Catching Raindrops New

Always fancied helping some of the world’s poorest people but don’t know how? Getting an engineering degree might be a good start…


ENGINEERS are a technical bunch, highly skilled at using state-of-the-art equipment and expertise to solve complex problems, improve processes and develop entirely new ways of doing things. But what if the high-tech kit isn’t available? What if there isn’t much money to build it? Well, it turns out, engineers are pretty good at that too.

Every year, engineers – be they chemical, mechanical, civil, electrical or from any other discipline – travel out to deprived areas in the developing world to provide clean water, better houses, and renewable electricity, and help grow more crops and improve sanitation. Here we look at some of the good work being done around the globe.

Many engineers volunteer to travel with charities that organise projects overseas, one of which is Engineers Without Borders UK (EWB-UK). EWB-UK’s head of international partnerships Jennifer Byram is responsible for building and maintaining relationships with the organisations that run development projects.

“Volunteers really get a sense of community. If they’re living and working within an area where they might be the only overseas support, bringing in different skills and knowledge, they really feel as though they’re making a difference,” she says.

Three-month placements attract undergraduates with an interest in international development, while six- and 12-month placements tend to attract recent graduates or those wanting to take a career break.

“Any kind of volunteering, particularly with an organisation with a reputation like EWB, is very good for people’s personal development, as well as their professional development,” says Byram.

There is a huge variety of projects. In the latest recruitment drive one year-long project looked at improving sanitation and providing safe drinking water in Kampala, Uganda. Two six-month projects aimed to install rainwater harvesting systems in Mexico City and adapt electrical devices in Bangalore, India, to run on solar power. Shorter three-month projects included developing STEM teaching modules in Sierra Leone and creating a wireless network to connect 14 schools in rural Nepal.

EWK-UK also has university branches. Students from these branches will submit proposals for overseas projects. One university branch at Imperial College London, submitted a proposal for a project to supply rainwater harvesting equipment to communities in rural Tanzania in Africa. The project is now a charity in its own right – Raincatcher.


Sarah Button, 25, has a degree in chemical engineering from Imperial and has been involved with Raincatcher from the start. In her day job she is a process engineer working on substitute natural gas at Johnson Matthey Davy Technologies. Button, however, moonlights as an international development worker, as a trustee of Raincatcher. It was for this that she was named IChemE’s Young Chemical Engineer of the Year 2013. She didn’t start out wanting to be a chemical engineer, however.

“I travelled quite a lot with my family when I was growing up and meeting people in Africa and Asia – children especially – who didn’t enjoy the home comforts and luxuries that I had left me with a sense of injustice, and I wanted to do something about it,” she says. “I had no idea what.”

The ‘what’ turned out to be chemical engineering. After beginning a chemical engineering course at Imperial College London, Button became involved with the student chapter of EWB-UK and soon ended up on the committee. The group received a proposal to build three rainwater harvesting systems on community buildings in rural Tanzania and decided to go ahead with it. Fundraising in the first year alone reached £14,500 (US$24,000) through events like sponsored walks and band nights, and including a donation from a charity called Raincatcher. It had started a rainwater harvesting scheme in the same village in Tanzania but had stalled. Button and another Imperial student later became trustees of Raincatcher and all the projects are now run through the charity.

Keep it simple

The most important thing is that the technology is simple and can be used by local people, and Button says it’s still something new recruits from the university struggle with.

“They’re used to thinking about the latest technology, but that’s simply not appropriate on a mud hut in rural Africa. It doesn’t work, and it’ll get stolen for a start,” she says.

The systems are generally installed on public buildings. Guttering is placed around the roof to catch rainwater, which is channelled into sealed, steel-reinforced concrete tanks. These can hold 46,000 l of water and measure around 5 m in diameter. Standard domestic-scale systems have a capacity of 2,000–5,000 l, while the smallest are around 200–300 l.

Research after the first programme has led to subsequent systems being fitted with a ‘first flush’ system. In the dry season, the roof can get very dirty, so water from the first rains is not collected in the main tank as it is not suitable for drinking. The first flush system can either be manual, where someone moves a pipe, or automated.

“We’re not even talking about something as complicated as a valve here,” says Button. “For example you can have a pipe that fills with water with a ball that floats on the top. When it reaches the top, the water is directed into the main tank.”

As ever, the key is appropriate technology. “None of us had any experience in international development but when we got there we quickly realised that you can’t just build a tank and leave it there,” says Button. “We saw lots of other development projects, including rainwater harvesting systems, that were unused because they were broken.”

Working with the community

tce_raincatcher_5The secret was getting the local residents involved. The tanks were built by local craftsmen, or mafundi, under the instruction of the EWB-UK/Raincatcher team, in such a way that they would be able to build them again themselves. Button and the team also helped to set up committees to look after each system and instigated a programme whereby local people contributed to a fund to maintain them. The tactic paid off. In the area the team visited two years ago, six more rainwater harvesting systems have been built. Raincatcher is planning a sixth trip to Tanzania this year, and Button says they hope to expand in the future. The charity also wants to find new ways of evaluating the success of the scheme, which she says can be hard to measure.

“If it’s on a school, is it going impact attendance or increase grades? If people took water from a well before the tank was built, it takes time to work out whether the water is making them healthier or not,” says Button.

She adds that they would also like to find better ways to educate people about the importance of hygiene, in a country where illness is still often put down to curses, and set up undergraduate academic research programmes.

Visit to watch a short film of Sarah talking about her work with Raincatcher.

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This article was written by Helen Tunnicliffe and originally appeared in the April 2014 edition of tce (The Chemical Engineer). We thank Helen and the Institution of Chemical Engineers for providing this copy for Future Morph.

For more information on IChemE  visit

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