streambed

noun

1. A channel through which a stream flows or used to flow.

   “Near-synonyms: riverbed, creekbed”

   “Thirty feet below her, where the Persians were crashing through the brush, the streambed kinked to the left side of the ravine and ran under an enormous thorn tree with a thick base.”

   “The easement restricts construction and will keep cattle mostly away from sensitive streambeds.”