Druid

Druids will mostly remain mechanically unchanged from the way they are in the PHB. There are no water-creating or water-controlling spells; spells that would perform these functions instead work with silt. Spells that influence survivability in water (waterbreathing, etc) also operate with silt, however - water walk may become siltstrider, for instance. This will keep the coastal Druid of the Land option viable, though the Arctic choice is not available in Dark Sun.

While they cannot choose to defile or preserve, because their magic is divine in nature rather than arcane, druids are almost exclusively aligned with the Path of the Preserver for obvious reasons.