About two weeks ago we lost a small fantail (2"). Yesterday, I found two snakes in the pond. One was trying to haul away a frog. I netted the snakes and released them away from the pond (frog made it back to pond!). Now I think I know what happened to the fantail.

It has very dry in this area lately. Could it be that the snakes are now more drawn to the pond?

Yes, snakes are more likely to visit a pond during times of drought, that goes for most primarily terrestrial animals.

When you say you "lost" the fantail, I assume that you mean it vanished. It may have indeed been eaten by the snake or another predator.

Water snakes are very good at taking frogs and fish. Terrestrial snakes like garter snakes aren't as good at it but like to go for a swim. I've never seen our black rat snakes in the water but they've hung out around the rocks on occasion. Water snakes tend to stick around until they've eaten what they can from the pond whereas land snakes don't stick around the pond for long.