When hiking the rocks slopes near the nature center, you may find indentations in the rocks  filled with water.  These pockets of water typically exist for a few days, then they vanish only to reappear with the next rainfall.  They are often home to a variety of interesting microbes, and provide needed water for birds, salamanders, frogs and even deer. Eggs of some creatures actually go thru a long cycles (sometimes years) of drying, even freezing, only to hatch when the next rain fall sufficient to fill the pool.