DWR releases needs assessment for Oroville Dam

Nov. 14--The Department of Water Resources recently published a comprehensive needs assessment for the Oroville Dam that identifies dam safety and operational needs following the reconstruction of the spillways that were heavily damaged in February 2017 -- that was when the Yuba City/Marysville area was evacuated for fear a portion of the dam might give way.

The report determined that the Oroville Dam Complex is safe to operate and that no urgent repairs are needed, though it did identify several risk-reduction projects that DWR has plans to implement, including the installation of new water pressure measurement devices to improve seepage monitoring and completion of a seismic stability analysis.

The Oroville Dam Safety Comprehensive Needs Assessment was first initiated in January 2018 and will be used by DWR management to make risk-informed investment decisions across State Water Project infrastructure.

The assessment is the most comprehensive risk analysis that DWR has undertaken for any of its facilities. The purpose of the assessment was to give a comprehensive look at the infrastructure that is currently in place, what kind of condition it is in, and whether or not there needs to be further upgrades and repairs.

"The Comprehensive Needs Assessment report is an important step in our efforts to ensure the ongoing safety and reliability of facilities that provide water and flood control for millions of Californians," said DWR Director Karla Nemeth in a press release.

Other near-term projects identified in the report that DWR plans to implement at the facility include raising the Parish Camp Saddle Dam by three feet, lining the Palermo Canal to reduce leakage and improving rock slope stability, and installing new remote starter and power connections to the spillway radial gates to improve reliability.

Takeaways

The team that put the report together included engineers, hydrologists and other experts in the field. The process was overseen by an independent review board of dam safety experts, as well as an ad hoc committee of community stakeholders appointed by Assemblyman James Gallagher and state Sen. Jim Nielsen to represent the surrounding communities.

"This is something we had really requested they do, and more specifically, we asked them to have an ad hoc committee of community members to provide input on the process, and they did," Gallagher said. "So all of that was positive. As for this document, it's a good first step. It's not everything that I would want, but it's a good step in the right direction."

Gallagher said one of the most positive projects highlighted in the report is the plan to install additional piezometers (water level measurement devices) at the facility. Another is a commitment made by DWR to forecast-based operations at the reservoir that allow for quick decisions on water releases from the dam based on real-time circumstances on the ground, which can prevent the undermining of levees downstream due to excessive releases.

"I like that they are now not just looking at the surface of the infrastructure but what's going on below the surface," Gallagher said.

The assessment also identified potential vulnerabilities that require further examination to better understand if there is a significant problem that needs to be addressed, Gallagher said.

The Oroville Dam Citizens Advisory Commission was created by a legislative bill authored by Nielsen in 2018 to be a public forum for discussing issues related to the dam's facilities. Commission members were given a presentation on the report during a virtual meeting on Friday.

"I'm very positive that they've done a really good job at fixing the spillways, but I'm concerned about how we get water out of that reservoir quickly in big storm events," said Sutter County Supervisor Mat Conant, who is one of a handful of local representatives on the commission. "I'm cautiously optimistic that we will find a solution to it, but we haven't done it yet."

DWR has committed to working with the commission to seek input and coordinate future Oroville Dam activities related to construction, operations, maintenance, flood management and public safety. The state department also stated it would conduct ongoing monitoring and assessment to maintain the safety and reliability of the complex.

Gallagher said additional steps he hopes to see moving forward include DWR considering establishing a low-level outlet at the dam to help with releases during a large storm event -- something currently being planned for at New Bullards Bar. The idea was identified in the DWR report but no funding or commitment was made, he said.

Beyond Lake Oroville, Gallagher said, the state needs to develop an infrastructure plan for all of California to ensure that the proper amount of investments are being made to upgrade and repair aging infrastructure, as it's much cheaper to carry out those types of projects than waiting for something to go wrong.

"As we've said, the public trust has been destroyed, and it's going to take a long, sustained effort from DWR to repair that. We want to see substantive changes in the way they operate and in the infrastructure," Gallagher said. "There were some good things in the report, but there is more work to be done."

To view the Oroville Dam Safety Comprehensive Needs Assessment Summary report, visit https://bit.ly/2UmZgYA or go to the website www.water.ca.gov.

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