Instead of letting the shower water drain away, we have been researching grey water systems for irrigating your garden and/or flushing toilets. The grey water concept is simple - use the water in your house, then reuse it. It is a great way to reduce water usage and also reduce water bills.
These systems can be as simple as rerouting the shower drain or washing machine to a container in your backyard. They can also be very complicated with filters and pumps, but also offer many more money saving benefits. Of course, there are many choices in between.
Choosing to irrigate the garden with grey water enables the ground to naturally filter water and return it to the water table or underground aquifer instead of sending the water to a treatment plant that cost money to run and purifies the water using chemicals (even better for the environment). While these systems require some time and cost investment, a grey water system in your home will save you money over time, maybe even the first year of operation. (Compare that to solar energy investment.)
With a grey water system installed, you can feel a less guilty about an occassional long showers (see previous post). This is a sustainable solution that you can feel good about for a long time.