Public Water Use in the United States
Q. How much water is used per person each day?
A. The answer depends on how we frame the question. In the United States, a typical urban resident uses about 50-70 gallons per person per day inside his/her home. Most of this indoor water is used for showers, bathing, toilet flushing and clothes washing. Only a small portion is used for actual “drinking”. In addition to the indoor residential water use, a rather large amount of water is sometimes used for outdoor residential purposes, such as for lawns and plantings. This varies a lot, both seasonally and geographically, and it is particularly large in the drier regions of the country. Adding indoor + outdoor residential uses, the average total residential water use in the United States is about 89 gallons per person per day.
In addition to residences, water is required for the many businesses, industries, schools and institutions within a city. A surprisingly large amount of water can also be lost to leakage within the vast water distribution networks of a typical city. Including all the above (residential indoor, residential outdoor, businesses, industries, schools, institutions, leakage) the total public water supply in urban areas in the United States averages about 157 gallons per person per day. Cities in dry regions of the country often use considerably more than this, and cities in wetter regions use considerably less. The above discussion does not include water used for agriculture, power generation, and other uses - in some states those industries account for much more water than the public water supplies.
Q. Why do we use so much water?
A. Good question. We have become accustomed to using water very generously, and the price of water is likely a factor. Municipally supplied water is relatively cheap in the United States – much less than a penny per gallon in most cities, and sometimes as low as 1/4 of a cent per gallon. In other developed countries, water prices are often much higher and water use is much lower - perhaps not coincidentally. It is also interesting to note that the prices of commercially bottled water products are hundreds of times higher that this (on a per gallon basis)! The true value of water is a complex topic affected by many factors, including water shortages, supply/demand, technology, public infrastructure, and regulations.
Q. What trends are developing for the future?
A. Well, we still use a lot of water, but most cities in the United States have been seeing a decreasing trend in water use per person in recent decades. This trend is due mostly to the implementation of lower flow toilets and fixtures, and also due to water conservation ordinances in some regions. The actual operating costs for water and sewer agencies (labor, equipment, chemicals, energy, etc.) are still going up, however. Cities are also facing a new era of major repairs and replacements within their aging water (and sewer) piping systems. Therefore, with capital and operating costs going up, and water use per person going down, the price per gallon is likely to increase considerably in the future. Higher prices for water, in turn, will likely result in further water use reductions per person. Stay tuned!
For more information, contact:
Ned Paschke, PE, DEE