Growing up with stage 4 water restrictions, the shower bucket and kitchen jug was a standard in our state.
The kitchen jug was used as potable water, we'd keep it handy for boiling pasta. The strained pasta water would be cooled and used to flush the toilet.
The shower drain, and laundry drain was connected to a grey water tank which was used for watering plants and the toilet cistern (which had a brick in it, because even though we already had a duel flush system, every drop counted) I remember having to swap to special shampoo to avoid ruining the grey water.
Occasionally dad would reroute the shower hose because he was just having a "quick rinse" (eg, no soap or shampoo) and he'd fill a separate drum that he'd then use to wash the car. Washing your car was banned unless you used grey water.
We still occasionally got a fine for using too much water for a household of our size.
As a kid I didn't really understand that this was an environmental issue, we kept it up long after the water restrictions were lifted so I thought it was just dad being frugal.
So when I moved out I just continued with my water saving habits, but it turns out water is really cheap when there isn't an active drought, and living in a share house with 10 other people who didn't have the same water saving habits quickly killed the shower bucket and kitchen jug.
Now that it's just me and my partner, I should reintroduce the shower bucket. My plants would love it.