Department of Water Resources submits plans to address spillways forensic report

SACRAMENTO – The state Department of Water Resources submitted its plan to the Federal Energy Regulatory Commission on Tuesday to address findings in the independent forensic report.

The extensive forensic report, released on Jan. 5, blamed “longterm systematic failure,” including faulty design and insufficient maintenance, for the Oroville Dam crisis in February 2017. It also had criticisms of DWR’S response to the spillways’ failure.

To address flaws pointed out by the independent forensic team, one thing the department has done is hire two executive-level engineers – one to report to the directorate and one to report to the chief dam safety engineer, Joel Ledesma, deputy director for the State Water Project, told FERC in a letter.

The department has also stepped up its inspections of other State Water Project spillways “including new testing, historical document reviews and engineering verification,” Ledesma wrote, adding that State Water Project dams would now be managed to International Standards Organization standards, exceeding what DWR is required by law to do. The State Water Project provides water to 26 million people from Northern to Southern California.

“Together we are confident these efforts are further improving dam safety across the SWP (State Water Project) in California,” he said.

He noted that the department also altered its construction plans after the forensic team released its initial findings about what may have caused the main and emergency spillways to fail. The Board of Consultants, the independent group looking into the redesign of the spillways, stated in a September report that those factors seemed to be adequately addressed.

DWR is also conducting a few studies of its own, including what the department is calling a “comprehensive needs assessment” for Oroville Dam as well as assessments for the other State Water Project dams, Ledesma said.

Possible contingencies at Oroville Dam such as a fully lined emergency spillway and a second gated spillway are being considered as part of the comprehensive needs assessment, department officials have stated in the past.

“DWR has also initiated a spillway inspection and condition assessment project for the other SWP dams, including the other FERC licensed dams,” Ledesma wrote. “This project includes the following major elements: detailed inspections, non-destructive testing and physical investigations, review of historical documentation from original design to present, analyses, and maintenance or major repairs, as warranted.”

The department also began an evaluation of the State Water Project’s Dam Safety Program in November, he said.