The river cuts Arabasta right down the middle from the north to the south, making travel around the country difficult.
Once an important source of fresh water for the kingdom, the river's current gradually lost force along the years, allowing the sea to overtake a significant portion of it. The river has canals that allow its water to be diverted to nearby cities, although it was noted that those were in need of repairing at the end of the Arabasta Arc.
A long time ago, the Sandora River provided nourishment for Arabasta, but as time passed, the river continuously weakened and let seawater displace some of its freshwater. This prevented the river from being used for consumption and irrigation of crops for certain communities like Erumalu's, forcing them to rely on rain ever since.
After resupplying at Nanohana, the Straw Hat Pirates sailed up the Sandora River in order to dock at Erumalu, following Vivi's plan to meet the rebels at Yuba. After anchoring at Erumalu, the crew was approached by a pack of Kung-Fu Dugongs, which, due to their own customs, became Luffy's apprentices after he defeated several of them.
At a later point in the adventure, the Straw Hats were required to cross the river from the west to the east of Arabasta, being attacked by a Sandora Catfish along the way (which was defeated by the Kung-Fu Dugongs Luffy befriended at Erumalu).
After the defeat of Baroque Works, a now-allied Mr. 2 located the Going Merry at Erumalu's riverbank and brought it upstream, near Alubarna, for the Straw Hats to board up safely and away from Captain Hina's forces, who were guarding the river's entrance.
- This river is most likely based on the Nile, a river which most of Egypt's population and cities have depended on since ancient times, just as Arabasta does.