Related Clues:

• What might block a channel
• What a foul mouth is full of?
• Accumulation at a bank
• It's sedimentary, my dear
• Fine riverbed sand
• Sedimentary material in a delta
• Deposit in a bank, perhaps
• It gets all dredged up
• Type of sediment
• Sediment on a riverbank
• River mouth buildup
• Fine sand by a river
• Granular sediment
• Lake bed sediment
• Material that's bad for the mouth?