Water for the developing world: engineering ideas to quench the thirst
The developing world is thirsty and engineering projects are finding novel ways to provide the water it needs.
The United Nations says 1.8 billion people in the world use a source of drinking water that is faecally contaminated. Up to 2.4 billion lack access to basic sanitation (toilets and latrines). Charity WaterAid estimates that a child dies every two minutes as a result of diarrhoeal diseases caused by dirty water and poor sanitation. Engineering promises to change that with projects that range from smart pumps to devices that capture water from thin air, although effective change is likely to go beyond technological fixes.
Water is everywhere; dig deep enough in many places and you will hit it. Naturally, the solution is to drill a hole and place a pump – machine or hand-operated – at the top. Cheap and simple, around 60,000 water pumps are installed across Africa every year. The problem is, they don’t always work. A 2009 report by the Rural Water Supply Network estimated that between 30 and 40 per cent of these aren’t functional at any one time, leaving entire communities without access to clean water.
It also marks a significant wasted investment, estimated by the World Bank to be around $1.2bn (£984m) in charitable donations or foreign aid.
Since 2010 the University of Oxford’s Patrick Thomson and colleagues have been using the functioning local phone network in regions of Kenya to help solve the problem of broken water pumps, creating what he describes as a smart water grid. “It is estimated that more Africans now have access to a mobile phone than a reliable water supply,” claims Thomson, describing the driving force behind his work.
Thomson and colleagues have designed a simple system that, when fitted to a hand pump, transmits data on usage and breakdowns. Using an app, local engineers can see where pumps have broken and quickly take action, restoring this vital resource to communities.
Supported by organisations like Unicef, what’s different about the approach of Thomson’s team is that the technology here is simply the enabler – the real focus is on developing the local infrastructure and support to manage the network.
Creating a series of small local businesses to manage the virtual grid, it’s about moving from the traditional ‘aid/development’ relationship to what Thomson describes as the ‘service delivery paradigm’. “Maintenance can be run on a professional basis, providing better results and economies of scale,” he claims.
The approach adopted by the team is about developing local solutions to the challenge, but also about developing scalable and successful local businesses. “Our measure of success will be if these businesses are still running after the research project has ended,” Thomson adds.
Water from air
In arid areas like deserts or mountainous areas high above the water table, hand pumps are useless – but there is hope. The Warka Water Tower is one of a new range of solutions being developed that could harvest the abundant moisture in the environment to create safe drinking water.
The design and function of the Warka Water Tower is inspired by nature, including the shell of the Namib beetle, the leaves of the lotus flower and the warka tree that gives the tower its name. The materials are reassuringly available – and robust. Constructed from local biodegradable materials like bamboo, fibre ropes and bio-plastics, the 10-metre tower catches rain, harvests fog and collects dew, filtering this to produce fresh water. Using gravity, condensation and evaporation, the tower needs no external power to function.
Capturing a modest 50 to 100 litres of water a day, a permeable mesh allows water to pass through the material, with the water drops rolling down to a collector. Before this water can be used it passes through a filter and is collected in a tank.
Taking less than a day to erect, the $1,000 tower is designed to be constructed using common tools. Although still in development, the company behind the Warka Water Tower hopes it will go into production in 2017, with the portable kits manufactured in Ethiopia.
In the mountainous Aït Baâmrane region of Morocco, a 600m2 wall of giant polymer net is already collecting moisture from the rich mountain fog. The nets use a technology aptly named CloudFisher, which can produce up to 65 litres of water per square metre in just 24 hours. The project is a partnership between Moroccan NGO Dar Si Hmad and German partners.
Using a series of solar-powered pumps, this essential source of water is carried down the mountain where it provides clean and fresh water for more than 400 local residents.
Halfway around the world, a project is looking at even more arid conditions. The Arizona desert may not be foggy, but even here there is some moisture to be harvested. Arizona start-up Zero Mass Water is secretive about the construction of its solar-powered panel. The energy from sunlight captured by the panel improves the ability of a proprietary combination of materials to absorb water from the air.
The panel adds calcium and magnesium to stabilise the pH and ensure the water tastes like water. At five litres per panel per day the production is modest but the company claims it is enough for a family of four. Describing it as a “leapfrog technology”, CEO Cody Friesen believes developments like Zero Mass Water can help to provide access to clean drinking water where it’s needed. “Technological innovation is critical to correcting this global problem,” he adds.
Spanning more than 5,000km, the Sahel is like a belt around the waist of Africa. From the Atlantic Ocean in the west to the Red Sea and Indian Ocean in the east, this semi-arid and drought-prone region could be transformed by one of the most ambitious engineering projects of recent times, the Trans-African Pipeline (TAP).
For a region as large as the Sahel, engineers need access to an abundant and accessible water source – in this case, the sea.
On opposite sides of the continent two solar-powered desalination plants will pull water from the Atlantic Ocean and Red Sea. Once treated, the water will be fed into a pipeline that will eventually span the entire continent of Africa. The TAP will loosely follow the route of the Great Green Wall, a 15km-wide strip of drought-resistant trees being planted along the border of the Sahara Desert that environmentalists hope will help stop the advance of the desert’s advance.
The TAP project could take up to a decade to complete but if successful the 1.2m-diameter pipe will convey 800,000 cubic metres a day of water, supplying an estimated 30 million people. Pumping stations powered by their own solar arrays will be located every 150-200km along the route, with up to 100 personnel on hand to maintain the systems.
The first phase of the project has begun, with the Canadian TAP Foundation signing its first agreement with Mauritania in May 2016. The country will host the first desalination plant and solar field, as well as 700km of pipeline – all at a total cost of $1.3bn. The team behind the pipeline hope to sign agreements with other countries along the route, but the combination of political challenges and funding issues mean it’s not likely to be easy.
Major engineering projects aren’t always philanthropic, but the team behind the TAP is clear about what will happen to the pipeline once completed. “Once those costs and debts are paid in full, ownership of sections of the pipeline will transfer to the country through which it runs,” says TAP co-founder Daphne Lavers.
One of the key issues for those involved is to ensure that the local capability exists to manage and maintain the pipeline. “TAP is depending on very large-scale transfer of knowledge and capacity to build and manage the pipeline,” Lavers adds.
Across the ocean in the drought-stricken Indian state of Maharashtra, water trains carrying hundreds of tonnes of water are a common sight. Each tanker wagon can carry up to 50,000 litres of drinking water, which has been pumped from the city of Miraj 342km away. These trains bring relief but it’s only temporary.
Delivering water by train is a pragmatic, rather than sustainable solution to the problem. Tackling the fresh water challenge in a country the size of India demands a radical solution, and there are few more radical – or controversial – than the Indian Inter-River Linking Project.
The plan is simple: to shift water from flood-prone areas in the north to the drought-affected south. At an estimated cost of more than £250bn, engineers propose joining 30 rivers by digging thousands of kilometres of canals, and diverting India’s two biggest rivers, the Ganges and Brahmaputra, to create a water grid covering the vast country.
The concept has existed for over a hundred years and was originally proposed by British military engineer Arthur Thomas Cotton in 1858, but only now seems to be gathering momentum, with India’s Prime Minister Narendra Modi announcing that work could soon begin on pilot projects linking the Ken and Betwa rivers.
The scale of the plan is huge. The proposed 12,500km of canals built will be 50-100 metres wide, and six metres deep. There will also be 3,000 individual water-storage facilities.
Should the project go ahead, construction will take around 30 years, and will displace an estimated 1.5 million residents. More controversially, it could severely affect neighbouring Bangladesh, whose people rely on the Brahamaputra and Ganges for around 85 per cent of their fresh water flow in the dry season.
Relief is no substitute for local development
Erik Harvey, head of programme support unit at WaterAid, is wary about the belief that a simple new technology will be designed to solve the crises across the world, calling it ‘silver bullet syndrome’.
Tracking the development of WaterAid since the 1980s, Harvey describes how the focus of the organisation has changed from one of providing immediate relief – in the form of water pumps or water purification technologies – to one of developing capacity and capability. This may take the form of local engineering knowledge, but can also involve developing leadership and political capabilities, as well as supporting bids for international funding.
One of the biggest concerns for Harvey is that the current approach – where solutions are developed and funded by the West – is that it perpetuates a culture of dependency, where the skills and knowledge are developed and in some cases owned by external actors.
What Harvey, and pressure organisations like Engineering For Change (E4C), are calling for is an end to the perception of charity and a much stronger investment in developing local infrastructure, capacity and capability.
While new technologies developed in the West are important, experts like Harvey are clear that in achieving global access to water we should be supporting local communities to develop their own capacities and capabilities. “Our role is about getting behind local development plans,” Harvey claims. “It’s not about pushing and pulling.”
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