In which river did the Tangjiashan dammed lake in Wenchuan occur?

After the Wenchuan earthquake, a huge landslide cut off the Yujiang River in Loufangping Village, qushan town, Beichuan County, forming a Tangjiashan dammed lake that shocked the world.

Juanjiang River is an important river in the northwest mountainous area of Chengdu Plain. Originated in the southwest of Taizicheng Peak (elevation 48 14m) in Longmen Mountain, Pengzhou City, with a total length of 139KM and a drainage area of 2057.3km2. ..