Water under Oroville spillway may have triggered February break, consultants say. News. Home Page ... Subsequent erosion of foundation material caused progressive failure both upstream and ...

Oroville Dam’s badly damaged main spillway is still deteriorating from an onslaught of fast-paced water, but state officials insist that it is “stable” as they make repairs.

The new spillway will include some 330,000 cubic yards of material, 15,500 cubic yards of concrete, and 5.4 million pounds of reinforcing steel. "Structurally, it'll be more sound than what we had ...