Blog · October 14, 2026 · California
Reading the Brentwood Flood Zone Map for a parcel
The zone on FEMA's map affects insurance, building and resale near Danville.
Main page: Contra Costa County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Weighing a property around Pittsburg? A quick look at the Brentwood flood zone map shows whether the lot falls inside a mapped floodplain, and no account is needed. This Brentwood guide covers: locating a parcel on FEMA's map, decoding A, AE and X, and confirming the outline on the county map.
Getting started with the Brentwood flood zone map
The official source is FEMA's Flood Map Service Center: search an address around Concord, and choose the dynamic map. Vacant ground around Concord can still be found: pan from the closest town and click the spot.
Pulling up a parcel
Lots and tracts near Antioch can be looked up on the Contra Costa County parcel viewer, which opens without registering. In and around Clayton, enter a street address, an owner's name or a parcel number, then pick the result to center the map on it. For land near Pittsburg, write down the parcel ID while you have it open; each clerk in the county will want it.
Brentwood and the county around it
Brentwood sits in Contra Costa County, California, so its parcels are on the county's map. For land near Danville, city or town hall handles things like zoning, permits and utilities for lots inside the boundary, while the county keeps the tax map. Lots just outside the city limits out by Danville generally answers to county rules instead.
Reading A, AE and X
An AE label includes a base flood elevation (BFE), while plain Zone A does not; builders around Clayton design to it. For acreage around Pittsburg, a shaded X area marks moderate flood hazard, roughly the 100- to 500-year range; unshaded X means minimal mapped risk.
Legal descriptions in California
California uses the Public Land Survey System, so rural legal descriptions near Clayton cite section, township and range. Each section is nominally a mile square, about 640 acres, with 36 sections to a township, though sections near Danville can be irregular. Write down the legal description for the tract near Clayton when you talk to a surveyor.
Use the county map alongside FEMA
FEMA's map shows zones but not ownership, so check the Contra Costa County parcel viewer too to confirm you have the right parcel near Pittsburg.
Land on the county line
Contra Costa County meets Alameda County, Marin County, Sacramento County, San Francisco County, and San Joaquin County; every one of them runs a separate parcel map. Acreage along the edge near Danville may be split across two assessors' files, so open the neighboring map too. On ground around Oakley, the Platbookmapper state page links every neighboring county map for California.
Offices that can help
For assessment questions about property around Oakley belong with the County Assessor, which maintains the tax roll. Questions about what you can build around Danville are for the local planning and health departments, depending on whether the land is inside town limits.
What a flood zone means for a buyer
For land near Oakley, get the Elevation Certificate if one exists: it compares the building to the BFE. New construction in a floodplain near Danville often needs a floodplain permit; ask the local floodplain administrator early.
The paper trail behind a parcel
Before you sign anything, get the recorded deed through the County Recorder; the parcel map near Pittsburg only summarizes it. If the land is near Antioch, have ready the document number listed on the parcel record and the lookup takes minutes.
Low spots and local drainage
Small streams around Danville aren't always studied in detail, so walk the land after rain. Wetlands near Pittsburg can limit building even outside a flood zone; check the National Wetlands Inventory mapper for a first look.
On site with the map
Most viewers work in a phone browser, handy when you're parked on a road near Danville, but coverage can be spotty out of town. A printout of the tract near Oakley is a good backup.
Places you'll see on the map
Martinez serves as the county seat, where most land records are kept. Smaller places on the map include Oakley, Antioch, Pittsburg, and Clayton, where town lots give way to larger tracts. Around 1,155,025 people call Contra Costa County home (Census estimate, 2023) spread over roughly 717 square miles. Landmarks such as Clayton-Marsh Creek-Greenville Fault, San Pablo Dam Reservoir, and Mount Diablo State Park make handy reference points on the map near Antioch.
What to request from a seller
Ask the seller about past flood claims on the property near Pittsburg; getting a quote early keeps the budget honest.
Questions about the Brentwood flood zone map
What does Zone AE mean near Danville?
For most people, AE is a Special Flood Hazard Area with a published base flood elevation, so builders near Concord design to that elevation.
Can a flood zone near Oakley change?
Good question; a new study can move a zone line near Clayton; your community is notified before changes take effect.
What is a base flood elevation around Clayton?
A BFE near Antioch tells builders how high the lowest floor should be; local rules may require building above it.
Does the county parcel map show flood zones near Concord?
Generally, a flood layer may appear in the Contra Costa County parcel viewer layer list; confirm a lot near Clayton on FEMA's map either way.
Does the parcel map work on a phone in Brentwood?
The map near Clayton usually works on a phone; screenshots help offline.
Open the official Contra Costa 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.