Tree-protection ordinances answered
for property owners.

In most North Bay jurisdictions you need a permit before removing a tree if it meets any of the following:

• The trunk diameter at breast height (DBH) is at or above the jurisdiction's protected threshold — commonly 4 inches for native oaks and certain protected native species and 6–10 inches for other species.
• The species is on the protected list (coast live oak, valley oak, interior live oak, redwood, bigleaf maple, California buckeye, and others vary by jurisdiction).
• The tree has been formally designated as a heritage tree.
• The removal is part of an activity (grading, construction, utility trenching, driveway work) that triggers a development permit regardless of species.

The threshold and the protected-species list differ by jurisdiction, so confirm with the local planning or building department before any removal. Unpermitted removal of a protected tree in most North Bay jurisdictions carries civil penalties that scale with the appraised value of the tree and may require mitigation replanting at a 1:1 to 3:1 ratio or greater. Permit-ready arborist reports handle the full documentation if you'd rather not navigate the counter alone.

Trunk diameter at breast height — DBH, measured at 4.5 feet above grade — is the standard threshold metric. Common North Bay thresholds:

• Marin County unincorporated areas protect native oaks at 4 inches DBH and most other species at 10 inches DBH.
• Sonoma County's April 2024 protected native tree ordinance lowered the threshold for native oaks and certain other native species to 4 inches DBH.
• Santa Rosa generally protects trees at 6 inches DBH within the city; Petaluma, San Rafael, Novato, Sonoma (city), St. Helena and Healdsburg each have their own thresholds.

Multi-trunk and co-dominant-stem trees are typically measured by adding the DBH of the largest two or three stems, depending on the ordinance. Always confirm the current threshold with the issuing jurisdiction — these numbers change and an outdated figure is the most common permit-counter surprise. The North Bay Tree Ordinance Reference compiled by CanopyMetrics summarizes the current per-jurisdiction thresholds and protected species lists.

Most North Bay ordinances allow removal of an imminently hazardous tree without a prior permit, but the process still requires documentation and a follow-up notice. The standard pattern:

• A certified arborist — ISA Certified Arborist with TRAQ — inspects the tree and documents the imminent hazard using a TRAQ risk rating of High or Extreme, with photographs of the specific defect.
• The property owner or arborist notifies the jurisdiction by phone or in writing before removal if the timeline allows.
• The tree is removed.
• A written after-the-fact permit application or hazard-abatement filing is submitted within a stated window (commonly 7 to 30 days, depending on jurisdiction) with the arborist's documentation attached.

Even in emergencies, the burden of proof that the tree was actually an imminent hazard — not merely inconvenient — is on the property owner. If a dispute arises later with a neighbor or insurer, the arborist's contemporaneous TRAQ-based documentation is what protects you. Permit-after-the-fact documentation is one of the engagements CanopyMetrics routinely accepts on short notice.

A heritage tree is a tree formally designated by a city or county for protection based on criteria that combine size, age, species, historical significance, and community value. Typical heritage criteria:

• Trunk diameter above a defined threshold (commonly 24–36 inches DBH depending on jurisdiction), or
• Age exceeding 100 years, or
• Association with a recognized historical event or property, or
• Species of exceptional rarity in the area

Designation is usually a public process: the property owner is notified, the designation is recorded against the parcel in the county recorder's office, and removal of a heritage tree generally requires a higher permitting standard than ordinary protected trees — often an arborist report, a public hearing, and replacement at a 2:1 to 5:1 ratio or full appraised-value mitigation. Once designated, a heritage tree status runs with the property regardless of subsequent owners. Most North Bay jurisdictions maintain a publicly searchable heritage tree inventory; check your parcel's tree inventory before any removal or major pruning project. Heritage-tree permit applications require a higher bar of documentation than ordinary removals.

Protected species vary by jurisdiction, but the most commonly protected across the North Bay are: coast live oak (Quercus agrifolia), valley oak (Quercus lobata), interior live oak (Quercus wislizeni), Oregon white oak (Quercus garryana), California buckeye (Aesculus californica), coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), Monterey cypress where native, native bigleaf maple (Acer macrophyllum) in some jurisdictions, western sycamore (Platanus racemosa), and madrone (Arbutus menziesii).

Some jurisdictions — Sonoma County after the 2024 amendment and several cities — explicitly protect blue gum eucalyptus (Eucalyptus globulus) under specific circumstances, particularly where it provides nesting habitat. Heritage-tree designation under each ordinance can extend protection to nearly any mature tree regardless of species.

The North Bay Tree Ordinance Reference has the current protected-species list for every North Bay jurisdiction; species lists are revised periodically and outdated informal guidance from neighbors is not reliable for permit planning.

Yes — in nearly every North Bay ordinance, a tree with co-dominant trunks or multiple stems is measured by totaling the diameters of the largest stems, not by the largest single trunk alone. The standard pattern:

• If a tree has two co-dominant stems both exceeding the protected threshold, the tree is protected.
• If one stem is above threshold and another is below, the sum often still triggers protection, depending on the ordinance.
• Some jurisdictions count the largest two stems; others count the three largest.

Multi-stem measurement prevents the common workaround of splitting a mature oak's growth across two trunks to fall below the threshold. For a permit application that addresses a multi-stem tree, the arborist report should include a written measurement methodology describing how the DBH was calculated — this prevents a permit-counter question that delays issuance. Species like California sycamore, valley oak, and many mature coast live oaks routinely display multi-stem architecture; this measurement rule is the difference between a permitted removal and an unpermitted-removal penalty. Pre-removal measurement and reporting is something we routinely build into every permit application.

Tree roots can absolutely damage foundations, sidewalks, driveways, and underground utilities — particularly shallow foundations on clay soils that swell with moisture changes. Under California law, a neighbor is generally not strictly liable for damage caused by the natural growth of roots from a healthy tree; however, liability arises if the neighbor knew or should have known of a dangerous condition and failed to act.

The legal posture commonly turns on: (a) whether the tree showed observable signs of decay or instability that would lead a reasonable property owner to inspect, and (b) whether the injured party gave notice before the damage occurred. As to permits — removing or major-pruning a protected neighbor's tree requires that neighbor to pull the permit; you cannot. Damage remediation on your own side, such as root-barrier installation, may or may not require a permit depending on the jurisdiction and whether the work crosses the property line.

Document damage with photographs as it occurs, send written notice to the neighbor, and consult an attorney if the damage is significant. CanopyMetrics provides arborist reports that document causation for insurance subrogation or boundary-tree claims. See the ordinance reference for the jurisdiction-specific rules on root work.

Responsibility depends on whose tree and whose infrastructure is affected, and on whether the lift created a trip hazard or property damage. If a city-owned tree's roots lift a public sidewalk, the city is generally responsible for the sidewalk repair but commonly pursues the adjacent property owner for cost recovery when the tree is private.

If a private tree's roots lift a private driveway or damage a neighbor's hardscape, the property owner of the tree is potentially liable under California negligence standards, particularly if the lifting was observable in advance. As to permits — root cutting within a Tree Protection Zone of a protected tree requires a permit, even when the cutting is intended to fix infrastructure. Most North Bay ordinances treat root pruning on a protected tree, regardless of motive, as a regulated activity requiring either a tree-work permit or a development permit.

The right sequence is: document the damage, contact the tree's owner, contact the city's public works department if the sidewalk is in the public right-of-way, and engage an ISA-certified arborist before any roots are cut. Cutting roots without proper documentation can convert a fixable infrastructure problem into a tree-removal liability. Where dispute follows, arborist causation reports carry the technical record.

California case law establishes a qualified right to self-help: you may trim branches and roots that cross onto your property up to the property line, but the trimming must be performed in a manner that does not kill or destabilize the tree, and the trimming must be at your own expense. The California Court of Appeal decision in Boarman v. Ledbetter establishes that the self-help right applies but is bounded — trimming that amounts to destruction, including topping or removing a material portion of the canopy, exposes you to liability.

Practically: a small amount of routine trimming at the property line (the kind a homeowner can do with hand pruners or pole pruners on a small branch) usually falls within the self-help right. Larger trimming that requires a chain-saw, that exceeds the standard pruning guidelines for the species, or that targets a protected species or heritage tree exposes you to a claim by the tree's owner and potentially to a municipal penalty.

If the overhang is from a protected species or heritage tree, the cleaner path is to ask the neighbor to file a pruning permit with the city and to contribute to the cost; if the neighbor refuses, an attorney can advise on next steps. For documented disputes that escalate, arborist boundary-tree reports document the technical record.

California law does not give a private property owner a direct right to compel a neighbor to remove a healthy tree under most circumstances; the legal pathway for a dangerous tree depends on whether actual damage has occurred or whether a competent professional assessment establishes an imminent hazard. If an arborist inspection using ISA TRAQ methodology documents a High or Extreme risk rating with a target on your property, you have a basis to put the neighbor on written notice, to require them to act, and — if they refuse — to seek a court order or pursue damages if failure to act results in injury or property loss.

If the tree has already caused damage and falls on your property or structure, California Civil Code 3346 and case law establish the neighbor's potential liability subject to the reasonable-care standard. The right legal instrument depends on whether the situation is preventive (a risk-rated tree that has not yet failed) or retrospective (a tree that has already caused damage). CanopyMetrics prepares documented TRAQ assessments and arborist reports that establish the technical case for either posture. We do not perform the tree work itself — independence on that point is what the report's credibility depends on. See the per-jurisdiction rules if the disputed tree is a protected species.

Each ordinance defines these three categories differently, but the standard pattern across North Bay jurisdictions is:

• Removal means taking the entire tree down to or near grade, typically requiring a full removal permit with replacement-tree mitigation.
• Pruning means selectively removing branches to maintain tree health or structure, often permitted without a separate permit if it stays below a stated threshold — commonly 25% of the live canopy within a 12-month period.
• Severe pruning (sometimes called "excessive pruning" or "topping") means removing more than the permitted percentage of live canopy, removing the central leader, or cutting back to large-diameter cuts that exceed the species' pruning threshold.

Severe pruning is treated under most ordinances as a regulated activity closer to removal than to routine maintenance, with mitigation requirements similar to removal. The 25% live-canopy threshold is the most common rule of thumb across the North Bay but is not universal — some jurisdictions use 15% or 30%, and the rule can differ for native oaks versus other species. Always confirm the prevailing definition with the jurisdiction before authorizing pruning work on a protected tree. Pruning-permit documentation is built around the same TRAQ methodology as removal permits.

Most North Bay jurisdictions require replacement-tree planting as a condition of any removal permit, and the replacement ratio — the number or size of replacement trees required per removed tree — varies by jurisdiction and by the reason for removal. Common patterns:

• 1:1 inch-for-inch replacement — the total trunk inches of replacement trees (measured at planting) must equal or exceed the DBH of the removed tree — for routine removals.
• 2:1 or higher ratio for heritage-tree removals.
• Appraised-value replacement under CTLA methodology when the jurisdiction requires value-based rather than size-based replacement.
• Species substitution rules — most jurisdictions require native or approved species for replacement trees.

For trees removed without a permit, the mitigation ratio is commonly more punitive — 3:1 to 5:1 or appraised-value-plus-penalty — and the property owner is also subject to civil penalties. Replacement trees must be documented in a follow-up arborist inspection confirming species, size at planting, and survival through an establishment period (typically one to three growing seasons). The arborist report accompanying your removal permit should include the proposed replacement plan to avoid permit-counter confusion. See the per-jurisdiction rules for the specific ratio that applies to your parcel.