Lake Oroville Spillways Construction Update - June 27


Workers construct a stay-form that will hold leveling concrete in place on the upper chute of the Lake Oroville main spillway in Butte County,

Workers with Kiewit Infrastructure construct a stay-form that will hold leveling concrete in place on the upper chute of the Lake Oroville main spillway in Butte County, DWR/2018

SACRAMENTO – Today the Department of Water Resources (DWR) provided an update on construction-related activities for the Lake Oroville Spillways Emergency Recovery Project.


Construction on the Main Spillway

  • Crews are continuing foundation cleaning and placing dental and leveling concrete to prepare for placement of structural concrete walls and slabs on the 730 feet of the upper chute.
  • Slab anchor drilling is complete on the middle chute and crews began placement of structural concrete slabs on June 26.
  • Hydro-blasting of the energy dissipaters, or dentates, at the bottom of the main spillway is complete. Mechanical demolition will continue to prepare for a new layer of structural concrete anchored with epoxy-coated steel dowels.
  • Removal and replacement is complete of the top layer of a structural concrete slab placed on the main spillway last year that did not meet DWR’s quality control standards due to a poor surface finish.
  • November 1, 2018 is a public safety construction milestone to complete major work and placement of all concrete on the main spillway. Additional work, including dry finishing and curing of concrete, joint sealing, connecting drainage systems, backfilling side walls, and site clean-up on the main spillway will continue after November 1.


Construction on the Emergency Spillway

  • Construction of the northern half of the roller-compacted concrete splashpad is complete.
  • Foundation preparation in advance of RCC placement at the southern half of the splashpad site continues. 
  • Work at the emergency spillway site is not dependent on the November 1 public safety construction milestone and will continue past November 1, 2018.


Recreation and Other Updates

  • The free access program for day use and boat launching at the Lake Oroville State Recreation Area continues next week on July 5 and 6. The remaining free access days are August 2-3 and September 6-7.
  • The Thermalito Diversion Pool, and Burma Road and Brad Freeman Trail on the northern shore of the diversion pool, will re-open to the public from Friday, June 29 through Wednesday, July 4 for hiking, biking, fishing, kayaking and more. Visitors can access the area off Thompson Flat Cemetery Road.
  • DWR and State Parks will re-open a portion of the Dan Beebe Trail between Glen Pond and Canyon Drive on Friday, June 29. Visitors will have access to over three miles of trails, which run along the southern shore of the Diversion Pool.
  • DWR is investing more than $30 million to build new boat ramp lanes, extend existing lanes for low-level water access, and add additional parking and new site amenities at recreation sites across the lake.
  • For more information on these recreation improvement projects, visit DWR’s Lake Oroville recreation improvements page.
  • The independent Board of Consultants will meet with DWR for the 19th time on July 16 and 17.


To view photos and video of the Lake Oroville Spillways construction, visit DWR’s Oroville Spillway photo gallery and YouTube channel.




For more information, follow us on Twitter or Facebook, read our news releases or visit our Oroville Spillway Incident webpage.


Erin Mellon, Assistant Director, Public Affairs, Department of Water Resources

(916) 651-2440 |