Topographic Surveys in Santa Rosa, CA

Slope is a regulatory number in Santa Rosa, not just a design condition. The city's Hillside Development Standards in Zoning Code Chapter 20-32 apply to proposed subdivisions and to other development on that portion of a site with a slope of 10 percent or greater, and they set a ceiling: the average slope of each proposed lot shall not exceed 25 percent. Development on land sloping 10 percent or more has to minimize alteration of topography, drainage patterns, and vegetation. Ten percent is a low threshold once you leave the valley floor. The Fountaingrove ridges, the parcels climbing into Rincon Valley, and the Bennett Valley foothills cross it routinely, and the number that decides whether a project is feasible comes from a topographic survey, not from a slope estimate off a county contour layer.

That is a demanding measurement to make well on steep, brushy ground, which is why we scan. A conventional topo means a rod person walking the slope for a few hundred shots, slowly and sometimes unsafely. Our Trimble terrestrial laser scanner captures millions of survey-grade points from a series of setups, and we classify and filter vegetation out of the cloud to produce a true bare-earth model beneath oak canopy, manzanita, and the fast regrowth that has come back on burned slopes since 2017. Average slope, cut and fill quantities, drainage divides, and the top and toe of every existing bank come out of the same dataset. Down on the flat, around downtown and Santa Rosa Creek, the same density solves the opposite problem: finding the inches of fall that control drainage on a nearly level lot.

Deliverables are 1-foot contours or tighter, spot elevations, a DTM, slope analysis where the hillside standards apply, and a layered DWG/DXF base map, with the registered point cloud for your civil engineer and geotechnical consultant. See our Santa Rosa parcel maps when the terrain feeds a land division.