This project aims to help Utahns understand water usage in the state and how we can work to build effective water policy together. All calculations and references can be found on the reference page and links to sources are bracketed in each section. I have all of my calculations in a spreadsheet here. All numbers presented are good faith estimates based on the best numbers I was able to find. If you see any errors or discrepencies please reach out at [name of this site]@gmail.com. The nature of this information naturally requires some assumptions. I've done my best to make it clear how I've done my calculations. If you feel any calculation is missleading again please reach out the goal is to improve our understanding of water usage through concrete data.
At the level of states water is often measured in Acre Feet. It represents the amount of water needed to cover one acre of land (~43.5k ft^2) to a depth of one foot. If you're having trouble thinking about how much water that really is you're not alone. It roughly comes out to 385,000 gallons. Let's play a game. Below you will be presented with common activities and items that use water, your job is to guess how many times you could use or make the item with an acre foot of water.
If you took a 10-minute shower every day, how many years could you shower with an acre foot of water?
42 Years! That's 15,516 Showers!
Assuming you use the toillete 5 times a day how many years could you flush to your heart's content?
111! That's 203,655 Flushes!
Assuming you do laundry once a week how many years could you keep your clothes clean?
272! That's 14,000 Loads of Laundry!
How many residential pools could you fill?
16
How many tons of alfalfa can you grow?
1.875
How many days can you feed a dairy cow with alfalfa?
63
An acre foot is A LOT of water! As a person we can shower or use the bathroom for most of our lives with an acre foot of water. We went through the above information to get a better sense of the data that will be presented below. (You can find the calculations in the reference section.) [2]
I often hear that our growing population is putting a strain on our water resources. It's true that more people means more water consumpation but given that human based water consumpation is about 10% of total water used it doesn't have that big of an effect on the total water consumed by the state. Take a look below. We see that the population grew by 82% the total water usage in that time went up and down. Funnily enough the correlation between the water usage and population over that time period is -0.15.[1]
Wow! Agriculture is the main water user in Utah! We can see from the above plots that about 85% of water is used for agriculture. To better understand our states water usage let's explore how that water is used and what crops we grow! [3][4][5][6][7][8][9][10]
We grow a lot of neat stuff! If we use money as a proxy for value and look at the total impact these crops have on our states economy we see that they are barely a blip. The largest contributor is alfalfa and hay at just .2% of our GDP! But it uses 53% of ALL of our state's water. We spend the majority of our desert water on a commodity that brings in almost no money for our state and our people.[3]
These economics are interesting. If we look at what normal people pay for water as a resident it's about $2.09 per unit. A unit is 748 gallons of water. If we look at the economics from above we can see that if 100% of the sale price of alfalfa was the water, not accounting for any farmer labor, they would be selling the water for $0.37 per unit. Alfalfa farmers are selling water at a HUGE discount to their clients when compared to the actual cost of the water. If we look at this difference between the price of the water and the sale price as a subsidy then alfalfa farmers in the state of Utah receive a $748,000,000 handout from the government every year! This is a greater handout than they produce with their land! This isn't entirely fair. City water is potable and so we have to be upcharged for water treatment plants and such. But even if it was half as much it would be almost the same amount as the total revenue from alfalfa production.
We grow hay to sell it. So where does the hay go? Over the last 20 years the countries that purchased our hay have changed. In the most recent few years China has been our largest foreign customer purchasing $75 million on average over the last five years. Exporting goods to other countries is how we grow our wealth as a nation so this can be a very good thing! However when we look at these numbers in terms of our precious desert water they become a bit concerning.[16]
Let's look at these foreign exports in terms of Utah water. You can think about every ton of alfalfa that we ship overseas as the purchasing nation using 1.38 acre feet of Utah's water. I'm going to assume that the amount of diverted water in Utah is constant each year over these 20 years at 4.8 Million Acre Feet. I think this is a reasonable estimate but finding the exact number per year has proved challenging. Given that indoor domestic water use is about 2% of all diverted water. In every year foreign nations have used more water than individuals living in our state for their immediate needs. It feels kind of crappy that places like China get more water without complaint than my family, friends, and I.
Here's a plot of a few activities and how much water they use. Most of these numbers are estimates based on 2023 water usage and population data. The one I think is most fun is estimating how much water single citizen farmers like Governor Cox use. Based on [17] we estimate that if Gov. Cox's farm is 130 acres, and each acre can be used to grow about 8 tons of alfalfa at 450k gallons of water per ton then his farm alone uses about 1436 acre feet of water per year. That's the same amount of water as ~60,000 utahn's showering for a year.
Again calculations involve assumptions and can be complicated. I've created a google sheet with the calculations in the open so anyone can check the work here
[0] Cover Photo by Matthew Montrone:
https://www.pexels.com/photo/green-grass-and-body-of-water-under-blue-sky-1204430/
[1] https://nwis.waterdata.usgs.gov/ut/nwis/wu
[2] https://www.utahfoundation.org/reports/background-water-utah/#:~:text=Of%20the%205.2%20maf%20of,and%20industrial%20(M%26I)%20use
[3] https://www.nass.usda.gov/Quick_Stats/Ag_Overview/stateOverview.php?state=UTAH
[4] https://www.grainunitconverter.com/#:~:text=I.e.%20there%20are%2060%20lbs,when%20trading%20pulses%20or%20cotton
[5] https://watercalculator.org/water-footprint-of-food-guide/
[6] https://gpm.nasa.gov/education/sites/default/files/lesson_plan_files/water-for-wheaties/AG_3_GrowingWheat.pdf
[7] https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1752&context=extension_curall
[8] https://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/agriculture-and-seafood/agricultural-land-and-environment/water/drought/665000-3_forage_crop_and_irrig_mgmt-drought_factsheet_no3.pdf
[9] https://pacinst.org/wp-content/uploads/2015/04/CA-Ag-Water-Use.pdf
[10] https://hammondcon.org/cropwaterrequirements.html
[11] https://www.uga.org/wp-content/uploads/sites/11/2019/09/Enviromental-and-Economic-Impact-Study.pdf
[12] https://www.perennia.ca/wp-content/uploads/2018/04/water-for-dairy-cows.pdf
[13] https://waterdesk.org/2022/12/one-crop-uses-more-than-half-of-utahs-water-heres-why
[14] https://www.slcdocs.com/utilities/PDF%20Files/Rates/2025-07%20Proposed%20effective%20Rates%20for%20Webpage_water.pdf
[15] https://brazos.org/About-Us/Education/Water-School/ArticleID/249
[16] https://usatrade.census.gov/
[17] https://kjzz.com/news/local/from-rural-utah-to-the-governors-mansion-gov-spencer-coxs-heart-is-in-fairview