Blog · October 14, 2026 · California
Foster City Flood Zone Map: checking a property's flood zone
Flood zones are set by FEMA, and checking one near Burlingame takes a few minutes.
Main page: San Mateo County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
Platbookmapper is an Amazon Associate. If you buy through an Amazon link on this page, we earn a commission. The link is a product, not the county map.
Thinking about a house near San Carlos? Checking the Foster City flood zone map reveals whether the lot falls inside a mapped floodplain, and it costs nothing to check. Covered here for Foster City: locating a parcel on FEMA's map, reading the zone codes, and pairing it with the San Mateo County parcel viewer.
Checking the Foster City flood zone map step by step
The official source is FEMA's Flood Map Service Center: type an address near San Mateo, and pick the FIRMette or map view. Rural land near Burlingame with no street number is still easy to locate: zoom in from the nearest road and click inside the land.
Opening the official parcel viewer
Your first stop is the San Mateo County parcel viewer; it maps each tax parcel in the county, San Mateo included. For a parcel near Belmont, type a street address, an owner's name or a parcel number, and the matching parcel lights up. On ground around San Mateo, the record panel normally shows the owner of record, assessed acreage, the parcel number and in many cases the last transfer.
When a parcel crosses a boundary
San Mateo County borders Alameda County, San Francisco County, Santa Clara County, and Santa Cruz County, and each of those keeps its own parcel map. Acreage along the edge near Belmont may be split in two county records, so check the neighboring map as well. If you're looking near Burlingame, the Platbookmapper state page lists each bordering county map for California.
Low spots and local drainage
Small streams around Belmont aren't always studied in detail, so look for water marks and debris lines. Marshy spots near Hillsborough can limit building too; check the National Wetlands Inventory mapper for a first look.
Limits of the parcel data
Acreage on the record is a tax-roll number; only a licensed surveyor establishes the real boundary for a parcel near San Carlos. If you're looking near San Mateo, records update in batches, so a deed recorded last month might lag behind.
Offices that can help
If the acreage or value on a parcel near San Mateo looks off are handled by the County Assessor, since that office keeps the assessment data. Questions about what you can build around Burlingame need the planning or permitting office, depending on whether the land is inside town limits.
Where Foster City fits in
Foster City sits in San Mateo County, California, which means parcel data comes from the county. If the land is near San Mateo, City or town hall handles things like zoning, permits and utilities for lots inside the boundary, and the county still keeps the parcel and deed records. Lots just outside the city limits near Belmont often follows county rules, not municipal ones.
Questions to ask before you buy
Ask the listing agent about past flood claims for the house near Hillsborough; an insurance quote early avoids surprises.
Reading A, AE and X
An AE label comes with a base flood elevation, while plain Zone A does not; builders around Belmont design to it. For land near Burlingame, minimal risk is not no risk: according to FEMA, many claims come from moderate- and low-risk areas.
Taking the map into the field
Most viewers work in a phone browser, which helps when you're standing on land near Hillsborough, but coverage can be spotty out of town. A saved image of the lot near San Mateo and its lines helps when you meet an owner or agent.
Matching the zone to the lot lines
Where a floodplain cuts across acreage near Hillsborough, the location of the house or building pad decides a lot.
A quick look at the area
Redwood City serves as the county seat, which is where the courthouse records live. Smaller places on the map include San Mateo, Belmont, and San Carlos, each with its own cluster of lots. Around 726,353 people call San Mateo County home (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 Redwood City.
Insurance, lenders and building
Closer to Hillsborough, get the Elevation Certificate if one exists: it can change the insurance price a lot. Remodeling a house in a zone near Redwood City often needs a floodplain permit; check with the county or town building office early.
Deeds, plats and who keeps them
For anything that matters, get the recorded deed from the County Recorder; the parcel line is a drawing of it, and that holds around Burlingame too. Older tracts near Burlingame can go back through a long string of deeds, and a title company earns its fee before a purchase.
Questions about the Foster City flood zone map
What does Zone AE mean near Burlingame?
An AE zone has a 1% annual chance of flooding and a base flood elevation, which shapes building rules near Hillsborough.
What is a base flood elevation in Foster City?
In most cases, the BFE is printed in AE zones on FEMA's map; surveyors near Belmont use it often.
What is a LOMA in Foster City?
In most cases, you can ask FEMA for a LOMA if surveyed elevations show the building near Redwood City is above the BFE; it starts with an elevation survey.
Why did my flood zone near Redwood City change?
Short answer: a new study can move a zone line near Redwood City; your community is notified before changes take effect.
Is the parcel map a survey in Foster City?
The map near San Mateo is approximate.
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.