Sathubas is the Underdark region beneath Imgangreth. Half-way into the Lith-Crillion Era, the region's water tables began to rise. The region's aboleth were behind all this, upsetting the water balance to create more living space. At the time, places like Ophudehk were projected to reach their population limit in another five hundred years. A long-lived race, with time to plan and patient enough to wait for the fruits of their labor, began the work of re-channeling water from the region above. They were careful in the process, making sure not to redirect too much into the lower depths. Nearing the end of the Lith-Crillion Era, the great lake around Ophudehk had become a sea, and many caves and tunnels were now underwater. Seeing the waters rise ever so slowly, many of Sathubas's non-aboleth packed up and left for dryer land. The holdouts, water lapping at the edge of their settlements, became easy pickings for their aquatic foes. The grimlock city-state Akalgas worked long to counter the oncoming waters. Aided by earth elementals, they built a series of great water wheels and canals called the Akalgas Wheel. This device was not alone in the work, others were built, eventually stabilizing the region's water table.