Technology

because the real water savings never came from stupid showers:

Another factor is that your shower water is very probably

unless you have some sort of gray-water irrigation system going on or something

heading to a sewage treatment plant, and if we wanted to do so, we can purify the water there, make that closed loop and feed back into the water supply, recover basically all the water from treatment.

The UK does it:

https://www.washingtonpost.com/world/2022/08/29/uk-drink-sewage-water-squeamish-wastewater-recycle/

California and some other states are doing it:

https://www.pbs.org/newshour/nation/california-is-set-to-become-2nd-state-to-approve-rules-for-turning-wastewater-into-drinking-water

California has been using recycled wastewater for decades. The Ontario Reign minor league hockey team has used it to make ice for its rink in Southern California. Soda Springs Ski Resort near Lake Tahoe has used it to make snow. And farmers in the Central Valley, where much of the nation’s vegetables, fruits and nuts are grown, use it to water their crops.

But it hasn’t been used directly for drinking water. Orange County operates a large water purification system that recycles wastewater and then uses it to refill underground aquifers. The water mingles with the groundwater for months before being pumped up and used for drinking water again.

California’s new rules would let — but not require — water agencies to take wastewater, treat it, and then put it right back into the drinking water system. California would be just the second state to allow this, following Colorado.

The new rules require the wastewater be treated for all pathogens and viruses, even if the pathogens and viruses aren’t in the wastewater. That’s different from regular water treatment rules, which only require treatment for known pathogens, said Darrin Polhemus, deputy director of the division of drinking water for the California Water Resources Control Board.

In fact, the treatment is so stringent it removes all of the minerals that make fresh drinking water taste good — meaning they have to be added back at the end of the process.

“It’s at the same drinking water quality, and probably better in many instances,” Polhemus said.

Plus, in California and a lot of other places, we can (and do) desalinate water.

https://www.sdcwa.org/your-water/local-water-supplies/seawater-desalination/

In November 2012, the Water Authority approved a 30-year Water Purchase Agreement with Poseidon Water for the purchase of up to 56,000 acre-feet of desalinated seawater per year, approximately 10 percent of the San Diego region’s water demand.

It costs more than pulling from a river, and that's economically-difficult for agriculture...but it's just not prohibitive for residential use, and there's a whole ocean of water out there.

https://www.sdcwa.org/wp-content/uploads/2020/11/desal-carlsbad-fs.pdf

Based on current electricity cost estimates, the Water Purchase Agreement sets the price of water at about $3,400/ acre-feet for fiscal year 2024.

An acre-foot of water will, depending upon where in the country you are

usage levels vary by area

supply about one to four households for a year at average usage. And that price is in California; electricity is a major input to desalination, and California has some of the highest electricity prices in the US, generally second only to Hawaii and something like double most of the country. It'll be significantly cheaper to desalinate water in most other places.