Related Clues:

• Beaver work
• Gardiner or Mica
• Sink-drain problem
• River block
• A river runs to it
• Clog, as traffic
• China's Three Gorges, for one
• What paper towels do to a toilet
• It checks the water
• Structure whose name might make kids giggle (3)
• Keep from flowing
• Pipe blocker
• Hydroelectric power site
• Pedigree listing
• Drain pain