A watershed can act something like a funnel. Depending on its ability to retain water, some—or most—of the water that falls anywhere within a watershed will eventually reach the outlet. To illustrate, think of land on a hill, miles from the nearest stream. When it rains, some of the water soaks into the soil and some evaporates into the air. The water that is not absorbed and used by plants or doesn’t evaporate, runs off the land. That water joins small streams and wetlands that drain into lakes and rivers, and eventually flows to the ocean.