Colombia: 1973, 1985, 1993
Kenya: 1989, 1999
Mexico: 1970, 1990, 2000
United States: 1960, 1970, 1980, 1990
Vietnam: 1989, 1999

Colombia 1973: All households.
Colombia 1985: Occupied [not vacant] dwellings.
Colombia 1993: All households.
Kenya 1989: Not group quarters.
Kenya 1999: All households.
Mexico 1970-2000: All households.
United States 1960: Not group quarters, not in cities of 50,000+ residents.
United States 1970-1990: Not group quarters.
Vietnam 1989: All households with dwelling information.
Vietnam 1999: All households.

WATER describes the source of each housing unit's water supply. The basic distinction is whether or not the household had access to piped water. In the absence of piped water, the WATER variable indicates the source of water in most samples.

The first digit of WATER is comparable across samples and indicates whether the household has access to piped water. For other digits, the detail varies by country and census year. "Piped water" is further divided into two categories for those samples that note whether water is piped inside the dwelling/building or piped outside. Across samples, different details are available for the "non-piped" responses.

Colombia 1973 and 1985 are fully comparable, but the 1993 census offers no information on the source of non-piped water.

The "well, cistern, reservoir" category includes only wells. The "other" non-piped water category indicates water from springs, creeks, rivers, cisterns, or other sources.

Piped water in the 1999 Vietnam sample can refer to water piped either inside or outside the structure. Neither the 1989 nor the 1999 Vietnam sample specifies whether piped water is for the exclusive use of the household.