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WEBVTT TONIGHT BECAUSE OFTHE WRITING ASKED THE RISINGWATERS HERE AT LAKE OROVILLE.OROVILLE RESIDENTS WATCH ANDWONDER HOW THIS IS ALL GOING TOPAN OUT.>> IT LOOK SCARY IS WHAT ITLOOKS LIKE.DANA: THEY'VE BROUGHT BINOCULARSAND CURIOSITY.>> I'VE SEEN THE HOLES, PICTURESOF THE HOLES AND I'M JUST REALLYCURIOUS ON HOW THEY'RE GONNA FIXIT.DANA COMPARED TO HOURS BEFORE: WEDNESDAY'S STREET -- STRESSTEST.THE WHOLE HAS GROWN SINCE.PARTS OF THE RIGHT SIDE WALL NOWSOMEWHERE IN THE FEATHER RIVER.>>

Advertisement DWR: Test releases further erode Oroville Dam spillway Officials: Erosion on spillway was expected during test water releases Share Shares Copy Link Copy

Erosion on the Oroville Dam spillway got worse Wednesday after officials conducted test water releases. The increased erosion was expected, and engineers said they are pleased with the test results. The California Department of Water Resources released about 20,000 cfs of water around 3:50 p.m. and kept the gates open for several hours. Officials said earlier that the test will further erode the spillway. “With the test flows, engineers will verify how much flow the spillway can handle,” the DWR said in a statement before the test. “The spillway is necessary to maintain reservoir operations, given the immediate forecast of continued rain for the next two days and also in preparation for the remaining runoff season.” Parts of the right-side wall were lost and the hole in the middle of the spillway has gotten bigger, DWR officials said. Crews were sent to the erosion site to take measurements. The DWR closed the gates around noon Tuesday after a gaping hole was discovered in the spillway that leads to the Feather River. Officials were releasing water through the Hyatt Power Plant at 14,000 cfs when the dam's gates were closed. In the upcoming days, officials will continue to investigate ways to protect the spillway. They are also discussing whether to conduct more test water releases. Currently, Lake Oroville is at 85 percent capacity –- 3 million acre-feet, which is well over the desired flood control conservation level, according to DWR statistics. "Enough vacant space exists in the reservoir to capture the flow of the rains expected through Friday afternoon," the DWR said in a statement. "The dam is sound, and no imminent threat to the public exists." Crews are also working to remove trees and debris from the area near the dam where water will naturally flow into in case an emergency spillway is needed. Jerry Antonetti, a former DWR engineer who has worked on similar spillways, believes the best option is to continue water flows regardless if more damage could occur. He said if water makes it to the emergency spillway, it could make things worse. “Because it’s gonna be rocks, trees, mud -- liquid concrete -- going down that river,” Antonetti explained. The emergency spillway is not gated and will automatically allow water to flow from the lake if it reaches capacity -– which is 3.5 million acre-feet with the water level at 901 feet. “I’d open her up, sacrifice the bottom of that thing," Antonetti said. “It’s gonna go in the river. Clean it out next year and build a new spillway.”