Blog · October 14, 2026 · California
San Ramon Flood Zone Map, California: a practical guide
Flood zones are set by FEMA, and checking one near Moraga takes a few minutes.
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 Lafayette? A quick look at the San Ramon flood zone map shows whether the lot falls inside a mapped floodplain, and no account is needed. In this San Ramon guide: finding the address on FEMA's map, decoding A, AE and X, and pairing it with the Contra Costa County parcel viewer.
The San Ramon flood zone map: start here
Start with FEMA's Flood Map Service Center: type an address near Lafayette, and pick the FIRMette or map view. Vacant ground around Clayton can still be found: search the nearest road and click inside the land.
The free map to start with
Property in and around Moraga appear on the Contra Costa County parcel viewer, a viewer that needs no account. Near Lafayette, enter a street address, an owner's name or a parcel number, and the viewer zooms to the match. For a home near Concord, the parcel card normally shows the owner of record, acreage on the tax roll, a parcel ID and in many cases the last transfer.
City limits and county records
San Ramon sits in Contra Costa County, California, so its parcels are on the county's map. For a tract near Concord, the municipality handles things like zoning, permits and utilities within town limits, but the county runs assessment and recording. Acreage past the town limits near Danville often falls under county rules rather than the town's.
Reading A, AE and X
Near Walnut Creek, any A or V zone are Special Flood Hazard Areas, land with a 1-percent chance of flooding in any year. On ground around Walnut Creek, minimal risk is not no risk: according to FEMA, floods happen outside mapped zones too.
Getting your bearings
Martinez is the county seat, home to the main records offices. You'll also find Danville, Walnut Creek, Moraga, and Clayton. Roughly 1,155,025 people live in Contra Costa County (Census Bureau estimate, 2023) on some 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 Moraga.
Matching the zone to the lot lines
Where a floodplain cuts across acreage near Lafayette, the location of the house or building pad decides a lot.
The paper trail behind a parcel
The map is an index, not the title: deeds, plats and easements for land near Moraga are kept by the County Recorder. For a home near Lafayette, have ready the book and page from the tax record so staff can find the deed fast.
Neighboring parcel maps
Contra Costa County borders Alameda County, Marin County, Sacramento County, San Francisco County, and San Joaquin County, and each of those keeps its own parcel map. Acreage along the edge near Moraga can be split in two county records, so check the adjacent map as well. Out toward Danville, our state page links every bordering county map across California.
What a flood zone means for a buyer
For property near Clayton, an Elevation Certificate from a surveyor helps: it can change the insurance price a lot. New construction in a floodplain near Clayton usually means extra permit review; call the permitting office before you plan.
Questions to ask before you buy
Ask the seller about past flood claims for the house near Moraga; an insurance quote early keeps the budget honest.
A word on accuracy
Parcel lines are drawn for taxes, not surveyed, so a tree line near Lafayette can sit some distance off the line on screen. Out toward Concord, records update in batches, so a deed recorded last month might lag behind.
Low spots and local drainage
Creeks and ditches near Moraga aren't always studied in detail, so look for water marks and debris lines. Marshy spots near Moraga can limit building too; check the National Wetlands Inventory mapper for a first look.
Legal descriptions in California
California uses the Public Land Survey System, which means a tract near Lafayette is described by section, township and range. Each section is nominally a mile square, about 640 acres, with 36 sections to a township, though real sections near Danville vary in size. Copy the legal description from the record for the parcel near Clayton before you request a deed or survey.
San Ramon: common questions
What is a LOMA near Danville?
Generally, you can ask FEMA for a LOMA if surveyed elevations show the building near Lafayette is above the BFE; it starts with an elevation survey.
Do I need to worry about flooding in Zone X for land near Walnut Creek?
Zone X near Walnut Creek means moderate (shaded) or minimal (unshaded) mapped risk; FEMA notes that a large share of claims come from these areas.
Is AE a high-risk flood zone around Lafayette?
Good question; an AE zone has a 1% annual chance of flooding and a base flood elevation, which shapes building rules near Clayton.
What is a base flood elevation around Concord?
It depends, but a BFE near Concord tells builders how high the lowest floor should be, and an Elevation Certificate compares the building to it.
What's a legal description near Danville?
For property near Concord, deeds use lot and block, metes and bounds or survey descriptions; copy it for any survey or title request.
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.