Erayga "runnel" waa magac tilmaamaya durdur yar ama kanaal cidhiidhi ah oo ay biyuhu dhex maraan. Caadi ahaan waxaa loo isticmaalaa in lagu qeexo marin-biyood yar iyo gacmeed, oo inta badan laga helo dhul buuraley ah ama dhagax leh. Erayga "runnel" waxaa mararka qaarkood loo adeegsadaa si isku mid ah "rill" ama "brooklet."
