Related Clues:

• Hydroelectric facility
• Beaver creek project
• Block the pipes
• It goes against the flow
• Become blocked
• Cousin of a 55-Down
• A river runs to it?
• Beaver endeavor
• Aswan, for one
• Reason to call Roto-Rooter
• Form a certain front, in meteorology
• Drain blockage
• Beaver's construct
• Hoover or Aswan
• Sink jam-up