Reduce your water bills with this tip that re-uses the fresh water from your shower in an incredibly convenient fashion!

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The Issue:

Depending on climate and the distance from a hot water heater to a shower, it can take 60+ seconds of running a shower to finally get warm water from the shower head.

That means that a full minute’s worth of shower water is going straight down the drain, for no benefit to anyone!

A person could hypothetically collect that water in a giant bucket (placed on the floor of the shower), and could later haul the bucket outside to water plants or pour into their coffeemaker. (Remember, this is clean tap water!)

However, moving water around like this would be labor-intensive and annoying.

Proposal:

With a little bit of plumbing work, we could easily save this water for productive use without requiring a ton of legwork.

The basic idea is that before the water is hot, we’ll redirect it to a storage tank above a toilet (where it will later be used to flush the toilet). Then, after the water is warm enough, a valve will close and the water will be directed to the shower as usual. See Figure 1 for details.

Fig. 1: Water (light blue arrows) is flowing up from the bottom of this figure. While the water is still cold, the valve (“F”) will direct it to the purple pipe (“A”), where it will be stored in a water tank (“C”) above a toilet (“D”). Once the water has warmed up enough, the valve at “F” will switch positions to allow the now-hot water (“G”) to spray from the shower head (“B”). As a convenient safety feature, there’s an overflow pipe (“E”) from the tank to the shower, so excess water will be redirected back into the shower (rather than overflowing into the bathroom).

Conclusion:

This might not actually be worth the engineering effort, but it could be a straightforward way to avoid wasting (and paying for) several gallons of water that would otherwise just go straight down the shower drain.

PROS: A practical and financially-savvy approach to water conservation!

CONS: Somewhat unclear how valve F in Figure 1 would actually decide when to close. Might require annoying head-height pipes to be installed if the shower and toilet are not immediately adjacent.

Originally published 2026-08-10.