Possible Clues:

• Seems like where Mother may be sold for water
• Water provided by disposal of a barrier on river
• Liquid refreshment mother found in a northern town
• Water - a conserver of it is on offer
• Water a mare, perhaps, where one's got a bargain
• Where one might be selling 8 across, just for water
• It's only water where a mother may be going cheap, perhaps
• Mother, among a lot of special offers, found type of water
• Perhaps where a mother might be bought for water
• Notice a fellow has swallowed second drink