Related Clues:

• Plumbing problems
• Wooden shoes
• Roosevelt and Hoover
• River structures
• Footwear that may rot
• Some four-footed mothers
• Obstructs
• Emulates beavers
• Beavers' creations
• River barriers
• Glen Canyon and Grand Coulee, e.g.
• River blockers
• Kid producers
• Hydroelectric structures
• Blocks the flow