Delta Tunnel: DCA and DWR Reject Findings of Independent Technical Review Panel

Under the supervision of the California Department of Water Resources (DWR), the Delta Conveyance Design and Construction Authority (DCA) is providing “engineering, field studies and design work to inform the environmental planning process, and assist[ance] in evaluating and minimizing community impacts” for the Delta Tunnel project.

On December 4-6, 2019, the DCA convened an Independent Technical Review Panel for the single tunnel project design.  The panel included engineers from major international tunneling contractors – Herrenknecht, Dragados, Kiewit, Frontier-Kemper, Obayashi, and McMillen-Jacobs.


For the review, the Independent Technical Review Panel was given a copy of the July 2018 WaterFix Conceptual Engineering Report, even though all project approvals have been rescinded. A draft copy of a construction schedule for a project with a single tunnel in the WaterFix main tunnel alignment, which is now called the “Central Corridor,” was also provided.  Clearly the DCA has been considering a modified version of the WaterFix project.

But as explained in our February 24, 2020 blog post, the Independent Technical Review Panel threw a major monkey wrench into those plans.  The panel unanimously found that the Central Corridor  is ‘impractical,” and recommended that the route not be studied further.

On January 20, 2019, the Department of Water Resources issued a Notice of Preparation of an Environmental Impact Report on the Delta Conveyance.   Potential routes included both the Central Corridor and an Eastern Corridor.

Single tunnel NOP map

On January 31, 2019, the Independent Technical Review Panel submitted their formal report to the Delta Conveyance Design and Construction Authority.   The report was not disclosed until mid-February, when it was included in the packet for the February 20, 2020 Delta Conveyance Design and Construction Authority Board meeting.

Both the Delta Conveyance Design and Construction Authority, and the Department of Water Resources have since rejected the recommendations of the Independent Technical Review Committee.  The minutes of the February 26, 2020 DCA Stakeholder Engagement Committee meeting record that Ms. Mallon as stating:

As part of the ITR team’s analysis, they took a bus tour around the Delta. As contractors, their perspective is about ease of access to locations, how to get workers and equipment to possible siting locations, as well as rescues in case of emergency. From this standpoint, Stockton looks great. DCA’s first reaction to that, however, is that there are environmental justice (EJ) and air quality issues. DCA could have told the ITR team that they went outside their purview in remarking on the corridors, but instead their recommendation was included in the report and made transparent to SEC members.

Carrie Buckman, the Department of Water Resources’ Environmental Program Manager  stated:

The recommendations in the ITR are not necessarily determining factors for the overall project, and it is too early in the process to know whether or not those recommendations will be used to make ultimate decisions. The ITR is one piece of information in a large process that will include a lot of other pieces of information. The ITR is useful to help understand the logistical challenges of the Central Corridor and helps bring greater understanding to what would need to be done in order to resolve the logistics issues, but the ITR recommendation is in no way a screening out of the Central Corridor.

Thus it seems clear that both the DCA and DWR are continuing to pursue a single tunnel in the Central Corridor / WaterFix project alignment, even though the Independent Technical Review Panel stated that the logistics for the Central Corridor made it difficult to even bid.

In response to statements by Kathryn Mallon and Carrie Buckman, Stakeholder Engagement Committee member Dr. Mel Lytle, the Deputy City Manager for the City of Stockton, stated,

The people brought in to conduct the ITR were major experts on very difficult projects. Werner Berger [Herrenknecht] is tunneling beneath the Alps. The team at McMillen Jacobs are the ones who engineered the third intake on Lake Mead that was so dangerous and controversial. The things they said should not be discounted. The ITR didn’t just address logistics. Drive length and TBM maintenance was also addressed. They also addressed posed questions for consideration such as how to respond if the TBM gets stuck. Their input should be very seriously considered, and it was no accident who DCA brought in to participate in the process. The team even included the firm who was in charge of the Alaska Way Viaduct [Dragados], where the 57-foot TBM “Big Bertha” got stuck underneath the city and it took 2-3 years to figure out how to resolve the problem.

The proposed project is a 40-foot diameter TBM that is tunneling 40 miles. There may be four TBM’s, but the process is the same. What happens if the TBM gets stuck? What about safety in the tunnels? These questions raised by the ITR team really need to be expounded upon. Logistics, worker safety, tunneling through a gassy area, etc. are all important considerations. The ITR was a watershed moment for SEC members because it raised a lot of important issues that there have been questions about.

After the “watershed moment” for the DCA’s Delta Stakeholder Engagement Committee, the DCA has arranged for the committee members to have private bus tours of the two alignments.  The bus tours were not disclosed on the DCA’s website nor are they open to the public, or even to outside experts working with Delta Stakeholder Engagement Committee members.

The DCA’s lead Counsel, Joshua Nelson, stated today that the DCA’s partner agency (DWR) would not allow the tours to be open to the public.  Nelson also stated that since the tours would be split so as not to have a quorum of Stakeholder Engagement Committee members on any one tour, he thought the tours are not subject to the Brown Act.

The private tours arranged by the DCA for Delta Stakeholder Committee members contrast poorly with tours set up by other state agencies.  The Delta Independent Science Board had a boat tour of the Delta on May 2nd of last year with the US Geological Study.  The tour was both noticed on the Delta Stewardship Council’s website, and open to the public as space allowed.   The Delta Protection Commission also had a tour of the McDonald Island Gas Field on July 18. The tour was both noticed on the Delta Protection Commission’s website, and open to the public as space allowed.

2 thoughts on “Delta Tunnel: DCA and DWR Reject Findings of Independent Technical Review Panel

  1. Clearly, DWR and DCA, both public agencies, are not paying sufficient attention to the Independent Technical Review Panel. This taints the entire Delta Tunnel design and construction process! Where is this process headed? –Clearly toward a monumental disaster! God help our water resources and endangered aquatic life.

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