The Water Planet is actually a moon of the gas giant remnant Cohen 136 (Iridia) V. It was colonized by Biran and Humans before the fall of the Empire.
Physical Planetography
The moon is very similar in size and bulk composition to the Biran homeworld; Biran scientists expressed some initial surprise that it did not already have life. It is covered in water and has been seeded with genetically engineered photosynthetic organisms, but the atmosphere is not yet breathable.
It was also quickly noted that the moon was, despite abundant liquid water, outside the habitable zone of Cohen 136, even when accounting for the high salinity of its ocean. Huge Builder ruins were discovered on the planet, apparently a heat-exchange plant that may have melted what was originally an ice moon. Indeed, the Water Planet is slowly cooling and will eventually refreeze if appropriate terraforming steps are not taken. The rate of cooling, while slow in human (or Biran) terms, implies a striking recency of the wormhole gate's construction, in comparison to others which are known to be billions of years old.
History and Culture
The world was colonized by Biran during Imperial times. Humans joined them later. They survived the Dark Age and were re-contacted by New Iridia when that planet redeveloped space travel.
The Water Planet is part of the Federal States of Greater Iridia, a democratic confederal republic and a member state of the Allied Worlds.
Though it is definitely a moon, the inhabitants tend to insist on the name being The Water Planet.
Economy
The Water Planet exports propellant, biochemicals, pharmaceuticals, advanced materials, and organic chemistry products. Metal and manufactured goods are imported.