Possible Clues:

• The Danube's destination
• Water to north of Turkey
• Spooner's sagging worker needs vast amount of water
• Reflecting no light this water between Europe and Asia
• Shortage in peas comes from all that dark water
• Has crime a place by it?
• Tideless expanse of salt water between Russia, Turkey etc
• Not blue? Maybe that's because it's without water at last