New Oroville Dam Spillway Has Tiny Cracks

Nov 29, 2017

The new, mostly completed Oroville Dam spillway is riddled with tiny cracks, but state officials insist there is nothing wrong and nothing to be concerned about.

Even as officials celebrated meeting a Nov. 1 construction deadline, problems were already evident and documented. A letter federal regulators sent the California Department of Water Resources a month earlier referred to “a small number of cracks” appearing in upper layers of the new concrete.

In their letter, officials from the Federal Energy Regulatory Commission, which licenses the dam noted that DWR “at least initially expressed some concern about the cracks.” DWR changed some practices and brought in more experts. 

On Nov. 7, DWR attributed the cracks to extra anchors, additional reinforcing steel and other steps to build an especially strong spillway. DWR said the cracks are “not expected to affect the integrity of the slabs.”

Department of Water Resources spokeswoman Erin Mellon said Tuesday that hairline cracks aren’t abnormal and appeared about every 10 feet. Since the near disaster in February just under half a mile of the spillway was demolished and rebuilt. That easily works out to more than 200 cracks.

After state officials determined that no repairs are needed earlier this month, a week ago, federal officials agreed. Nevertheless, federal regulators noted that DWR is planning steps to prevent cracks from forming in work scheduled for next year.