Related Clues:

• Beavers' structure
• Beaver-built barricade
• River restraint
• A mad animal mum
• Barrier to hold back water
• Water retainer
• Mother of quadruped
• Barrier against water
• Barrier to contain flow of water
• A mad animal mother
• Barrier to contain the flow of water
• Water barrier, quite mad
• A mad kind of mum
• A mad sort of mum
• Mad as an animal mum