Overpopulation/Technology/Food/Water

There is one topic that the world over seems to ignore as a general rule yet effects every living being from the tiny insects to the "concious" thinkers, humans... overpopulation.

Quickly let me just piece together an interesting visual. Think of a saturated sponge dripping with water, what happens as time passes, water evapoates right? Yes, of course it does. But the sponge can only hold so much water and has a pretty set time to which it runs out. Now lets think about a planet. Everyone agrees that natural resources are limited, or renew so slowly that they are considered limited, but what is the one resource that all others depend on to some degree, moisture.

Water, seemingly unlimited, if not fresh water, there are oceans of saltwater... but how vast is the expanse of water? The deserts are expanding territory at alarming rates, certain areas get less rain...other more but what causes it? Less and less land is able to be farmed because of lack of water, and is now typical to have water shortage warning in states like California or in the southeast where states were "fighting" for water. Is it possible to drain the earth of water?

We use water for washing cars, watering lawns, showers, cooking, cleaning, drinking, and in so many products that we use in everyday life. Is there less water? I think, using LA as an example that the reason there is a continual water shortage is because there is simply too many people living in an area that can no longer sustain them. Over the years I have been here, rainfall hasn't really varied and the climate and temps seem pretty much the same... only thing that really changed is the number of people. Every year more and more come in and take the water that isn't increasing in supply, obviously. So what happens, water shortages. Now don't kid yourself, this is probably related to the water supply for farmers and that damn little fish... but I digress and say simply that we are drying up areas and when they are dry... thats it. Think of Mars, it is like one big dried out sponge, a vast desert. Sound something like our deserts on our planet?