SAN FRANCISCO (AP) - California state officials say small cracks that have appeared in the brand new concrete spillway at Oroville Dam were expected and do not pose a threat.
KQED radio of San Francisco reports Tuesday that previously undisclosed letters show federal regulators asked Department of Water Resources officials to explain the hairline cracks on the dam's new massive concrete flood-control chute.
In an October letter, the Federal Energy Regulatory Commission also asked water officials what, if any, steps might be required to address the issue.
California water officials responded in November that steps taken to build a more durable spillway caused the cracks and was anticipated.
University of California civil engineering professor Robert Bea says cracking in high-strength reinforced concrete structures is never expected.
- Small cracks have appeared in the new Oroville spillway
- New cracks found in concrete at Oroville Dam Spillway
- DWR: cracks on spillway are normal, expected
- DWR releases pictures of Spillway cracks
- Oroville spillway looter charged with stealing
- 1 year anniversary of Oroville Spillway Crisis
- Oroville Dam Spillway Crisis: One Year Later
- Update on Oroville Dam Spillway Work
- Update on Oroville Dam Spillway Construction
- Voices of Oroville: One year after Oroville Dam Spillway Crisis