Oroville – Many questions remain unanswered about the status and plans for the damaged Oroville Dam spillways. However a lot of work is underway, Department of Water Resources officials said during a press conference Thursday in Oroville.
Even so, the water will have to be released down the damaged main spillway starting at 9 a.m. Friday to make room for water flowing into Lake Oroville from the current storm and more on the way, and later for snowmelt.
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As of 7 p.m. Thursday, the lake was at 864.4 feet above sea level, which is up three feet in 24 hours. The top of the problematic emergency spillway is 901 feet.
The spillway flows will gradually be ramped up to 35,000 cubic feet per second, and flows will be shut down through the Hyatt Powerhouse under the dam. The spillway flows will continue for 10 to 14 days, according to acting DWR Director Bill Croyle.
Meanwhile, the DWR plans to choose a contractor this weekend to repair the spillway, even though the reconstruction plans have not yet been completed. Also, the crew hauling away debris near the spillway will continue into the near future. And to track down the cause of the spillway failure, a “forensic team” arrived on scene Thursday to begin investigating.
MORE STORMS
As of Thursday, the 2016-2017 water year officially broke the record for wettest year for the Northern Sierra eight-station index. The last year that was nearly as wet was 1982-1983. For this year, so far, 89.7 inches of precipitation has fall in the watershed, and more storms are on the way, Croyle said. This places the year at 207 percent of average for this time of year.
The 10-day forecast for the Feather River basin calls for two more storms, as well as more snow.
“I think I have said before, we have enough snow and enough water,” Croyle said.
REBUILDING SPILLWAY
As soon as this weekend a contractor will be hired to do repair work to the Oroville spillway, even though the plan for the work has not yet been completed. The firm that is hired will start work Monday.
DWR’s chief engineer Jeanne Kuttel said even without actual design plans, the company hired will have plenty to do. Work will begin on a detailed schedule. Equipment can begin to be moved into the area. Work areas can be assessed, security details can be made and haul routes mapped. Concrete and other raw materials can also be moved into the area, she explained.
Croyle said the quick pace is important. Normally a project of this size would take years just for the planning. “We need hours and days for approval vs. weeks, months and years,” he said. Rather than have paperwork shuffle back and forth, staff from agencies will meet together, Croyle said.
HYATT POWERPLANT
A complicated system of power poles connects Lake Oroville to other areas of the state. When the spillway failed, several of those power connections were relocated. To finish the job, the “physical tie-in to the power plant,” is scheduled to be rebuilt once water stops flowing through the turbines at Hyatt Powerhouse next week.
After the work is done, water will be increased through the plant to 6,000 cfs, which is half the capacity of the plant, he explained.
April 22, one of the penstocks bringing water to the power plant will be shut down for four to five weeks to “tune up the system for a much longer run this summer, at full capacity,” Croyle explained.
That will include regular maintenance and preparations to replace turbine one, which has been out of service a couple of years.
Tracking down problems
Thursday was the first day at the dam for a team of “forensic investigators” who will determine the cause of the failure of the spillway at Lake Oroville, and determine whether failure could happen again.
Feb. 13, the Federal Emergency Regulatory Commission sent a letter to DWR calling for an independent review of what went wrong.
DWR engineer Kuttel explained that FERC requires that the team members are independent of the state water agency. To help assemble, the team, DWR reached out to the United States Society of Dams,
www.ussdams.org and the Association of State Dam Safety Officials,
www.damsafety.org, Kuttel said.
The team did inspections of the site Thursday and plans to head to Sacramento Friday to look at records on the dam, she said.
Butte County Sheriff Kory Honea attended a meeting with the investigation team after the press conference. He said he was impressed by the credentials of those in the group, and has confidence they will work hard to find answers.
COMMUNITY OUTREACH
This week Croyle announced the first of several planned community outreach meetings, which will be held at 5 p.m. April 27 in Gridley at the Butte County Fairgrounds. The format will be “open house,” where people can talk with DWR and ask questions.
Other meetings are planned in Oroville, Marysville, Yuba City, Chico and Sacramento, but dates have not yet been set.
SECRET DOCUMENTS
In the past week, state Sen. Jim Nielsen and Assemblyman James Gallagher have called for the end to secrecy regarding documents related to the dam and spillway problems. At the press conference Thursday, Croyle said DWR is going through those documents with plans to release items that are not necessary to keep confidential.
In response, state Sen. Jim Nielsen, R-Gerber, and Assemblyman James Gallagher, R-Yuba City, issued a joint statement that they were “encouraged” by Croyle’s comments.
“We heard loud and clear the frustrations from our constituents with regards to the need for transparency in what occurred at Oroville and the planned repairs. It is understandable that some highly sensitive, verifiable information should be withheld for legitimate national security purposes — but blocking entire reports and requests for information is unacceptable.”
Re: Oroville Dam... (California, Spring 2017 - current)
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The bit about Beal AFB was quite intriguing! 
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