Blog · October 14, 2026 · California
Belmont Flood Zone Map, California: a practical guide
The zone on FEMA's map affects insurance, building and resale near Hillsborough.
Main page: San Mateo County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Weighing a property around Burlingame? A quick look at the Belmont flood zone map shows whether the lot falls inside a mapped floodplain, and no account is needed. What this Belmont guide covers: locating a parcel on FEMA's map, decoding A, AE and X, and pairing it with the San Mateo County parcel viewer.
The Belmont flood zone map: start here
The official source is FEMA's Flood Map Service Center: type an address near Burlingame, then open the map view for that panel. Vacant ground around Burlingame can still be found: zoom in from the nearest road and click inside the land.
The viewer San Mateo County publishes
Your first stop is the San Mateo County parcel viewer; it includes every tax parcel around San Mateo and Foster City. Around San Mateo, type a street address, an owner's name or a parcel number, then pick the result to center the map on it. If the land is near San Carlos, write down the parcel ID from that panel; each office in the county will want it.
San Mateo County in a few facts
Redwood City holds the county offices, which is where the courthouse records live. Smaller places on the map include San Carlos, San Mateo, and Foster City. Roughly 726,353 people live in San Mateo County (Census estimate, 2023) on about 449 square miles. Landmarks such as Don Edwards San Francisco Bay National Wildlife Refuge make handy reference points on the map near San Carlos.
What the map can't tell you
The acreage figure is an assessed number; only a licensed surveyor establishes the real corners for a parcel near Hillsborough. Records update in batches, so a fresh transfer around Redwood City might lag behind.
On site with the map
The parcel map usually runs in a mobile browser, useful out on a road near Foster City, but coverage can be spotty out of town. A saved image of the lot near Foster City and its lines helps when you meet an owner or agent.
Land on the county line
San Mateo County borders Alameda County, San Francisco County, Santa Clara County, and Santa Cruz County, all with their own assessor records. Ground near Foster City that runs to the line may be split across two assessors' files, so check the adjacent map as well. For a parcel near Redwood City, the Platbookmapper state page lists every bordering county map for California.
City limits and county records
Belmont is part of San Mateo County, California, so its parcels are on the county's map. Around Foster City, City or town hall handles matters such as zoning, permits and utilities inside its limits, and the county still keeps the parcel and deed records. Land beyond the town limits near Hillsborough often answers to county rules rather than the town's.
Low spots and local drainage
Low-lying fields near Foster City aren't always studied in detail, so walk the land after rain. Wet ground around San Mateo is a separate issue from flood zones; check the National Wetlands Inventory mapper for a first look.
Legal descriptions in California
California is laid out under the Public Land Survey System, so rural legal descriptions near Hillsborough cite section, township and range. A standard section is about one square mile, roughly 640 acres, and a township holds 36 of them, though corrections make some sections near Foster City odd-sized. Write down the legal description for the tract near Foster City before you request a deed or survey.
Questions to ask before you buy
Ask the listing agent for any Elevation Certificate for the house near San Carlos; an insurance quote early avoids surprises.
Reading A, AE and X
With a lot near San Carlos, zones beginning with A or V mark the Special Flood Hazard Area, meaning a 1% or greater chance of flooding each year. Out toward Hillsborough, shaded Zone X marks moderate flood hazard, between the 1% and 0.2% annual chance floods; unshaded X means minimal mapped risk.
Lining it up with the parcel map
Where a floodplain cuts across acreage near Hillsborough, the structure's footprint is the key question.
Insurance, lenders and building
With a lot near Redwood City, an Elevation Certificate from a surveyor helps: it compares the building to the BFE. New construction in a floodplain near San Mateo usually means extra permit review; check with the county or town building office before you plan.
Belmont: common questions
How often are flood maps updated for land near San Mateo?
In most cases, a new study can move a zone line near San Carlos; your community is notified before changes take effect.
How can I tell if a house near Redwood City is in a flood zone?
It depends, but FEMA's free map shows the zone for any spot near Foster City; no account is needed.
Is AE a high-risk flood zone around Hillsborough?
Both are high-risk zones, but only AE has a base flood elevation, so builders near Burlingame design to that elevation.
Is flood insurance mandatory near San Carlos?
Generally, for a building near Burlingame in an A or V zone with a federally backed or regulated mortgage, it's generally required; elsewhere it's optional.
How do I save a parcel from the viewer in Belmont?
Most viewers have a print or export tool, and it's worth keeping the parcel ID visible for land near San Carlos.
Open the official San Mateo 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.