How much does it cost to reach one person? 

4 min read
Image: WaterAid/Alexia Webster

Our supporters often ask us how much it costs to reach someone with clean water, decent sanitation or good hygiene. So how do we calculate the answer? Erik Harvey, Programme Support Unit Director and Emma Stewart, Programme Data Analyst at WaterAid UK, explains the process behind our average ‘cost per user’ figures.

This article was updated by Emma Stewart on 23 May 2018.


Telling our supporters how many people their money could help is a good way of showing them that even a small donation can have a big impact. The cost of reaching the poorest and most marginalised people varies greatly across the different countries and contexts where we work. But we can calculate an average.

Doing the maths

We start with everything we’ve spent in our country programmes and regions in the past three years, plus the cost of our UK-based Programme Support Unit.

We then work out what portion of this money was spent on water, sanitation or hygiene and divide each total by the number of people we reached with each service.

Using the average cost from 2014 to 2017, these numbers are £15 for clean water, £10 for decent sanitation and £2.20 for good hygiene.

Our figures are higher than those given by other organisations. That’s because our amounts are not simply the cost of digging a well, building a toilet or providing soap for handwashing. They include a lot more that goes on behind the scenes to make sure these services go on changing lives for good – training water committees, skilling up utility companies and local governments, and persuading ministers to roll out similar services across the district and beyond. Just putting taps and toilets in communities would be much cheaper – but the results would be less sustainable, and, ultimately, reach fewer people. 

What we don’t do

1. We don’t provide a figure for reaching one person with clean water, decent sanitation AND good hygiene

We believe everyone, everywhere should have clean water, decent sanitation and good hygiene, to receive the maximum health benefits. So we work in communities where different people may lack one, two or all three of these services. Although we can calculate an average cost of providing each of these services to one person, coming up with an average cost of providing all three is more problematic, because our work varies so much between communities.

2. We don’t compare the cost per user between countries  

We don’t even calculate the cost per user for individual countries. We work with the poorest and most marginalised people, and this can be expensive. We would not want our teams around the world to make, or feel they should make, programmatic decisions aimed at reducing the cost per user. And we don’t want them to think, “With £XX of funding you should reach X number of people.” Our staff should make programmatic decisions based on the best approach for a community. Factors that can increase the cost per user in a particular country include the price of locally available construction materials and the exchange rates.

3. We don’t use average costs to assess value for money

For the same reasons, the average cost per user figures are not a valid indicator for value for money. You can read more about our approach to value for money here

4. We don’t compare our costs per user over the years, or analyse trends

Many factors can affect the cost per user year on year, and, because it is not a value for money indicator, we don’t draw comparisons.

5. We don’t claim that these amounts deliver services for life

Sustainability is at the heart of everything we do. The average costs per user do include supporting service providers to strengthen the systems needed for taps and toilets to go on changing lives year after year. But they don’t include the money needed to maintain and deliver reliable services, which needs to be generated locally. 

Providing an average cost for reaching one person with clean water, decent sanitation or good hygiene helps show the public just how much of an impact their support can have.

Erik Harvey tweets as @harerik.