Oroville dam-rushing water takes out land

The emergency spillway hasn't been tested in the dam's 48 year history.

(CNN) – More concerns this weekend about California’s Oroville dam. The department of water resources announced it is dialing back water releases over the battered main spillway by about 15 percent.

The want to keep erosion along the side of the spillway from “compromising” the power line towers that fuel the dam’s power plant.

But, slower releases could cause the rushing water to top the emergency structure and flow into the emergency spillway.

The department wants to avoid using the emergency system because the cascade of water will push trees and other debris into the Feather River.

The emergency spillway hasn’t been tested in the dam’s 48 year history.