The Oroville Dam is the tallest dam in the nation which stays intact, but the emergency spillway started to erode Sunday. This left 188,000 people evacuating from several Northern California counties, especially near Lake Oroville. ‘“I’m not going to lift the evacuation order until I have a better idea of what that means and what risk that poses," said Butte County Sheriff Kory Honea”. - cnn.com
Heavy rainfall in Northern California filled Lake Oroville to the point of overflow and includes the water from the northern Sierra Nevada mountain range. The Oroville Dam is located about 75 miles north of Sacramento and provides flood control around the region. There are two spillways: the primary and the emergency, and both are experiencing problems. The primary spillway was damaged by erosion, and the emergency spillway is also getting damaged by erosion.
35,000 people from Butte County, 65,000 from Yuba County, 76,000 from Yuba City and 12,000 from Marysville City make up the 188,000 that were evacuated. After the evacuation was issued, authorities noticed decreases in the water flowing over the emergency spillway which then stopped Sunday. The primary spillway is still releasing water at 100,000 cubic feet per second which is way more than normal: 55,000 cubic feet per second. ~ Keeley Hester