Related Clues:

• It can hold its water
• Lake maker, perhaps
• Block, in a way
• Block up
• Flood preventer
• Hoover or Tarbela, e.g.
• Sire's counterpart
• River sight
• Generator
• Flood control
• Paddock parent
• Irrigation project
• Hoover, e.g.
• Block (up)
• Glen Canyon structure