So much water is tumbling out of Lake Oroville that it has eroded a 200-foot-long strip in the lower half of the reservoir’s concrete spillway.

The state shut off spillway flows at noon Tuesday after workers noticed the erosion, which the Department of Water Resources said does not pose a threat to the earthen dam or public safety.

Oroville, California’s second-largest reservoir, is part of the State Water Project, which sends Northern California supplies to the urban Southland.