DELTA CONVEYANCE PROJECT: The Delta Independent Science Board discusses the upcoming environmental review

Back in April of 2020, the Delta Independent Science Board (DISB) submitted a letter to the Department of Water Resources during the comment period for the Notice of Preparation for the Delta Conveyance Project.  The letter indicated that the Delta Independent Science Board planned to review the environmental impact report for the Delta Conveyance Project as part of their legislative mandate in the 2009 Delta Reform Act to provide scientific oversight of programs that support adaptive management.  In addition, the letter shared insights and expectations based on the previous review of the environmental documents for both the Bay Delta Conservation Plan and the California Water Fix.

The Department of Water Resources came to the August DISB meeting to provide an overview of the project including timeline and review process, as well as some thoughts on the Board’s letter.

Past Delta conveyance efforts

Carrie Buckman, Environmental Program Manager, began her presentation with a rundown of the recent history of Delta conveyance planning efforts.  From 2006 to 2015, the Department of Water Resources was working on the Bay Delta Conservation Plan which was a habitat conservation plan; it was then bifurcated into the California Water Fix that was focused on conveyance and the EcoRestore effort that focused on habitat restoration. 

From 2016-2018, the Department was working on California Water Fix, and in July of 2017, approved the California Water Fix EIR.  In Governor Newsom’s first State of the State address, he withdrew his support for the California Water Fix Project.  Subsequently, in May of 2019, the Department withdrew all prior Water Fix approvals and ceased all planning on that project.

Purpose and objectives of the Delta Conveyance Project

The Delta Conveyance Project is a proposal to add diversion and conveyance facilities for the State Water Project in the Delta, based on Governor’s direction to study a single tunnel conveyance project rather than the dual tunnel project that was considered in Water Fix.  The Notice of Preparation was issued in January of 2020. 

The purpose of the Delta Conveyance Project is to develop new diversion and conveyance facilities in the Delta necessary to restore and protect the reliability of State Water Project water deliveries in a cost-effective manner, consistent with the state’s Water Resilience Portfolio.

The project has four objectives:

  • Address sea level rise and climate change
  • Minimize water supply disruption due to seismic risk
  • Protect water supply reliability
  • Provide operational flexibility to improve aquatic conditions

The map on the slide is an updated version that has some more specifics.  The project facilities include two intake facilities on the Sacramento River; the Notice of Preparation identified three potential locations, but they will only pick two.  There are then tunnel reaches and tunnel shafts to connect those intakes to the South Delta. 

There is a southern forebay adjacent to Clifton Court Forebay and a pumping plant that pumps water from the tunnel up into the southern forebay, and then a conveyance facility to connect that southern forebay to the existing south Delta pumping plants.

The map shows two potential tunnel alignments: an eastern alignment and a central alignment (of which they will pick one).

Differences between the Delta Conveyance Project and the California Water Fix

Ms. Buckman noted that the central alignment of the Delta Conveyance Project is a similar alignment to the California Water Fix proposed project, but there is a decrease in the number of intakes and overall capacity.  California Water Fix had three intakes at 9,000 cfs capacity and Delta Conveyance Project has two intakes for a total of 6,000 cfs capacity.

There’s also a decrease in the size and the number of tunnels.  California Water Fix had two tunnels with a 40 foot inside diameter; the Delta Conveyance Project is looking at one tunnel with a 36-foot inside diameter.  She pointed out that one of the implications of the change in the size of the tunnel is that there will be less reusable tunnel material produced by construction of the tunnel.

She also noted that the Delta Conveyance Project does not have an intermediate forebay as the hydraulic analysis found it was not necessary; the Water Fix had an intermediate forebay on Glenville Tract.  The Delta Conveyance Project does have a larger southern forebay based on the known engineering details at this time. 

The Delta Conveyance Project is only looking at tunnels and will have no open channels; with Water Fix, there were some open channels and tunnels to connect to the existing pumping facilities.  With Water Fix, there were 5 temporary barge landings proposed, but the Delta Conveyance Project is not proposing any barge landing as part of the proposed project.

The Delta Conveyance Project’s eastern alignment is similar to the California Water Fix east alignment alternative, but whereas the Water Fix east alignment terminated in a forebay south of Clifton Court Forebay, the Delta Conveyance Project east alignment terminates in the same location as the central alignment which is to the west of the Clifton Court forebay.

The other major difference is the eastern alignment alternative for Water Fix looked at canals with siphons or tunnels under waterways, but the Delta Conveyance Project’s eastern alignment is all tunnel, so there’s a substantial difference in the surface impacts, Ms. Buckman said.

Progress of the project

The graphic shows the process that the project will be taking.  The Department has already started on line 1 with the Notice of Preparation, conducting scoping meetings, and compiling a scoping summary report.  They are currently working on the agency outreach plan.

They have also started on line 2 and developing alternatives.  They will be working to further define the project and the alternatives, complete technical reports to analyze technical aspects of those alternatives, and then putting that all into an impact and mitigation analysis that will be documented in the draft EIR in line 3.  That draft EIR will be the document that is circulated for review, which will be when the ISB review occurs.  After the public review, they will address all the comments, respond to those comments, and incorporate the changes into a final environmental impact report and then the Notice of Determination.

At this point in time, they have started working on the early stages of the draft EIR, primarily documenting existing conditions and working on methodologies for how the different resource area impacts will be analyzed.  Also, National Environmental Policy Act (NEPA) compliance is moving forward.  The Army Corps of Engineers has indicated they are preparing an environmental impact statement; they are planning to start that process by issuing a Notice of Intent later this summer which will start their scoping process.  They have finalized a mitigated negative declaration for soil investigations which will help the understanding of soil conditions and geology and inform the planning of the project.

Developing alternatives

Ms. Buckman said that the Department has been working to identify alternatives. 

We received a lot of suggestions for alternatives during the scoping process, and so we’ve developed a process to consider and screen all of those alternatives based on the CEQA criteria for identifying a reasonable range of alternatives,” she said.  “So first we’re putting the alternatives through a filter to look at how well they meet the basic project objectives, and if they meet at least most of those objectives, then moving the filter 2 to see if they have the potential to avoid or substantially lessen expected significant environmental effects of the proposed project without causing other significant environmental effects of an alternative.  So if it passes those filters, it will be considered.”

We will document this in extensive detail in the draft EIR.  We’ll have an appendix that goes through and considers all of the alternatives and compares them to this screening criteria and identifies how well they satisfy those criteria and why they are or are not moving forward for further analysis in the main body of the EIR.”

Ms. Buckman also noted that they are considering a new alternative whereby the tunnel would terminate at Bethany Reservoir, rather than a new forebay adjacent to Clifton Court.  “This would not require the construction of a new southern forebay, and so that would result in fewer surface impacts because we don’t need to have that major construction effort,” she said.  “Additionally, we wouldn’t need the two tunnels that are proposed to connect to the southern Delta conveyance facility.  However, we’re still in the early days of this.  I don’t know if it will live up to its potential.  It will have a significantly sized pumping plant to get water up to Bethany Reservoir which is at a higher elevation, and so we’re going to have to see how the impacts compare, but we think it has the potential to lessen impacts because of that decreased surface size of the construction effort.”

Responding to the Delta Independent Science Board’s letter

Ms. Buckman then turned to addressing the comments in the DISB letter, reiterating that they are in the early phases of developing the environmental impact report, so there are some things they are still trying to figure out how to work through.

Adaptive management:  The DISB letter said that adaptive management should be considered in all phases of the Delta Conveyance Project, including the early phases of project planning.  “We are planning to take these comments into consideration when developing a more detailed adaptive management plan, and we are planning to consider that earlier, but at this point, we’re still trying to define the project, so it’s still a little bit early for this discussion,” she said.  “We are planning to talk about this during our continued early consultation with the Delta Stewardship Council, and we expect and hope that we’ll receive additional feedback from the ISB on this topic when you are reviewing the EIR.”

Scientific information:  The ISB’s letter suggested that the EIR should incorporate new findings from recent scientific work throughout the process, including findings from climate change science.  “The EIR team is working to update background information and methodologies for all resource areas that will be analyzed, including climate change and seismic risk to levees.  We also acknowledge that for Delta Plan consistency, the best available science is considered right up to the submission of the certification of consistency, whereas it’s a little different than developing a baseline for CEQA which is established at the time of the publication of the Notice of Preparation.”

Communication:  The ISB suggested clear communication of principle findings, alternatives, and uncertainties throughout the EIR documents, including the use of graphics and informative summaries.  “I will say this is not the only comment we received on the topic of making this understandable.  I think a lot of people had issues with the readability and understandability of the Water Fix EIR.  We get a lot of people who did not appreciate the length of the EIR and the sheer volume of information that was included.  So we’re working on it.  We’re trying to figure out how to increase the readability of the document.”

This might include moving some of the highly technical discussions to appendices to keep the main body of the document readable.  They are also hoping to limit the number of alternatives, as the Water Fix had 18 alternatives, which made it hard to get through all the contents. 

We’re also considering a companion document to help the public understand what’s included in the EIR, as a lot of the EIR and even the Executive Summary is focused on CEQA requirements, which isn’t always helping the general public understand the project and the tradeoffs, so we’re thinking about trying to have something that’s focused a little more on the public audience that isn’t aimed at complying with CEQA but is sort of aimed at summarizing the key findings in a way that will be interesting and useful for the public.”

Long-term effects:  The ISB’s letter suggested that the EIR document should consider future uncertainties such as groundwater changes and timing of sea level rise in the analysis of the long-term performance of alternatives and the EIR document should discuss contingencies when possible and risk analysis should be included in the process.

Our proposed methodology does include expanded modeling to look at long-term climate change and sea level rise in a more robust way,” said Ms. Buckman.  “And we have been talking about SGMA and how we should incorporate groundwater considerations as the comments talked about how this could change agricultural conditions within the San Joaquin Valley.  CEQA compares what would happen with the project to existing conditions, so with SGMA, we do expect there would be less pumping in the future and therefore there may be a change in growing patterns.  If Delta conveyance does help provide some part of a portfolio of actions that would allow a little bit of additional agricultural activity compared to existing conditions, we don’t expect it to increase that production.  However, NEPA does require comparison of the future without projects to a future with project conditions, so there may be some changes there under that analysis.”

Delta residents and visitors:  The ISB recommends the impacts of project construction on Delta residents and visitors should be summarized and presented in a coherent and understandable way. 

We acknowledge the importance of synthesizing information for Delta residents and visitors.  It’s not necessarily a requirement for CEQA but we do know it’s important so we’re trying to consider ways we can do this.  And we are continuing to meet with the Delta Protection Commission to discuss Delta as a place considerations.”

Q&A highlights


Ms. Buckman was asked about when the document would be ready for DISB review.  She said the Army Corps of Engineers is just starting their NEPA process so they are working to define the schedule between the two agencies.  The Corps will produce a separate EIS rather than a joint EIS/EIR, so there will be two documents out for public review and they would like to align those two review periods. 

Earlier documents indicated that we’d have a public review EIR at the beginning of 2021.  I expect that will slip as we work through the process with the Corps but we don’t have a revised timeline yet,” she said.

Readability of the document

The DISB members had several comments related to the readability:

  • Jay Lund: Find succinct ways of summarizing of comparison of alternatives for the EIR,  Moving stuff to an appendix is fine, but really the summary needs to be readable. 
  • Liz Canuel: Each chapter should have an executive summary written for a lay audience. Use graphics to help readers understand the information.
  • Tracy Collier: In the pdf, embed hyperlinks in the text to make it easier to navigate the document for the information.

Risk assessments

Question: Do you envision as part of this to put some of the changes into a risk assessment framework?  EIRs talk about the magnitude of change, but it can be hard to understand if that magnitude of change is meaningful.  Are you going to incorporate risk assessments?

I don’t know yet is the simple answer,” Ms. Buckman said.  “From my perspective as a practitioner, I understand where you’re coming from.  Risk assessment to me is a pretty specific set of processes and I’m not sure we would be applying that to a lot of things, but I think your point of being able to explain the magnitude in a way that people can understand is meaningful and is something we definitely need to work on in the environmental document.”

Narrowing down alternatives

Question: You mentioned that the goal is to have a smaller number alternatives, but how will you work through those in terms of public engagement and transparency in the whittling down of those different alternatives?

Ms. Buckman said as part of this effort, there is a JPA of water agencies called the Delta Conveyance Design and Construction Authority (or DCA) whose purpose at this point is to work on the design and eventually the construction of a potential project, so at this point they are supporting DWR’s efforts by providing design information.  The DCA has a stakeholder engagement committee that meets regularly, where the DCA goes over the design work in detail and the stakeholders discuss different aspects of the project.  The DCA tries to shift facilities where possible to reduce the potential for community effects, so they are focusing with this group on trying to identify designs that would minimize effects to the local communities.  The alternatives are being shared with the committee and publicized on the website as well.

Field work?

A question was asked about new field work that might be necessary.

We’re working on having some additional field work but we’re trying to focus on areas that we think it might really be beneficial to the alternatives valuation,” said Ms. Buckman.  “At this point, we’re looking at some additional biological and cultural field work and some traffic monitoring in the fall during the agricultural harvest period.  There are a few other potential efforts but really since there has been so much data collection, mostly what we’re looking at now would be helpful, but if we don’t end up being able to obtain that information, we think we have enough information to complete a solid analysis.

The Delta Protection Commission weighs in

Next, Erik Vink, Executive Officer of the Delta Protection Commission, then shared his thoughts.

Background on the Delta Protection Commission

The Delta Protection Commission was the initial Delta agency for the state that was formed in 1992 primarily over concern about urbanization encroaching into the Delta.  Initially, the Commission was intended to be a regional land use agency of sorts, where the Commission would ensure that local government land use decisions were consistent with the plan that was adopted by the Commission, but over time, they were granted additional responsibilities, including trying to create a trail network through the Delta to link the Bay Trail in Contra Costa County with the Sacramento River Trail in Sacramento. 

The Commission’s role changed significantly with the passage of the 2009 Delta Reform Act, which created the Delta Stewardship Council and the Delta Conservancy, and significantly modified the Commission’s governing legislation.   Most importantly, the Delta Protection Commission’s membership was increased to 15 with 11 of those being local officials from the Delta region, including county supervisors from each of the five Delta counties, three city council members from different parts of the Delta, and Reclamation District trustees, which are primarily farmers from the three different regions of the Delta.  Then there are four state agency representatives which are primarily designees of agency secretaries.

It’s that local focus that makes us a little bit unique among state agencies because we’re directed by statute to represent the Delta voice,” said Mr. Vink.  “We are a state agency.  We don’t necessarily align with the Governor’s proposals, particularly related to Delta conveyance … People say, how can you be critical of what the Governor is proposing with the Delta tunnel, and aren’t you a state agency?  We are, but we are specifically directed by statute to ensure that we do what we can to protect and enhance what we call the unique Delta values, which are Delta agriculture, recreation, Delta cultural values, which are largely embedded within our historic communities in the Delta, and then the Delta’s natural resources.”

He said when he refers to ‘Delta as place,’ it’s shorthand for how to protect and enhance those unique Delta values as the coda to the coequal goals states.  “We all know about water supply reliability and restoring the Delta ecosystem, but our role is to give the constant reminder that those two goals are to be accomplished as the statute states, in a manner that protects and enhances the unique Delta values as an evolving place.”

The other significant change was that the Delta Protection Commission was given a specific role to advise the Delta Stewardship Council in Delta as a place and to inform the Delta Plan, but also on any ongoing projects that might follow the adoption of the Delta Plan

We take that charge very seriously,” said Mr. Vink.  “We work very closely with the Delta Stewardship Council and the chair of our Commission is a member of the Delta Stewardship Council, so we have a direct voice at the Council level in these types of issued and deliberations, but we really strive to represent the Delta region as we implement and make changes to the Delta Plan.”

Mr. Vink said the Commission is very appreciative of the DISB’s involvement and extensive comments in the Bay Delta Conservation Plan and Cal Water Fix and those environmental documents.  He also said they appreciate the focus on social science.   

That’s really central to our role in representing people in the Delta region and we believe it’s going to be critical in evaluating the Delta Conveyance Project as an environmental impact report and EIS are released next spring,” he said.

For the Delta Conveyance Project EIR, Mr. Vink then gave his comments.

Adaptive management:  “The first is that adaptive management for Delta as place where the impacts are uncertain, and this was something we felt was extremely deficient in the previous iterations of this project,” he said.  “Maybe adaptive management would have been implemented or utilized if the project had moved forward, but we certainly didn’t see any indications that there was going to be any review of these impacts to the Delta region, which are substantial from such a significant industrial-scale project stretching over more than a decade.  So we thought that was critically important and we hope that is better addressed in this go around.”

Peer review of the evaluation of impacts to Delta as place:  “Peer review of economic studies to consider the feasibility of mitigation measures.  Our Commission believed that the mitigation measures were insufficient in the previous iterations, in part because the understanding of what it would mean on the ground was not well understood, given the very conceptual nature of the project.  Presumably that will be different this time around with the detailed engineering and design work that the JPA DCA is completing on this project, so we hope that’s different this time.

Monitoring impacts during construction so that mitigation can be addressed based on actual conditions:  “We really hope that there’s an enhanced consideration of the human environment and frankly that the human environment in the form of impacts to the Delta region is considered as carefully as the natural impacts,” said Mr. Vink.  “The amount of time and space devoted to biology and hydrology – and I’m not slighting those in any way, they deserved every bit of the attention they got, but it incredibly dwarfed the amount of attention given to the human impacts in the region that’s going to bear the brunt of the effects from the construction of this project.”

Delta levees:A deficiency we believed in the previous effort and unfortunately I’m afraid it’s still true in this effort is that there’s no proposal for improving Delta levees, which frankly are essential for maintaining a dual conveyance system,” he said.  “DWR has stated explicitly that they still intend to maintain a dual conveyance system, both the isolated conveyance with the single tunnel but also the existing through-Delta conveyance, and so ensuring the integrity and health and durability of levees in the Delta is going to be critical, not only to ensuring water supply reliability but frankly also to ensuring that we can maintain the billions of dollars of regional infrastructure that crosses the Delta, not to mention the people we work with at the Commission, the people who farm and live and do their work within the leveed islands.”

Mr. Vink said he appreciated the Board’s comments about the readability of the environmental documents.  “I hope that’s something you all continue to champion because the last few documents were almost impenetrable for the lay audience and there has to be a way to better summarize a very complicated environmental review for a lay audience, so please continue to knock the drum on that.  We will as well.”

In conclusion, Mr. Vink said that the Commission has greatly appreciated the openness that the Department of Water Resources has extended in their initial planning, the ongoing communication, and the detailed sharing of information through the stakeholder engagement committee.

Delta Stewardship Council Planning Director  Jeff Henderson adds his comments

Delta Stewardship Council Planning Director Jeff Henderson than gave some concluding remarks.  The Council is engaged in early consultation with the Department of Water Resources because the Delta Conveyance Project is a potential covered action under the Reform Act.  The Department would file a certification of consistency with the Council which would highly likely be appealed, at which point the Council would be determining whether or not that project and its record is supported by substantial evidence that supports DWR’s conclusion that the project is indeed consistent with the Delta Plan.

That makes this EIR a very critical piece of the record that ultimately supports that process, and it’s why the Council staff is interested in also having some dialog with the Independent Science Board regarding the project,” he said.  “We will be, as part of that early consultation process, discussing a number of key issues with the staff at the DWR particularly for the purview of this board concerning adaptive management, best available science, and some Delta as place considerations.  And in all of that, we also intend to keep a key focus on the human dimension issue that underly those considerations.  Council staff may also seek to elevate some key adaptive management and best available science questions to the ISB as those emerge through the early consultation process, and we would continue to report that progress to the board and pose those questions to be considered as part of your review at a later time in the future.”

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