Waterfalls becoming dry is not a rare occurrence. In fact Yosemite falls in the United States is experiencing shorter and shorter wet seasons. This is due to the fact that Yosemite falls is fed almost entirely by the winter season's snowfall.

Can waterfalls dry out?

Thus, waterfalls lose their vigor the deeper into the season you get. Autumn is typically the time of year when many waterfalls have exhausted their freshwater supply and go dry unless you get early winter storms momentarily bringing them momentarily back to life.

Can waterfalls run out of water?

If the sun were to stop shining, then all the waterfalls in the world would eventually stop. It is the sun which provides all of the energy needed to lift water from the ocean to the head of the river valley so that waterfalls can continually have water falling over them.