Permitting one winery at a time
Winery process water discharged to land was regulated case by case. A winery might hold general waste discharge requirements, individual requirements, or a conditional waiver, depending on its regional board and when it came up.
Finding 2 puts the result plainly, on the Wine Institute’s numbers. Of roughly 3,612 bonded wineries in California, an estimated 2,070 discharge process water to land in a way that would fall under a statewide order. As of a 2020 estimate, 589 were actually permitted. Not 589 of the 2,070. 589 of all of them.
So the majority of wineries that should have been regulated were not, and the ones that were had been handled inconsistently. That is the gap the Order exists to close, and it is why the Board reached for one instrument covering everyone rather than continuing to issue permits individually.
One order replaces all of it
The State Water Resources Control Board adopted Order WQ 2021-0002-DWQ. It covers winery process water discharged to land, from 10,000 up to 15,000,000 gallons a year, and sorts facilities into five categories by annual process water design flow. Below 10,000 gallons is exempt. Above 15,000,000 needs an individual permit rather than this one.
Requirements scale with the category. Tier 1 is a filing and an annual summary. Tier 4 carries groundwater monitoring wells and twice yearly reporting. That scaling is the whole design: the Board's stated intent was requirements commensurate with the complexity of the discharge.
The other 43 percent of wineries are outside it, generally because their process water goes to surface water under a different permit, or leaves the site by truck.
Why Napa is only feeling it now
Napa County has run its own winery wastewater program since 1979, long before the statewide order existed. Napa wineries were not unregulated. They were regulated locally, by the County, under an arrangement that predated all of this.
The shorthand is 1979, and the full chain is worth having, because it is all set out in one place: the background section of Napa County Agreement No. 8676.
- 1979. The Water Board issued a letter authorizing Napa County to permit subsurface disposal from small wineries. A letter, for small wineries, for subsurface disposal only.
- 1982. A Memorandum of Understanding between the County and the Water Board "designated to Napa County the primary responsibility of approval and regulation of winery wastewater discharges." That is the instrument that really built the program.
- 1991 and 1992. The Memorandum was updated, adding conditions, criteria for treatment and storage ponds, and a procedure for waiving state waste discharge requirements. It took effect November 21, 1991 and the Board of Supervisors approved it February 11, 1992. Sources that cite 1991 and sources that cite 1992 are describing the same document from different ends.
- 2003. The County also began permitting advanced treatment with storage of treated process water in tanks, followed by land surface discharge, with Water Board staff concurrence.
- 2024. Agreement No. 8676 supersedes the 1991 memorandum and governs the transition until the County holds an approved Local Agency Oversight Program.
When the statewide Order arrived, an interim agreement between Napa County and the San Francisco Bay Regional Water Board gave wineries already in the County program a three year extension on their application date, running to January 20, 2027. That is why the rule has been in force since 2021 while Napa wineries carried on with the County. The extension is what is now expiring.
The Regional Board published its transition flyer in August 2026. For most Napa winery owners, that flyer is the first direct communication they have had about any of this, which is exactly why it feels sudden. It is not new. The local alternative to it is ending.
Why Sonoma's answer is a different answer
Sonoma is split between two boards, and the half this chapter is about is the North Coast one: the Russian River, the Laguna de Santa Rosa and the drainages that reach the Pacific directly. Sonoma Creek, the Petaluma River and Tolay Creek reach San Pablo Bay and are San Francisco Bay Region 2, where none of the programs below apply. The North Coast board runs its own program for wine, beverage and food processors. There is a conditional waiver for smaller volumes, Order No. R1-2026-0001, and general waste discharge requirements above that, Order No. R1-2016-0002.
Sonoma County Vintners argued to legislators and Board staff that a single statewide approach was an unsustainable burden on small and mid sized North Coast wineries. A Sonoma County Vintners bulletin reports that the State Water Board approved the program on August 4, 2026 and the waiver opened to new winery enrollments.
That August 4, 2026 date comes from a trade association bulletin rather than a Water Board document and we have not been able to source it. The nearest event in the Board’s own record is the adoption of Order R1-2026-0001 on February 18, 2026. Treat the August date as unconfirmed.
The 5 to 1 ratio is a different matter, and an earlier version of this page had it wrong. It is not from a bulletin and it does appear in the published order: Findings 6 and 7 of Order R1-2026-0001, and the ratio itself was in its expired predecessor R1-2021-0001 before it. It is also not a route for larger wineries. It is a ceiling. A facility at 1,500 gallons per day or less may apply; a winery reaches 3,000 gallons per day only if it also produces no more than five gallons of wastewater per gallon of wine annually. Above 3,000 gallons per day, no ratio returns you to the waiver. And those gallons per day are an average, not a peak day. Finding 7 of Order R1-2026-0001, which is the winery finding, measures them as the total wastewater produced over the 30 consecutive days of greatest production, divided by thirty. That formula is new in the 2026 order: the expired R1-2021-0001 said only “as measured during the peak production period” and never defined the term, so do not read the averaging rule back into the period before February 2026. A winery that hits 4,000 gallons on its biggest crush day but averages 2,500 across that window is inside the tier, not outside it.
What the other fifty six counties turned out to be
This page used to end at Sonoma, because the site did. It covers all nine regional boards and all 58 counties now, and what that survey found is the real answer to why any of this needed writing down.
The question almost every winery asks is whether an existing regional permit lets them wait. All nine boards were checked, and not one has said so in adopted order text. Two came close, in staff reports rather than orders. Two told wineries the opposite in writing. One reserved the right to move its enrollees into the statewide Order whenever it chooses. And four have published nothing about wineries at all, which for an operator in those regions means the statewide Order and their own Notice of Applicability are the whole of it.
Which board holds you is not a county question either. Water Code section 13200 divides California into nine regions by drainage, and it has not been amended since it was enacted in 1969. A county list is a summary of a hydrologic definition, which is why the State Water Board’s own 2013 fact sheet gets several counties wrong.
Section 13200 then hands the precise lines to somebody else: the regions “shall be as precisely delineated on official maps of the department.” Those maps could not be found. The Department of Water Resources publishes 37 boundary services on its own GIS server and none of them are the section 13200 regions. The State Water Board’s boundary layer is digitised from Calwater, which states plainly that it “does not represent State of California Regional Water Quality Control Board (RWQCB) jurisdictions.” There is no working public address lookup either. The Board built one and unlinked it, and its Winery Order page still points operators at the version that is down.
And both of the counties this site was built around turned out to be split. Sonoma between North Coast and San Francisco Bay, on Finding 2 of adopted Order R2-2016-0020. Napa between San Francisco Bay and Central Valley, on Finding 6.a.i of adopted Order R2-2020-0034, which hands the Lake Berryessa and Putah Creek watershed to a different board entirely.
This site said Napa was Region 2, flatly, until 30 August 2026. It was wrong, and wrong in the way that costs a reader something: a winery in Pope Valley was being pointed at the wrong board, the wrong office and a January 2027 date that is very likely not theirs. That correction is in the changelog with everything else, because a correction that quietly disappears is worse than the mistake.