I like this much more... because not all buildings will be in the swamp.... and here are my suggestions:
Level 1: Troglodyte burrows - Dark ravines
Level 2: Lizard caves - Grotto of Shadows
Level 3: Gnoll towers - Ancient towers
Level 4: Snake nests - ? (+breeding ground will increase snake production)
Level 5: Gorgon lair - Halls of Darkness
Level 6: Chapel of Silence - Temple of Silence
Level 7: Shrine of Horror - Cathedral of Death
P.S.: You wrote that the race worships the Water Dragon, so why would a statue of the Water Goddess be erected?

Not bad, but...! The word SHADOW shouldn't be here at all, and the Cathedral doesn't fit either!
Level 1: Troglodyte burrows - Swamp ravines
Level 2: Lizard caves - Dark grotto (+larger caves will increase lizard production)
Level 3: Gnoll towers - Ancient towers
Level 4: Snake nests - Snake Hive (+breeding ground will increase snake production)
Level 5: Gorgon lair - Halls of Darkness
Level 6: Chapel of Silence - Temple of Silence
Level 7: Basilisk estate - Shrine of Horror
Now, about the Water Goddess! What difference does it make, for example, the Mother of Darkness doesn't look like a dragon!
Dragon of Light - Elrath, Dragon of Darkness - Malassa, Dragon of Air - Silat, Dragon of Earth - Silanna, Dragon of Fire - Arkat, Dragon of Water - ? (I don't remember the name)! I need to look it up somewhere!