Monument Preservation in Petaluma, CA

Business and Professions Code section 8771 is short and unforgiving: a monument that will be disturbed or destroyed by construction has to be referenced by or under the direction of a licensed land surveyor before the work happens, and a Corner Record or Record of Survey has to be filed. It is not a courtesy. Street centerline monuments, tagged points in the old townsite grid, and the well monuments at intersections are the physical evidence that the boundary system of an entire block depends on, and a paving contractor with a grinder can erase a century of survey record in an afternoon.

Petaluma generates this work constantly. Downtown and the west-side grid are old streets under repeated repaving, utility trenching, and ADA curb-ramp reconstruction. The SMART corridor and its crossings, river bridge and levee projects, and the water and sewer replacements that come with infill development all put equipment over monuments. So do private projects: a driveway approach, a new sidewalk, a curb cut for a new commercial entrance. Contractors often do not know a monument is there until the well cover comes up in the spoil pile, which is the expensive version of this problem.

Our process is straightforward. We research the record with the Sonoma County Surveyor at Permit Sonoma and the Clerk-Recorder, locate and recover the monuments in the work area, tie them to durable reference points outside the construction limits, and file the Corner Record before the work starts. After construction we reset the monument in its true position from those references and file the follow-up documentation. A Trimble scanner helps here too, because a single scan of the intersection preserves the surrounding physical evidence, curb returns, wall corners, and hardscape, that corroborates the reset position later. Sonoma County also collects a survey monument fee under Government Code section 27585 to fund remonumentation of historical division lines. For related work, see our Petaluma parcel maps and our explainer on monument preservation and 8771.