Why can a stream keep flowing when rain has stopped?

A stream may keep moving under a clear sky. Some of its water is arriving from wet ground beside and beneath it. Earlier rain soaked underground and is only now reaching the stream.

Water can move slowly through spaces in soil and cracked rock. Where that wet ground meets a lower stream, water seeps into the channel. Many tiny flows join together. We may see no large pipe or waterfall, yet water is still arriving.

The ground can release its stored water long after a shower ends. But that store is not endless. During a long dry spell, less water may reach the stream and its flow can shrink. Other streams receive melting snow or water from lakes too. Flowing water can therefore tell a story that began before today's weather.