OROVILLE SPILLWAY: Construction update (with video)
Continued Construction on the Main Spillway
- Construction efforts at the Lake Oroville spillways have remained focused on repairing and reconstructing the gated flood control spillway, also known as the main spillway, by November 1.
- While this date is an aggressive timeline for construction, it’s a conservative date for reservoir operations. The main spillway has only been used before January 1 four times. In fact, the spillway has only been used in 26 of 49 years.
- Demolition, excavation and site preparation is now 99 percent complete for the 2,270 feet that will be reconstructed this year. “The (Board of Consultants) is impressed with the progress and quality of the foundation cleaning.” – BOC Memo 10
- Placement of roller-compacted concrete (RCC) is now 10 percent complete, with approximately 25,000 cubic yards poured.
- Crews reached a major milestone last week by placing the first structural concrete slabs, which include reinforced steel, on the lower portion of the spillway chute.
- Recently, DWR received approval of the final 2017 design and construction work by federal, State and independent oversight groups.
Construction at Emergency Spillway
- After gaining information from thorough geologic exploration and test drilling in June, DWR determined the exact location for the underground cutoff wall, also known as the secant pile wall.
- Now that progress is being made on excavating trenches, drilling bore holes and placing concrete, DWR has a clearer schedule for construction of the underground cutoff wall, with a target completion date of late December 2017 or early January 2018.
- Consistent with a recommendation from the independent Board of Consultants (BOC), DWR will relocate temporary transmission towers near the cutoff wall site in a timely manner to minimize their impact on construction.
- DWR’s prime contractor, Kiewit, brought in a heavy-duty percussion drilling rig – the BG Bauer 50 – to improve the current rate of drilling.
Independent Board of Consultants and Forensic Team
- This week, the Forensic Team finished conducting interviews with DWR employees in Sacramento.
- DWR also sent an email to all employees encouraging them to share any information they have that could help with the investigation. Information shared with the investigative team will not be shared with the Department.
- The Forensic Team’s final report is scheduled to be released this fall.
- The ninth and tenth memos from the independent Board of Consultants are now posted on the Lake Oroville spillways webpage.
DWR is committed to informing the surrounding communities and the general public about the construction on the Lake Oroville spillways and related impacts to roads, recreation, public access and surrounding infrastructure and ecosystems. These updates will continue through the summer and fall.
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