Water Use in the United States
Public Supply Water Use
Public supply refers to water withdrawn by public and private water suppliers that provide water to at least 25 people or have a minimum of 15 connections.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.
2010 Water Use
(source: Maupin, M.A., Kenny, J.F., Hutson, S.S., Lovelace, J.K., Barber, N.L., and Linsey, K.S., 2014, Estimated use of water in the United States in 2010: U.S. Geological Survey Circular 1405, 56 p., http://pubs.usgs.gov/circ/1405/.)
Approximately 42,000 Mgal/d of water were withdrawn for public supply in 2010, 63 percent from surface-water sources.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 Florida, the U.S. Virgin Islands, and Massachusetts. Saline groundwater withdrawals for public-supply use were identified in Florida, California, Texas, Virginia, and Utah.
An estimated 268 million people relied on public-supply water for their household use in 2010. This number represents about 86 percent of the total U.S. population. In 38 States, including the District of Columbia, 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 38 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, Florida, Idaho, Mississippi, Nebraska, Iowa, and New Mexico.
Public-supply withdrawals in 2010 were 5 percent less than in 2005, marking the first decline since public-supply withdrawals were initially reported in 1950.
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.