Public Supply Water Use

Science Center Objects

Public supply refers to water withdrawn by public and private water suppliers that provide water to at least 25 people or have a minimum of 15 connections. Public-supply water is delivered to users for domestic, commercial, and industrial purposes. Part of the total is used for public services, such as public pools, parks, firefighting, water and wastewater treatment, and municipal buildings, and some is unaccounted for because of leaks, flushing, tower maintenance, and other system losses. Domestic deliveries represent the largest single component of public-supply withdrawals.


Public Supply  •  Domestic  •  Irrigation  •  Thermoelectric Power  •  Industrial  •  Mining  •  Livestock  •  Aquaculture


Water tower, DeKalb County, Georgia

Water tower, DeKalb County, Georgia (Credit: Nancy Barber, USGS)

2015 Water Use

(source: Dieter, C.A., Maupin, M.A., Caldwell, R.R., Harris, M.A., Ivahnenko, T.I., Lovelace, J.K., Barber, N.L., and Linsey, K.S., 2018, Estimated use of water in the United States in 2015: U.S. Geological Survey Circular 1441, 65 p.,

Approximately 39,000 Mgal/d of water were withdrawn for public supply in 2015, 61 percent from surface-water sources. Public supply represents about 14 percent of total freshwater withdrawals. In some States, public-supply water sources include desalinated seawater or brackish groundwater that has been treated to reduce dissolved solids. Saline surface-water withdrawals for public-supply use were reported in U.S. Virgin Islands, Texas, Florida, and Massachusetts. Saline groundwater withdrawals for public-supply use were identified in Florida, California, Texas, Virginia, Kansas, and Utah.

Public Supply Water Use in 2015

An estimated 283 million people relied on public-supply water for their household use in 2015. This number represents about 87 percent of the total U.S. population. In 36 States, including Puerto Rico and the U.S. Virgin Islands, surface-water sources provided more than half of the total public-supply withdrawals. Three States—California, Florida, and Texas—accounted for 37 percent of total groundwater withdrawals for public supply. States that relied on groundwater for 75 percent or more of their public-supply withdrawals were Hawaii, Idaho, Florida, Mississippi, Iowa, and Nebraska.

Public supply withdrawals, top States, 2015
[percentages calculated from unrounded values]
State Percentage 
of total withdrawals
Cumulative percentage 
of total withdrawals
California 13% 13%
Texas 7% 21%
New York 6% 27%
Florida 6% 33%
Illinois 4% 37%

Public-supply withdrawals in 2015 were 7 percent less than in 2010, continuing the decline first observed in 2010. Restrictions on public-supply water use were either mandated or encouraged in California and Texas in 2015, in response to severe droughts.

Public supply water withdrawals, 1950-2015

Data sources

Methods for estimating public-supply withdrawals, source of water, population served, and domestic deliveries varied by State. Common sources of information about withdrawals by source included data collected from water suppliers by State water regulatory agencies or through surveys. Estimates of the population served by public supply were derived using various sources, including reports from State agencies, the EPA SDWIS database, U.S. Census data, and information on service connections from public suppliers. Methods for estimating domestic deliveries included surveys of public-supply sales information, calculations using coefficients for per capita use, and development of average percentages of deliveries to various customer categories.

Category history

  • 1950: Municipal
  • 1955 and later: Public Supply

Public supply deliveries:

  • 1960-1965: combined estimate of deliveries for industrial and commercial use broken down by air conditioning and other, and combined estimate for domestic deliveries and losses
  • 1970-1975: combined estimate of deliveries for industrial and commercial use, and combined estimate for domestic use and losses
  • 1980: combined estimate of deliveries for industrial and commercial use, and combined estimate for domestic and public use including losses
  • 1985-1995: estimates of deliveries for domestic, commercial, industrial, thermoelectric power, and public use and losses
  • 2000: no estimates of deliveries
  • 2005 and later: estimates of deliveries for domestic use and a combined estimate of all other uses and system losses

Graphic of category changes over time