Why is it important?

Access to a reliable water supply is important for survival and for ensuring sanitary conditions within settlements, helping to prevent the spread of disease. Water that is supplied needs to be of adequate quality for purpose, depending on whether it is to be used for drinking, cooking, bathing or for livelihoods (such as for agricultural irrigation or animal rearing). At the same time water needs to circulate through the settlement, removing greywater (from washing) or blackwater (human and animal waste) safely, and in a way that does not contaminate watercourses.

Water Supply Checklist

  • Have you developed an integrated watershed management plan (perhaps in partnership with other agencies) to show that you know of the sensitivities of water supply?
  • Can you respond to the need to recover data (metering) to show that you can respond to environmental issues before they become serious (e.g. over abstraction)?
  • Can you make a good case study from the work you have done?
Case Study

Environmental Impact

Water Availability

The sudden influx or localized displacement of population will inevitably pose a strain on locally available resources. If access to these is not done sustainably so as to reduce depletion, it can result in tension with neighbouring communities and local government, environmental degradation, reduction of ecological capacity, and put a strain on rural livelihoods and food supply.

Water Availability Info
Water Availability

Water availability is the volume of renewable water available to the environment.

Water availablity has a dramatic effect on human populations. Without a source of fresh water people quickly die from dehydration. If there is not enough water available to the local environment it cannot sustain any kind of plant life including those required for agriculture.

Water Pollution & Soil quality

Excessive water extraction, inadequate grey or blackwater (see Sanitation) disposal and unsustainable agricultural practices can lead to contamination of local watercourses.

Furthermore, spilled water at water points (pumps, taps, etc.), can increase localised water logging and soil degradation (link to Operation). Water pollution can lead to environmental degradation, loss of habitat and the rapid spread of diseases throughout the settlement.

Water Pollution info
Water Pollution

Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compound.

Water pollution reduces security for a population by contaminating otherwise available clean water. It also increases stress on non-polluted water supplies which would antagonise local populations and increases costs due to a need to import fresh water – this also leads to greenhouse gas emissions

Soil Quality info
Soil Quality

Soil quality reflects how well a soil performs the functions of maintaining biodiversity and productivity, partitioning water and solute flow, filtering and buffering, nutrient cycling, and providing support for plants and other structures. Soil management has a major impact on soil quality.

A reduction in soil quality reduces the environments ability to sequester water leading to an increased risk of flooding and reduces the environment’s ability to produce food, leading to an increased nutritional risk for local and displaced populations.

Drainage & flooding

During heavy rainfall, a tightly built-up settlement with inadequate drainage infrastructure can suffer from water accumulation and flooding which can damage settlement structures and increase the health risks of an already vulnerable population.

Drainage & Flooding info
Drainage & Flooding

Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies. A flood is an overflow of water that submerges or “drowns” land.

If drainage and flood risks are not properly managed then a population is at increased risk of flooding but also of having unusable agricultural lands. Furthermore, stagnant water produces a risk of water borne diseases or increased vector pathways and flooding with saline water can contaminate clean wells in coastal areas.

Greenhouse gases and air pollution

Supplying water to site via a tanker long-term can be a costly and environmentally harmful option. Heavy Goods Vehicles (HGVs) rely on diesel fuel; where these have to be transported long distances to bring water to site they can contribute significantly to greenhouse gas emissions which exacerbate climate change, and their movement can contribute to land degradation and loss of habitat. HGVs can also impact air qualty due to dust or the particulate content of exhaust fumes.

Greenhouse gas info
Greenhouse Gases

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect which maintains the stable temperature of the Earth.

Since the Industrial Revolution there has been a 40% increase in greenhouse gases in the atmosphere which is believed to be contributing to a change in the Earth’s climatic systems. Changes in this system is increasing the vulnerability of many populations.

Air Pollution info
Air Pollution

Air pollution is the introduction into the atmosphere of chemicals, particulates, or biological materials that cause discomfort, disease, or death to humans, damage other living organisms such as food crops, or damage the natural environment or built environment.

Household air pollution can have a significant impact on the a population’s respiratory health.

Mitigation Strategies

Integrated Watershed Management (IWM)

IWM requires the systemic consideration and management of water supply, including water extraction, water access points, quality, drainage, stormwater runoff and also water rights. It supports the 3Rs of ground and rainwater management in water supply plans of Retaining, Recharging and Reusing water.

It has the benefits of increasing water available locally, reducing material costs, increasing income generating practices and reducing dependence on fossil fuels. It also encourages consideration of water needs during income generating practices.


Once legitimate access to locally available water resources is negotiated and secured, water withdrawal needs to take into account the rate of replenishment of the particular source.


Pipework and pumps used for water transportation and distribution need to be correctly installed and regularly maintained (link to Operations) to minimise the unnecessary waste of energy and water during transportation.

Water access points

The location and number of water access points needs to be carefully managed. Their number needs take into account population numbers to reduce conflict and long queues. A higher number of water access points will be needed in areas of concentrated activity (for example communal cooking or trading locations). Water points need to be protected from malicious activity and regularly maintained (linked to Operations), and have adequate drainage. Water access points are an opportunity to improve the local environment, reduce conflicts, and the time drudgery of water collection.

Maximise use of Rainwater

ainwater harvesting can reduce the amount of water that needs to be extracted or transported by vehicles to site, thus reducing strain on local resources. It can also reduce the stormwater runoff during heavy rain and prevent flooding or agricultural leaching into watercourses. It also offers water storage for better water distribution management, particularly during dry periods. Rainwater is already of high quality, reducing the need for water treatment and the danger of spreading of disease.

Rainwater can be harvested at the household level through pipework on the roof of shelter structures and collected in water butts. At the site level, water retention ponds can act as natural features for collecting water during rainfall. These can be useful for agricultural and animal rearing purposes.

Stormwater runoff can also be reduced if deforestation in the local area is prevented, and if the creation of grassed waterways and wetlands is supported (link to Site Selection).

Point-of-use water treatment

Where the quality of water supplied cannot be ensured, various point-of-use technologies can be distributed at a household level to ensure safe drinking water. These include biosand filters, arsenic biosand filters, solar disinfection (SODIS) technologies, chlorine solution or encouragement of water boiling before consumption.

Efficient water use

TDuring operation, (link to Operation), occupants need to be made aware of, and if necessary trained on, water-saving and hygiene practices. This includes minimising waste at water collection points, regular hand and raw food washing and correct use of point-of-use water treatment technologies. Knowing when such technologies are no longer treating water sufficiently and are in need of replacement is also very important. Participatory site maintenance can be enforced where structures are in place for occupants to report on equipment in need of repair or replacement.