State Water Board reinstates immediate diversion ban after Fort Jones gauge records 145 cfs—five below the May threshold—following calibration adjustments in both directions within a six-day window
FORT JONES — The State Water Resources Control Board has reinstated curtailments for all surface water rights in the Scott River watershed, ordering immediate cessation of all surface water diversions after the Fort Jones USGS gauge recorded flows substantially below the May minimum requirement.
In Addendum 9 to Order WR 2024-0024-DWR, the Board cited a reading of 145 cubic feet per second (cfs) at the Fort Jones gauge as of 10:00 a.m. Thursday—five cfs below the mandatory May minimum of 150 cfs established under the Scott and Shasta River Watersheds Drought Emergency Regulation.
“Due to flows substantially falling below the minimum requirement of natural flows up to 150 cubic feet per second for May, the State Water Board is reinstating curtailments that require the immediate cessation of all surface water diversions,” the Board confirmed in written response to Siskiyou News.
Diverters must halt all surface water diversions immediately and “may not resume diversions until otherwise informed by the State Water Board,” the order states.
Calibration Swings Raise Reliability Questions
The curtailment arrives with fresh questions about the gauge’s accuracy—a concern Siskiyou News first reported in July 2025, when local water users noted that the Fort Jones gauge sits upstream of cold-water tributaries including Kelsey, Canyon, Tompkins, and Mill Creeks. Those tributaries contribute significant flow that the gauge does not capture, raising the possibility that regulatory readings routinely underestimate actual downstream conditions.
The current order reveals calibration volatility that sharpens those concerns. According to the State Water Board’s written response, field measurements taken May 14 resulted in an upward adjustment to flow readings at the Fort Jones gauge. A subsequent USGS field measurement on May 20 produced a downward adjustment—two corrections moving in opposite directions within a six-day window.
The regulatory threshold is 150 cfs. The recorded reading is 145 cfs. The margin between compliance and curtailment is five cfs—a difference well within the range of adjustment produced by a single field calibration visit.
Siskiyou News asked the State Water Board to confirm whether past curtailments issued under similar readings were later found to be in error and subsequently lifted. That question was not addressed in the Board’s response.
A Pattern With Precedent
This is not the first time gauge accuracy has complicated curtailment decisions on the Scott River.
In August 2022, USGS recalibrated the Fort Jones gauge after it went two months without field verification. The corrected reading more than doubled—from 3.37 cfs to 8.94 cfs. Retired watershed consultant Sari Sommarstrom, who has observed the Scott River for three decades, said at the time that precision matters when the gauge functions as a regulatory trigger. “Getting accuracy is very important when the State Water Board is using the USGS flow gage as a regulatory tool,” she said.
The pattern raises a straightforward question that remains unanswered: if a downstream measurement would show flows at or above 150 cfs, are ranchers and irrigators being shut off on the basis of an incomplete number?
Regulatory Background
The curtailment framework originates with the Scott and Shasta River Watersheds Drought Emergency Regulation, first adopted August 30, 2021. The regulation was extended through January 1, 2031, under Assembly Bill 263, signed September 26, 2025.
The State Water Board acknowledged in its curtailment notice that “the lack of snowpack, seasonal forecasts, and historic flows indicate curtailment will be necessary for much of the irrigation season,” while committing to continued monitoring.
Limited Exceptions
The regulation preserves limited diversion rights for non-consumptive uses such as run-of-river hydropower with full returns to the same stream, minimum human health and safety needs including drinking water, cooking, sanitation, and firefighting, and minimum livestock watering.
Water right holders who submitted certification or petition forms under prior addendums do not need to refile unless updating their information.
What’s Next
The State Water Board directed water right holders with questions, or those who believe curtailment is being applied in error, to contact Board staff at [email protected] or (916) 327-3113. Current flow data is available through the USGS National Water Information System at waterdata.usgs.gov.
Siskiyou News will continue to monitor gauge readings, calibration records, and any adjustments to curtailment status as the irrigation season progresses.
