The existence of hair line cracks in the Oroville Dam Spillway created a news frenzy last week as a letter from the Federal Energy Regulatory Commission, Division of Dam Safety and Inspections, was released to the public.
Erin Mellon of the Department of Water Resources said," The integrity of the newly reconstructed Oroville spillway is not in question. The assessment of our experts is the concrete has cured as expected and is certified to handle flows of 100,000 cubic-feet per second or more this winter.
This is backed up in a letter from the Federal Division of Dam Safety and Inspections to DWR The letter dated November 21, 2017 says "We have reviewed the letter and technical memorandum. We concur with your assessment that the current condition of the hairline cracking does not warrant repair at this time. We understand that you will continue to monitor and evaluate the hairline cracks throughout the 2017 flood season and the 2018 construction season. We also understand that you will be evaluating a number of construction measures this winter that might be implemented next construction season that might reduce the likelihood of hairline cracking. " signed Frank L. Blackett, P.E. Regional Engineer.
According to the Appeal-Democrat the Mayor of Oroville, Linda Dahlmeier, is unhappy with DWR for not communicating with her town, just below the Dam, that the cracks were expected. Instead a "firestorm" was created for the people of Oroville.