As in our own bodies, water is the glue that holds this complex system together, through flowing streams, wetlands, and moisture that allows unique plants and animals to survive in the sand. The impressive dunes and the incredible diversity of life in and around them depend on these life-giving waters for survival. These streams and wetlands are not simply beautiful features of a national park. They are critical parts of a huge natural system that shapes and maintains the Great Sand Dunes as we know them today.