Contra Costa County property record for 640 Walnut Ave, Martinez, CA 94553
| Property Type | Single Family Home |
|---|---|
| Details | 4 bd · 2.5 ba · 2,274 sqft · built 2012 |
| Lot Size | 0.228 acres (9,931 sqft) |
| Owner | 2 Individual Names on Record |
| Last Sale | $645,000 (Dec 2013) |
| Tax Bill | $8,308 (2025) |
| Flood Zone | Zone AO (high risk) |
| APN | 370-292-036-8 |
| Primary APN | 370-292-036-8 |
|---|---|
| Alternative APNs |
|
| Bedrooms | 4 Beds |
|---|---|
| Full Baths | 2.5 Baths |
| Half Baths | 1 Half Bath |
| Total Rooms | 9 Rooms |
| Stories | 2 Stories |
| Building Area | 2,274 sqft Living Area |
| 1st Floor Area | 1,172 sqft |
| 2nd Floor Area | 1,102 sqft |
| Year Built | Built 2012 |
|---|---|
| Effective Year Built | Effective 2013 |
| Lot Area | 9,931 sqft (0.228 acres) |
| Garage Type | Attached |
| Garage Area | 576 sqft |
| Parking Spaces | 2 Parking Spaces |
| Heating Fuel | Gas |
|---|---|
| Sewer | Municipal |
| Water Source | Commercial |
| Street Address | 640 WALNUT AVE |
|---|---|
| City | MARTINEZ |
| State | CA |
| Zip | 94553-3962 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Local Zoning Code | R10 |
| Legal Description | ALHAMBRA VALLEY GARDEN #1 POR LT 9 |
| Legal Subdivision | ALHAMBRA VLY GARDEN |
| Legal Lot Number | 9 |
| Jurisdiction | CONTRA COSTA CA |
| Township / Civil Division | CENTRAL CONTRA COSTA |
| Census Block Group | 1 |
| Census Block | 1007 |
| Census Tract | 319001 |
Source: Contra Costa County records, as of July 14, 2026
Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.
| Owner of Record | 2 Individual Names on Record |
|---|---|
| Mailing Address | 640 WALNUT AVE, MARTINEZ, CA 94553-3962 |
| Occupancy | Owner Occupied |
| Owner Type | Individual |
| Vesting | Joint Tenants |
| Deed Names | 2 Names on Deed |
|---|---|
| Last Sale | Dec 5, 2013 · Amount on Record |
| Deed Sale | Dec 5, 2013 · Amount on Record |
| Prior Sale | Jun 23, 2011 · Amount on Record |
| Deed Document Number | 2013282112 |
| Prior Transfer Date | Sep 20, 2012 |
| Prior Transfer Doc | 0000243494 |
| Record Updated | Sep 20, 2026 |
Source: Contra Costa County assessment roll, as of July 14, 2026
| Type | Name |
|---|---|
| State | California |
| County | Contra Costa County |
| Municipality | Martinez City |
| Unified School District | Martinez Unified School District (KG - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $645,185 (+2%) Land $275,077 Building $370,108 | |
| 2025 | $8,308.00 (+6.51%) Homeowner's exemption | $632,535 (+4.04%) Land $269,684 Building $362,851 |
| 2023 | $7,800.00 (+1.67%) Homeowner's exemption | $607,975 Land $259,213 Building $348,762 |
| 2022 | $7,672.00 |
Assessed value is set for property tax purposes and is not a market price estimate.
Source: FEMA National Flood Hazard Layer, effective October 12, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone AO high risk · sheet flow 1–3 ft |
|---|---|
| 100-Year Floodplain | Yes 1% annual chance |
| Floodway | No |
| Base Flood Elevation | Varies along the reach; see FIRM |
| Flood Insurance Requirement | Required federally backed loans |
| Flood Insurance Cost | Premium on Record median of 38 policies |
| Nearby Flood Policies | 38 in force |
| Nearby Flood Claims | 1 (2023) |
| Most Recent Claim | Jan 2023 · Severe Winter Storms, Flooding, Landslides, And Mudslides |
Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Moderate above 43% of the US · lower than 74% of California |
|---|---|
| Wildfire Likelihood | 0.07% annual chance |
| Exposure | Indirect within ember reach |
| Adjoins Burnable Land | Yes |
Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.
Source: EPA Safe Drinking Water Information System, as of September 2026
| Water System | CITY OF MARTINEZ serves 31,015 people · EPA ID CA0710006 |
|---|---|
| Water Source | Purchased surface water from CONTRA COSTA WATER DISTRICT |
| Last State Inspection | Oct 2025 |
| Lead | Under 1 ppb (2023–2025) action level 15 ppb |
| Water Quality | None last 10 years |
|---|---|
| Treatment and Procedure | None last 10 years |
| Monitoring and Reporting | None last 3 years |
Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.
Source: FCC Broadband Data Collection, based on 212 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Xfinity Cable | 2,000 / 250 |
| AT&T Fixed Wireless · DSL | 100 / 20 |
May also be available: Astound Broadband, T-Mobile, Unwired, Verizon.
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