The challenge of collecting water in African countries is a staple of aid agency appeals. Now the first rigorous study has calculated the staggering cost of the lack of access to nearby water supplies.

"The journey to collect water every day harms health, uses up limited human energy and takes time away from other opportunities," said Dr. Jay Graham of George Washington University in a statement. The role falls almost exclusively to women and children. Graham added, "By reducing the distance to water – preferably by having water piped to each property – many women and girls would be freed up for work, school or other activities."

Proposed technological fixes include solar-powered filtration devices, structures that catch the mist, and lower tech improvements in transportation. Remarkably, however, estimates of the size of the problem have been vague. Graham addressed this by collecting data from 24 sub-Saharan African countries, calculating that 17 million people spend more than half an hour a day collecting water. Even this is an underestimate, since no data was available from several countries.

Graham published his findings in PLOS ONE. He relied on World Bank surveys for his data, but adjusted it for factors such as urbanization, which has previously not been adequately considered.

The women and children forced to spend more than half an hour a day on water collection is just the tip of the iceberg, with Graham referring to previous estimates that “more than two-thirds of the population of sub-Saharan Africa must leave their home to collect water.” Even where this just involves a water pump at the end of the street, there can be severe consequences from needing to collect water externally.

Nevertheless, the effects are most serious for those who have to make a longer journey. The consequences of long treks for water lie not just in wasted time; carrying these heavy loads can cause spinal damage, while diseases such as trachoma are twice as common where washing is a challenge. Waterborne diseases are a major source of disease, and increase with distance to supply.

^{While it is best if there is no need to leave the house for water, access to a nearby clean source can make a huge difference. Ricardo Mayer/Shutterstock}

The paper quotes research showing that people without access to nearby water “cooked little, and only once a day,” to save the precious resource, with consequences for nutrition.

Four countries – Ethiopia, Nigeria, Mozambique, and Malawi – account for three-quarters of the problem.

Graham stressed the significance of the gender imbalance, with the burden of water collection falling overwhelmingly on women. In every country women were more likely to be the primary water collectors, but the ratio of women to men collecting varied from near equality in Nigeria to an appalling 54 to 1 in Guinea. "We didn't look at the underlying reason for the gender imbalance in water collection," Graham said in a statement. "However, in some African countries collecting water is considered a low-status job and often falls to women and girls."