Sr. Statistics and Monitoring Specialist
Water, Sanitation and Hygiene/JMP
Division of Policy and Practice
United Nations Children’s Fund
Postal Address:Three United Nations Plaza,New York, NY 10017
Telephone: 1 212-326-7975
Fax: 1 212-735-4422
www.wssinfo.org and www.childinfo.org
Water, Sanitation and Health
World Health Organization
Postal Address:20, Avenue Appia, 1211 Geneva 27, Switzerland
Telephone: +41 22 791 1624
Fax: +41 22 791 4159
The proportion of the population using an improved drinking water source, total, urban, and rural, is the percentage of the population who use any of the following types of water supply for drinking: piped water into dwelling, plot or yard; public tap/standpipe; borehole/tube well; protected dug well; protected spring; rainwater collection and bottled water (if a secondary available source is also improved). It does not include unprotected well, unprotected spring, water provided by carts with small tanks/drums, tanker truck-provided water and bottled water (if secondary source is not an improved source) or surface water taken directly from rivers, ponds, streams, lakes, dams, or irrigation channels. Definitions and a detailed description of these facilities can be found at the website of the WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation at
The indicator is computed as the ratio of the number of people who use an improved drinking water source to the total population, expressed as a percentage. The same method applies for the urban and rural breakdown.
Coverage estimates are based on data from nationally representative household surveys and national censuses, which in some cases are adjusted to improve comparability among data over time. Survey and census data for urban and rural areas are then plotted on a time scale from 1980 to present. A linear trend line, based on the least-squares method, is drawn through these data points to estimate urban and rural coverage for the baseline year 1990 and for the year of most recent estimate.
A linear regression line is drawn only if at least two survey data points are available, and they are spaced five or more years apart. The linear regression line may be extrapolated up to two years after, or before, the latest or earliest survey data point. Outside of these time limits, the extrapolated regression line is flat for up to four years, as necessary. If the extrapolated regression line would reach 100% coverage or beyond, or 0%, a flat line is drawn from the year prior to the year where coverage would reach 100% (or 0%).
Total coverage estimates are computed from the urban and rural coverage estimates using the latest population estimates and distribution of urban and rural population provided by the United Nations Population Division
More information on this methodology is available at
Use of an improved drinking water source is a proxy for access to safe drinking water. Improved drinking water sources are more likely to be protected from external contaminants than unimproved sources either by intervention or through their design and construction. The indicator does not take actual drinking water quality into account, nor does it reflect the time spent on getting water from improved sources, which are not on premises. Both these determinants though are important parameters of access. Given the lack of comparable historic and current data on these parameters, these determinants are not reflected in the global indicator to measure progress towards MDG 7, Target 7C.
Sustainable access is currently not measured for reasons of a lack of common understanding what constitutes sustainable access and how to reliably measure it at global scale.
The origins of the most common discrepancies between internationally reported and nationally reported figures are:
Often discrepancies are found between survey and census findings and routinely reported data. Surveys and censuses provide a net estimate of facilities that are in use, including those constructed by different actors and excluding those facilities that have fallen in disrepair and which are no longer in use.
Routinely reported data from line Ministries, also known as administratively reported data, often only record cumulative totals of facilities constructed based on records from government-supported programs and/or data reported by water utilities. Administrative data often do not take into account facilities constructed under NGO supported programs or facilities constructed by individual households without outside support. For these reasons administrative data are not used at international level for tracking progress towards the MDG drinking water and sanitation target.
Primary data sources used for international monitoring include nationally representative household surveys, including Multiple Indicator Cluster Surveys (MICS), Demographic Health Surveys (DHS), World Health Surveys (WHS), Living Standards and Measurement Surveys (LSMS), Core Welfare Indicator Questionnaires (CWIQ), (Pan Arab Project for Family Health Surveys (PAPFAM), and population censuses. Most of the survey data can be downloaded from the organizations that supported these surveys through the Internet. Census data are often obtained directly from National Statistics Offices.
The use of drinking water sources and sanitation facilities is part of the wealth-index used by household surveys to divide the population into wealth quintiles. As a result, most nationally representative household surveys include information about water and sanitation.
To seek out these national data sources that might otherwise be overlooked, UNICEF conducts an annual exercise called the Country Reports on Indicators for the Goals (CRING). CRING gathers recent information for all indicators regularly reported on by UNICEF, including the water supply and sanitation indicators. Surveys found through CRING include Household Budget Surveys, Reproductive Health Surveys, Labour Force Surveys, and Welfare Monitoring Surveys, etc.
The WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation (JMP) is charged with international monitoring of the MDG drinking water and sanitation target. When the JMP receives new survey or census data, its staff assesses the validity of the data by review, using a set of objective criteria. New survey data are entered into the JMP database only when the accompanying survey documentation is available to JMP. Provider-based (reported) data are only used when there are no survey or census data available for a country for the period going back to 1980.
The survey questions and response categories pertaining to access to drinking water are fully harmonized between MICS and DHS – which make up over 70 percent of all survey data in the JMP database. The same standard questions are being promoted for inclusion into other survey instruments and can be found at
Countries with missing data are assigned regional averages when generating regional and global estimates.
Data are available for approximately 160 countries.
National-level household surveys are generally conducted every 3-5 years in most developing countries, while censuses are generally conducted every 10 years. The latest data on which the estimates are based generally stem from surveys and censuses conducted up to two years ago. This is a common lead-time required to conduct the surveys, analyze them and report on the findings. On average, the results of 25 - 40 new surveys or censuses emerge every year with peak years of up to 80 surveys when a round of MICS has been conducted.
The WHO/UNICEF Joint Monitoring Programme updates global, regional, and country estimates for Water Supply and Sanitation (JMP), every 2 years, as global estimates of water and sanitation coverage do not change significantly on an annual basis. JMP publishes coverage estimates on a biennial basis.
Regional and global estimates are based on population-weighted averages weighted by the total population. These estimates are presented only if available data cover at least 50% of the total population in the regional or global groupings.
Biennial coverage updates are typically released in the first half of every even second year. Reports, tables, graphs, and data files are available at
www.wssinfo.org (the JMP website) or at www.childinfo.org (UNICEF’s statistics website).