We've been looking at reducing water use this spring; someone else might find these products useful:
OAS(1) showers cap water at 5-10L per use, no matter how long you shower. Getting this installed also means we can swap our water heater to run on the solar array entirely, since you're not flushing all that energy down the drain while you shower.
Waterless urinals(2) use no water at all. They work by keeping a layer of oil in the trap instead. Pee sinks under the oil layer and out of the trap, oil stays in the trap since it floats on top. So, stays just as clean as a regular toilet, with no water hookup.
Disclosure: None, I've got nothing to do with these companies, other than buying their products for my cabin.
The economics of those OAS filters don't motivate me much, since two adults taking 15 minute showers a day each would result in $40/month for filters alone. 15 minute showers per day per person in a normal shower would cost me less than $15/month in water bills.
Obviously there are use cases that need that more than I do, since I live in a wet, temperate area with plentiful water tables, but I think it demonstrates that our problems with water, and pollution, and other environmental issues have come from taking the cheapest/easiest options, so we need to work hard to make more attractive sustainable solutions for the average person.
OAS(1) showers cap water at 5-10L per use, no matter how long you shower. Getting this installed also means we can swap our water heater to run on the solar array entirely, since you're not flushing all that energy down the drain while you shower.
Waterless urinals(2) use no water at all. They work by keeping a layer of oil in the trap instead. Pee sinks under the oil layer and out of the trap, oil stays in the trap since it floats on top. So, stays just as clean as a regular toilet, with no water hookup.
Disclosure: None, I've got nothing to do with these companies, other than buying their products for my cabin.
(1) https://orbital-systems.com/
(2) https://www.waterless.com/