Water continues to spill over Oroville emergency spillway

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OROVILLE, Calif. (KCRA)

Water began spilling over the Oroville Dam emergency spillway Saturday morning as Lake Oroville reached full capacity and water outflows by way of the damaged spillway were decreased.

As of noon Saturday, the California Department of Water Resources believes water will continue to spill over the emergency spillway for the next 38 to 56 hours.

This is the first time the uncontrolled emergency spillway has been used in the dam"s 48-year history and can only happen once the lake reaches full capacity at 901 feet elevation. Flows over this secondary chute will likely range between 6,000 and 12,000 cfs, the California Department of Water Resources said.

DWR posted aerials images and video of the emergency spillway.

The flows were seeing are extremely low compared to the design of the structure, DWR Acting Director William Croyle said. Based on our current situation, there is no threat.

DWR is continuously monitoring the damaged spillway to ensure no more erosion occurs. They are letting out 55,000 cfs on the spillway to prevent further erosion to it.

Croyle"s objective is to have a new or repaired spillway in place before the next wet season, hopefully by October.

He added that crews will have to turn off the spillway during the next dry period to fix the eroded spillway. During this process, water may flow over the emergency spillway again, Croyle said. He added that this has to be done to ensure more water can be released from the damaged spillway in the future.

DWR focused their attention Saturday on ways to get the Hyatt Power Plant back in operation. The power generation was halted when the water levels in the channel, which lead from the power plant, became high enough to compromise operation, DWR said.

The department added that the water levels rose when debris from the eroded concrete spillway piled up in the channel below. The same erosion also threatened the towers that hold the power lines that take electricity from the power plant to the electrical grid, DWR said.

"DWR, Pacific Gas & Electric Company and other partners are working to safeguard the hydroelectric facility and power lines," the department said.

Click here to view lake levels, inflows and outflows throughout the day.

Inflow and outflow levels at Lake Oroville, as of 8 a.m. Saturday.

The total flows between the two spillways will not exceed 65,000 cfs over the next 24-48 hours, the County of Sutter Office of Emergency Managament said. The total flow is lower than the amount of water currently in the Feather River.

Although inflows decreased Friday and into Saturday morning to 83,600 cubic feet per second, of 10 a.m., water officials have also decreased outflows from the damaged spillway to 55,000 cfs, according to DWR.

There are no flood concerns or concerns for the structural integrity of the Oroville Dam. The outflows from the lake are expected to remain well within the downstream flood system capacity on the Feather River, according to DWR.

The total flow of water from the reservoir between both the spillways is expected to be much less -- 65,000 cfs -- than what the river can handle over the next 24 to 48 hours and is consistent with releases made at this time of year, the DWR said.

"While DWR does not expect flows to exceed downstream channel carrying capacity,the rate of flow into the ungated emergency spillway may change quickly," the department said in a released statement Saturday morning.

Water officials debated back and forth since discovering the spillway erosion hole Tuesday morning as to whether the lake would reach levels that would allow the emergency spillway to be used.

At noon Friday, DWR officials believed it was less likely that the emergency spillway would be used, based on the amount of water that was being let out in comparison to how much was coming in. But by Friday night, they anticipated it would again be used as officials cut back the outflows through the damaged spillway.

Crews began working Wednesday to clear out trees and vegetation below the uncontrolled spillway to reduce the amount of debris that flows into the Feather River.

Stay with KCRA for updates.

WEBVTT LETICIA: WE ARE TAKING YOU TOLIVECOPTER 3 AND DAVE ALLEN OVEROROVILLE RIGHT NOW WITH ANIMPRESSIVE SCENE, SOMETHING WEHAVE NOT SEEN IN 48 YEARS.DAVE: WE ARE SEEING THEWATERFROM LAKE SPILL OVER INTO THEEMERGENCY SPILLWAY.THERE IS A ROAD RIGHT THERE,LOOKS KIND OF MUDDY.THIS IS THE ROAD THAT TAKES YOUINTO THE RECREATIONAL AREAPARKING LOT.I WILL PLAY A MEAN TRICK ONJORGE AND HAVE THEM COME BACK TOTHE RIGHT -- WHAT IS HAPPENINGHERE IS THAT WILL ACT LIKE AMINI CATCH BASIN, IF YOU WILL.IT WILL FILL UP IN THAT AREA.THEN IT IS GOING TO SPILL OVERTHAT AND HEAD ON DOWN THERE.I WILL SEND IT OVER TO MARK ANDWE CAN TALK MORE ABOUT HOW THISWILL SPILL DOWN.MARK: THE MAINSPILLWAY YOU"VEBEEN SING TO THE RIGHT, THAT"SBEEN PUTTING UP 55,000 CUBICFEET PER SECOND.THAT WAS VERY IMPRESSIVE.A LITTLE OVER 40,000BECAUSE YOUHAVE TO TAKE OUT 12 COMING FROMTHE POWER PLANT.WE"VE BEEN TALKING ABOUT HOWMUCH WATER STILL HAS TO COMEOUT.OVER THE NEXT COUPLE OF HOURS,THERE WILL BE 30,000 COMING OVERTHE EMERGENCY SPILLWAY.IT IS JUST BEGINNING.IMAGINE HOW MUCH WATER WILL COMEDOWN THE AREA DAVE IS SHOWING USRIGHT THERE.EVEN THOUGH THE CATCH BASIN ISJUST STARTING, IT WILL BE MOREDRAMATIC HERE IN THE NEXT HALFHOUR.FOR THOSE OF YOU THAT MAY BEJUST JOINING US, THE EMERGENCYSPILLWAY JUST ORDER TO SPELL --JUST STARTED HIS BILL.CATCH IT JUST STARTED TO-- THEEMERGENCY SPILLWAY JUST STARTEDTO SPILL.THE WATER WILL GET DEEPER OVERTHE EDGE AND THEN STARTCASCADING DOWN THE HILL IN THOSEAREAS THAT DAVE HAS BEEN SHOWINGUS.THOSE ARE REMARKABLE PICTURES UPTHERE.ARE USING MORE OF A TRICKLE COMEDOWN THE AREA WE WERE TALKINGABOUT?DAVE: IT IS FILLING UP THATCATCH BASIN RIGHT THERE.YOUSEE A LOT MORE WHITEWATERCOMING OVER THAT CASCADE.

Source: http://www.kcra.com/article/water-begins-to-spill-over-oroville-emergency-spillway/8732032