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I have read different statistics on residential water use. One EPA chart I saw had residential use of water taking up half of all water, which seems unbelievable to me. Another writer claimed that only 1% of water is used by residential consumers. Quite a big difference.

One statistic I saw said that 45% of water "withdrawals" was for thermoelectric power, but presumably water can still be used by other consumers after it has gone through a dam power plant.

If we split water use between (1) residential consumption, (2) agricultural irrigation, (3) industrial consumption, and (4) commercial business consumption, there would seem to be four basic types of consumers. What is the relative balance of water consumption between these four types?

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  • $\begingroup$ Worth noting that a significant amount of surface water is reused in some areas; water used by agriculture upstream on the Colorado River, for example, gets discharged into the river and then withdrawn downstream, getting 3 to 4 times saltier as it goes: watershed.ucdavis.edu/education/classes/files/content/page/… Some that winds up getting filtered out of my drinking water here in San Diego. $\endgroup$ – jeffronicus Mar 1 at 23:27
  • $\begingroup$ Typically the hydroelectric dams I have seen do not use the water from the electric generation for other uses because it means putting the water into a pipe at some pressure with reduces the effective head used to generate the power. $\endgroup$ – Friddy Mar 1 at 23:54
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    $\begingroup$ I think there are a couple of real definitional problems here. What is mean by "all water": what goes through treatment plants, rain that falls on fields and forests, rivers that flow into the ocean, or the oceans themselves? And what is meant by "used"? Just human uses? Rain falling on fields & forests is used by plants, some of which may be used by humans. If you're an urbanite, the water from your tap goes to a treatment plan t& back to a river, so that a raindrop falling on the headwaters of the Mississippi might be re-used dozens of times before reaching the Gulf. $\endgroup$ – jamesqf Mar 2 at 19:29
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Dams are hydroelectric, thermoelectric is something else.

Thermoelectric refers to water extracted to boil to power a generator or used to cool the fluid used in said generator, In the US mostly coal, gas, and fuel oil plants but other ones like geothermal, nuclear, and mass solar also count, basically if it works off heat it consumes water (thermo- literally means heat). Much of this water of course evaporates. And yes it is quite high. About the same as we extract for irrigation.

enter image description here https://water.usgs.gov/watuse/wuto.html

Public water (purple), can be further divided, the USGS estimates public use as follows. You'll note no differentiation is made between commercial and industrial.

enter image description here

Wikipedia actually has a decent entry with further EPA estimate breakdowns, if you want to dive further.

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    $\begingroup$ Note that there are huge regional variations. In California, the majority (~60%) of the water withdrawn is used for irrigation purposes, per USGS statistics. Note that this data is from 2010 and California has since seen long-term reduction in urban water usage in response to a multi-year drought, which presumably has somewhat increased the percentage of withdrawals used for agriculture. $\endgroup$ – njuffa Mar 1 at 21:08
  • $\begingroup$ I saw this diagram. It does not answer the question because "public supply" includes both residential and commercial use. $\endgroup$ – Tyler Durden Mar 1 at 21:10
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    $\begingroup$ @TylerDurden For California this 2014 article states: "About 6 percent of the state's water is consumed by industries, commercial operations, and governments. About 14 percent is poured into bathtubs, toilets, and washing machines or sprayed over residential lawns." $\endgroup$ – njuffa Mar 1 at 21:18
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    $\begingroup$ @TylerDurden the chart is split up the way it is because some places (mostly small towns) with "city water" AKA public water don't differentiate industrial vs residential consumption. fewer still differentiate commercial vs industrial. $\endgroup$ – John Mar 2 at 13:45
  • $\begingroup$ You could include a cooling tower image . $\endgroup$ – Keith McClary Mar 2 at 19:54

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