The World Bank stated recently that nearly half of the world's population does not have enough water and that demand is rising and will continue to do so. Water shortages moreover, are exacerbated by population growth and seen as a barrier to development and as a source of potential international conflict. The study examines the assumptions about water usage underlying such statements.

Migration is the most important factor in population growth in both villages and towns in Northern Tanzania. Rather than looking at population growth as a cause of water shortage, the researchers examined how water availability influences migration. The study covered three broad areas of water use: agricultural, other rural uses, and urban use. Questions included: How is water used? How much water is needed? How much water is available? The study also looked at how the assumptions of water engineers in developed countries that emphasise purity, private access, pumping and irrigation - lead to unhelpful policies in developing countries.

Key findings include:

• taken together, both rain-fed and irrigated cultivation can give a better estimate of how self-sufficient a community might be
• ideal standards of water use are based on water-rich nations and as such may be unrealistic for countries such as Tanzania
• short migrations between villages are influenced by water availability whilst longer distance moves are more strongly influenced by land availability
• infrastructure rather than water supply is often the problem: piped water networks in urban areas are failing to keep up with population growth
• households that have recently migrated to urban areas have poorer access to water having settled where infrastructure is worst.
• migrants lack the social networks of long term-residents who often sell water to each other.

Policy implications include suggestions that:

• national estimates of water availability for food production should take into account rain-fed agriculture and not just irrigated agriculture
• building up urban infrastructure may be more crucial than increasing overall water supplies
• charging for water obtained from standpipes could help recover costs and contribute to better planning and investment in the standpipe network
• selling of water by private households should either be metered, or regulated through a licensing system
• communal facilities for water use, such as bathhouses and laundries, could help alleviate the burden on the poor of increased charges.

Contributor(s): Basia Zaba, ; Ndalahwa Madulu

Source(s):
'A Drop to Drink? Population and water resources: Illustrations from Northern Tanzania' by B. Zaba and N. Madulu, 1999
'The Effects of Water Stress on Population: An illustrative study of Tanzania' ESRC End of Research Report by B. Zaba 1996

Funded by: UK Economic and Social Research Council Global Environmental Change Programme

Date: 2000 June 12

Further Information:
Basia Zaba
Centre for Population Studies
London School of Tropical Hygiene and Medicine
99 Gower Street
London WC1E 6AZ

Tel: +44 (0)171 3883071
Email: bzaba@lshtm.ac.uk

Other related links:
Global Environmental Change Programme

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