Blog · October 14, 2026 · California
Larkspur Flood Zone Map: checking a property's flood zone
The zone on FEMA's map affects insurance, building and resale near Ross.
Main page: Marin County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Before you buy or build near Ross, pull up the Larkspur flood zone map: FEMA's zone label affects insurance, building rules and resale. What this Larkspur guide covers: finding the address on FEMA's map, reading the zone codes, and confirming the outline on the county map.
Where the Larkspur flood zone map lives
If you'd rather pan and zoom, use the National Flood Hazard Layer viewer, which draws the zones over aerial imagery. Vacant ground around Ross is still easy to locate: zoom in from US Route 101 and click inside the land.
Where the parcel data lives
Property in and around Tiburon are published on the Marin County parcel viewer, which opens without registering. For a tract near Mill Valley, type a street address, an owner's name or a parcel number, and the viewer zooms to the match. With a lot near San Anselmo, the record panel usually lists the owner of record, assessed acreage, a parcel ID and in many cases the last transfer.
Water near Ross
Creeks and ditches near Corte Madera may not have detailed mapping, so look for water marks and debris lines. Marshy spots near Ross can limit building too; the National Wetlands Inventory mapper shows mapped wetlands.
Legal descriptions in California
California follows the Public Land Survey System, which means a tract near Tiburon is described by section, township and range. A standard section is about one square mile, roughly 640 acres, and a township holds 36 of them, though real sections near San Anselmo vary in size. Keep the legal description for land near San Anselmo before you request a deed or survey.
City limits and county records
Larkspur lies within Marin County, California, and the county assessor maps its lots. For a home near San Rafael, the municipality handles things like zoning, permits and utilities for lots inside the boundary, and the county still keeps the parcel and deed records. Acreage past the city limits out by Tiburon usually follows county rules instead.
What the zone letters mean
For a home near San Rafael, zones beginning with A or V mark the Special Flood Hazard Area, meaning a 1% or greater chance of flooding each year. With a lot near Tiburon, shaded Zone X is moderate risk, between the 1% and 0.2% annual chance floods; unshaded X is minimal risk.
Land on the county line
Marin County touches Contra Costa County, San Francisco County, Solano County, and Sonoma County, and each of those keeps its own parcel map. Ground near Corte Madera that runs to the line may show up in two county records, so look at the adjacent map before you assume the acreage. Closer to Tiburon, our state page lists each neighboring county map for California.
Using it on a phone
Most viewers work in a phone browser, which helps when you're standing on land near Corte Madera, though signal can drop in rural spots. A screenshot of the parcel near Tiburon with its ID keeps working without signal.
A short flood checklist
Request for any Elevation Certificate on the property near Tiburon; an insurance quote early keeps the budget honest.
Offices that can help
For assessment questions about property around San Rafael belong with the County Assessor, the office behind the parcel record. Building or septic questions for a lot near Ross go to planning, building or health offices, and the answer depends on jurisdiction.
Before you lean on the lines
The acreage figure is an estimate; only a licensed surveyor sets the real corners on land around Mill Valley. For property near Mill Valley, records update in batches, so a deed recorded last month might lag behind.
Matching the zone to the lot lines
FEMA doesn't draw property lines, so pair it with the Marin County parcel viewer to see exactly which lot near San Rafael you're looking at.
Insurance, lenders and building
For a structure inside an A or V zone and the loan is federally backed or regulated, mandatory purchase rules apply where the community participates in the National Flood Insurance Program, whether the land is near Mill Valley or elsewhere in the county. Remodeling a house in a zone near Tiburon often needs a floodplain permit; check with the county or town building office before you plan.
Questions about the Larkspur flood zone map
What does Zone AE mean near San Rafael?
It depends, but both are high-risk zones, but only AE has a base flood elevation, which shapes building rules near Mill Valley.
What is a base flood elevation near Mill Valley?
In most cases, a BFE near San Rafael tells builders how high the lowest floor should be; surveyors near Ross use it often.
How do I check the flood zone for an address in Larkspur?
In most cases, search the address near San Anselmo on FEMA's Flood Map Service Center, and the zone code appears on the map.
Is Zone X safe from flooding around Corte Madera?
It depends, but X zones around Mill Valley are lower risk, not no risk, and floods still happen outside high-risk zones.
What's the tax parcel number used for near Tiburon?
The parcel ID identifies one tax parcel near Ross; copy it before you call anyone.
Open the official Marin County, CA parcel map See it in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.