OROVILLE DAM, Thursday update: Spillway progress continues; Reoperation of Hyatt Power Plant possible Friday

Heavy equipment work continues Wednesday morning March 1, 2017 to remove the huge debris field in the diversion pool at the base of the damaged Oroville Dam spillway. Once finished the Edward Hyatt Powerplant can go operational, which will allow for better management of reservoir levels during the upcoming spring runoff season.
Brian Baer/ California Department of Water Resources, FOR EDITORIAL USE ONLY

From the Department of Water Resources:

Crews removing a debris pile continue to make rapid progress three days after the Department of Water Resources (DWR) halted flows down the damaged Oroville Dam flood control spillway.  Debris removal at the base of the spillway will help lower the water level in the channel so the Hyatt Power Plant can resume operation.  The power plant will give DWR an additional way to release water from the reservoir.

“Crews have made such tremendous progress removing the debris that we anticipate reoperation of the Hyatt Power Plant could begin by mid-day tomorrow,” said DWR Acting Director Bill Croyle.

Once operational, the Hyatt Power Plant can discharge up to 14,000 cubic feet per second (cfs) which will allow DWR to better manage reservoir levels through the remaining spring runoff season.

There is an estimated 1.7 million cubic yards of debris at the base of the spillway.  Approximately 110,000 cubic yards of debris have been removed since flows were halted three days ago.  Lake Oroville is not expected to rise above 860 feet elevation while spillway flows are halted.  That lake level would be 41 feet below the level of the emergency spillway.  The current lake level is 846 feet elevation.  Inflows are roughly 19,000 cfs, which has resulted in a three-foot rise in lake elevation since yesterday.

If Hyatt Power Plant function is not restored within several days, DWR will use the flood control spillway again to regulate reservoir levels.

DWR does not expect the anticipated wet weekend weather to interfere with additional debris removal or to create a lake elevation concern.  DWR will continue to monitor the weather forecast.

Flows necessary to meet environmental requirements in the Feather River downstream of the dam are being maintained at 2,500 cfs through use of water stored in the Diversion Pool and Thermalito Forebay and Afterbay.  DWR and the California Department of Fish and Wildlife continue to survey the Feather River downstream of Oroville Diversion Dam and rescue fish that might become stranded in pools as the river level falls.

Work continues on the area below the emergency spillway, access roads, and other areas eroded by the emergency spillway runoff.  Rock benches and check dams are being constructed to slow water and minimize erosion should the emergency spillway need to be used again.

DWR continues to monitor the status of the dam, spillways, the Hyatt Power Plant and the progress of repair activities.  DWR is coordinating with Caltrans to address the impact of emergency response activities on local roads, and this will continue throughout the operation.

For information on lake conditions; including lake levels, inflows, and outflows visit:  http://cdec.water.ca.gov/cdecapp/resapp/resDetailOrig.action?resid=ORO .

For a timeline of events regarding the Oroville spillway incident:
http://www.water.ca.gov/oroville-spillway/index.cfm

The latest video from Department of Water Resources …

 

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