A tree inventory is a systematic record of every tree that matters on a property: what species it is, how big it is, what condition it is in, and where it stands. It is the document that turns a wooded parcel from an unknown into a plannable asset, and it is the foundation under most of the other reports on this site, because a CEQA analysis, an Oak Technical Report, and a tree protection plan all begin by knowing exactly what is there. I am Christopher Hodge, an ISA Board Certified Master Arborist, and I perform tree inventories and surveys across El Dorado, Sacramento, Placer, and Amador counties.
Who orders a tree inventory, and when
- Developers and builders, before the site design is fixed. The cheapest moment to learn where the protected trees stand is while the building pad can still move.
- Permit and CEQA applications, where the reviewing agency expects a tree survey with counts, sizes, and species as the basis for impact analysis and mitigation.
- HOAs and property managers, who need a baseline: what the community owns, what condition it is in, and which trees need attention first, so budgets stop being guesses.
- Estates and property transactions, where mature trees are a real asset and a real liability, and a documented inventory serves both sides of that fact.
- Agencies and districts that need a defensible record of the trees in their care.
What gets recorded on every tree
- Species, identified correctly. This region's oaks are routinely confused with one another, and because valley oak carries different protections than its neighbors in some jurisdictions, a misidentified oak is not a small error.
- Trunk diameter, measured to the standard that applies. This is the detail that separates a survey from a walk with a clipboard: El Dorado County sums the three largest stems of a multi trunk oak, Rocklin measures the largest trunk only, and the same tree can fall inside or outside protection depending on whose rule is used. I measure to the ordinance your parcel actually answers to, at the correct height, from the uphill side on slopes.
- Condition and structure: health, visible defects, and decay indicators.
- Retention suitability, where the inventory feeds a design or permit: which trees are worth planning around, and which are not.
- Location and a numbered tag. Each inventoried tree is tagged in the field and keyed to your site plan, so the tree in row 41 of the table is findable on the ground by anyone, years later.
What you receive
A written inventory report: the numbered table of trees with species, size, condition, and notes, keyed to tags on the trees and marked locations on your site plan, with photographs where they earn their place. It is formatted so the people downstream can use it directly, a county reviewer, a project engineer, a board, or the arborist writing the protection plan, and it plugs straight into the Oak Technical Report, CEQA analysis, or development report when your project needs one, usually from the same site visits.
What a tree survey costs
Inventories are quoted by scope: the number of trees, the terrain, and the level of detail the receiving agency requires. A small residential parcel often fits within a standard site assessment starting at $450; larger parcels and development surveys are priced per project after a short conversation about the site and the tree count. Call or text (530) 391-6100 with the parcel location and what the survey is for, and you will get a real number rather than a range.
Jurisdiction sources for measurement standards
- El Dorado County Zoning Ordinance Chapter 130.39, Oak Resources ConservationThe county standard: single trunks at six inches, multi trunk oaks summed across the three largest stems.
- Rocklin Municipal Code Chapter 17.77, Oak Tree PreservationThe contrasting rule: multi trunk oaks measured by the largest trunk only.
- Placer County Code Article 19.50, Woodland ConservationPlacer County's woodland conservation standards, including its named conservation areas.
Frequently Asked Questions
What is a tree inventory?
A systematic record of the trees on a property: species, trunk diameter, condition, and location, with each tree tagged and keyed to a site plan and a written table. Depending on its purpose it can also rate structure and retention suitability. It is the base document that permit applications, CEQA review, protection plans, and management budgets are built on.
How much does a tree survey cost?
It scales with the number of trees, the terrain, and the detail the receiving agency requires. Small parcels often fit within a site assessment starting at $450; development scale surveys are quoted per project. The honest way to price one is a short conversation about the parcel and the purpose, after which the number is fixed rather than hourly and open ended.
What is the difference between a tree survey and an arborist report?
The survey is the record; the report is the judgment. An inventory or survey documents what exists, tree by tree. An arborist report interprets it for a decision: what a project will do to those trees, whether one is a hazard, what the ordinance requires. Most projects need both, and the survey usually comes first because everything else cites it.
Do you tag the trees?
Yes. Each inventoried tree gets a numbered tag in the field, and that number is the key that ties the table, the site plan, and the tree together. Tagging is what keeps an inventory usable years later, when the question is which tree exactly the county conditioned, and nobody wants to re argue it from memory.
Why does it matter how the trunks are measured?
Because protection thresholds are written in inches and the measuring rules differ by jurisdiction. El Dorado County adds the three largest stems of a multi trunk oak; Rocklin takes the largest stem only; heights and slope conventions vary too. The same oak can be protected under one rule and exempt under another, so an inventory measured to the wrong standard can misclassify trees and surface as a permit problem at the worst possible time. Measuring to the applicable ordinance is the whole craft of the survey.