Streams or rivers form when water that does not find an underground aquifer, drains off the land by either seeping through the soil or spilling over the surface into the river or stream bed.
Key Characteristics of Rivers and Streams. Streams or rivers form when water that does not find an underground aquifer, drains off the land by either seeping through the soil or spilling over the surface into the river or stream bed. Water in streams and rivers is in constant motion.
