Answer: All the water we have on the Earth has been cycled and recycled for millions and millions of years. The water in the ocean evaporates and becomes clouds. The clouds cool and the water vapor condenses and becomes rain, or if cold enough, snow or ice. That precipitation falls on the land where some of it remains on mountain tops until it melts and runs down into streams and rivers and back to the ocean. Some of the rain seeps into underground rivers and caves called aquifers. From the aquifers, wells can pump the water up to homes and factories where we use it for drinking, cooking and manufacturing and flushing toilets. And returned to rivers that flow into lakes, reservoirs, and is pumped back into cities or irrigation systems.
Water from the sky or from the irrigation systems is also absorbed by plants and is used in the process of photosynthesis to produce carbohydrates-- nutrition for the plants and trees, and food for us animals. And we return it to the cycle. You may not like the thought of it, but a bit of the water you use today may have been drunk by a dinosaur, and returned to the water cycle all in the course of nature's ways.
