The Jang Hui River is situated on an island of the eastern Fire Nation. The village of Jang Hui exists as a boardwalk village in the middle of the river and a factory that made weapons for the Fire Nation Army was once located near it.
The Jang Hui River was one of the most beautiful rivers in the Fire Nation. However, in 90 ASC, a factory was built near the river and pollutants were constantly dumped into it. This caused terrible pollution in the waters of Jang Hui, which resulted in illnesses developing among the locals and wildlife was dying or mutating. The entire ecosystem was driven into shambles. It was this polluting of the river which forced the Painted Lady, who was protecting the village, to flee, leaving the people living nearby to fend for themselves. Aang and his friends came to Jang Hui and saw the damage that the factory was causing. Katara and Aang later destroyed the smelting plant, and after the residents of the town cleaned the river, the natural splendor of the Jang Hui River and the health of its environs were restored almost immediately.