Dwarves not drinking booze in barrels right next to them

My current fortress is on year 3 or 4 since my embark. My dwarves recently all started showing thirsty symbols (blue down arrow), and I don't know why they won't drink. The thirsty dwarves include idle dwarves standing in the meeting zone right next to a food/drink stockpile. The dwarves moved two booze barrels from elsewhere into that stockpile after I noticed they were thirsty and set that stockpile to use barrels; I wanted to see if moving booze closer to the meeting area would help. And no, I didn't forbid those barrels after they moved them.

I also have multiple un-forbidden (and empty) buckets and have designated a water source zone if they want to drink water instead. I also have not created a military yet (I read that military can reserve food/drink). What else can I do to prevent fort death from dehydration? Maybe force them to swim in 7/7 water? Is it possible for drowning dwarves to die of thirst?