Tree Survey in San Antonio, TX

A tree survey — sometimes referred to as a landscape survey or arborist survey — is a detailed mapping and inventory of the trees on a property. For each qualifying tree, the surveyor records the exact location, species, trunk diameter measured at breast height (DBH), canopy spread (drip line), and health condition. The data is compiled into a scaled survey map and a numbered inventory table that cross-reference each other.

In San Antonio, tree surveys are required by the City of San Antonio Tree Preservation Ordinance, codified in UDC Section 35-523. Before the City Arborist will issue a tree permit, you must submit a tree preservation plan that includes a professional tree survey showing every significant and heritage tree on the property.

The ordinance applies to new construction, site clearing, grading, subdivision platting, commercial development, and any project that may affect protected trees within city limits and the ETJ. Failure to comply can result in fines, project delays, and mandatory mitigation costs that far exceed the cost of the survey itself.

A tree survey from Alliance Land Surveyors includes:

Tree locations — each tree mapped to scale on a survey plat, with a unique ID number corresponding to the inventory table.

Species identification — every tree identified by common and/or scientific name to determine protected status under the ordinance.

Trunk diameter (DBH) — diameter at breast height (4.5 feet above grade), the measurement the City uses to classify trees as significant or heritage.

Canopy spread / drip line — the area beneath the outermost edge of the canopy, which defines the root protection zone during construction.

Health and condition notes — general assessment of each tree's health, structural integrity, and any visible disease or damage.

Property context — the survey also shows property lines, easements, proposed improvements, and existing structures to support site planning.

What is a tree canopy survey?

A tree canopy survey measures the total canopy coverage across your property — the combined area of ground shaded by the outermost edges (drip lines) of all qualifying trees. This is expressed as a percentage of the total site area and is increasingly required by the City of San Antonio for development projects, subdivision platting, and environmental review.

Unlike a standard tree survey that inventories individual trees (species, DBH, location), a canopy survey focuses on the aggregate canopy footprint — how much of the site is covered by tree canopy before and after development. This data is used by planners and the City Arborist to evaluate whether a project meets canopy preservation goals.

Alliance Land Surveyors maps each tree's drip line (the outermost edge of the canopy projected onto the ground), calculates the total canopy area in square feet, and expresses it as a percentage of the total lot or development area. This data is integrated into the tree preservation plan and civil drawings.

When canopy coverage matters:

Subdivision and MDP submittals — the City of San Antonio may require canopy coverage data at the Master Development Plan or preliminary plat stage to evaluate a project's impact on existing tree cover across the development.

Tree preservation plan compliance — the tree ordinance (UDC 35-523) requires preserving 35% of significant trees by diameter inches. Canopy coverage provides a complementary measure that shows how much shade and environmental benefit is retained after development.

Edwards Aquifer and environmentally sensitive areas — projects in the Edwards Aquifer recharge zone or contributing zone may have enhanced canopy requirements as part of environmental compliance. Canopy data documents the baseline before disturbance.

Commercial development and site plans — some commercial projects and PUD (Planned Unit Development) applications require canopy coverage analysis as part of the development agreement or zoning case.

Mitigation planning — if canopy must be removed, the canopy survey provides the data needed to calculate mitigation requirements — how many replacement trees or what mitigation fund contribution is needed to offset the lost canopy.