Public supply water use is the third largest category in the United States and represents 14 percent of the total freshwater withdrawals. Public water supply refers to water withdrawn by public and private water suppliers and delivered to users. Public water suppliers provide water to domestic, commercial, and industrial users, to facilities generating thermoelectric power, for public use, and occasionally for mining and irrigation. A public water supply is a public or private water system that provides water to at least 25 people or has a minimum of 15 service connections. Estimating withdrawals for public supply is a complex problem because many different factors affect daily public-supply system withdrawals, including but not limited [...]
Summary
Public supply water use is the third largest category in the United States and represents 14 percent of the total freshwater withdrawals. Public water supply refers to water withdrawn by public and private water suppliers and delivered to users. Public water suppliers provide water to domestic, commercial, and industrial users, to facilities generating thermoelectric power, for public use, and occasionally for mining and irrigation. A public water supply is a public or private water system that provides water to at least 25 people or has a minimum of 15 service connections. Estimating withdrawals for public supply is a complex problem because many different factors affect daily public-supply system withdrawals, including but not limited to physiographic factors, demand for water by users, and physical limitations of the supply system, and(or) the source of the water. Additionally, the problem is complicated by systems in which the water is withdrawn in one location and used in another area or is sold to other systems. Systems have different percentages of categories of use that they supply water for (for example domestic, commercial, industrial, or thermoelectric use) also complicating the problem. In order to be able to evaluate data of the users of the water, service-area boundaries need to be identified and linked to the source withdrawal sites. For these reasons, unlike other water use types that have established physics-based formulations for estimating withdrawals and consumption, like for irrigation and thermoelectric, public supply water use must rely on data driven, statistical models. The U.S. Geological Survey (USGS) Water Use Program is developing an operational modeling framework to provide estimates of water use for public supply. Models are being developed that consist of 3 important design features, including (1) automated data retrieval for model input, (2) simulation of daily water use, and (3) periodic updating of model simulations to provide current and forecasted model results.
