As the Newsom administration nears the end of its term, the Department of Water Resources (DWR) continues to seek key approvals for the Delta Conveyance Project (DCP), which would divert up to 6,000 cubic feet per second from the Sacramento River in southern Sacramento County and convey it via a 45-mile long, 40-foot diameter tunnel to the south Delta for export.
The Delta Stewardship Council (Council) has scheduled a hearing on October 15, 2026, on the three appeals of DWR’s Revised Certification of Consistency with the Delta Plan on Remanded Items (Revised Certification) for the DCP. The Revised Certification responds to deficiencies identified in the Council’s April Decision D20257 on DWR’s October 2025 certification for the DCP; namely, that DWR failed to support findings (1) under Policy ER P5, Avoid Introductions of and Habitat Improvements for Invasive Nonnative Species, regarding the golden mussel, and (2) that it sited the approximately 600-acre proposed Twin Cities Complex (TCC) to avoid or reduce conflicts with Sacramento Area Sewer District’s (SacSewer) Harvest Water Program.
The appeals were filed on August 24, 2026, by SacSewer, a collection of local agencies including San Joaquin, Solano, and Yolo Counties, and a collection of individuals with interests in the TCC site, including the property owner and agricultural user. Written submissions supporting the appeals are due on September 22, 2026, as is any written submission to be offered by the Delta Protection Commission in its advisory capacity. DWR’s written submission responding to the appeals is due on October 12, 2026. Its regulations require the Council to adopt a decision on the appeals by December 14, 2026, within 60 days of the hearing. Confirmation of the DCP’s consistency with the Delta Plan is necessary before DWR can begin construction per the Delta Reform Act (Wat. Code, § 85225 et seq.).
Resolution of DWR’s Revised Certification is occurring parallel to other proceedings that will determine the DCP’s future. One such proceeding is the hearing before the State Water Resources Control Board’s Administrative Hearings Office (AHO) on DWR’s petition for changes to water rights necessary to construct and operate the DCP (Hearing).
The Hearing has proceeded since 2024 in three phases – cases in chief and rebuttal by DWR and protesting parties, and surrebuttal by DWR. DWR’s surrebuttal testimony concluded on September 3, 2026. The next steps and timing for resolution of this proceeding are currently unclear. Multiple protestants have requested the opportunity to provide their own surrebuttal testimony on impacts to Delta water quality, groundwater, climate change and essential public infrastructure, among other issues, and the Hearing Officer will be considering those requests in late September. If protestants are permitted to submit surrebuttal testimony, additional Hearing dates will be scheduled to allow direct and cross-examination of surrebuttal witnesses. If protestants’ requests are denied, the Hearing will proceed to the briefing phase. The AHO and parties are considering deadlines and page limits for their closing and reply briefs, which are expected to be discussed during a status conference in October. Briefing is anticipated to be highly complex given that the proceeding has included over 80 days of Hearing, almost 2,500 exhibits, and approximately 150 pieces of individual witness testimony, a substantial amount of which is highly technical expert testimony, since the change petition was assigned to the AHO in June 2024.
Additionally, 10 lawsuits challenging the DCP and its environmental impact report have been proceeding in Sacramento County Superior Court concurrent with these administrative proceedings. Several key issues will be decided in the coming months, with hearings scheduled on plaintiffs’ motion to augment the administrative record and DWR’s motions for a protective order and to quash discovery scheduled to be heard in late October and early November. Resolution of those motions will dictate when and how the cases can be briefed and heard on the merits.
In the meantime, DWR’s ability to fund the project remains uncertain. Per the Delta Reform Act, construction of the DCP cannot begin until State Water Project (SWP) contractors, or a joint powers authority representing those entities, “have made arrangements or entered into contracts to pay for both” the costs of all “environmental review, planning, design, construction and mitigation for construction, operation and maintenance” of the DCP and “full mitigation of property tax or assessments levied by local governments or special districts for land used in the construction, location, mitigation, or operation” of it. (Wat. Code, § 85089.) DWR has estimated that the DCP will cost over $20 billion, but it plans to produce an updated cost estimate in 2027. Based on expert testimony in the Hearing, project opponents expect that true costs could reach between $60 and $100 billion. DWR initially pursued bond funding to finance the DCP with the adoption of bond resolutions in 2020, which were invalidated by the Sacramento County Superior Court in January 2024, a decision upheld by the Third District Court of Appeal in December 2025. DWR filed a new bond validation action to fund the DCP in January 2025, before the appellate decision was issued, and then voluntarily dismissed that action in May 2026, after the California Supreme Court denied DWR’s petition for review of the appellate court’s decision. The dozens of prevailing parties in the two Delta tunnel bond validation actions, which include local agencies in, north and south of the Delta, SWP contractors, environmental and other non-governmental organizations, and a tribe, have filed attorney fee motions seeking to recover over $5.3 million in fees and costs incurred in defending against DWR’s two validation attempts. It is unclear how or when DWR will pursue financing to construct the DCP – a fundamental question upon which the project’s fate relies.
Somach Simmons & Dunn represents several parties in the administrative proceedings and litigation described above.
For questions regarding DCP proceedings, please contact:
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