Oroville Spillways Construction Update, August 8, 2018


Workers applying cure onto new concrete sidewall of the Lake Oroville main spillway

Workers apply a cure onto the new concrete sidewall on the middle chute of the Lake Oroville main spillway to prevent it from drying out and cracking during Phase 2 of the recovery effort. DWR/2018

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

Construction on the Main Spillway

Placement of erosion-resistant concrete, or ERC, structural slabs began Monday, Aug. 6, on the uppermost 730 feet of upper chute. Placement of ERC structural walls is anticipated to start later this month. This section of upper chute is 45 percent complete.

Placement of ERC structural slabs and walls on the middle chute continues. Crews have placed 109 of 228 slabs and 21 of 76 walls to date. The middle chute is now 58 percent complete.
Demolition is complete and crews will begin placing reinforcing steel and concrete framework on the energy dissipaters, or dentates, at the base of the main spillway in the coming weeks.

Placement of structural concrete on the dentates is anticipated to begin near the end of August. 

November 1, 2018 is a public safety construction milestone to complete placement of all concrete on the main spillway. Dry finishing, concrete curing, joint sealing, completing sidewall backfill and site clean-up on the main spillway will continue after November 1.

Construction on the Emergency Spillway

Crews continue placement of roller-compacted concrete, or RCC, on the southern half of the new emergency spillway splashpad, which is 58 percent complete.

The RCC buttress at the base of the emergency spillway weir will be built later this year. Drilling of steel dowels into the emergency spillway monolith structure that will support the buttress is 94 percent complete.

Work at the emergency spillway site is not dependent on the public safety construction milestone and will continue past November 1, 2018.

Other Updates

Oro Dam Blvd. East was recently reopened to the public. The speed limit has been reduced to 25 mph on this stretch and cars will not be allowed to stop on the road except at designated turn outs where people can get a view of the spillways construction site.

An underground transmission project along Oro Dam Blvd. East between Glen Drive and Canyon Drive started today, Wednesday, Aug. 8. One-way traffic controls will be in place from 6 a.m. to 6 p.m. as work progresses until it is complete in mid-October.

September 6 and 7 are the next free access dates at the Lake Oroville State Recreation Area as part of DWR’s free access program.

DWR will meet with the independent Board of Consultants for the 19th time on September 5 and 6.

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 | erin.mellon@water.ca.gov