Possible Clues:

• Pent-up, held back
• Blocked up
• Blocked, as a river
• Blocked, beaver-style
• Held back, obstructed
• Obstructed and unable to escape from the pit, we hear?
• Obstructed and anathematised, so to speak
• Halted the flow of
• By the sound of it, to hell with this if the river is blocked
• Pent-up like river water