Related Clues:

• Job for a drain cleaner
• River barrier
• Backup cause, often
• Get stopped up
• TVA project
• Gardiner, for one
• It retains water
• Plumbing stop-up
• Keep from running
• Thoroughbred's mother
• Leave it to beavers
• Beaver barrier
• Block the flow
• Roto-Rooter target
• Beaver's oeuvre