There are numerous practical interventions and WASH technologies which help strengthen community resilience to the impacts of climate change.
Groundwater development (using springs)
In its most basic form, spring development involves protecting the immediate area around a spring and constructing a facility where water can be collected safely. The flow from upland springs (which are often some distance away from water users) can be partially diverted into pipes and tanks that supply tap stands in communities. Such schemes can serve large numbers of users. Examples exist in Ethiopia, Madagascar, Timor-Leste and Nicaragua.
Springs can provide a reliable year-round supply of clean water, if their catchment areas are protected from environmental degradation, and leakage in distribution systems is well-controlled.
Groundwater development (using dug wells)
Hand-dug wells are manually constructed using hand tools. They vary in diameter from 1.5m to several metres. They are typically no deeper than 30m because digging becomes increasingly difficult (and unsafe) at greater depths, but some wells do exceed 30m. If wells are dug using de-watering techniques, they are more likely to be able to accommodate seasonal fluctuations in water availability. Wells dug without de-watering are prone to drying, which could mistakenly be attributed to climate change. Examples exist in many countries where WaterAid works.
Dug wells can provide year-round access to water and are a suitable climate change adaptation option in areas where groundwater is relatively close to the surface. In areas where groundwater moves at very slow rates, wide diameter dug wells are appropriate solutions because they provide greater storage capacity than boreholes do. This storage is less likely to be exhausted by manual pumping.
Groundwater development (using boreholes or tubewells)
Groundwater acts as a giant natural storage reservoir that can provide water when surface sources have dried up or are contaminated. The natural filtering property of aquifers ensures that groundwater is generally (although not always) of good quality. If groundwater is well managed and protected from pollution, it can provide reliable year-round supplies. Groundwater can be accessed and developed by drilling boreholes into underground water-bearing fractures, soil or rock formations. Boreholes may be fitted with a manually operated pump that can lift water from 45 to 60m, or a motorised pump that can lift water from deeper depths. Motorised pumping can supply large piped schemes. Examples exist in most countries where WaterAid works.
Research by the British Geological Survey, investigating the likely impact of climate change on groundwater, indicates that groundwater is more resilient to changes in climate than rivers, lakes and ponds.Well-sited, well-designed, well-constructed and supervised boreholes tapping into groundwater are a credible climate change adaptation strategy. Because groundwater can usually be developed close to the home, the hardship of water collection is reduced, meaning people can collect more water in less time to meet their daily needs. Well-sealed and well-protected boreholes provide water for hygiene and help to reduce the incidence of water-transmitted diseases, meaning people are better able to cope with the impacts of climate change.
This involves construction of tanks, cisterns, dams and reservoirs to capture and store water when it is available. Examples exist in many countries where WaterAid works.
Storage is an essential component of any water supply system. Without storage, there is no way to make water available in times of scarcity or to accommodate changing demands. Storage capacity in many countries is extremely low, meaning water is not always available in times of need. Tanks and reservoirs provide much-needed storage to cover water shortages, helping people to adapt to climate variability.
Elevated water points
These are hand pumps installed on elevated platforms in flood-prone areas. They tap into groundwater. Examples exist in Bangladesh.
They provide access to groundwater during floods. If the borehole the pump draws from is well-sealed, it is possible that water supplies will be protected from inflow of contaminated water.
These are latrines built on stilts or a concrete or brick plinth. Waste may drain into a sealed chamber to be emptied, or into a septic bank buried beneath the ground. Examples exist in Nicaragua and Bangladesh.
Elevated latrines provides access to sanitation facilities during floods.
- Sand dams involve constructing a barrier across a river channel that contains high volumes of coarse grained sediments. The barrier allows water to flow but traps coarse grained sediment behind it. This sediment acts as an artificial aquifer, storing water below the surface and protecting it from contamination. Sand dams are only appropriate in very specific hydrogeological conditions. Examples exist in Ethiopia and Burkina Faso.
Sand dams can store and provide large volumes of water in times of scarcity. They may contribute to increased soil water availability in the immediate vicinity of dams, improving prospects for crop growth. Water can be used for irrigation and livestock watering, strengthening livelihood and food security.
- Sub-surface dams involve digging into a river bed and building a dam under the surface, which slows the underground flow of water. No recent examples exist in countries where WaterAid works.
Like sand dams, sub-surface dams constructed in river channels can retain water behind them, making supplies available in times of scarcity.
- Small dams involve constructing a barrage across a river channel, storing surface water in a pond or reservoir behind it. Examples exist in Mali and India.
Small dams constructed in river channels store water, making it available for crop watering and other uses in times of scarcity.
Rainwater harvesting (rooftop catchment with tank)
Rainwater falls onto a clean roof surface and is channelled by guttering and pipes into a storage tank. Storage tanks can vary in capacity, and can provide for households, schools or health centres. People draw water from a tap connected to the storage tank. Examples exist in Uganda, Pakistan, Nicaragua, Burkina Faso, Papua New Guinea and Rwanda.
They provide a means of capturing and storing a relatively clean supply of water that can be used in times of scarcity. If used sparingly, for drinking, washing and cooking only, rainwater can provide essential supplies during dry periods. Supplies may not last for a full dry season, but can act as a buffer, supplementing water available from other sources.
Rainwater harvesting (ground catchment with water flowing into protected tanks)
In certain areas, where there are outcrops of impermeable rock, it is possible to capture rainwater runoff and direct it into storage tanks. Relatively large catchments can be enclosed within small walls, resulting in collection and storage of large amounts of water. In some desert areas in South Asia this ancient practice is employed to capture precious rainwater in protected tanks. Example exists in Pakistan.
It provides a means of capturing and storing a relatively clean supply of water that can be used in times of scarcity. Supplies can be used for kitchen garden and small livestock watering, strengthening household food security and resulting in people being better able to adapt to impacts of climate change.
Rainwater harvesting (ponds)
This involves the construction of ponds that collect rainwater or runoff diverted into them from the surrounding area. Examples in Bangladesh have used slow sand filters to treat the water.
In areas where the groundwater is saline or contaminated, rainwater collection in sealed ponds can make critically needed supplies of fresh water available in times of scarcity. However, pond water must be filtered before it can be used for human consumption. These supplies can provide much-needed water in areas with intermittent rainfall.
Managed groundwater recharge
This involves capturing and channelling water into recharge wells that replenish groundwater during the rainy season. Examples exist in Nepal and Bangladesh.
In areas with high groundwater salinity, fluoride, arsenic or obstruction of recharge (for example in urban areas), managed groundwater recharge can help to dilute salinity, arsenic and fluoride concentrations in the area around a well, provided that groundwater flows do not take diluted water away from the well area. Increased availability of cleaner water helps people adapt to water shortages that may emerge due to climate variability.
This involves promoting solutions that remove faecal waste from the environment. Sanitation solutions typically capture, store, transport, treat and safely dispose of faecal waste. Examples exist in all countries where WaterAid works.
Safe capture, storage, transportation, treatment and disposal of faecal waste is critical if exposure to disease is to be minimised. With reduced exposure to disease, people are better able to cope with the impacts of climate change.
This involves the removal of harmful constituents from water so that it is safe to drink. This can be done using a variety of techniques, which include sedimentation, filtration, addition of chemicals, adsorption, boiling, distillation, ion exchange, reverse osmosis and solar disinfection. Examples exist in Nicaragua, Nepal, India, Pakistan, Bangladesh, Uganda and other countries where WaterAid works.
Water treatment, coupled with improved hygiene and sanitation, can help to reduce the incidence of debilitating diseases that weaken people’s ability to sustain livelihoods. With reduced exposure to disease, people are better able to cope with the impacts of climate change.
This involves promoting improved hygiene behaviours, such as handwashing with soap at critical times of the day, for example after using the toilet, and before food preparation and meals. Examples exist in all countries where WaterAid works.
Improved hygiene behaviours help reduce exposure to waterborne and water-washed diseases that occur now and may be accentuated by climate change. With reduced exposure to disease, people are better able to cope with the impacts of climate change.
To find out how climate change policy and finance can support access to WASH services and improve water security, click here.