UPDATE, Nov. 2 — Kiewit crews completed repairs to the Oroville Dam's main spillway Wednesday, meeting the project's Nov. 1 deadline in time for the impending rainy season, according to the Mercury News. To determine other necessary updates, California officials will order an overall safety review using today's engineering standards that federal, state and private experts will collaborate on. Repairs to the 770-foot dam have cost $640 million, so far.
Dive Brief:
- The California Department of Water Resources said on Tuesday that crews are on track to complete repairs to the main spillway of the Oroville Dam by the Nov. 1 deadline, according to The Mercury News, in time for the upcoming rainy season.
- Contractor Kiewit was pouring the last bit of concrete on Oct. 31 after completing other work that will allow the spillway to handle water overflow, if necessary, of 100,000 cubic feet per second (cfs). After repairs to the main spillway work are complete, crews will then work on concrete seams, drain pipes, drain seams, clean up and the emergency spillway and cutoff wall below.
- After all work on the spillway is complete in January 2018, the emergency system should be able to handle 270,000 cfs. During heavy rainfall in January of this year, damage to the spillway system forced the evacuation of almost 190,000 nearby residents on fears of total spillway failure and flooding.
Dive Insight:
Last month, the DWR reported that the projected cost of spillway repairs had almost doubled from $275 million to $500 million, an increase the authority said was necessary after crews were able to fully assess the damage. At the heart of the increase was the extra digging required to hit bedrock and a concrete pour that was double the size of what was originally anticipated.
The state has requested that the Federal Emergency Management Agency (FEMA) absorb 75% of the total spillway repair bill, just one relatively small piece of what the agency will fork over this year in disaster relief.
FEMA is still tallying the damage done to the U.S. and its territories from Hurricanes Irma, Harvey and Maria, but the total price tag is expected to be approximately $300 billion.
To help with the recovery from Harvey and Irma, Congress voted to provide the agency with an additional $15 billion. However, after Hurricanes Nate and Maria hit the U.S. Gulf Coast and Puerto Rico and after Northern California wildfires burned through more than 200,000 acres of residential and commercial properties in October, federal legislators authorized a second aid package, this one adding up to $36.5 billion. The cost of damage from the wildfires is expected to hit $65 billion, and insurance claims for this year's hurricane season alone are anticipated to reach $100 billion.