Volatile weather patterns are increasingly affecting urban slums in Africa. Climate change is already aggravating urban flooding. When floods occur, residents of marginalised areas have only a limited set of options. They need urgent help to reduce risk and improve prospects for emergency action and safe evacuation.

ActionAid International reports findings from a participatory vulnerability analysis in six African cities which explored local people’s perceptions of why floods occur, how they adjust to them and what support they need.

Urbanisation worsens flooding. It restricts where floodwaters can go, as large parts of the ground are covered by roofs, roads and pavements, and it obstructs natural channels. Building drains ensures that water moves to rivers faster than it did under natural conditions. As more people crowd into cities, even moderate storms produce dramatic flows. To make matters worse, 12 percent of urban Africans live less than 10 metres above sea level.

Slum dwellers report that there are few, if any, collective mechanisms either for reducing flood risks or for managing floods once they happen. Poor people have to find a way to cope on their own. There is little effort to address the problem. Poor urban Africans seldom feature in National Adaptation Programmes of Action on vulnerability to climate change – an initiative of the Global Environment Facility. Many countries now have national disaster reduction plans but lack the resources to carry out effective disaster mitigation, especially for the poorest communities.

ActionAid identifies four major types of urban flooding:

• There is frequent localised flooding because the ground is compacted and drains are blocked by waste.
• Small streams rise quickly after heavy rain: culverts carrying water under roads are no longer adequate and have not been maintained.
• Rivers flowing through urban areas are affected by land use changes: dams trap sediment, causing rivers to erode their banks downstream while building on floodplains has reduced the areas into which floods can naturally overflow.
• In coastal cities wet season flooding can now last for months as tidal surges and rainfall combine to raise the levels of water in swamps.

Urban flooding has disproportional impacts on poor people. It increases waterborne diseases, damages food stocks, causes further deterioration of sanitation and reduces access to schools and health-care facilities. It is vital to invest in improved drainage, regulate developments upstream and give urban residents greater security of tenure so that they can invest in making their homes more flood resistant.

ActionAid argues it is also essential to ensure that:

• urban residents play the key role in managing of localised flooding
• NGOs, donors, national governments and regional agencies cooperate to map flood risk areas, maintain urban stream channels, control building on floodplains and provide emergency assistance
• neighbouring states work together to follow integrated river basin management principles
• each government has an agency cutting across ministries with a particularly rural or urban focus in order to prevent activities in rural areas worsening urban flooding downstream.
• urban planning incorporates the Hyogo Framework of Action agreed at the World Conference on Disaster Reduction in 2005.

Source(s):
‘Unjust waters: climate change, flooding and the urban poor in Africa’, International Institute for Environment and Development,  Environment and Urbanization 20, pp187-205, by Ian Douglas, Kurshid Alam, Maryanne Maghenda, Yasmin McDonnell, Louise McClean and Jack Campbell, 2008. Full document.
‘Unjust waters: climate change, flooding and the protection of poor urban communities: experiences from six African cities’, ActionAid International, 2006 (PDF) Full document.

Funded by: ActionAid International

id21 Research Highlight: 13 August 2008

Further Information:
Ian Douglas
School of Environment and Development
University of Manchester
Manchester M13 9PL
UK

Tel: +44 161 2753642
Fax: +44 161 2757878
Contact the contributor: ian.douglas@manchester.ac.uk

School of Environment and Development, University of Manchester, UK

Yasmin McDonnell
ActionAid International
Hamlyn House
MacDonald Road
Archway
London N19 5PG
UK

Tel: +44 20 75617561
Fax: +44 20 72720899
Contact the contributor: yasmin.mcdonnell@actionaid.org

ActionAid International

Kurshid Alam
Flat A3, House 23
Road 23, Block B
Banani
Dhaka
Bangladesh

Tel: + 88 01713 083 783
Contact the contributor: alam@khurshidalam.org

Kurshid Alam, Bangladesh

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'Mozambique as a model for national disaster response strategies'

'Durban adapts to climate change'