Aren't these supposed to hold drinking/boiling water for the town? Seems a bit odd and disgusting to have people (and their dog) swim in it. Lol. Or do they serve a different purpose? These things don't exist where I live so I might be off.
shareSteam locomotives need water to operate; in fact, if they run out they explode. When the boiler runs low, the engineer will run the train close to the tower, where there is a spout on a pivot with a rope attached to it. He jerks the rope down and angles the water into the boiler of the locomotive.
Some small "town" train stops were nothing but tanks holding water for the engine of the locomotive. This is why these tiny communities were known as "jerkwater towns."