Clean water is an essential element for human health, wellbeing and prosperity. Whether used for drinking, cleaning, food production or industrial output, access to sufficient water resources is a basic human need. Access to sufficient and safe sanitation facilities is also vital for hygiene, disease prevention, and human health.
The World Health Organization highlights the contribution of poor water and sanitation access to health, mortality and reduced poverty alleviation.1 2 Contaminated drinking water, poor sanitation facilities and open defecation contribute to the transmission of infectious diseases such as diarrhoea, cholera, dysentery, typhoid, and polio, and can also have severe impacts on malnutrition. The WHO estimates that in 2015, the deaths of 361,000 children under 5-years-old could have been avoided by addressing water and sanitation risk factors.3
In this entry we present data on progress on improved water access, access to sanitation facilities, and the incidence of open defecation. Freshwater — whilst a basic human need — is also a finite, and in some regions, scarce resource. This entry also presents data on levels of freshwater use, withdrawals by sector, and levels of freshwater scarcity/stress. Balancing human needs for freshwater with sustaining long-term supplies will continue to pose an important development challenge in the decades to follow.
Access to improved water sources is increasing across the world, rising from 76 percent of the global population in 1990 to 91 percent in 2015.
In the chart below we see levels of freshwater access across the world, measured as the percentage of the total population with access to improved water sources. The World Bank definition (which is covered in more detail in our section on Data Quality & Definitions) of an improved drinking water source includes "piped water on premises (piped household water connection located inside the user’s dwelling, plot or yard), and other improved drinking water sources (public taps or standpipes, tube wells or boreholes, protected dug wells, protected springs, and rainwater collection)." Note that access to drinking water from an improved source does not ensure that the water is safe or adequate, as these characteristics are not tested at the time of survey. But improved drinking water technologies are more likely than those characterized as unimproved to provide safe drinking water and to prevent contact with human excreta. See Data Quality & Definitions for more details.
In 2015, most nations had improved water access in greater than 90 percent of households. This marks significant progress since 1990 where most countries across Latin America, East and South Asia, and Sub-Saharan Africa were often well below 90 percent. Access remains lowest in Sub-Saharan Africa where rates typically range from 40 to 80 percent of households.
The share of rural households with improved water sources was lower than the total population in 2015, with 85 percent access. The global distribution of improved water sources in rural populations is shown in the chart below.
Gaining access to improved water sources can often require infrastructural investment and connection to municipal water networks; this is can be more challenging in rural areas hence we may expect access to be lower. Nonetheless, rural access has risen at a faster rate (based on the relative increase in the share of the population) than total access, increasing by 22 percent since 1990.
The visualisation below shows the share of urban population with access to improved water sources. Globally 97 percent of urban households had improved water access, with most nations now having close to 100 percent penetration.
In 2000 as part of the Millennium Development Goals (MDGs) the world pledged to half to share of people without access to an improved water source by 2015 from 1990 levels. The world surpassed this target by 2010, increasing access to 91 percent by 2015.
Globally, 2.6 billion people gained access over this period — more than a third of the world's population have gained access to improved water since 1990.4 The progress over this 25-year period is shown by region in the chart below, as the share of the population who have gained access since 1990.
The chart below shows the total number of people with and without access to an improved water source from 1990 onwards. Note that these trends can be seen by countries and regions using the "change country" option.
In 1990, 1.26 billion people across the world did not have access to an improved drinking water source. By 2015, this had nearly halved to 666 million.
This improvement occurred despite strong population growth over this period. In 1990, 4 billion people had access to an improved water source; by 2015 this had increased to 6.7 billion. This means that over these 25 years the average increase of the number of people with access to improved drinking water was 107 million every year. These are on average 290,000 people who gained access to drinking water every single day.5
The chart below shows the total number of people without access to an improved water source by region from 1990. The regional breakdown of those without access has changed significantly over the past 25 years.
In 1990 nearly 42 percent of those without access were in East Asia & the Pacific. By 2015, this had fallen to 20 percent. In contrast, Sub-Saharan Africa was host to 22 percent of those without water access in 1990; by 2015 this had increased to nearly half of the global total. In fact, the absolute number of people without access has fallen across all regions over this 25-year period with the exception of Sub-Saharan Africa. The number of people in Sub-Saharan Africa without access to an improved water source has increased from 271 million to 326 million in 2015.
A growing global population and economic shift towards more resource-intensive consumption patterns means global freshwater use — that is, freshwater withdrawals for agriculture, industry and municipal uses — has increased nearly six-fold since 1900. This is shown in the chart below. Rates of global freshwater use increased sharply from the 1950s onwards, but since 2000 appears to be plateauing, or at least slowing.
Global freshwater use since 1900 is disaggregated by broad regional groupings — OECD nations; BRICS countries (Brazil, Russia, India, China and South Africa); and Rest of the World (ROW) in the chart below. Although absolute freshwater use has growth over this period, the distribution of uses between these regional groupings have not changed significantly over the last century; OECD nations use approximately 20-25 percent; BRICS countries use the largest share at approximately 45 percent; and ROW at 30-33 percent.
This breakdown of total freshwater withdrawals is shown by country in the chart below over the period from 1967. In 2014, India had the largest freshwater withdrawals at over 760 billion cubic metres per year. This was followed by China at just over 600 billion m3 and the United States at around 480-90 billion m3.
Levels of water use vary significantly across the world. The visualisation below shows the average level of water withdrawal per capita per year. As described in detail in our Data Quality & Definitions section, water withdrawal is defined as the quantity of freshwater taken from groundwater or surface water sources (such as lakes or rivers) for use in agricultural, industrial or domestic purposes.
As seen below, there is large variance in levels of water withdrawal across the world - this can depend on a range of factors, including latitude, climate, and the importance of a country's agricultural or industrial sector, as explored in the sections below.
To maintain sustainable levels of water resources, rates of water withdrawals must be below rates of freshwater replenishment. 'Renewable internal freshwater flows' refer to to internal renewable resources (internal river flows and groundwater from rainfall) in the country.
Renewable internal flows are therefore an important indicator of water security or scarcity. If rates of freshwater withdrawal begin to exceed the renewable flows, resources begin to decline. The chart below shows the level of renewable internal freshwater resources per capita.
Per capita renewable resources depend on two factors: the total quantity of renewable flows, and the size of the population. If renewable resources decline — as can happen frequently in countries with large annual variability in rainfall, such as monsoon seasons — then per capita renewable withdrawals will also fall. Similarly, if total renewable sources remain constant, per capita levels can fall if a country's population is growing.
As we see below, per capita renewable resources are declining in many countries as a result of population increases.
The chart below shows the average per capita renewable freshwater resources, measured in cubic metres per person per year.
Water is an essential input to global agriculture, whether in the form of rainfed sources or pumped irrigation. The visualisation below shows the total quantity of freshwater withdrawals which are used in agriculture, whether in the form of food crop, livestock, biofuels, or other non-food crop production. Data on agricultural water consumption is typically not reported on an annual basis, and often gathered over several year increments.
In 2010 India was the world's largest agricultural water consumer at nearly 700 billion m3 per year. India's agricultural water consumption has been growing rapidly — almost doubling between 1975 and 2010 — as its population and total food demand continues to increase. China is the world's second largest user, at approximately 385 billion m3 in 2015, although its agricultural freshwater use has approximately plateaued in the recent past.
How do agricultural freshwater withdrawals compare to industrial and domestic sources? Globally we use approximately 70 percent of freshwater withdrawals for agriculture.6
However, this share varies significantly by country - as shown in the chart below which measures the percentage of total freshwater withdrawals used for agriculture. Here we see large variations geographically and by income level. The average agricultural water use for low-income countries is 90 percent; 79 percent for middle income and only 41 percent at high incomes.
There are a number of countries across South Asia, Africa and Latin America which use more than 90 percent of water withdrawals for agriculture. The highest is Afghanistan at 99 percent. Countries in the global north tend to use a much lower share of water for agriculture; Germany and the Netherlands use less than one percent.
Irrigation — the deliberate provision or controlled flooding of agricultural land with water — has been an important input factor in the observed increase of crop yields across many countries in recent decades. It has also been a strong driver in the quantity of water used for agriculture.
The share of total agricultural area (which is the combination of arable and grazing land) which is irrigated is shown in the chart below. As we see, irrigation is particularly prevalent across South & East Asia and the Middle East; Pakistan, Bangladesh and South Korea all irrigate more than half of their agricultural area. India irrigates 35 percent of its agricultural area.
Levels of irrigation in Sub-Saharan Africa have increased, and continue to have, lower levels of irrigation relative to South Asia and the Middle East & North Africa. Poorer progress in increasing crop yields in recent decades in Sub-Saharan Africa has been partly attributed (among other factors including fertilizer application rates and crop varieties) to lower uptake of irrigation in Sub-Saharan Africa.7
Water is used for a range of industrial applications, including dilution, steam generation, washing, and cooling of manufacturing equipment. Industrial water is also used as cooling water for energy generation in fossil fuel and nuclear power plants (hydropower generation is not included in this category), or as wastewater from certain industrial processes.
The visualisation below shows the total annual water withdrawals which are used for industrial purposes. Globally, the United States is the largest user of industrial water, withdrawing over 300 billion m³ per year. This is significantly greater than China, the second largest, at 140 billion m³.
Most countries across the Americas, Europe and East Asia & Pacific regions use more one billion m³ for industrial uses per year. Rates are typically much lower across Sub-Saharan Africa and some parts of South Asia where most use less than 500 million m³.
Globally, just under 20 percent (18-19 percent) of total water withdrawals are used for industrial purposes. The visualisation below provides an overview of industrial water withdrawals measured as the share of total water withdrawals (which is the sum of agricultural, industrial and domestic uses).
In contrast to the global distribution for agricultural water withdrawals, industrial water tends to dominate in high-income countries (with an average of 44 percent), and is small in low-income countries on average 3 percent).
Estonia uses the greater share of withdrawals for industrial applications at 96 percent. The share in Central and Eastern Europe tends to be greater than 70 percent; 80 percent in Canada; and approximately half in the United States. Across Sub-Saharan Africa and South Asia, this tends to contribute less than 10 percent to total withdrawals.
Municipal water is defined as the water we use for domestic, household purposes or public services. This is typically the most 'visible' form of water: the water we use for drinking, cleaning, washing, and cooking.
Municipal water withdrawals are shown in the chart below. With the largest population, China's domestic water demands are highest at over 70 billion m³ per year. India, the next largest populace is the third largest municipal water user. The United States, despite having a much lower population, is the second largest user as a result of higher per capita water demands.
Despite being the most visible use of freshwater, domestic demands for most countries are small relative to agricultural and industrial applications. Globally around 11 percent of withdrawals are used for municipal purposes.
Municipal uses as a share of total water withdrawals across the world is shown in the chart below. The majority of countries use less than 30 percent of withdrawals for domestic purposes.
The share of municipal water in some countries across Sub-Saharan Africa can be high as a result of very low demands for agricultural and industrial withdrawals. Domestic uses of water withdrawals can also dominate in some countries across Europe with high rainfall, such as the United Kingdom and Ireland where agricultural production is often largely rainfed and industrial output is low.
As global population grows (increasing agricultural, industrial and domestic demands for water), and water demand increases, water stress and the risk of water scarcity is now a common concern. This is even more applicable for particular regions with lower water resources and/or larger population pressures.
Water stress is defined based on the ratio of freshwater withdrawals to renewable freshwater resources. Water stress does not insinuate that a country has water shortages, but does give an indication of how close it maybe be to exceeding a water basin's renewable resources. If water withdrawals exceed available resources (i.e. greater than 100 percent) then a country is either extracting beyond the rate at which aquifers can be replenished, or has very high levels of desalinisation water generation (the conversion of seawater to freshwater using osmosis processes).
The chart below shows the total internal renewable freshwater resources by region.
The visualisation below provides a measure of levels of water stress across the world. This is measured based on freshwater withdrawals as a share of internal (renewable) resources. The World Resources Institute categorise water stress in the following ways: if withdrawals are less than 10 percent of resources then a country has low water stress; 10-20 percent is low-to-medium stress; 20-40 percent medium-to-high; 40-80 percent high stress; and greater than 80 percent is extremely high stress.8
As shown, several countries across the Middle East, North Africa & South Asia have extremely high levels of water stress. Many, such as Saudi Arabia, Egypt, United Arab Emirates, Syria, Pakistan, Libya have withdrawal rates well in excess of 100 percent — this means they are either extracting unsustainably from existing aquifer sources, or produce a large share of water from desalinisation.
Most countries across South Asia are experiencing high water stress; medium-to-high across East Asia, the United States and much of Southern and Eastern Europe. Water stress in Northern Europe, Canada, much of Latin America, Sub-Saharan Africa and Oceania is typically low or low-to-medium.
In 2000, the world set a target as part of the Millennium Development Goals (MDGs) to half the proportion of people without access to improved sanitation facilities by 2015 from 1990 levels. Over this period, progress was made in increasing the share with access from 54 to 68 percent. However, this fell short of the 77 percent target by 2015.9
Universal access to sanitation therefore remains one of the world's greatest development challenges. Over the period from 1990-2015, a further 29 percent of the global population gained access to sanitation. Although, as shown in the chart below, progress varied significantly by region.
The chart below shows the total number of people with and without access to improved sanitation facilities from 1990 [note that this data can also be viewed by country and region using the "change country" function].
Over this 25-year period, the total number of people without access to improved sanitation has remained almost constant: in 1990 this figure was 2.49 billion, and in 2015 it has reduced to 2.39 billion. Total population has of course grown over this period, meaning the number with access has increased from 2.8 billion to nearly 5 billion in 2015. This means that although the total number without access has remained almost constant, the share of the population without access has fallen.
The chart below shows the total number of people without access to improved sanitation facilities by region. Over 90 percent of those without access in 2015 resided in Asia, the Pacific or Sub-Saharan Africa. The largest region share was from South Asia, accounting for 40 percent and nearly one billion without access. This was followed by Sub-Saharan Africa with nearly 30 percent (706 million), and East Asia & Pacific with around 22 percent (520 million).
There remains large inequalities in levels of access to improved sanitation. The maps below show the total share of the population with improved sanitation facilities, as observed through time from 1990. Also shown in the maps which follow is this share for rural and urban populations of a given country.
Access across Europe, North America, North Africa and some of Latin America is typically greater than 90 percent (and in most cases between 99 and 100 percent). Between 80 and 90 percent of households in Latin America and the Caribbean have improved sanitation. Access is slightly lower across Central and East Asia, typically between 70 and 80 percent.
In South Asia, progress has been varied. Sri Lanka has achieved a 95 percent access rate; Pakistan and Bangladesh both have access of over 60 percent; whereas India lags behind in this regard with just under 40 percent. Regionally, access is lowest in Sub-Saharan Africa where most countries have less than 40 percent access rates. In South Sudan, only 6-7 percent of the population had improved sanitation in 2015.
Open defecation refers to the defecation in the open, such as in fields, forest, bushes, open bodies of water, on beaches, in other open spaces or disposed of with solid waste. Open defecation has a number of negative health and social impacts, including the spread of infectious diseases, diarrhoea (especially in children), adverse health outcomes in pregnancy, malnutrition, as well as increased vulnerability to violence — particularly for women and girls.10
The charts below detail the share of people practicing open defecation from 1990 onwards, as a percentage of the total population, rural and urban population. In 2015, 15 percent of the world's population were still practicing open defecation, presenting a reduction of approximately half since 1990. Regionally, prevalence was highest in South Asia where the average share is 36 percent. India in particular still has high rates, with nearly 45 percent still using open defecation.
In Sub-Saharan Africa, this rate was 23 percent. However, some countries in particular — such as Niger, Chad, South Sudan and Eritrea — still have a prevalence between 60-80 percent.
The visualisation below shows the relationship between access to improved water sources versus gross domestic product (GDP) per capita. We see that there is a general link between income and freshwater access.
Typically most countries with greater than 90 percent of households with improved water have an average GDP per capita of more than $10,000-15,000. Those at lower incomes tend to have a larger share of the population without access. However, there are some notable exceptions: for example, more than half of Equatorial Guinea's population lacks access to improved water despite having an GDP per capita above $27,000. In this case, the country's wealth is highly concentrated; the mean GDP per capita is therefore far from the median GDP (i.e. there are high levels of inequality). Equatorial Guinea is one of the few remaining autocracies in the African continent. Its politics and governance therefore has a much stronger influence than average income.
Although income is an important determinant, the range of levels of access which occur across countries of similar prosperity further support the suggestion that there are other important governance and infrastructural factors which contribute. For example, Malawi has achieved a 90 percent access rate despite having a GDP per capita just over $1,000. Mozambique which has a similar income levels has just over 50 percent access.
In addition to the large inequalities in water access between countries, there are can also be large differences within country. In the chart below we have plotted the share of the urban population with access to improved water sources versus the share in rural areas. Here we have also shown a line of parity; is a country lies along this line then access in rural and urban areas is equal.
Since nearly all points lie above this line, with very few exceptions — notably Palestine — access to improved water sources is greater in urban areas relative to rural populations. This may be partly attributed to an income effect; urbanization is a trend strongly related to economic growth.11 The infrastructural challenges of developing municipal water networks in rural areas is also likely to play an important role in lower access levels relative to urbanised populations.
In the chart below we see agricultural water withdrawals as a share of total water withdrawals versus gross domestic product (GDP) per capita. Overall, we see a negative correlation: agriculture's share of total water withdrawals tend to decrease at higher incomes. This links strongly to the structure of economies; at lower incomes, agriculture forms a higher share of total GDP and a larger share of agricultural employment.
Globally, 70 percent of water withdrawals are used for agriculture. However, water requirements vary significantly depending on food type. The charts below show the global average water footprint/requirement for the production of one tonne of product (in cubic metres); per kilocalorie (per litre); and per gram of protein (per litre).
This water footprint is the sum of water requirement across the full value chain (for example, the requirement of meat production includes the water requirement of the animal as well as the demand of the crops grown for animal feed). This value also includes the quantity of wastewater or water which is polluted as a result of agricultural production.
Similarly to improved water access, the provision of sanitation facilities tends to increase with income. In the chart below we see the share of the population with access to improved sanitation versus gross domestic product (GDP) per capita.
Overall, we see a strong relationship between the two. However, the typical 'threshold' for reaching 90-100 percent sanitation provision is notably higher than that of improved water sources. Even countries with an average GDP per capita greater than $25,000 have rates of access below 75 percent.
In the chart below we see the share of urban households with improved sanitation facilities versus the share of rural households. Similarly to our analysis of the share with improved water sources, we have shown the parity line whereby a country lying along this line has the same level of access in urban and rural areas.
As we see, the majority of countries lie above this line, meaning that the share of urban populations with sanitation facilities is higher than in rural areas.
As we see above, rural access to improved sanitation facilities typically lags behind urban areas for most countries. Although having access to improved sanitation facilities does not necessitate open defecation (some households can have very basic or shared sanitation facilities), we also see that open defecation is predominantly a rural issue for most countries.
In the chart below wee see the prevalence of open defecation in rural areas versus urban areas. For the majority of countries, open defecation in urban areas is typically below 20 percent of the population. For rural populations, however, the share of the population practicing open defecation can range from less than 20 percent to almost 90 percent. Although open defecation in urban areas is still a pressing in many countries, the problem much more strongly concentrated in rural areas.
The World Health Organization highlights the contribution of poor water and sanitation access to health, disease and mortality12 13 Contaminated drinking water, poor sanitation facilities and open defecation contribute to the transmission of infectious diseases such as diarrhoea, cholera, dysentery, typhoid, and polio, and can also have severe impacts on malnutrition. The WHO estimates that in 2015, the deaths of 361,000 children under 5-years-old could have been avoided by addressing water and sanitation risk factors.14
In the chart below we see rates of child mortality (measured as the number of children who die before their 5th birthday per 1,000 live births) versus the share of the population practicing open defecation — a key measure of poor sanitation and hygiene. There are a number of important contributing factors to child mortality, including nutrition, healthcare and other living standards. However, overall we see that countries with very low child mortality rates tend to have negligible shares of open defecation. In countries where open defecation is greater than 10 percent, typically more than 20 children per 1,000 die before their 5th birthday.
However, this relationship is not directly related: several countries with very low rates of open defecation still have very high child mortality rates (close to 1-in-10). Sanitation is therefore just one of many contributing factors to health and disease prevention.
Stunting — determined as having a height which falls below the median height-for-age WHO Child Growth Standards — is a sign of chronic malnutrition.15 Although, linked to poor nutritional intake (which we cover in our entry on Hunger and Undernourishment), it is linked to a range of compounding factors, including the recurrence of infectious diseases, childhood diarrhea, and poor sanitation & hygeine.
In the chart below we see the prevalence of stunting (measured as the share of children under 5-years-old defined as being more than two standard deviations below the median international height) versus the share of the population with improved sanitation facilities. Overall we see a negative correlation: rates of childhood stunting are typically higher in countries with lower access to improved sanitation facilities.
Improved water sources: "An improved drinking water source includes piped water on premises (piped household water connection located inside the user’s dwelling, plot or yard), and other improved drinking water sources (public taps or standpipes, tube wells or boreholes, protected dug wells, protected springs, and rainwater collection).
Access to drinking water from an improved source does not ensure that the water is safe or adequate, as these characteristics are not tested at the time of survey. But improved drinking water technologies are more likely than those characterized as unimproved to provide safe drinking water and to prevent contact with human excreta. While information on access to an improved water source is widely used, it is extremely subjective, and such terms as safe, improved, adequate, and reasonable may have different meanings in different countries despite official WHO definitions. Even in high-income countries treated water may not always be safe to drink. Access to an improved water source is equated with connection to a supply system; it does not take into account variations in the quality and cost (broadly defined) of the service." 16
Improved sanitation facilities: "An improved sanitation facility is defined as one that hygienically separates human excreta from human contact. They include flush/pour flush (to piped sewer system, septic tank, pit latrine), ventilated improved pit (VIP) latrine, pit latrine with slab, and composting toilet.
Improved sanitation facilities range from simple but protected pit latrines to flush toilets with a sewerage connection. To be effective, facilities must be correctly constructed and properly maintained." 17
Open defecation: "People practicing open defecation refers to the percentage of the population defecating in the open, such as in fields, forest, bushes, open bodies of water, on beaches, in other open spaces or disposed of with solid waste."
Water withdrawal: Water withdrawals, ( also sometimes known as 'water abstractions'), are defined as freshwater taken from ground or surface water sources (such as rivers or lakes), either permanently or temporarily, and used for agricultural, industrial or municipal (domestic) uses.
The UN Food and Agricultural Organization (FAO) AQUASTAT Database defines total water withdrawal as: "Annual quantity of water withdrawn for agricultural, industrial and municipal purposes. It can include water from primary renewable and secondary freshwater resources, as well as water from over-abstraction of renewable groundwater or withdrawal from fossil groundwater, direct use of agricultural drainage water, direct use of (treated) wastewater, and desalinated water. It does not include in-stream uses, which are characterized by a very low net consumption rate, such as recreation, navigation, hydropower, inland capture fisheries, etc."
Total withdrawal is equal to: [withdrawals for agriculture] + [withdrawals for industry] + [withdrawals for municipal/domestic uses].
The UN Food and Agricultural Organization (FAO) AQUASTAT Database gives the following definitions for agricultural, industrial and municipal withdrawals:
Agricultural water withdrawal: "Annual quantity of self-supplied water withdrawn for irrigation, livestock and aquaculture purposes. It can include water from primary renewable and secondary freshwater resources, as well as water from over-abstraction of renewable groundwater or withdrawal from fossil groundwater, direct use of agricultural drainage water, direct use of (treated) wastewater, and desalinated water. Water for the dairy and meat industries and industrial processing of harvested agricultural products is included under industrial water withdrawal."
Industrial water withdrawal: "Annual quantity of self-supplied water withdrawn for industrial uses. It can include water from primary renewable and secondary freshwater resources, as well as water from over-abstraction of renewable groundwater or withdrawal from fossil groundwater, direct use of agricultural drainage water, direct use of (treated) wastewater, and desalinated water. This sector refers to self-supplied industries not connected to the public distribution network. The ratio between net consumption and withdrawal is estimated at less than 5%. It includes water for the cooling of thermoelectric and nuclear power plants, but it does not include hydropower. Water withdrawn by industries that are connected to the public supply network is generally included in municipal water withdrawal."
Municipal water withdrawal: "Annual quantity of water withdrawn primarily for the direct use by the population. It can include water from primary renewable and secondary freshwater resources, as well as water from over-abstraction of renewable groundwater or withdrawal from fossil groundwater, direct use of agricultural drainage water, direct use of (treated) wastewater, and desalinated water. It is usually computed as the total water withdrawn by the public distribution network. It can include that part of the industries and urban agriculture, which is connected to the municipal network. The ratio between the net consumption and the water withdrawn can vary from 5 to 15% in urban areas and from 10 to 50% in rural areas."
Renewable internal freshwater resources refers to the quantity of internal freshwater from inflowing river basins and recharging groundwater aquifers. Data on renewable resources should be treated with caution; since this data is gathered intermittently, it fails to capture seasonal and annual variance in water resources which can be significant in some nations. Data at a national level also fails to capture variability at more local levels, which can be important when analysing the sustainability of particular groundwater aquifers or surface water basins.
Water stress is defined in its simplest terms as occurring when water demand or withdrawal substantiates a large share of renewable water resources. The World Resources Institute (WRI) define baseline water stress based on the ratio of annual water withdrawals to renewable resources.18
It defines water stress categories based on this percentage (% of withdrawals to renewable resources) as follows:
- <10% = low stress
- 10-20% = low-to-medium stress
- 20-40% = medium-to-high stress
- 40-80% = high stress
- >80% = extremely high stress
Water scarcity is more extreme than water stress, and occurs when water demand exceeds internal water resources.
World Development Indicators – World Bank
- Data: Access to improved water sources, improved sanitation facilities, open defecation, water consumption by sector and related health indicators
- Geographical coverage: Global – by country and world region
- Time span: 1990 onwards
- Available at: https://data.worldbank.org/indicator
WHO/UNICEF Joint Monitoring Programme ( JMP ) for Water Supply and Sanitation
- Data:Water and sanitation sources access
- Geographical coverage: Global - by country and world region
- Time span: 2000 onwards
- Available at: https://washdata.org/
UN Food and Agricultural Organization (FAO) AQUASTAT
- Data:Water uses, withdrawals, resources and management
- Geographical coverage: Global - by country and world region
- Time span: 1965 onwards
- Available at: http://www.fao.org/nr/water/aquastat/main/index.stm