Last February 7 during heavy rains, the Oroville Dam’s concrete spillway failed, launching fears of a complete dam failure, and forcing the evacuation of 188,000 people downstream from the structure. As the anniversary approaches, the total costs of the spillway reconstruction, including emergency response, have risen to $870 million according to the state Department of Water Resources. This government agency has no trouble charting costs but other issues remain on the murky side.

The massive January 5 Independent Forensic Team Report: Oroville Dam Spillway Incident, blames the failure on “a complex interaction of relatively common physical, human, organizational, and industry factors, starting with the design of the project and continuing until the incident.” The principal designer for the Oroville spillways was a post-grad student with “no prior professional experience designing spillways.” The forensic team did not name the unqualified designer, and former DWR engineer Don Colson, who worked on the dam, claims “there was no such” person and anybody who says there is “must be suffering from an advanced case of mental illness.” Both sides can’t be right, but DWR bosses and legislators are failing to resolve the mystery, hardly an academic matter.

A new concrete spillway is showing cracks that could lead to safety issues. The city of Oroville has filed a lawsuit against the DWR for mismanagement of the dam. Taxpayers statewide should not be surprised if the total costs wind up well north of $1 billion. And whoever the original spillway designer was, residents in Oroville and points south would have to be crazy to think the 1968 structure is safe.