Improving water supplies in rural African villages may have negative knock-on effects and contribute to increased poverty, new research published Nov. 14 has found.

Rural development initiatives across the developing world are designed to improve community wellbeing and livelihoods but a study of Ethiopian villages by researchers at the Universities of Bristol and Addis Ababa in Africa has shown that this can lead to unforeseen consequences caused by an increase in the birth rate in the absence of family planning.

The study, published in PLoS ONE and funded by the Leverhulme Trust, also established that resulting population pressures encourage young adults to move to urban areas. Such urbanisation in less developed countries concentrates poverty in cities which already have stretched public services.

Projections for Ethiopia, currently one of the least urbanised countries in the world, indicate that the proportion of people living in urban centres will double over the next 40 years, from 17 per cent in 2010 to 38 per cent in 2050.

Academics argue that the results of this study highlight the need for policy-makers to take into account this link between development projects and changes in demography, especially as over 90 per cent of urbanisation is taking place in the developing world.

By looking at longitudinal survey data collected from 1,280 households before and after the installation of water taps in five Ethiopian villages, researchers were able to show that family size increased due to the reduced time and energy women spent carrying water on their backs and a dramatic reduction in child mortality.

This increase has placed greater pressure on the household's resources, namely food and land, leading to higher rates of childhood malnutrition and inequalities in access to education.

Feeling pressurised by this increased competition, the study concluded that those aged 15 to 30 with access to taps were three times more likely to migrate to a larger city or town than those without ready access to water.

Overall, migration from rural areas to cities is motivated by the desire for a high school education and employment, facilitated by improved infrastructure, transport and communications.

Dr Mhairi Gibson, from the University of Bristol's Department of Archaeology and Anthropology, said: "The importance of the research lies in its identification of previously unforeseen consequences of international development. While improved access to water has reduced women's workloads and improved child health, it has unexpectedly led to higher birth rates and larger family sizes which have increased household shortages.

"These population pressures have encouraged young adults to migrate to urban areas, which actually contributes rather than relieves population pressure. The demographic consequences of rural intervention initiatives are rarely considered, but it is imperative that they should be. One of the key challenges of the 21st Century relates to population pressures, and this work highlights the need to develop a better understanding of the relationship between demography and development."

The report identifies that improved roads, connectivity and aspirations of 'modernity' may contribute to a positive and generalised cultural outlook on migration to cities, but a key challenge for the next century is managing the scale and pace of urbanisation.

In Ethiopia, it was found that many towns are currently struggling to provide the jobs, housing and services to support the growing demand. Although most of the young adults in the study returned to their village within a year of leaving, this brought with it some positives for educated individuals, particularly men who achieve elevated social status and greater success in securing high status marriages upon their return.