Originally Posted by
Utopian
If you are in fact being serious, I will answer this.
If you are using cold water, then the issue is only as below. If you are using hot water, then the issue expands to the entire problem of the environmental impact of essentially committing deficit spending for our energy resources. We are burning, in the form of coal, oil, and natural gas, the products of millions of years of solar energy converted into carbon rich energy resources. Burning those products is creating an obvious problem for our environment. You either get it or you don't.
If you are using water that has come from a municipal water treatment plant, then there is most definitely an environmental impact. "Clean" and relatively "pure" water comes to you after going through a long process of physical, chemical, and biological treatment of that water. That water is going to become an increasingly scarce resource in the next century.
:OT
If it matters, I do what I can to avoid wasting water. I live in an area, like many others, that obtains part of its water from surface (river) water and part of it from deep underground aquifers. Every aquifer in the country is being depleted. That means that more water is being removed than is being replaced and the obvious result is a gradual reduction in the levels of those aquifers. The obvious implication is that, like carbon based fuels, we are on borrowed time with our water usage.
If you really care about this, and you are not squeamish, I strongly suggest that you try googling and reading an online book called the Humanure Handbook. If you don't like the concept, please don't bother criticizing it. You may consider it to be gross, but in my opinion, it is nowhere near as gross as sh*tting in your drinking water.