Simplify the following text for a Grade 9 native English-speaking person.
Original: Located close to the Tinguiririca River ( a tributary of the Rapel ) in a fertile valley , San Fernando sits 1,112 feet ( 339 m ) above sea level .
Simplified: It is located near to the Tinguiririca River , in the valley of Colchagua , San Fernando is 1,112 feet ( 339 m ) above the level of the se .