Complex sentence: The dam impounds Lake Oroville, the second largest man-made lake in the state of California, capable of storing more than 3.5 million acre-feet (4.4 km 3), and is located in the Sierra Nevada foothills east of the Sacramento Valley.
Split into simpler sentences: The dam impounds Lake Oroville, the second largest man-made lake in the state of California, capable of storing more than 3.5 million acre-feet (4.4 km 3). It is located in the Sierra Nevada foothills east of the Sacramento Valley.