Many African cities are struggling to provide safe drinking water to their inhabitants. One of the main reasons for this is urbanization; the population of cities is growing rapidly as more and more people from rural areas settle there.

Another reason, in some areas, is water scarcity.

Researchers have long suspected that informal urban settlements lag behind their formal counterparts in access to safe drinking water. But this reality can be obscured when data is aggregated at the city level rather than being examined at a granular and localized level.

Numerous studies have been carried out to examine inequalities in access to drinking water. Most measure this access according to the type of source, such as access to tap water. Some have incorporated other dimensions of water service delivery, including water quality. However, relatively few studies have examined intra-urban differences in the volumes of water consumed.

In our study in the Kenyan capital, Nairobi, we looked at domestic running water distribution patterns between 1985 and 2018. We used data from the Nairobi water and sanitation service using small areas that they call it “routes”. These have an average population of 700. We also looked at granular demographics from the WorldPop mapping initiative and relied on spatial age data from different neighborhoods for the years 1975 to 2014 from the Global project. Human Settlement.

These data allowed us to examine the differences between neighborhoods in terms of sufficient domestic water consumption, cost and access to water. Mostly, we could look at changes over time. The data revealed that the newly developed low-income urban neighborhoods – which are home to up to a third of Nairobi’s population – are not as well served as older, richer and less densely populated areas.

Our hope is that these results can influence governance and policy in the water sector. The water supply must be reliable, safe and affordable for all who live in Nairobi.

Main conclusions

Data has shown that water sufficiency in Nairobi differs depending on several factors. These include the age of a neighborhood, income level, type of water access, and population size by route.

The World Health Organization recommends at least 1,500 liters of water per person per month for home use. We found that residents of high and middle income areas were six and four times more likely to receive 1,500 liters. Less densely populated areas were more likely to receive higher volumes of water.

The way people access water also differs by income. Residents of high and middle income areas tend to have piped connections in their homes. Those in middle, low and low income areas more often obtained water from communal taps or water kiosks (water vendors who sell water purchased from the utility company).

We have also found that a large amount of water – an average of 3.5 billion liters per month – is wasted either through broken pipes, theft or irregular meters. That’s more than double the amount of water needed by every city resident, in all areas, to access the recommended 1,500 liters per month.

Tackle the problem

There are three ways to address the spatial inequality of access to water in Nairobi: good data to plan water services and prices, invest in infrastructure and governance.

Data on water supply and consumption are essential to assess gaps in the water distribution process. It can also help ensure better management of sometimes scarce or limited water supplies. Historically, government data has been poorly stored.

However, there have been positive improvements in this regard as governments increasingly ensure that their data is accessible, stored electronically, complete and consistent. This allows for future research and planning. Kenya digitized water consumption data and made the water pricing structure publicly available.

Improving water supply will also require appropriate investments from the government. The growth of the urban population should be accompanied by investments in infrastructure to support the provision of potable water to the population – including appropriate financing of water utilities to improve their performance. Investments should be organized according to the residential category and age of the neighborhood, with an emphasis on groups whose data show they are not well served.

Finally, good governance is necessary to minimize both water losses and social inequalities. There should be a deliberate priority to water supply and infrastructure development in low income areas, both in newer and older neighborhoods, and in densely populated areas. This is essential if Kenya is to meet the water access goals set out in the African Union’s Agenda 2063 and the United Nations 2030 Sustainable Development Goals.

Mutono Nyamai, doctoral student, University of Nairobi; Henry Mutembei, professor of veterinary and obstetrical reproduction, University of Nairobi; James Wright, Professor of Geographic Information Science and International Development, University of Southampton, and Thumbi Mwangi, Associate Professor, Washington State University