Definition
The proportion of the population with sustainable access to an improved water source, urban and rural, is the percentage of the population who use any of the following types of water supply for drinking: piped water, public tap, borehole or pump, protected well, protected spring or rainwater. Improved water sources do not include vendor-provided waters, bottled water, tanker trucks or unprotected wells and springs.
Goal/target addressed
Goal 7. Ensure environmental sustainability.
Target 10. Halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation.
Rationale
The indicator monitors access to improved water sources based on the assumption that improved sources are likely to provide safe water. Unsafe water is the direct cause of many diseases in developing countries.
Method of computation
The indicator is computed as the ratio is the number of people who use piped water, public tap, borehole or pump, protected well, protected spring or rainwater to the total population, expressed as a percentage. The same method applies for the urban and rural breakdown.
Access to safe water refers to the percentage of the population with reasonable access to an adequate supply of safe water in their dwelling or within a convenient distance of their dwelling. Global Water Supply and Assessment Report 2000 defines reasonable access as “the availability of 20 litres per capita per day at a distance no longer than 1,000 metres”. However, access and volume of drinking water are difficult to measure and so sources of drinking water that are thought to provide safe water are used as a proxy.
The United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO), through the Joint Monitoring Programme, assess trends in “access to improved drinking water sources” by drawing a regression line through the available household survey and census data for each country (details are available at http://www.childinfo.org). Regional and global estimates are aggregated from these national estimates using population-weighted averages.
Data collection and source
Since the late 1990s, data have routinely been collected at national and subnational levels in more than 100 countries using censuses and surveys by national governments, often with support from international development agencies. Two data sources are common: administrative or infrastructure data that report on new and existing facilities, and data from household surveys, including Multiple Indicator Cluster Surveys, Demographic and Health Surveys and Living Standard Measurement Surveys. Before these population-based data were available, provider-based data were used.
Evidence suggests that data from surveys are more reliable than administrative records and provide information on facilities actually used by the population.
References
The State of the World’s Children, annual, United Nations Children’s Fund (www.unicef.org/publications).
Global Water Supply and Sanitation Assessment 2000 Report, 2000, World Health Organization and United Nations Children’s Fund (www.who.int/water_sanitation_health/Globassessment).
Indicators of Sustainable Development: Guidelines and Methodologies, 2001, United Nations Division for Sustainable Development (www.un.org/esa/sustdev/natlinfo/indicators/isd.htm).
World Development Indicators, annual, World Bank (www.worldbank.org/data).
World Health Organization Yearbook (www3.who.int/whosis). [Can’t find this report on this Web site or WHO site. World Health Report meant?]
Toolkit on Gender in Water and Sanitation, World Bank (www.worldbank.org/gender/resources/wstlkt4.pdf).
“Water, Sanitation and Gender Equality”, Gender and Development Briefing Notes, 2003, World Bank (www.worldbank.org/gender/resources/briefing).
Periodicity of measurement
Administrative data are often available annually. Household surveys are generally conducted every three to five years.
WHO and UNICEF annually compile international data and prepare regional and global estimates based on household survey data.
Gender issues
Women and men usually have different roles in water and sanitation activities. These differences are particularly pronounced in rural areas. Women are most often the users, providers and managers of water in rural households and the guardians of household hygiene. If a water system breaks down, women are more likely to be affected than men because they have to travel farther for water or use other means to meet the household’s water and sanitation needs.
Disaggregation issues
The indicator should be monitored separately for urban and rural areas. Because of national differences in characteristics that distinguish urban from rural areas, the distinction between urban and rural population is not amenable to a single definition applicable to all countries. National definitions are most commonly based on size of locality, with rural population as the residual of population that is not considered urban.
International data comparisons
World Health Statistics, annual, World Health Organization (www3.who.int/whosis). [Can’t find this publication. Do you mean World Health Report? www.global-health.gov/worldhealthstatistics.shtml]
Demographic and Health Surveys, www.measuredhs.com.
Living Standards Measurement Study, www.worldbank.com/lsms.
The State of the World’s Children, annual, United Nations Children’s Fund (www.unicef.org/publications).
World Development Indicators, annual, World Bank (www.worldbank.org/data).
Comments and limitations
When data from administrative sources are used, they generally refer to existing sources, whether used or not. Despite official WHO definitions, the judgment about whether a water source is safe is often subjective. Also, the existence of a water supply does not necessarily mean that it is safe or that local people use it. For these and other reasons, household survey data are generally better than administrative data, since survey data are based on actual use of sources by the surveyed population rather than the simple existence of the sources.
While access is the most reasonable indicator for water supply, it still involves severe methodological and practical problems. Among them:
Agencies
National statistical offices.
United Nations Children’s Fund.
World Health Organization.