Special to WaterWrights.net
WaterWrights.net is now sharing Weekly Updates in partnership with our friends at WaterOne.ai. We all know SGMA is evolving rapidly. And this is another step for us to keep everyone informed.
Must Knows this Week
The State Water Board Adopted the Bay-Delta Plan Update; the Voluntary Pathway Starts by October 2027
Building on our October 26 report, the State Water Resources Control Board adopted amendments to the Bay-Delta Plan on October 29, according to the Board’s Bay-Delta Plan page, after two days of hearings on the first comprehensive update to the Sacramento–Delta components since 1995. Under the plan as presented at the hearing, covered water rights would follow either a regulatory pathway that starts at 55% of unimpaired flow, with water-supply adjustments initially setting the requirement at 55%, 45% and 35% from the wettest to the driest third of conditions, or the voluntary Healthy Rivers and Landscapes pathway, proposed to begin in October 2027 for an initial eight years. Solano Irrigation District said applying the proposed criteria to 25 years of data would have produced zero Lake Berryessa allocation in one of every five years, a projection rather than an allocation change. At the October 29 session, California Farm Bureau warned that under the revised plan any new water right obtained after December 31, 2025, including a high-flow groundwater-recharge right, counts as a new water-supply project, and staff said new water-supply projects would be subject to the regulatory pathway. The Governor’s office said the update now goes to the Office of Administrative Law for approval, and the Board says it will post the adopted resolution and amendments by November 5. Read More
Pleasant Valley Adopted Acreage-Based Allocations for 2027; Staff Expects a Transitional-Yield Announcement by February 1
Following our October 5 report that the allocation fight had moved to October, the Pleasant Valley GSA board approved, on a divided roll-call vote, a Groundwater Allocation and Use Policy that bases native-yield allocations on assessed acreage, while historical use stays relevant to transitional-yield eligibility. Counsel called allocations an administrative demand-management tool, not a determination of groundwater rights, and transitional yield, which represents overdraft pumping, comes last in the order of use; staff expects to announce by February 1 whether any will be available for 2027 and at what level. The board also adopted a recharge-credit policy, again on a divided vote, and said State Water Board staff asked to meet every six to eight weeks to revisit sustainability criteria. Read More
Saucelito Is Now Applying a Groundwater Allocation of 0.27 Acre-Feet per Acre, With Overpumping Costing $500 an Acre-Foot Plus Replacement Water
Building on our September 14 report that Saucelito dropped the ET option, Saucelito Irrigation District began applying a native groundwater allocation of 0.27 acre-feet per acre on October 1, a subbasin wide figure the manager called a starting point. Pumping beyond allocation and credits carries a $500-per-acre-foot penalty plus replacement-water cost, which district officials warned could total upwards of $1,200 per acre-foot, so growers were urged to use surface water first. Read More
A 95% Chance of Breaching a Subsidence Threshold Near Tulare by 2040, and Kaweah Wants Wider Study
At the East Kaweah GSA, an uncertainty analysis presented by INTERA estimated an approximately 95% chance of exceeding the subsidence minimum threshold at Site 20, near Tulare, by 2040 under current groundwater-level thresholds; raising those thresholds 10 to 30 feet reduced the modeled risk without eliminating it, and even a 50-foot increase left about a 60% chance of more than 2 feet of subsidence between 2040 and 2070. None of the 13 modeled sites is within Eastern Kaweah, and staff recommended extending the analysis to all 13. Building on our October 19 report, at Greater Kaweah GSA, minimum thresholds at 13 western-area sites sat roughly 50 to more than 100 feet below median estimates of critical head, the level below which subsidence can be triggered; the estimates carry substantial uncertainty, no thresholds were changed, and the technical committee recommended expanding the work. Read More
Trends in the Valley
Getting Ready to Catch El Niño Floodwater.
With a possibly strong El Niño ahead, Friant Water Authority staff said Millerton Reservoir could need flood-management actions around mid-January under one forecast and noted a new executive order offering potential CEQA and permitting exemptions for certain flood work through January 31, subject to Natural Resources Agency approval. Aliso Water District is working with Rain for Rent on a proposed temporary pipeline to move roughly 50 cubic feet per second of flood water to its reservoir, and East Kaweah GSA is targeting the second week of December for its Flying Dragon recharge project so it is ready for potential flood flows. Valley Water continued its El Niño emergency action, while Turlock Irrigation District staff cautioned that El Niño does not guarantee a wet year.
Groundwater Penalties Are Being Reworked.
The Cuyama Basin GSA advisory committee discussed moving from percentage-based penalty tiers ($250 per acre-foot for the first 5% over an allocation and $500 above that) to tiers based on the volume of excess pumping, without agreeing on a threshold. Following our October 19 report that it authorized up to $10 million in penalty revenue for supplemental water purchases, Greater Kaweah GSA plans to move away from tiered overdraft allocations in Water Year 2028, beginning October 1, 2027, toward growers paying for supplemental water they use. At the Ojai Basin Groundwater Management Agency, directors discussed a more uniform written collections process, and the agency is considering placing unpaid penalties on the county tax roll as an enforcement option; its attorney said it does not have direct lien authority. None of these changes has been adopted.
Agencies Are Arranging Exchanges, Transfers and Water to Bank.
Westlands Water District approved a pilot under which the Santa Clara Valley Water District (Valley Water) may deliver up to 5,000 acre-feet of CVP water by December 31, 2028, with Westlands returning up to 80% within 10 years. Santa Clarita Valley Water Agency identified about 15,000–18,000 acre-feet of surplus imported water available for banking, transfer or exchange, and the Central Coast Water Authority expects a supplemental transfer of roughly 7,600 acre-feet to Dudley Ridge and Kern that would reduce its San Luis Reservoir storage.
About WaterOne
WaterOne is a Fresno-based water management firm serving Central Valley growers, founded by a team from Stanford that combines agricultural expertise with AI engineering. The team offers easy-to- adapt water management tools designed for SGMA. The company actively monitors GSA and irrigation district board meetings, maintaining a database of rule changes for each district while working directly with growers across the Central Valley. You can access their updates on major meetings at GSAs, Irrigation Districts, and State Board from their GSA Database from https://gsa.waterone.ai.
About the Team
Ryo Takanashi is Co-Founder & Chief Product Officer at WaterOne. He brings
extensive expertise in commodity trading and agricultural engineering. As the youngest Chief Corn Trader for Japan’s largest commercial importer, Ryo managed 20% of the country’s corn imports while stationed in Kansas and Minneapolis. With an Urban Engineering background, he combines technical infrastructure knowledge with hands-on commodity market experience that required constant analysis of crop conditions, yield forecasts, and supply chain logistics. He holds MS-MBA from Stanford.
Tomo Kumahira is Co-Founder & CEO of WaterOne. Prior to starting WaterOne,
Tomo managed one of Africa’s largest agro-forestry operations as CFO, partnering with small-scale 30,000 farmers and covering 40% of commercial afforestation in Kenya. He began his career in natural resources investment at Mitsubishi Corporation. Tomo holds MS-MBA from Stanford (Knight-Hennessy Scholar and Rotary Global Scholar).
Disclaimer of Responsibility
Waterwrights.net strives to provide its clients with the most complete, up-to-date, and accurate information available. Nevertheless, WaterWrights.net does not serve as a guarantor of the accuracy or completeness of the information provided, and specifically disclaims any and all responsibility for information that is not accurate, up-to-date, or complete. WaterWrights.net’s clients therefore rely on the accuracy, completeness and timeliness of information from WaterWrights.net entirely at their own risk. The opinions expressed in this report are those of the author and do not represent any advertisers or third parties.
ALL RIGHTS RESERVED. Copyright 2026 by WaterWrights.net
