The Vesi

culture
all live within a single city

Water/Riverside Settlement, Pescatarian

political structure
a bunch of priests and priestesses, selected based off of power, make all political decisions.

they vote on things

among them elect a Speaker

magical ability
They don't have magic but they can use magic i.e. charms and make potions. They abused the power of the water and gained "more magic" in their blood

Perhaps they poisoned main water supply and this affected the druids and the Ix, whereas they kept a fountain/a body of water for themselves and got involved in stronger magic. Magic is going to run out!

Building a more technologically advanced society

general appearance
Fair Skin, Blue/Green Eyes