Parcel Maps in Martinez, CA

Martinez is the one city in Contra Costa County where the entire map-recording apparatus sits in town: the Contra Costa County Recorder and the County Surveyor, whose office examines every parcel map before it records, are both located in downtown Martinez. When we process a parcel map here, plan-check comments, mylar corrections, and recordation happen minutes from the site rather than across the county. Under the Subdivision Map Act, a parcel map is the vehicle for divisions creating four or fewer lots, and it is also the framework for lot line adjustments and mergers — all of which we handle from feasibility review through tentative approval, final map, and recordation.

The two ends of Martinez generate very different mapping problems. The downtown grid was platted in the 1800s along the Carquinez shoreline — among the oldest plats in the county — so a lot line adjustment between two commercial parcels there often turns into a reconciliation project: original plat dimensions, later deeds, and occupation lines rarely agree after 150-plus years. South of town, the semi-rural parcels of the Alhambra Valley are where we see genuine splits — large lots with the acreage to divide, but with well and septic siting, access easements, and hillside grades that must be resolved at the feasibility stage, before anyone pays for a tentative map. We always start there: a candid look at whether the division the owner imagines can actually be approved and built.

Our Trimble terrestrial laser scanner earns its keep on these jobs because a parcel map rarely travels alone. In one mobilization we capture the boundary evidence and a survey-grade topographic base — grades, driveways, structures, drainage — so the civil design for an Alhambra Valley split works from the same data as the map itself. Where a division will disturb existing monuments, we address perpetuation under Business & Professions Code §8771 as part of the map, not as an afterthought. See our combined boundary and topographic surveys for how that single-visit approach works.