Administrative Hearings Office Requires More Modeling for Proposed Sites Project and Delta Tunnel
The Hearing Officer in the respective water rights hearings for the proposed Sites Reservoir Project and the proposed Delta Tunnel, who happens to be the same individual, has ordered more modeling in each proceeding. The State Water Board’s Administrative Hearings Office (AHO) assigns a Hearing Officer to each water rights proceeding.
New Modeling for the Proposed Sites Reservoir
In closing and reply briefs in the Sites Reservoir hearing, CSPA and allies argued that the Hearing Officer should order updated modeling for Sites. Such modeling is needed to understand how much water would be available to fill the proposed reservoir and, indirectly, to determine the unit cost of water.
The Sites Project Authority did not update its modeling after the California Department of Fish and Wildlife (CDFW) issued its Incidental Take Permit (ITP) for the Sites Project. CDFW issued the ITP while the Sites water rights hearing was ongoing. The ITP would make less water available for diversion than the modeling that the Sites Project Authority presented in its testimony in the water rights hearing.
An egret is seen nearby as California Department of Water Resources Groundwater Hydrogeologist Ky Dupuis, works on their routine groundwater monitoring well run in Colusa County. Image: Xavier Mascareñas and the California Department of Water Resources
The Authority has said in several written and oral statements that the exact cost and the amount of water available did not matter to the water rights decision since there were entities ready to proceed with the Project. CSPA and allies argued that the there was a public interest in knowing how much water Sites would divert and how much it would cost, especially since some of the funding would come from public agencies.
In a public meeting on September 9, 2025, the U.S. Bureau of Reclamation (Reclamation) stated that it had worked with the Sites Project Authority on updated modeling. The new modeling that Reclamation reported evaluates new requirements and uses a newer, more up-to-date model. On September 10, attorneys for CSPA and allies submitted a letter informing the Hearing Officer of this development. On October 20, the Hearing Officer directed the lead attorney for the Sites Project Authority to produce the new modeling information the Authority had already developed. The Hearing Officer requested this information in a form that was comparable to the presentation of information in previous submittals.
Now, the Sites Project Authority must submit new modeling information into the record for the proceeding by November 3. Other parties to the hearing have until November 21 to request the right to cross-examine witnesses for Sites on the new information.
New Modeling for the Proposed Tunnel under the Delta
On October 10, 2025, the Hearing Officer in the ongoing water rights hearing for the Delta Tunnel, aka the Delta Conveyance Project or DCP, sent a supplemental information request to the lead attorney for the project’s proponent, the California Department of Water Resources (DWR). The information request stated in part:
The AHO has determined that the administrative record developed to date is inadequate to inform the State Water Board’s decision concerning what Delta flow criteria would be appropriate for the DCP, as required by the Delta Reform Act, and to evaluate requirements that may be necessary to ensure consistency with the proposed updates to the Bay-Delta Plan.
The information request asked DWR to model diversion criteria for the proposed Tunnel that would require DWR to not divert into the Tunnel various percentages, ranging from 35% to 65%, of the unimpaired flow at the Tunnel intakes.
The information request also asked DWR to model each scenario to account for different degrees of climate change, centering on the year 2040 and on another year between 2070 and 2085.
During the October 27, 2025 hearing on the Delta Tunnel, experts spent over two hours discussing technical issues associated with how DWR should comply with the information request. The resolution of these issues will determine both the substance of new modeling and, to some degree, the timeline for its completion and submittal. There will be additional correspondence regarding these issues before they are fully resolved.
Schedule for Next Phases of Delta Tunnel Hearing Tentatively Announced
On October 22, 2025, the Hearing Officer issued the Eighth Amended Hearing Notice for the Delta Tunnel water rights proceeding. The Eighth Amended Notice provides dates for rebuttal testimony. Rebuttal testimony is limited to responses to written and oral testimony that parties presented in the case-in-chief phase of the hearing that will conclude in early November.
The AHO announced that DWR and parties that support DWR will present their rebuttal testimony first. Following completion of DWR and supporters’ rebuttal testimony and cross-examination by “protestants” of DWR’s petition, protestants will submit their rebuttal testimony and stand for cross-examination.
The due date for submittal of DWR and supporters’ rebuttal testimony is December 22, 2025. Hearing dates for DWR and supporters’ testimony will begin on February 20, 2026 and extend into March.
The due date for submittal of protestants’ rebuttal testimony is April 30, 2025. Hearing dates for protestants’ rebuttal testimony will begin on June 1, 2026 and extend through the rest of June.
DWR and the State Water Contractors objected to allowing protestants to have a later submittal date, particularly because it allows protestants to consider the cross-examination of DWR and supporters. DWR also objected that the timeline was not shorter. Depending on the Hearing Officer’s response to these objections, some of the due dates and timelines may change.
Objections to Case-in-Chief Testimony of Parties other than DWR Due November 17
With presentation and cross-examination of the protestants’ cases-in-chief drawing to an end, objections to testimony and exhibits are due November 19. These objections, largely by DWR and the State Water Contractors, are likely to be extensive in some cases. Responses to objections are due December 10.
By Way of a Summary
Water rights hearings are extremely time and energy intensive. The Delta Tunnel water rights hearing is at least doubly so. The Delta Tunnel hearing is taxing CSPA’s very limited resources beyond reason. CSPA always aims to add real value at a high level, because the stakes are so great.
CSPA truly misses those who were with us in the last iteration of the Tunnel. The late Bill Jennings brought such breadth of knowledge and vision between 2015 and 2018. The current effort is also lessened without attorney Mike Jackson, who has retired from active practice.
CSPA shall persist. CSPA continues to bring institutional knowledge as well as specific expertise. The organization and its small staff so greatly appreciate those who have supported CSPA’s engagement on the Tunnel and also on Sites.
For those who haven’t contributed to CSPA in the recent past, please join those supporters with a membership or donation today. Donating to CSPA is an excellent way to honor Bill Jennings, CSPA’s dedicated team, native fish species, and the natural environment that CSPA seeks to protect. Thank you for your continued support.