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Russian River Weekly Update 11/3/25

Lake Mendocino in October 2025 by Will Bucquoy
 Lake Mendocino in October 2025 by Will Bucquoy

Reservoir Storage & Operations:

Water supply information provided by Sonoma Water (find more water storage info here).

PG&E will not be increasing the East Branch Russian River diversion from 5 cfs to 25 cfs on November 1, 2025 as allowed by the flow variance due to storage conditions at Lake Pillsbury.

Lake storage data for Mendocino, Pillsbury, Sonoma on 11/2-11/3: Current storage, target/FIRO curves, percent curve use, 7-day changes.
Lake Mendocino storage graph (2018-2025) in acre-feet; highlights Nov 3, 2025, at 59,078 acre-feet.
Graph of Lake Pillsbury storage and targets from 2018-2025 in acre-feet, showing different storage scenarios and projections.
Lake Sonoma storage graph (2018-2025) in acre-feet, showing fluctuating water levels peaking in 2023. November 3, 2025: 222,408 acre-feet.

 

PG&E’s Final Surrender Application for Potter Valley Project

FERC has issued the public comment period for PG&E’s application for Surrender of License and Non-Project Use of Project Lands. Deadline for filing comments, motions to intervene, and protests is December 1, 2025 5:00 PM EASTERN TIME (2:00 PM Pacific Time.)

2025, 10- 31 FERC Notice of comment period for PGE PVP Decommissioning.pdf

 Comments Submitted to FERC on Decommissioning:

The SWRCB filed a Motion to Intervene with no comments.

 

PG&E License Amendment Application to FERC

FERC has issued the public comment period for PG&E’s application for Non-Capacity Amendment of License. Deadline for filing comments, motions to intervene, and protests is December 1, 2025 5:00 PM EASTERN TIME (2:00 PM Pacific Time.)

2025, 10- 31 FERC Notice of comment period for PGE PVP Lic Amendment.pdf

Comments Submitted to FERC on License Amendment:

The SWRCB filed a Motion to Intervene with no comments.

 

2025 Potter Valley Project Operations

FERC approved PG&E's requested flow variance to allow for repairs in November.

2025, 10-31 FERC approval of November Flow Variance for repairs.pdf

 

FIRO at Lake Mendocino

UC San Diego Today: New Forecast-Informed Decision-Making Tool Implemented at Northern California Reservoir 10/27/25

Leaders from the U.S. Army Corps of Engineers, Sonoma Water,, the Center for Western Weather and Water Extremes (CW3E) at UC San Diego’s Scripps Institution of Oceanography, and California Department of Water Resources (DWR) entered a new era in reservoir operations with the signing of updates to the water control manual for Coyote Valley Dam and Lake Mendocino. The revised manual redefines the operating rules around flood control schedules for the first time in the dam’s 66-year history by incorporating the principles of modern-day forecast-informed reservoir operations, or FIRO, to enhance the facility’s dual mission of flood risk management and water supply security. “FIRO allows us to be informed by the forecast and make better decisions.” In the last drought, FIRO enabled a 19% increase in water storage at Lake Mendocino, totaling more than 11,000 acre feet that sustained water supply for agriculture and communities throughout the watershed.

 

Two new DWR reports on groundwater sustainability progress

Last week, DWR released two new reports — the Semi-Annual Groundwater Conditions Update and a draft of California's Groundwater Update 2025 (also known as Bulletin 118) — demonstrating measurable progress toward groundwater sustainability under the Sustainable Groundwater Management Act. The reports highlight progress made by local groundwater sustainability agencies (GSAs) in implementing tailored solutions to manage groundwater and creating flexible strategies to cope with a changing climate. Both reports and the California's Groundwater Live platform combine historical data with near real-time insights to help GSAs monitor conditions and adjust their sustainability plans. A 45-day public comment period is now open on the draft California Groundwater Update 2025 report. DWR will present a 90-minute virtual overview of this report on Tuesday, Nov. 4, starting at noon. Registration is required. For more information about these reports, see DWR’s recent press release.

 

SWRCB Storm Water Capture and Use Workshop November 18, 2025

The State Water Resources Control Board (State Water Board) will hold a public workshop at its regularly scheduled Board Meeting on November 18, 2025, to present information about urban stormwater capture and use. The workshop item is scheduled to begin no earlier than 1:00 p.m. For additional details on attending, viewing, and participating in the Board Meeting, please click here to view the public notice: https://www.waterboards.ca.gov/board_info/calendar/docs/2025/nov/notice-swcuwksp.pdf

 

Ukiah Reading and Discussion on the Newly Updated CA Naturalist Handbook 2nd Edition

The Mendocino Book Company (102 S School St, Ukiah, CA) is hosting a reading and discussion about the newly updated California Naturalist Handbook 2nd Edition Thursday at 5:30, co-authored by Deborah Edelman, Greg de Nevers, and Adina Merenlender. The book is an engaging introduction to California's unique natural history, and the discussion will cover new updates to the second edition, such as more information about southern California’s urban environment, desert ecology, expanded discussions of Indigenous knowledge and stewardship, and current climate change information, including fire and forest management, drought, groundwater, and recognition of climate grief. There will also be information about the local California Naturalist class. Also, tune in to KZYX's Turning Pages show on Wednesday November 5 at 3:30 to hear an interview with book authors.

 

📢 UPDATED - State Water Board Announces New Water Rights Reporting System - CalWATRS

CalWATRS, short for California Water Accounting, Tracking, and Reporting System, is the State's new-and-improved water rights data system, replacing the legacy eWRIMS platform. With CalWATRS, water right holders will have a streamlined way to view all their water right records, file annual reports, and request water rights services. CalWATRS successfully launched on Oct. 7, as planned.

Learn more:

Related articles (repeats from previous updates):

 

Fall 2025 Groundwater Sustainability Agency (GSA) Forum November 19th

The Department of Water Resources’ (DWR) Sustainable Groundwater Management Office invites you to register for the Fall 2025 Groundwater Sustainability Agency (GSA) Forum (GSA Forum) to be held virtually on Wednesday, November 19, 2025, from 9:00 AM to 12:30 PM. The theme is SGMA after 10-years – How to Keep the Momentum Going. Register for the event here.  

The GSA Forum will feature interviews with GSA representatives, highlighting approaches they have taken to navigate SGMA implementation challenges. These critical insights will include discussions of onboarding GSA staff, and experiences towards making progress on projects and management actions. DWR will also host a Q&A session about Periodic Evaluations and an informational session on current and planned tools, resources, and opportunities to aid GSAs during implementation. An opportunity for attendees to share experiences and resources through breakout sessions will also be provided.  View the agenda for the event here.    

 

Notice of Additional 15-Day Written Comment Period for Proposed Water Measurement and Reporting Revisions (SB88)

The State Water Resources Control Board (State Water Board) has updated the text of the proposed revisions for the Water Measurement and Reporting Regulation. The additional changes to California Code of Regulations, title 23, chapter 2.8 (Measuring and Monitoring) are needed to improve clarity and postpone effective dates of some requirements. As a result, updated measurement requirements are delayed and expected to be effective October 1, 2026. Please note that the State Water Board will only accept written comments on the additional changes to the proposed regulatory text. The State Water Board will not be accepting additional comments on the revisions previously released. 

A copy of the updated proposed regulation text with new changes, along with a notice of the additional 15-day written comment period, can be found on the Water Measurement and Reporting Rulemaking webpage: https://www.waterboards.ca.gov/waterrights/water_issues/programs/diversion_use/rulemaking.html.   

 

In the press:

 

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