the need to conserve water

As a non-conformist by nature, I have a tendency to question everything I hear, the wisdom of anything being preached etc. So the first time I heard about the need to conserve water, as a child, I immediately felt - why?
After all, isn't water a constantly renewed resource? Don't rains replenish all the freshwater we use every year?
When I grew to know more, I learned about the water table depletion, and how rainwater is not percolating down to replenish it at a fast enough rate. A bit rather like the oil deposits which are being pumped out without being replenished.
Still, that didn't make that much sense about why water needs to be conserved. It didn't make as much sense as, say, conservation of energy.
That is until I figured out the energy bit of the equation. The water that runs out of your tap or faucet does not get there by magic or by itself. The water that you use represents a significant amount of energy investment. It too a lot of energy to get that water to your tap. So when you waste water, it's not just water you're wasting. It's also the energy that was required to bring it to your tap.
Similar arguments hold true for any product we use... paper included. The trees represent only one part of the equation. The other part is the energy spent in processing the wood into paper.
So don't waste water, don't waste paper, don't waste energy.