can be implemented more gradually. Each city will find to reduce demand for or avoid the necessity of buying its own priorities and optimal programme of action, but the bottled water and the polluting knock-on effects of this, and following is a suggested set of interventions in a rough order investing in recycling of waste water. The latter option, while that will enhance their mutual reinforcement. currently out of reach for most African cities, will become a necessity for many in time. Address the “Brown Agenda” To a significant extent, “Green Urban Development” in Control traffic and vehicle emissions Africa equates to “Basic Urban Development” in Africa. The majority of African cities need to address growing For example, as demonstrated by the Nakivubo study in congestion problems that have led to increased emissions Kampala (see Box 2), extending basic sanitation services through increased vehicle numbers, travel time and the throughout African informal settlements is likely to have increased proportion of high-emitting vehicles such as as many beneficial impacts on the natural environment – motorbikes. Improved planning for greater urban spatial including water quality and the wetland ecosystems that are efficiency and management of urban traffic flows are symbiotically related to it – than any other measures that required to mitigate these emissions. Short-term solutions could be considered. At its most fundamental, this it involves include better enforcement of emission standards and the supply of decent latrines to all unserved areas, but it improving traffic management; medium-term solutions is also important to provide adequate drainage diversions, may include the provision of bus lanes and bicycle lanes sludge removal services, sewerage systems and treatment and investing in other public transport solutions such as bus facilities to minimise health and environmental impacts. As rapid transit systems, where these are financially sensible. cities get these problems under control, so these systems can be further refined with the use of engineered treatment wetlands and other measures to polish effluents and further reduce their environmental impacts. Equally, the collection and removal of solid waste, and the effective implementation of anti-dumping regulations, Box 8: would lower pollution levels and have extensive positive Links between cities, water impacts on a variety of natural assets and ecosystems throughout African cities. And widened access to electrical consumption and aquatic ecosystems power, particularly from renewable sources, would lower rates of fuel wood and charcoal consumption, thus slowing the degradation of forests and improving the quality of city Cities can have serious impacts on aquatic ecosystems atmospheres. The first priority, then, must be to extend within and around them as a result of their aggregate basic services in African cities to un- and underserved water demands. These include the damming and populations in an equitable manner which does not extraction of water from catchment areas which encourage overconsumption, and which places as much reduces freshwater flows in river systems and impacts emphasis on dealing with the waste that urban populations biodiversity and ecosystem services. It also includes the and activities create as it does with providing the goods and impacts of importing water into a concentrated area and services that they consume. As everywhere, the first step in releasing it as treated sewage into rivers and estuaries, the “greening” of African cities is to deal effectively with the also changing their functioning, biodiversity and “brown agenda” that cities inevitably create. economic value. In order to reduce these impacts, cities need to reduce their per-capita water demands, minimize Manage natural resource use wastage due to leakage, and invest in lower-impact Managing the delivery and consumption of natural resources solutions such as recycling of waste water. As options for such as water is another area in which more effective and increasing water supply from catchment areas become efficient delivery will simultaneously benefit the natural more limited, so these more environmentally sustainable environment. Water supply and use affects cities – and options will become more affordable. Apart from the city budgets - directly, especially in water-stressed areas. obvious health benefits, the provision of good quality Cities need to develop comprehensive policies that address water will also reduce plastic pollution brought about by the impacts of water consumption on the environment the need to purchase bottled water. URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 41 F Box 9: Evaluating the potential returns to investing in Green Urban Development in Durban (Source: Turpie et al., 2017b) A scenario-based approach was stormwater management measures retention of natural green open spaces used to explore the potential costs is still extremely costly, even when in the city to meet conservation targets. and benefits of undertaking a green accounting for economies of scale. Of all This strategy had a significant impact on urban development approach to the source control measures that could flooding, by virtue of the fact that the address flooding, water quality and be feasibly implemented, only detention hardened area was reduced. It also had biodiversity loss in Durban, and to basins could be justified in terms of their a moderate impact on water quality. explore the potential trade-offs cost savings. It is feasible that the rest The net benefits of this strategy far between engineered interventions will become more affordable in time, outweighed any other. Smart planning and the conservation of natural open as necessity will continue to drive this with green open space areas coupled space areas. Flows and water quality kind of innovation, and bringing these with the other interventions creates the in the central Umhlatuzana - Umbilo requirements into law in Durban will also greenest city, in terms of meeting water catchment were modelled under a drive this process. quality and biodiversity conservation series of hypothetical back-casted goals, and is an economically justifiable The study also analysed the impacts of scenarios in which the development strategy in terms of overall costs and a planning scheme which allows greater of the area had involved different benefits. combinations and extents of GUD measures including better sanitation, stormwater management (including infiltration trenches, subsurface soakaways, permeable paving, green roofs, detention basins, and treatment wetlands) and conservation measures (protection of natural open space areas As per zonation scheme and riparian buffers). The scenarios were evaluated in terms of their implications for aquatic ecosystem health as well as the infrastructure costs and the losses in property value, tourism and fishery values that would have been avoided under these alternative scenarios. There was relatively little backlog in sanitation, but addressing this issue and engaging in waste water recycling made a significant difference As at present in water quality in the catchment. With or without this improvement, green engineering interventions were found to have a significant effect. The measures that were specifically designed for stormwater management – source controls (infiltration trenches, soakaways, permeable paving and green roofs) and detention basins – reduced flood peaks by about 10%, and 35%, respectively, and also Meeting conservation targets contributed to improved water quality. Legend Under improved sanitation conditions, Conservation Areas treatment wetlands were very effective Forest at improving water quality in the Grassland catchment. However, the large-scale Thicket application of some of the low-impact Woodland Rivers 42 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Changing the trajectory: Green Urban Development in Africa Beyond these general – or indirect – measures, however, Combine engineering, spatial planning, environmental elements of a more targeted policy agenda can also be management and other interventions to produce greener developed and used in appropriate combination in African outcomes for particular urban development interventions cities. Key measures include: One of the challenges of achieving green urban development is to shift the focus from reliance on conventional grey Control specific sources of pollution through prohibitions infrastructure and “end of pipe” measures, and find the right and incentives balance between ecological and green or grey engineered Multiple options exist to control and disincentivize the infrastructure to tackle problems closer to source and generation of particularly problematic types of waste, ranging maintain healthier, more vibrant and more resilient cities. For from the banning of plastic packaging to the imposition of example, in Dar es Salaam, where active structural measures levies and charges for wastewater discharge and recycling for stormwater retention are difficult to implement, the incentives. Already, a number of African countries and cities restoration of forest areas and rehabilitation of river systems have instituted such systems (see Box 10), but these systems may be a more viable way of alleviating flooding problems in are largely in their infancy in Africa and much greater scope the Msimbazi floodplain while also generating other benefits exists for utilizing them than has been exercised thus far. from reversing environmental degradation (Box 11). National and local governments need to cooperate to develop legislation to produce regulations and instruments which can Invest in a greening programme make a significant contribution to greater control of solid African cities need to invest in creating or upgrading and liquid waste at source. And, where regulations already public parks and the greening of streets by planting trees exist, poor monitoring and enforcement – widespread in and gardens. These uplift citizens and make cities more African cities – need to be strengthened. Cities need to invest attractive for doing business. Furthermore the investments in manpower and laboratories for long-term monitoring, should be substantial so as to be sustainable and yield increasing the transparency and availability of data and the desired returns. They will involve the creation of tree information, and better enforcement of their regulations. nurseries so that large trees can be planted that are more likely to survive, and they will require the installation of Protect and restore the natural environment within and water supply systems. Innovative mechanisms may need to around cities be designed for their development and maintenance, such Cities need to make space for biodiversity as well as as involving the private sector to fund their upkeep in return capitalise on the capacity of natural systems to supply for advertising rights. Cities can also consider measures ecosystem services and contribute to their tourism such as doing away with large numbers of badly-maintained economies. Cities therefore need to embark on a strategic community parks and investing in fewer, larger and safer conservation planning exercise to: develop an understanding multi-use parks, as well as green corridors, e.g. along rivers, of the natural resources, species and ecological process that allow increased access and promote outdoor exercise, within the planning area, understanding the nature and value as well as contributing to ecological integrity. of the ecosystem services they provide; and use established methods to devise an efficient strategy for protection. This planning should go hand in hand with spatial development and economic planning, to determine which areas are to be left undeveloped to improve overall functionality and to enhance the tourism assets of the city. These areas also Combine engineering, spatial need to be monitored and managed. In addition, measures need be taken to ensure the ecological integrity of the river, estuarine and coastal ecosystems within and downstream of urban areas. This includes protection from sewage effluents planning, environmental and industrial pollution, and control of potentially damaging activities such as sand mining, agriculture and fishing. The efficacy of existing regulations and enforcement efforts need management and other to be assessed, and appropriate regulations, enforcement measures and incentives put in place. Investments in interventions to produce sanitation, stormwater flow attenuation measures, pollution control measures, riparian green belts, and water greener outcomes management will play an important role in maintaining healthy and safe aquatic ecosystems. Instruments – such for particular urban as user fees and payment for ecosystem services (Box 9) – which provide incentives for communities in and around development interventions. cities to manage the natural environment in a manner which enhances environmental quality should be explored as means of supporting this objective. __ URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 43 F Box 10: Measures for managing environmental externalities in urban areas (Source: Black & Rowcroft 2016) There are a number of policy and other instruments that public agencies within African cities may consider for mitigating the negative environmental externalities deriving from urbanization. Plastic bag levies Pollution charges consumers to return tires to a location The plastic bag levy has been Pollution charges include disposal fees, for suitable disposal. By mid-2014, more successfully implemented in several effluent permit fees and emission than 17,000 tons of used tires had been African nations. In Botswana overall fees. There are few examples of such collected and diverted from landfill plastic bag use dropped by 50% in schemes in African cities, other than and the waste tire recycling rate had just 18 months. In South Africa, while the Wastewater Discharge Charge increased from 4% to 19% by the end there has been an overall decline Scheme (WDCS) in South Africa, of 2014. in the number of plastic bags used, which is still in its pilot phase. There the effectiveness of the levy has are two charges associated with the Environmental funds also declined over time. This can be WDCS: a Waste Discharge Levy which In Tanzania, the Eastern Arc Mountains attributed to consumers becoming provides a disincentive or deterrent to Conservation Endowment Fund is a accustomed to the levy and it no longer the discharge of waste, and a Waste trust fund established in 2001 as a joint acting as a strong disincentive. Mitigation Charge which covers the initiative between the Government costs of measures to mitigate waste of Tanzania, the World Bank, and the discharge related impacts. Global Environmental Facility. The fund 50 aims to provide reliable, long-term % Tax exemptions on alternative fuels The setting of zero Value Added Tax financing for community development, biodiversity conservation and applied (VAT) on Liquid Petroleum Gas (LPG) research projects. Among others, the has been adopted in a number of Government of Norway has committed in 18 months African countries including Uganda, US$5.9 million over a five-year period Senegal, and Botswana. In Senegal, a from 2011. LPG Program was initiated in 1974 when wood fuel consumption accounted Payment for ecosystem services (PES) The plastic bag levy for 90% of energy use. The removal The Equitable Payments for Watershed of import duties on gas canisters and Services (EPWS) in the Uluguru has been successfully cookers, as well as subsidies on LPG, Mountains, Tanzania was initiated in implemented in several has resulted in a decline in wood fuel 2006. Unsustainable farming practices African nations. dependence and annual savings of and land use change upstream of Dar approximately 70,000 tons of wood fuel es Salaam reduce water quality in In Botswana overall and 90,000 tons of charcoal. the catchment and have an impact plastic bag use dropped by of water treatment costs in the city. 50% in just 18 months. Deposit-refund schemes The PES scheme involves two major In South Africa, a tire recycling scheme industrial water consumers paying was implemented in 2012 in response upstream villages to adopt more water- to the high numbers of illegally friendly agricultural practices. As a disposed scrap tires. Manufacturers result of the scheme, sediment levels and tire importers are charged a levy in the catchment have fallen and the plus VAT on every kilogram of new productivity of participating farmers’ rubber tire and the cost of waste tire has increased over threefold. collection is passed on to consumers. The revenue generated by the levy is used to subsidize the recycling of the tires and acts as an incentive for 44 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services Changing the trajectory: Green Urban Development in Africa Box 11: Investing in ecosystem rehabilitation to ameliorate flooding in Dar es Salaam (Source: Turpie et al., 2016b) The potential feasibility of investing in green urban development (GUD) interventions to alleviate flooding problems in the Msimbazi catchment in Dar es Salaam was investigated by analysing a range of stormwater management scenarios. Sustainable urban drainage (green annual losses from flooding. The impacts Absolute benefits increase as more engineering) measures such as of the interventions were estimated measures are combined, but so do infiltration trenches, porous paving on the basis of their potential storage costs. All measures would be expensive and green roofs were found to be capacity during a high rainfall event. because of the fact that people have largely infeasible due to the nature Changes in the expected annual losses settled illegally in the forest reserve, of the soils and built environment. A under different combinations of the riparian reserve and floodplain areas, feasible set of GUD interventions to above interventions were estimated with the full combination amounting reduce the magnitude of floods was based on the expected effects of the to US$138.5 million. Taken alone, identified: restoration of forests in the interventions on the flood hydrograph catchment rehabilitation measures upper catchment, rehabilitation and as well as the change in structures at (US$84 million) would provide higher enhancement of riparian and floodplain risk. All scenarios led to decreases in net benefit than moving people from areas in the middle catchment, river the damage costs of flooding, with the flood prone areas (US$62 million), cleaning in the middle catchment average annual cost savings from US$10 and would also yield the highest rates of and floodplain rehabilitation in the million to US$26 million, or 21% to 54% return. The addition of a storage basin lower catchment. River and floodplain of present expected annual losses. The (+US$40 million) added least value, but rehabilitation involved the restoration GUD interventions were designed to this was largely because opportunities of vegetated riparian areas plus the have a significant cumulative effect for the location of such an intervention creation of recreational and agricultural on the flood hydrograph. This led to were too low down in the catchment spaces on either side of rivers that could an estimated 19.6% reduction in the to be particularly effective. The results double up as flood storage. The above number of buildings at risk and a 39% suggested that investment should be interventions were considered along decrease in expected annual losses. secured for the implementation of a with storage basins (feasible in the When GUD strategies were combined combination of rehabilitation measures lower catchment only), and the removal with the floodplain setback zone, in the Msimbazi catchment that are of people from the area at risk. this resulted in both reduction of the specifically designed to attenuate flood intensity (due to reduction in flows and improve drainage, including Available data only supported basic the hydrograph) and reduction of the formal solid waste management hydrological modelling, but relatively exposure (due to relocation of buildings and community-based river cleaning good data for the risk area allowed for a from a setback zone within the flood programs, reforestation, river and reasonable estimation of the expected prone area). floodplain rehabilitation. Reduce exposure Expected annual losses under No interventions in flood People and structures removed from different flood mitigation strategies prone areas 60m buffer zone in flood prone areas Reduce flood risk No interventions in Baseline Scenario 1 catchment US$47.30 million US$37.24 million (-21%) Scenario 2 Scenario 3 Catchment rehabilitation US$28.87 million (-39%) US$23.16 million (-51%) Catchment rehabilitation Scenario 4 Scenario 5 + storage US$27.78 million (-41%) US$21.64 million (-54%) URBANIZATION, THE ENVIRONMENT AND GREEN URBAN DEVELOPMENT IN AFRICA 45 G UNLOCKING THE BARRIERS TO GREEN URBAN DEVELOPMENT Strengthen institutions to manage green urban development Cities need to strengthen the institutions on which effective green urban planning and management rest by addressing structural limitations, accountability and capacity constraints. This includes finding better ways to integrate the protection and management of natural assets that pertain to a range of city and/or government departments. 46 Greening Africa’s Cities: Enhancing the relationship between urbanization, environmental assets and ecosystem services UNLOCKING THE BARRIERS TO GREEN URBAN DEVELOPMENT It is also important to recognize that the widespread planning not particular to environmental management concerns, failures evident in African cities are, in essence, a symptom of but in the long term it will be a necessary condition of institutional weakness. In a “greening” context, green urban putting African cities on a more environmentally sustainable planning fails to emerge because African urban management trajectory. For example, measures involving the extension institutions lack the capacity to generate such plans, and, or upgrading of waste management services will require whether or not they are environmentally sensitive, the plans increased revenues from new and existing users, including that are produced are seldom implemented or enforced. reductions in explicit or implicit subsidies in rate setting and increased public expenditure that has to be financed While the strengthening of government institutions is key, it in some other way by local governments. Other measures is also perhaps one of the most challenging issues to address. related to land use and pollution control will require public Waiting for good institutions to emerge should not be allowed expenditures for monitoring and enforcement, as well as to delay the transition from a downward spiral to green urban private compliance costs. development, as there is great urgency in transitioning to sustainable, resilient cities. Nevertheless, immense effort and More immediately, given the limited local revenue capacities innovation is needed to push this agenda: where cities are and authorities of most African cities, consideration needs to unable to manage natural assets effectively due, for example, be given to targeted environmental programmes supported to jurisdictional constraints, consideration should be given by conditional grants funded by national governments and/ to allocating these responsibilities to national or regional or development partners. Where feasible, the development institutions that have the incentives and capacity to do so. of innovative financing instruments where the costs of environmental interventions and infrastructure are ultimately Targeted finance recovered from those who benefit most, those interventions Finally, the green urban development agenda needs to be (such as Payments for Ecosystem Services (PES) schemes, or better financially resourced. 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