Seasonal restrictions: burn windows, bird nesting and fire weather
Clearance distances are seasonal only through 14 CCR 1253, which applies PRC 4292 through 4296 during the county's declared CAL FIRE fire season. The calendars that govern the work sit elsewhere: burning permits under PRC 4423, fire tools under PRC 4427, 4428 and 4431, the air district burn day, and the nesting statutes, which carry no dates.
A 12 kV distribution span crosses brush covered land in the State Responsibility Area of Nevada County. The clearance that span owes reads the same in January as it does in July. Everything else about working on it moves. CAL FIRE suspended burn permits across four Sierra foothill counties at 8:00 a.m. on Monday, June 15, 2026, and the slash piles from that circuit's reclear became something to haul out.
The permit required period that the suspension sits inside had already put a round point shovel next to every chainsaw on the job. Since February a red-tailed hawk has been nesting in a gray pine at midspan, and the buffer around it runs wider than the easement. Five calendars cross that one span. The clearance rules supply exactly one of them, and it is the one that governs the work least.
The one season in the clearance stack
14 CCR 1253 runs to a single sentence, and it is the only seasonal clause in California's powerline clearance regime. It switches PRC 4292 through 4296 on for a county when CAL FIRE declares that county's fire season, and it puts the declaration on the Department's website. Where that determination sits in Article 4 is its own subject, as is what it does to a span the Commission and CAL FIRE both reach.
The part worth holding here is direction. Section 1253 narrows when a duty is owed. Scheduling belongs to a different body of law entirely. The month to send a crew, the weather to stand down in and the answer on a nest all sit outside the clearance rules.
Four bodies of law hold those answers:
The burning permit period in the Public Resources Code.
The fire tool statutes that key to that same period.
The air district permit and the burn day.
Two sections of the Fish and Game Code that carry no dates at all.
The burning permit period, and the two ways it closes
PRC 4423 decides whether slash can be burned where it was cut:
A person shall not burn any brush, stumps, logs, fallen timber, fallows, slash, grass-covered land, brush-covered land, forest-covered land, or other flammable material, in any state responsibility area, area receiving fire protection by the department by contract, or upon federal lands administered by the United States Department of Agriculture or Department of the Interior, unless the person has a written permit from the department or its duly authorized representative or the authorized federal officer on federal lands administered by the United States Department of Agriculture or of the Interior and in strict accordance with the terms of the permit: (a) At any time in Zone A. (b) At any time in Zone B between May 1st and the date the director declares, by proclamation, that the hazardous fire conditions have abated for that year, or at any other time in Zone B during any year when the director has declared, by proclamation, that unusual fire hazard conditions exist in the area. The issuing agency may require the permittee to contact the agency to determine permit suspension status prior to burning.
Two calendars sit inside one section. Zone A runs all year and the permit is required at any time. Zone B opens on a fixed date, May 1, and closes on a moving one, the director's abatement proclamation. The section names the two zones and leaves them undrawn, which is a real gap in the printed law. In practice CAL FIRE issues and suspends permits by unit, and the department's burn permit system is where a crew learns which condition applies.
The last sentence of subdivision (b) adds a second duty. The issuing agency may require the permittee to call and check suspension status before lighting anything, which makes the permit a document to be revalidated on the morning of the burn rather than filed once in the spring.
PRC 4423.1 is the suspension mechanism, and it moves fast by design. A proclamation issues when the menace of destruction by fire "is, or is forecast to become, extreme."
The section lists the supporting grounds as "critical fire weather, fire suppression forces being heavily committed to control fires already burning, acute dryness of the vegetation, or other factors." It may be given as a verbal or audio recorded telephone message, a press release, or a posted order. Subdivision (c) releases the proclamation from the Administrative Procedure Act, so it takes effect on the terms it names, the moment it names them.
CAL FIRE's June 2026 suspension shows what that looks like from the receiving end: an 8:00 a.m. Monday effective time, announced the week before. It covered the State Responsibility Area in Nevada, Yuba, Placer and Sierra Counties. The same notice named the exit PRC 4423.2 supplies.
Restricted temporary permits stay available where the continuation of burning may be essential, and CAL FIRE stated that agriculture, land management, fire training and other industrial type burning may proceed if a CAL FIRE official inspects the burn site and issues a special permit. A utility with cut and piled slash in the unit reaches burning through that door, after an inspection and a fresh document.
The air district's permit, and the day CARB names
A burn in California needs two permissions from two agencies, and then a day. Health and Safety Code 41852 is the second permission:
No person knowingly shall set or permit agricultural burning unless he has a valid permit from the agency designated by the state board to issue such permits in the area where the agricultural burning is to take place.
Health and Safety Code 41855 supplies the day. The state board "shall determine and designate from meteorological data the days when agricultural burning shall be prohibited within each air basin." 17 CCR 80110 is how that determination arrives. The Air Resources Board specifies every day of the year as a permissive burn day or a no-burn day for each air basin. It announces the following day's designation by 3:00 p.m. Where conditions preclude a forecast, it announces by 7:45 a.m. that morning. Burning is prohibited on no-burn days.
Three permissions, three owners, three clocks.
What is required | Who issues it | When it is decided |
Written burning permit, PRC 4423 | CAL FIRE or the federal land officer | Held in advance, suspension status checked before burning |
Agricultural burning permit, H&SC 41852 | The air district designated by the state board | Held in advance, on district terms |
Permissive burn day, 17 CCR 80110 | California Air Resources Board | Announced by 3:00 p.m. for the next day, or 7:45 a.m. that morning |
Smoke management plan, 17 CCR 80160 | Submitted to the air district | Before a project over 10 acres or 1 ton of particulate matter |
The threshold in the last row catches utility work by surprise. 17 CCR 80160 requires districts to demand a smoke management plan for every burn project greater than 10 acres in size or estimated to produce more than 1 ton of particulate matter. A six mile reclear stays well under 10 acres, and the piles from it pass a ton of particulate easily. The plan has to exist before the day. Projects over 100 acres or 10 tons carry additional plan content, and projects over 250 acres carry monitoring.
Fire tools arrive with the permit period
This is the seasonal restriction most often missed, because it turns on the burning permit calendar and applies to a crew that burns nothing. Three statutes in the same article key their duties to the period when permits are required. Between them they reach every piece of equipment a line clearing crew owns.
PRC 4431 catches the chainsaw:
During any time of the year when burning permits are required in an area pursuant to this article, no person shall use or operate or cause to be operated in the area any portable saw, auger, drill, tamper, or other portable tool powered by a gasoline-fueled internal combustion engine on or near any forest-covered land, brush-covered land, or grass-covered land, within 25 feet of any flammable material, without providing and maintaining at the immediate locations of use or operation of the saw or tool, for firefighting purposes one serviceable round point shovel, with an overall length of not less than 46 inches, or one serviceable fire extinguisher. The required fire tools shall at no time be farther from the point of operation of the power saw or tool than 25 feet with unrestricted access for the operator from the point of operation.
PRC 4427 catches everything else that makes a spark, and hands the saw straight back. Over the same permit period it requires flammable material cleared for 10 feet around the operation. It requires a 46 inch round point shovel and a backpack pump water type fire extinguisher at the immediate area. Then it closes with one sentence: "This section does not apply to portable powersaws and other portable tools powered by a gasoline-fueled internal combustion engine."
PRC 4428 runs on its own calendar and catches the vehicles. It applies between April 1 and December 1 of any year, and at any other time when ground litter and vegetation will sustain combustion permitting the spread of fire. Its subject is internal combustion powered vehicles, machines, tools and equipment used in an industrial operation on or near forest, brush or grass covered land. Subdivision (a) requires a sealed toolbox holding "one backpack pump-type fire extinguisher filled with water, two axes, two McLeod fire tools" and sufficient shovels.
Statute | What it reaches | What switches it on | What it requires |
PRC 4427 | Welding, cutting torches, tarpots, grinding devices, stationary equipment | The permit required period | 10 foot clearing, 46 inch round point shovel, backpack pump extinguisher |
PRC 4431 | Portable gasoline powered saws and tools | The permit required period | Shovel or extinguisher, always within 25 feet of the point of operation |
PRC 4428 | Vehicles and equipment in an industrial operation | April 1 to December 1, or whenever litter will sustain combustion | Sealed toolbox, backpack pump, two axes, two McLeod tools, shovels, felling tools |
PRC 4442 | Any hydrocarbon fueled internal combustion engine | Every day of the year | Spark arrester in effective working order |
Two rows there deserve reading twice. PRC 4428's second trigger is a fuel condition rather than a date, so December 2 leaves the duty standing wherever the litter will carry fire. And PRC 4428 carves out the utility service vehicle by name:
No person, except any member of an emergency crew or except the driver or owner of any service vehicle owned or operated by or for, or operated under contract with, a publicly or privately owned utility, which is used in the construction, operation, removal, or repair of the property or facilities of such utility when engaged in emergency operations, shall use or operate any vehicle, machine, tool or equipment powered by an internal combustion engine operated on hydrocarbon fuels, in any industrial operation located on or near any forest, brush, or grass-covered land between April 1 and December 1 of any year
That exception exists because routine utility work otherwise sits inside the section, and it reaches emergency operations alone. A cycle trim in August falls outside it. Subdivision (d) defines vehicle and passenger vehicle and leaves industrial operation undefined, which puts the edge of that term into argument rather than lookup. Where it is argued, it is argued with the CAL FIRE unit that finds the truck.
PRC 4442 is the control case. It requires a spark arrester able to retain particles over 0.0232 of an inch, on forest, brush or grass covered land, and it carries no calendar of any kind. A chipper without one is out of compliance in February.
Fire weather is a forecast the clearance rules never name
The National Weather Service defines a Red Flag Warning as "a term used by fire-weather forecasters to call attention to limited weather conditions of particular importance that may result in extreme burning conditions." It is a forecast product issued by a federal weather office. Its standing in California vegetation compliance comes to this: GO 95 Rule 35 is silent on it, PRC 4292 and PRC 4293 are silent on it, and 14 CCR Article 4 is silent on it.
PRC 4423.1 holds the single place in the fire prevention chapter where a forecast carries statutory weight, in the phrase "is, or is forecast to become, extreme," and what it moves is burning permits. PRC 4428's fuel condition clause is the near relative, and it tests the ground rather than the sky.
That leaves the Red Flag stand down as a company document. A utility's wildfire mitigation plan is where the work restriction is written, and the plan is the instrument the Office of Energy Infrastructure Safety reviews and holds the utility to. Which body enforces which part of the stack decides how a finding lands, because a Red Flag work restriction is enforceable as a plan commitment. Who stands a crew down on a high wind day in October is the utility, on its own criteria, against its own filed plan.
Two sentences of the Fish and Game Code
Two sentences do most of the work on nests, and a month appears in neither.
3503. It is unlawful to take, possess, or needlessly destroy the nest or eggs of any bird, except as otherwise provided by this code or any regulation made pursuant thereto.
3503.5. It is unlawful to take, possess, or destroy any birds in the orders Falconiformes or Strigiformes (birds-of-prey) or to take, possess, or destroy the nest or eggs of any such bird except as otherwise provided by this code or any regulation adopted pursuant thereto.
The trigger in both is an occupied nest, and one word separates them. Section 3503 says "needlessly destroy," which leaves room to argue necessity. Section 3503.5 states the prohibition flat, and hawks and owls are the birds most likely to be nesting in the tree a clearance crew has come to cut.
Fish and Game Code 12000(a) makes a violation of either a misdemeanor unless the code expressly says otherwise. The only exit written into the two sections is "except as otherwise provided by this code or any regulation adopted pursuant thereto," so relief has to arrive from elsewhere in the Fish and Game Code or from a CDFW regulation. Urgency on the ground supplies none.
The federal layer moved in 2025, and it moved the other way. On April 11, 2025, the Acting Solicitor of the Department of the Interior issued M-37085. It repealed M-37065 and reinstated M-37050, which had concluded that the Migratory Bird Treaty Act reaches intentional take alone. The instruction is one sentence:
All bureaus and offices are directed to consider M-Opinion M-37050 as authoritative and binding on the Department, except with respect to actions relying on such opinion that are to be taken within the jurisdiction of the United States District Court for the Southern District of New York.
California sits outside that district. On the Department's current position, a California utility's federal incidental take exposure runs to zero.
California held its own line in the same year. Fish and Game Code 3513 was repealed and re-enacted by AB 454, Stats. 2025, Ch. 365, effective October 6, 2025. It pins the protected list to migratory birds designated under the federal act before January 1, 2025, plus any designated later. A federal delisting therefore leaves the California list where it stands. Sections 3503 and 3503.5 ran independently of the federal act from the start, so the 2025 federal shift reaches neither.
The buffer is wider than the easement
The February to August windows in circulation come from somewhere, and PG&E's own filed document says exactly where. "Nesting Birds: Species-Specific Buffers for PG&E Activities," dated November 2015 and filed with the CPUC, opens by stating that "there are no standard nest buffers specified in the Migratory Bird Treaty Act (MBTA) or within California Fish and Game Code."
The buffers in it came out of the company's avian program, built from literature and avian biology. A nesting black-crowned night heron draws 400 feet. A buffer holds while a nest is active, meaning while it contains eggs or young. A biologist sets and adjusts it, defined in the document's own footnote as a person with a bachelor's degree or above in a biological science and demonstrated field expertise in ornithology, employed by PG&E or working under contract to it.
Go back to the gray pine at midspan. PG&E's table gives the red-tailed hawk a peak breeding season of February through September, a standard buffer of 250 feet, incubation of 28 to 32 days and fledging at approximately 42 days. That adds up to roughly seventy days of nest activity after the last egg, in a tree the crew was routed to that morning.
Two hundred and fifty feet is the number that changes the job. It exceeds any distribution easement and most transmission ones, so the restriction reaches across ground the utility holds no interest in. What the corridor is wide enough to authorize stays fixed while the buffer sits on top of it, and the two are measured from different points by different people for different reasons.
The clearance duty keeps running underneath all of that. PRC 4293's felling requirement for dead, decadent, rotten and leaning trees applies on the same span through the same months, and a Rule 18 Level 1 finding runs on its own clock. The Public Resources Code, GO 95 and the Fish and Game Code all leave that collision open.
The decision falls to the company's biologist, who sets or reduces the buffer on site specific conditions, with CDFW as the agency that reviews it afterward and a district attorney as the office that charges the misdemeanor. A record showing a considered call and the grounds behind it is the whole of the defense available.
What the record has to name
A seasonal position is testable later only if the file says which season it was. Seven facts make it testable.
The county, and whether its fire season stood declared on the day the crew worked. Under 14 CCR 1253 that fact decides whether PRC 4292 and PRC 4293 applied at all.
The burning permit, the issuing unit, and the suspension status as checked, with the date and time of the check, because PRC 4423(b) lets the issuing agency require it.
The air district permit and the burn day designation for the air basin on the burn date, which CARB announced the afternoon before or at 7:45 a.m. that morning.
The smoke management plan, where the project passed 10 acres or 1 ton of particulate matter.
The fire tools carried, against the statute that required them: PRC 4431 at the saw, PRC 4427 at a grinder, PRC 4428 on the truck.
The nest survey, with date, surveyor and qualification, species, nest status, the buffer assigned, and the reasoning behind any reduction from standard.
The date the nest was observed inactive, which is the date the buffer came off and the date that released the work.
One line carrying all of it looks like this:
``` Span 14-15, Nevada 1702, 12 kV, SRA, brush covered, Nevada County fire season declared. Trimmed 10/09/2026. PRC 4431 shovel at saw, permit period in effect. Red-tailed hawk nest, gray pine at midspan, active 02/18/2026 to 07/02/2026, 250 ft buffer per company standard, observed inactive 07/02/2026, S. Reyes, staff biologist. Slash chipped on site, no burn conducted. ```
Two years later, a records request for that span produces a document a stranger can test against 14 CCR 1253, against PRC 4431, and against Fish and Game Code 3503.5, one clause at a time. That is the whole of what a seasonal restriction asks of a file.
Further reading
PRC 4293: radial clearance in State Responsibility Areas: The clearance duty whose season 14 CCR 1253 sets, and the felling duty in the same section that does not pause for a nest.
Title 14 CCR sections 1250 to 1258: the implementing rules: Where the 'when' and 'where' determinations the Public Resources Code leaves open are actually made.
Removing a tree that cannot wait: What the stack gives a utility when the tree has to come down this week and something else says it cannot.
Frequently asked questions
Do the PRC 4293 clearance distances apply year round?
No. 14 CCR 1253 makes the minimum firebreak and clearance provisions of PRC 4292 through 4296 applicable during the declared CAL FIRE fire season for the respective county. GO 95 Rule 35 carries no seasonal limit, so on a span inside a State Responsibility Area one of the two clearance duties switches off with the county declaration and the other never does. The date on the inspection form is what decides which numbers a finding gets written against.
Is there a legal nesting season in California?
No. Fish and Game Code 3503 makes it unlawful to take, possess, or needlessly destroy the nest or eggs of any bird, and 3503.5 does the same for Falconiformes and Strigiformes without the word 'needlessly.' Neither section contains a date. The trigger is an occupied nest, whenever it is occupied. PG&E's own 2015 buffer document states there are no standard nest buffers specified in the Migratory Bird Treaty Act or within the California Fish and Game Code, so the February to August windows in circulation are program documents, not law.
What does a burn permit suspension actually stop?
It stops burning under permit in the proclaimed area. PRC 4423.2 lets the department issue restricted temporary permits where the continuation of burning may be essential, and CAL FIRE's June 2026 suspension notice for Nevada, Yuba, Placer and Sierra Counties stated that land management and other industrial type burning may proceed if a CAL FIRE official inspects the burn site and issues a special permit. The suspension does not switch off the fire tool requirements in PRC 4427, 4428 and 4431, which run off the permit required period rather than off the suspension.
Does a Red Flag Warning stop vegetation work in the corridor?
Not by operation of any California clearance rule. A Red Flag Warning is a National Weather Service product, and neither GO 95 Rule 35 nor PRC 4292, 4293 or 14 CCR Article 4 names it. PRC 4423.1 is the one place in the fire prevention chapter where a forecast has statutory effect, and it reaches burning permits rather than crews. A work stand down on a Red Flag day is a company procedure and a wildfire mitigation plan commitment, enforceable as a plan commitment.
