N. Bhattacharya 1 , J. Lamond 1
1
School of Built Environment,Wulfruna Street,University of Wolvrhampton,WV1 1LY UK
E-mail: N.Bhattacharya@wlv.ac.uk
The menace of urban flooding in African developing economies be it Accra, Lusaka, St. Louis or Lome is causing an enormous disruption in their path of development. The urban poor population are often hardest hit as the increasing hazard of small and medium floods coupled with massive urbanisation degrades living conditions. Existing research is reviewed and suggests that the perennial nature of these disasters and lack of forward preparation cripples the existing management framework of these developing economies and retards progress towards development goals.
Case study examples of urban flood scenarios in different
African developing economies demonstrate that causes of flood hazard are diverse across urban areas. However there are common causes of increasing risk which underpin the devastating impacts experienced by the poor and vulnerable. The conclusion from the study based on the key characteristics of African cities pinpoints the challenges and possible constraints in building effective institutional capacities in flood alleviation. Full understanding of the recurring challenges against disasters, that growing economies of Africa are facing today, demands institutional capacity building for effective flood management and risk reduction and broad dissemination across and within nations. This will increase awareness and encourage local authorities to place flood risk reduction and capacity building higher up in their planning agenda.
A recent UN habitat report on the state of African cities stated that Flooding is one of the major factors that prevents Africa’s growing population of city dwellers from escaping poverty, and stands in the way of the UN 2020 goal of achieving ‘significant improvement’ in the lives of urban slum dwellers [1]. In the era of climate change drought is often thought of as a serious future challenge for the continent of Africa but flooding is also an important and increasingly challenging natural hazard for urban Africans in particular. Serious flood incidents generated by unprecedented rainfall in Africa over the past decade or so include torrential rains in 1999 which led to the Kainji, Jebba and Shiroro dams in Nigeria being overwhelmed, resulting in a heavy death toll and property losses. In the same year, in Ghana, an overflowing White Volta River caused loss of life and homes. Flooding of the Komadugu
Yobe Valley in Nigeria in 2001 killed over 200 and displaced 35,000. Likewise in 2009, following the heaviest rainfall in 90 years, floods in Burkina Faso left seven dead and 150,000 homeless [2].
Over the period 1900-2010 the disaster database Em-Dat records a total of 754 flood disasters in Africa. The hardest hit countries being Ethiopia (49 disasters) and Algeria
(45 disasters).While floods in Africa are not generally on the scale of events in Pakistan and rarely make international headlines; the continual impact of flooding on even a small scale can cripple the capacity of urban Africans to improve their conditions because they must focus on coping with floods. Equally, to consider the flood risk picture of a whole sub continent such as Africa is a huge task and this paper does not purport to do this. Instead it seeks to draw some common themes which African Urban Flooding Risk situations share.

Over recent decades the number of floods disasters reported in Africa has increased sharply as
can be seen in
Figure 1 although this picture of accelerating flood events may be in part due to increased
reporting of events. Conversely the number of events listed, which is quite low compared to other continents such as East Asia, masks a general pattern of smaller flood events or regular flooding which goes unrecorded because it does not qualify as a disaster or because it is such a part of daily life that it is not considered worth reporting [3].
70
60
50
40
30
20
10
0
19
27
19
30
19
33
19
36
19
39
19
42
19
45
19
48
19
51
19
54
19
57
19
60
19
63
19
66
19
69
19
72
19
75
19
78
19
81
19
84
19
87
19
90
19
93
19
96
19
99
20
02
20
05
20
08
Figure 1: Number of reported flood events in Africa (Data sourced from Em-Dat)
Characteristics of African Urban Flooding
African flooding has also been characterised as: frequent localised slum flooding due to poor drainage; Small stream flooding due to inadequate culverts and blocked culverts; Major river flooding exacerbated by land use change, expansion of populations into the floodplain and inappropriate upstream engineering; Wet season flooding in lowland and coastal cities made worse by dumping of waste beneath dwellings, reducing storage [1].
Furthermore the responses of African authorities to flood risk also have some commonalities as evidenced by an Action Aid study of six African cities which concluded that there are few, if any, collective mechanisms either for reducing flood risks, or for managing floods once they do happen. Instead, poor people are left to fend for themselves with whatever individual coping strategies they can muster[1].
Causes of African Urban Flooding
Flood risk and consequent damage is a function of hazard with exposure and vulnerability to the hazard. In the context of Africa hazards commonly relate to:

Flooding from the sea due to storm surge and sea level rise at lagoons estuaries and deltas. Half of the continent’s 37 “million-cities” are within or have parts within the low-

elevation coastal zone. such as Alexandria, Cotonou, Dar es Salaam, Lagos Maputo and
Mombasa. This risk is expected to increase in the future due to climate change [3].

From heavy and intense rainfall causing river flooding along major and minor inland waterways and overland flash flooding anywhere but particularly in urban settlements.
Intense rainfall events are also expected to increase as a result of climate change.
In an urban context the hazard from fluvial and pluvial flooding is also increased by anthropogenic changes. For example flooding in Africa has been attributed to inadequate drainage causing overland flow and poor waste collection which can block drainage and water channels causing overland and river (fluvial) flooding [2]. In Kampala, Uganda, construction of unregulated shelters by poor people in slum areas has reduced infiltration of rainfall, increasing runoff to 6 times that which would occur in natural terrain [1].
Exposure to the flood hazard is also increased by occupation by settlements of areas liable to flooding. Africa is the worlds fastest urbanising region and African cities typically exhibit similar qualities which include: a large informal sector of jobs but also of poor quality unplanned housing; Informal settlements located on sites at risk from floods and other hazards; lack of infrastructure and services including drainage; ineffective local governments; limited wealth in the population to invest in better housing. Ironically rural to urban migration is driven by droughts which destroy rural livelihoods and these “environmental migrants” are then subject to the risk of urban flooding [1].
Four capital cities which suffer from major flood issues were selected to illustrate the flood situation in African fast growing and developing economies. These case studies signify major urban areas which suffer from recurring flood events and have specific flood characteristics.
The research seeks to identify the trends and observations from these floods and lessons learnt as a result of the disasters.
St Louis (Senegal)
St Louis, the capital of Senegal, is near the mouth of River Senegal with a high water season from July to October and low water season beginning in November and lasting till May or
June. Cross border cooperation with Mali, Mauritania via the Senegal River authority resulted in the construction of two dams, one in Senegal 27 Km upstream of St. Louis and another in
Mali. They were built to reduce the irregularity in river flow and bringing self-sufficiency in food production along the flood plain. However due faulty construction and lack of maintenance of the dam floods are still a regular occurrence for example when there was higher amount of river discharge during 1999 accentuated by man-made factors. There were floods happened in 1994, 2001 as well as 2003 covering large part of the valley for several weeks. Substantial parts of low lying St. Louis were inundated and the dykes constructed to protect the population upstream exacerbated the problem for the people living downstream
[5]. The people who are most affected by floods in the St. Louis area are generally the most poor and disadvantaged. They have high levels of vulnerability and low resilience and are not protected by physical infrastructure. Increased rate of urban population coupled with poverty and conflicting developmental demand has made the situation worst in the city area.
Lusaka (Zambia)
Lusaka, the capital city of Zambia, is spread over a series of hills covering around 70 sq. km.
The region has a long history of flooding with heavy seasonal rain and tropical storms. The main reason apart from natural causes of flooding in the area pertains to absence of basic infrastructural service in the form of drainage system and increasing pressure of population.
This is further worsened by the development of unplanned settlement, which is about 70% of

the total population [6]. In 2005, 50 houses were washed away and at least 250 were affected by heavy rainfall in Kalikiliki and Mutendere in Lusaka. More recently, in March 2010, water rose up to window level [5] in some areas causing immense damage to housing, crops and infrastructure along with resettlement of 300 people. According to the Zambian National
Broadcasting Corporation the township was overwhelmed with water after the Ngwenya Dam burst its banks. There were about 2521 cases of cholera admission after the flooding and the worst affected areas were the unplanned shanty compounds [5]. Eradicating unplanned settlements, while it appears desirable, is difficult because the problem of housing shortage and poor access to land is a long standing problem dating back to colonial times. Equally the people and enterprises within these settlements contribute to the economic growth of the city and, as Nchito [6] reported, the local settlers who stay in spite of knowing the flood risk have good reasons to do so such as proximity to workplaces and because they cannot afford the high standard of living within the organized residential area. Nchito [6] noted and also supported by Rakodi et. al. [7] that settlers ideas for resolving the problem were to construct new bridges, roads, and improved drainage system and to close down the dam reverting to the natural flow of water. Very few people actually suggested relocation. The problem exists with the authorities who have no zoning policy based on level of risk and even the Disaster
Management and Mitigation Unit (DMMU) does not pay much attention to the high flood risk zones. The lack of coordination between departments can be seen in non-participation of the potentially important Meteorological department plays no role in forecasting, warning and zoning as it has not been considered as part of the coordinating body with the other decision making authorities. Therefore it is necessary to have integration among the local, regional and national authorities to plan for risk reduction strategies.
Accra (Ghana)
The 2007 floods in Accra, the capital city of Ghana, caused hundreds of people to leave their houses and move to safer locations. Initial government figure indicates that there are about
260,000 – 270,000 people affected [8]. Similar situations occurred in 1995, 1999, 2001 and
2008 causing wreaking havoc. Flooding is a problem for a very long time in Accra and the government has recognised the importance of strategic management for effective flood control. The effect of flooding is likely to increase in regions like Accra since the pressure of population is growing at a very high rate compounded with urban development. The
Meteorological Services Department in Ghana is responsible for obtaining and archiving rainfall and climatic data while National Disaster management Organization (NADMO) is responsible for coordination between different organizations, mobilization of affected communities and relocation of people in a post disaster scenario, and ensuring the preparedness against flooding [9]. The relief activities performed by NADMO are well organized and much welcomed at times of disaster. Nevertheless, it is observed that the population in general do not have the education to be resilient and adaptive to the existing risk. The level of preparedness, recovery and response is very low thus increasing the chances of further damage. The concern is that very little has been done to develop systematic strategies for flood prediction and warning systems and building of flood defences from the decision making authorities. There is a need here for policies focussed towards development of warning and prediction systems and dedicated efforts in educating the population regarding how to handle emergency flood situations in an effective manner. International organizations can play an important role in this regard in terms of developing human resource by educating and training them.
Lome (Togo)
Lome, the capital of Togo, suffered from a flood event in June 2010 in which about 200,000 people were affected [10]. Apart from being part of a submerging coast and lagoon system

within coastal dunes the city has two wet seasons due to its location between two per-humid rainforest blocks. The coastal lowlands are the most populous regions and suffer from excessive pressure of formal and informal settlements, poor planning in urban areas, lack of proper drainage infrastructure and their maintenance, low level of education and social awareness among people and last but not least ignorance from the authorities in giving adequate attention to the problem of flooding. There is continuous influx of people to the city in search of employment and better standard of living [11]. This in turn is topping up the already existing problem of lack of infrastructure and management. The area suffers from the severe problem of semi-permanent flooding where flood water sometimes takes several months to recede. It is difficult even to apply techniques like pumping because of the saturated water table in the low lying coastal plain. The practice of illegal sand mining is becoming a serious problem as the demand for sand is increasing with increasing population and industries in the area [11]. Apart from causing coastal erosion and subsidence is also harmful for the ecological balance of the coastal flora and fauna. Regardless of having the largest Disaster risk Management plan in Africa by GFDRR Ghana still ranks highest in disaster risk profile [12].The area lacks in bringing together synergy between the traditional investment operations and modern scientific design to contribute to a long term solutions.
Analysis of the case studies in many ways supports the conclusions reached by previous studies of African urban flooding. Further they demonstrate that while the physical causes of flooding differs for the four case studies - from saturated swamp areas to mountainous flash flooding - the impacts are made worse by similar man made problems.
Most cities in sub-Saharan Africa have a large portion of their population living in informal slums which are outside the control of authorities charged with land use controls as seen in
Lusaka. Despite awareness of risk relocation is not an accepted solution unless there is provision for better alternatives which is highly unlikely given the lack of space for organized built-up areas. Proper infrastructure is like a back bone for development of any economy. It plays significant role in maintaining balance during the time of disaster and in risk reduction.
However, it has been observed that in most of the developing economies in Africa management of infrastructure and critical facilities are far from getting adequate attention.
There is either deficiency in construction of infrastructures as in Lusaka or lack of maintenance as in Senegal which de-generates the existing system. The efficiency of infrastructure depends on wisely directed government investment. However deficiency in coordination between different government authorities in risk reduction and management has led to the reverse in many sub-Saharan cities. Influx of population to the urban areas is common for all the case studies. It is the most vital aspect of increased risk and level of damage thus making it difficult for local authorities to cope with the growing challenge.
Poverty and higher vulnerability have an intricate relationship. It has been observed that in most of the cases the highest risk group with lowest level of resilience and are the poorest group too. There is also serious need for information sharing and technology transfer, early warning and contingency planning within and among the countries. Lessons learnt from historical flooding help in identifying the key risk zones, the most vulnerable group of population and potential sources of damage thus giving a pre-defined stage for risk reduction strategies. Awareness of preparatory measures and responding well to an event is essential for effective flood management. Lack of education, training and risk awareness is a general scenario in most of the urban growing economies, and shown here in Ghana, where they lack in the appropriate knowledge of response strategy.
The case studies show that although these flood situations vary there are common problems and therefore may be common solutions to African urban flood scenarios. Lessons can be

learned and transferred between developing African economies. One key point from the four case studies here are that poverty alleviation and housing and employment generation in a balanced manner would helping in reducing flood risk while also contributing to general development goals. It also emerged that international organizations providing reliefs and working towards risk reduction in developing economies can play a key role in encouraging education and training cooperating with the local authorities.
Floods have a serious effect on the disadvantaged and on the already fragile economies of developing countries. Exploitation of natural resources as seen in Lome sand mines threatens the sustainable equilibrium of nature and direct intervention is required to maintain balance within the system. Priority attention to disaster risk reduction by the government is necessary.
Comprehensive flood management planning is required to cope with the changing situation and increasing risk. This planning might encompass: infrastructure capacity building by rehabilitation of drainage, roads, buildings, water supply and energy can reduce the suffering of the people in general and give the developing economies a chance to generate adaptation to the ever increasing problem; Educating the public to generate awareness among the local people at risk towards keeping drainage clear and following emergency procedures;
Mainstreaming flood risk into government thinking via flood mapping and zoning with accompanying regulation and coordination of planning and maintenance departments.
Restriction of the growth of informal settlements into areas at risk could form a central plank of risk reduction policy.
Poverty and vulnerability to flood risk are seen from this discussion to go hand in hand. There is a requirement of comprehensive integration of environmental, social and economic viewpoints to understand and respond to flood risk. Full understanding of the recurring challenges against disasters, that growing economies of Africa are facing today, demands institutional capacity building for effective flood management and risk reduction. Further detailed research in the field of poverty and disaster is therefore required to identify the key policies within poverty reduction that can also address risk alleviation.
[1] Actionaid, Climate change, urban flooding and the rights of the urban poor in Africa
Key findings from six African cities. 2006, Actionaid.
[2] UN Habitat, The State of African Cities 2010: Governance, Inequality and Urban
Land Markets. 2010, UN Habitat: Nairobi.
[3] Satterthwaite, D., et al., (2007) Adapting to Climate Change in Urban Areas. The possibilities and constraints in low- and middle-income nations, in Human Settlements
Discussion Paper Series. IIED.
[4] Provention. (2004). Global Symposium for Hazard Risk Reduction. Working Paper,
World Bank, Washington D.C.
[5] Act alliance (2010). Flooding and Cholera outbreak, Zambia. In: Secretariat. Geneva.
[6] Nchito, W. S. (2007). Flood Risk in unplanned settlements in Lusaka. Environment and Urbanization, 19, pp. 539-551.
[7] Rakodi, C., Leduka, C. (2003) Informal Land Delivery Processes and Acess to land for the poor in six African Cities: towards a conceptual framework. Working paper 1 in the Informal Land Delivery Processes in African Cities Series, University of
Birmingham, UK
[8] Concern Universal (2007) Flood Relief in Northern Ghana - September 2007. http://www.concernuniversal.org/index.php?/where_we_work/ghana/flood_relief_in_n

orth_ghana,_september_2007 Date accessed 19.04.2011
[9] Ahadzie, D. K., Proverbs, D. (2010). Flooding and Post Flooding Response Strategies in Ghana. WIT Transactions on Ecological Environment, 33, pp. 281-291.
[10] ICRC. (2010). Togo: Emergency health programme aids flood victims [Online].
Lome: ICRC. Available: http://www.icrc.org/eng/resources/documents/newsrelease/2010/togo-news-2010-11-12.htm
[Accessed 19.04.2011 2011].
[11] Ayenagbo, K., Kimatu, J.N., Gondwe, J., Rongcheng, W. (2011). The Transportation and marketing implications of sand and gravel and its environmental impact in Lome-
Togo. Journal of economics and International Finance, 3, pp. 125-138.
[12] GFDRR. (2009) Disaster Risk Management for Priority Countries, World Bank,
Washington D.C.