DELTA COUNCIL: Delta Conveyance Project update

The Delta Stewardship Council met in July at Peter’s Steakhouse in Isleton.  On the agenda was an update on the Delta Conveyance Project.  Carrie Buckman, Environmental Program Manager for the Department of Water Resources, provided the update.

The Delta Conveyance Project is an infrastructure project that involves the construction of a tunnel to divert water around the Sacramento-San Joaquin Delta, rather than through it. By bypassing the Delta, the project aims to improve water supply reliability for the State Water Project and Central Valley Project, which provide water to millions of Californians and agricultural lands. The project has been a subject of debate due to concerns about its potential environmental impacts and high cost. However, proponents argue that it is a necessary adaptation strategy to safeguard the state’s water supplies in the face of changing climatic conditions.

In the first part of her presentation, Ms. Buckman discussed the purpose of and the need for the project as a response to the effects of climate change.  The project would ensure that the State Water Project could safely capture, move and store water in the winter during high flow conditions while meeting water quality and species protections.  Ms. Buckman said that if the project had been in place during the water year 2021-22, a critically dry year, the project would have been able to capture 236,000 acre-feet.  If it had been online in January of this year, the project could have captured an additional 228,000 acre-feet of water.

The final EIR is expected to be completed by the end of the year, with the Army Corps’ EIS following in early 2024.  The final EIR will include public comments and responses to those comments; Ms. Buckman said the comments won’t all be published in their exact form due to ADA compliance issues.  It’s difficult to make documents received from others fully compliant, so instead, they will be reprinting the text in its entirety as part of the comment tables.  The final will also include a mitigation monitoring and reporting program.

The Department is working towards initiating the formal consultation processes for the federal and state Endangered Species Acts that will ultimately result in biological opinions regulating the project’s operations.  The Department is also working on a financial analysis, including an updated cost assessment and cost-benefit analysis.

Soil investigations have been occurring since 2022, with 79 borings and 59 cone penetration tests completed so far.  The tests will wrap up with an additional 20 borings and 14 cone penetration tests this summer and fall.  Ms. Buckman said that the soil investigations were necessary because while they had a lot of information about the geologic conditions, more detail was needed.

“We’ve been using this data to understand if our assumptions were accurate, and so far, it’s been primarily confirmed,” she said.  “The general trend is that there are more competent soils along the Eastern or Bethany alignment compared to the central alignment alternatives.  Competent soils mean that it’s denser, stiffer soils and more suitable for constructing structures.  And overall, the data has confirmed the preliminary design criteria and construction assumptions that were part of the conceptual design of the project and alternatives.”

There was only one public comment from Osha Meserve, representing the Local Agencies of the North Delta.  “The part about the changing climate and the need to take more water during high flows that may be in the winter more so than other months – that’s really not backed up by the operational plans that were put in the draft EIR which says that the water could be taken all year long.  So we are concerned that, ultimately, a more aggressive operational plan would be used and that it would lead to permanent drought conditions in the Delta.  There’s really nothing in the documents we’ve seen that would restrict this project to high flow or flood flow conditions only, so I think that is somewhat of a misleading way to describe the project when there aren’t those kinds of sideboards around it.”

“There are obviously a lot of other options out there for how water supply reliability could be improved for export water agencies,” Ms. Meserve continued.  “We’ve continued to advocate for the DWR and the water export contractors to pursue those other options which we think would be more feasible and more affordable and also comply with the 2009 Delta Reform Act.”

Ms. Buckman responded by providing more information about the proposed operations.  “When we talk about operations over the course of the year, there are two seasons we’re planning for.  One is the summer and fall, and the other is the winter and spring, when we will likely have high flow periods.  So the high-flow operations are what we discuss in the winter and spring.  In the summer and fall, we contemplate a small amount of shifting operations from the south to the north.  It doesn’t increase diversions from the Delta overall, but it helps us with water management for the project.  So that is why you see diversions on and off throughout the year.  It’s not continuous.  There are sometimes months where there is no water being diverted, but there is water at times in the summer to help with the management of water quality.  And we do limit the flows that we would divert in that winter and spring period to excess flows in the Delta.  We would not be diverting water from storage.  And that is specified in the EIR as well.”

When asked to respond to the comment about the Department pursuing solutions other than conveyance, Ms. Buckman noted that the Delta Conveyance Project is part of the Governor’s Water Resilience Portfolio.

“Delta conveyance is part of a portfolio, and the things that people suggest – conservation, recycling, and desalination are important as well.  All of this needs to come together to address the real and significant problems that we have both now and moving forward into a hotter, drier future.  As we looked at the alternatives formulation, we did consider those as alternatives to the Delta Conveyance Project, but they did not ultimately meet our purpose and needs.  DWR, as the owner and operator of the State Water Project, is looking for ways to continue the functionality of the State Water Project in light of these many challenges.  So an alternative that would allow the State Water Project to continue to degrade did not meet our purpose for considering this project.”

Department of Water Resources signs agreement with Contra Costa Water District regarding Delta Conveyance Project

The Department of Water Resources (DWR) and Contra Costa Water District (CCWD) have signed an agreement that addresses CCWD’s concerns about the potential effects of the proposed Delta Conveyance Project on their customers, facilities, and operations if the project is built.

The CCWD website notes:  “This settlement will result in the construction, operation, and maintenance of new facilities that will offset any potential impacts of the Delta Conveyance Project without new impacts to other stakeholders.  The cost of the mitigation will be paid for by the state, not CCWD customers.  CCWD takes its role of serving our customers seriously and views this settlement as an insurance policy to prevent future impacts for customers, should the conveyance be built.

This legally binding settlement agreement will not result in customer rate increases or redirect any potential impacts.  The CCWD Board of Directors is not a proponent of the Delta Conveyance Project, and this agreement does not make the Delta Conveyance Project more likely to be built.  CCWD will remain active on outstanding issues related to federal financing and contract allocations.“

Read more and access the document here:

This article first appeared in Maven’s Weekly Water Blast, the newsletter for donors and sponsors that features all the upcoming meetings and events for the week, as well as exclusive news and insights not found elsewhere on the Notebook.  Don’t miss out!  Join the list by making a tax-deductible donation today.

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