To improve people’s water security, we use a combination of different approaches to bring clean, reliable water supplies closer to people’s homes.
We select technologies that will provide sufficient quantities of good quality water to meet people's basic needs. The sustainability of these services is key; ensuring there is adequate finance, skills and spare parts available to ensure the technologies can be operated, maintained and repaired using local resources.
The first step is to select the water source (PDF). The three main water resources – rainwater, groundwater and surface water (rivers, ponds and lakes) – offer a water source that can be used by people. Sourcing water from elsewhere – such as plants, fog, seawater or re-using wastewater – requires more complex and expensive technologies to obtain the same volume of water, so these are less commonly used.
The source of the water is the point at which people abstract water from the natural water cycle and it enters the water supply system. The most common water sources we use are:
- Rainwater harvesting (PDF). Collecting rain is one of the simplest forms of water supply and provides good quality water. Using and regularly maintaining simple technologies to harvest rainwater can protect the water from contamination.
- Protected springs (PDF). Natural springs can provide water that is as clean as groundwater, but without needing to pump it up to the surface. However, this water can be polluted easily, which is why springs need to be protected. Technologies can also make them more accessible.
- Hand-dug wells (PDF) are the traditional, and still the most-common, method of obtaining groundwater in rural, lower-income settings.
- Tubewells (PDF). On any given site, hand-dug wells may yield more water than tubewells depth for depth. But tubewells 100-150 mm in diameter are usually quicker and cheaper to sink, do not need de-watering during sinking, require less lining material, are safer to construct and use, and involve less maintenance.
- Boreholes (PDF) are common technologies, especially in areas where there is hard rock or where water must be collected from a greater depth. Boreholes can provide reliable high-quality water and increase resilience during times of water scarcity.
- River intakes (PDF). Surface water is vulnerable to contamination and often requires treatment, so is not prioritised as a source. However, where other water sources are not feasible, surface water is sometimes used.
- Sub-surface dams (PDF). In arid and semi-arid areas of the world, sand and gravel deposits from streams and rivers can provide water for drinking and irrigation. Such watercourses are generally seasonal, but can be perennial.
After water has been abstracted from the source, various technologies are used to transport it to where people collect it. Some of these key technologies are:
- Gravity-flow water systems (PDF). Natural water sources are not always in a convenient place for collecting water. These systems use gravity to transport water from the source to the user through a network of pipes. Bringing water closer to the people who use it reduces the time and effort spent to collect it – especially for women and girls. The water is also protected as it is transported, which prevents it from being contaminated.
- Hand pumps (PDF) provide a cost-effective and relatively easy-to-use mechanism for raising groundwater from a well or borehole, while also protecting it from contamination.
- Solar pumping (PDF). The cost of using solar power to pump water from boreholes has fallen dramatically in recent years, so is increasingly being used as a means of getting water closer to people. However, as is the case with any technology, if solar pumping is badly implemented or poorly managed, it will not be sustainable.
- Rope pump (PDF). A simple technology that can be constructed from recycled parts such as bicycle wheels, scrap metal and plastic.
- Water storage (PDF). The natural flow rate of a water source varies, but people need water all year round and at different times of the day when the supply may not be sufficient. Storing water balances the supply to meet the demand.
- Water kiosks (PDF) are set up by our local partners and run by attendants who provide their community with clean, safe water for an affordable fee.
In addition to being available in sufficient quantity, water must be safe enough to drink i.e. potable. If the water is naturally clean, it does not need to be treated. However, it is sometime necessary to purify water before consumption either by using water treatment technologies (PDF) or disinfection (PDF).
Top image: WaterAid trained pump mechanic and local leader, Gaudence Mukahabyarimana, washes her hands at the handpump in Nkange, Rwanda.