Topographic Surveys in San Rafael, CA

We produce laser-scanned topographic surveys across San Rafael, Marin County — contours, digital terrain models, and layered CAD base maps that carry hillside design review, additions, and grading design through the city's process.

Topographic Surveys in San Rafael: Local Conditions

In San Rafael the contour map is not background for the architect; it is the input to the numbers the city checks. Chapter 14.12, the hillside development overlay, reaches residential lots with an average slope of twenty-five percent or greater along with parcels carrying the hillside residential general plan designations, and the city derives that average slope directly from contour data: 0.00229 times the contour interval, times the total length of the contour lines, divided by lot area in acres. The same surface feeds the natural state requirement, which leaves twenty-five percent of the site plus the average slope percentage undeveloped and undisturbed, and it fixes the existing grade that height is measured from. Get the contours wrong on San Rafael Hill, in Dominican, in Sun Valley, or above Lucas Valley Road, and every downstream number moves with them.

The flat half of the city asks a different question. Downtown, along the Canal, and out the Francisco Boulevard corridor the ground barely moves, so the survey turns on tenths of a foot and on the vertical datum: FEMA mapping and Marin's sea-level-rise planning make defensible NAVD88 elevations the first thing a civil engineer or floodplain reviewer looks for. Our Trimble terrestrial laser scanner serves both settings. A conventional topo on a steep, oak- and ivy-covered Terra Linda slope is a few hundred rod shots gathered slowly and sometimes unsafely; the scanner collects millions of survey-grade points from stable setups in one visit, and we classify and filter vegetation in processing to pull a true bare-earth model out from under the canopy.

Deliverables are a stamped topographic map, 1-foot contours or tighter, spot elevations, a DTM surface, and a layered DWG/DXF base map built to your architect's or civil engineer's standards, with the registered point cloud available to the whole design team. Because the site lives in the cloud, a wall face or rim elevation nobody thought to ask for gets extracted in the office instead of on a return trip. Record research and the boundary basis run through the Marin County Surveyor and the Marin County Recorder, both here in San Rafael. See also our San Rafael ADU surveys and 3D laser scanning in San Rafael.

Full service details, process, and deliverables: Topographic Surveys & 3D Terrain Mapping · All surveying in San Rafael: San Rafael land surveying

What's Included

Trimble laser scanning: millions of points, one site visit
Contours, DTM, and spot elevations at any interval
CAD-ready DWG/DXF base maps for architects and engineers
No return trips for missed shots — the scan has everything
Vegetation-filtered ground models on brushy hillside lots
Point cloud deliverable available for design teams

Our Process

Scope & Research

We confirm the mapping limits, contour interval, and datum your project requires, and review record maps and benchmarks for the site.

Field Scanning

We capture the site with a Trimble terrestrial laser scanner plus GNSS/total-station control, recording millions of survey-grade points in a single visit — terrain, structures, walls, trees, and utility surface features.

Point Cloud Processing

Scans are registered onto project control, vegetation and noise are filtered, and a ground surface is extracted to build the digital terrain model.

Base Map Delivery

You receive a layered DWG/DXF topographic base map — contours, spot grades, features, and boundary if requested — with the point cloud available on request.

Topographic Surveys in San Rafael: FAQ

The city does not publish a blanket survey mandate for every project, but hillside design review under Chapters 14.12 and 14.25 turns on figures only a topographic survey produces: average slope computed from contours, the natural state area, and height measured from existing grade. Geotechnical and civil consultants need the same surface. In practice, a hillside application without survey-grade contours is an application that stalls.

The city uses the standard slope formula: 0.00229 multiplied by the contour interval, multiplied by the summed length of the contour lines, divided by the lot area in acres. Because both the interval and the total contour length come from the topographic map, the density and accuracy of that map change the answer. Our scanned surface produces contours derived from measured ground rather than interpolation between sparse shots.

Yes, the emphasis shifts from slope to datum. On low, flat ground the useful product is precise NAVD88 spot elevations, drainage flow lines, and rim and invert data, tied to published control so a floodplain reviewer or civil engineer can rely on them. We establish that datum on site and can extend the survey beyond your lines to show where water actually goes.

Topographic Surveys Across the East Bay

Need Topographic Surveys in San Rafael?

Call (510) 543-2220 or request a quote — we'll scope your San Rafael project and give you a fixed price.

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