Seems there’s a big component missing from this question: how long do you shower AND how frequently?
With regards to frequency, I see a pretty broad range, from once or twice per week all the way up to twice daily.
I'll add a third variable. What's the flow rate on your showerhead?
A 10 minute shower with a 1.5gpm head is 15 gallons a day, or 105 gallons a week if you shower daily. A 2.5gpm showerhead is 175 gallons per week in the same situation.
On a semi-related topic, I've been reading a lot more about water in the west now that we're watching lake Mead and lake Powell dry up. I've recently learned that our intuitive mental model of how water is "wasted" is pretty incorrect.
Taking a shower is considered a non-consumptive use of water. The water goes down the drain into a water treatment plant, and goes back into the water system. I recently read a number that on average, every drop of water in the Colorado river flowing into Utah has already been used seven times before it gets there. While I can't vouch for the accuracy of that specific number, I can say that the topic of water usage gets infinitely more interesting the more you learn about it.
So what are the main ways water is being wasted in your area? Agriculture? Landscaping?
I've come to realize how connected it all is, and how "waste" is subjective. Roughly 80% of the water in the Colorado river basin goes to agriculture. But I can't consider ag as wasteful. That's literally the food we eat. Something like 50% of the leafy green vegetables eaten in the entire US come out of the Imperial Valley, as they can grow them year round. Without the Imperial Valley, the simple idea of having a salad year-round would become a thing of the past.
A lot of people complain about the river being used to grow low-value crops like alfalfa. Which I kinda get, but we don't get any dairy or beef product without alfalfa. And while we could probably do with a bit less of both (as a society), I still struggle to call cheese and ground beef as wasteful.
Flood irrigation for crops is also widely considered wasteful, but that's not to say it doesn't exist for a reason. Converting farming to drip irrigation does massively reduce the amount of water used to grow the plants. But flood irrigation is also the process by which the underground aquifers are recharged, which the farmers rely on in the off-season, and some municipalities rely on year round. Drip irrigation also increases salinity in the soil over the long term, which will eventually destroy the lands ability to grow anything.
Where I live in Denver, it's a little more interesting. About 2/3 of our water comes from the Western Slope (the Colorado River basin), but our wastewater gets put into the Platte River basin. So my shower usage is pulling water from the Colorado and moving it into the Platte river. And while the Platte river is a little less drought-struck than the Colorado, it's not exactly overflowing as it is. Nebraska is already making noise about their rights on the Platte as Colorado continues to grow.
Personally, I think we could do with a lot less lawns (particularly Kentucky Bluegrass) and I think golf is stupid. I'd be happy getting rid of a huge chunk of both. But that alone won't be enough. The federal government is about to announce some major restrictions on Colorado River usage. It sounds like they're talking about something in the range of magnitude of 25%. But there are fixed treaty commitments to Mexico and Native American tribes that can't be touched, so it will have to impact everyone else even more. And with ~80% of the water going to ag, it's mathematically impossible to solve this with irrigation alone.
I'll recommend two books on the topic if you're interested.
"Where the Water Goes" follows the Colorado River from its headwaters in Rocky Mountain National Park, and traces its usage all the way to Mexico. The writing style is a little annoying, but it is incredibly informative.
"Cadillac Desert" is considered the classic book on the topic, and I'm about 1/3 of the way through it now. It's a little dated, but it is the history of the American West, as told by the water infrastructure we built. It's an amazing take on history that I highly recommend to anyone who wants to know why things are the way they are.
Links to both:
https://www.amazon.com/Where-Water-Goes-Death-Colorado-ebook/dp/B01K1ATYGO/ref=tmm_kin_swatch_0?_encoding=UTF8&qid=1660652341&sr=8-1https://www.amazon.com/Cadillac-Desert-American-Disappearing-Revised-ebook/dp/B001RTKIUA/ref=tmm_kin_swatch_0?_encoding=UTF8&qid=1660652561&sr=8-1