Contra Costa County property record for 3100 Castro St, Martinez, CA 94553
| Property Type | Commercial |
|---|---|
| Details | built 1971 |
| Lot Size | 0.106 acres (4,600 sqft) |
| Owner | Individual Name on Record |
| Last Sale | $250,000 (Apr 2024) |
| Tax Bill | $3,191 (2025) |
| Deeds & Mortgages | Apr 2024 Sale |
| Flood Zone | Zone AO (high risk) |
| APN | 370-251-011 |
| Primary APN | 370-251-011 |
|---|---|
| Alternative APN |
|
| Year Built | Built 1971 |
|---|---|
| Effective Year Built | Effective 1971 |
| Lot Area | 4,600 sqft (0.106 acres) |
| Street Address | 3100 CASTRO ST |
|---|---|
| City | MARTINEZ |
| State | CA |
| Zip | 94553 |
| Property Category | Commercial |
| Property Type | Commercial > Retail |
| Local Zoning Code | R1 |
| Legal Description | CASTRO ST EXT LOT 6 BLK 109 |
| Legal Subdivision | CASTRO STREET EXT |
| Legal Block | 109 |
| Legal Lot Number | 6 |
| Jurisdiction | CONTRA COSTA CA |
| Township / Civil Division | CENTRAL CONTRA COSTA |
| Census Block Group | 3 |
| Census Block | 3008 |
| Census Tract | 318000 |
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 | Individual Name on Record |
|---|---|
| Mailing Address | 2140 BOYNTON AVE, MARTINEZ, CA 94553-2750 |
| Owner Type | Individual |
| Deed Names | Name on Deed |
|---|---|
| Last Sale | Apr 9, 2024 · Amount on Record |
| Deed Sale | Apr 9, 2024 · Amount on Record |
| Prior Sale | Jul 27, 2006 · Amount on Record |
| Deed Document Number | 202432364 |
| Prior Transfer Date | Aug 28, 2004 |
| Prior Transfer Doc | 0000371417 |
| Record Updated | Sep 20, 2026 |
| Document Type | Grant Deed |
|---|---|
| Jurisdiction | CONTRA COSTA CA |
| Recording Date | Apr 9, 2024 |
| Property Address | 3100 CASTRO ST, MARTINEZ, CA 94553 |
| Document Number | 0000032364 |
| Map Reference | VOL 12 PG 271 |
| Instrument Date | Apr 2, 2024 |
| Instrument | 2024-032364 |
| Transaction Type | Transfer |
| Record Updated | Apr 18, 2024 |
| Title Company | CHICAGO TITLE COMPANY |
| Amount | Amount Recorded |
|---|---|
| Tax | $0.00 |
| Amount Accuracy | Rounded by County |
| Additional |
|
| Name | Verified Name |
|---|
| Name | Verified Name |
|---|---|
| Address | 3100 CASTRO ST, MARTINEZ, CA 94553 |
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 | $260,100 (+2%) Land $254,898 Building $5,202 | |
| 2025 | $3,191.00 (+34.93%) | $255,000 (+34.92%) Land $249,900 Building $5,100 |
| 2023 | $2,365.00 (-0.21%) | $189,000 Land $180,000 Building $9,000 |
| 2022 | $2,370.00 |
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 109 policies |
| Nearby Flood Policies | 109 in force |
| Nearby Flood Claims | 32 (1980–2019) |
| Claims Outside the SFHA | 3 of 32 |
| Most Recent Claim | Feb 2019 |
| Claims by Event |
|
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 59% of the US · lower than 64% of California |
|---|---|
| Wildfire Likelihood | 0.2% annual chance |
| Exposure | Indirect within ember reach |
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 358 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Xfinity Cable | 2,000 / 250 |
| Astound Broadband Fiber · Cable in parts of the area | 1,500 / 1,500 |
| Verizon Fixed Wireless | 300 / 20 |
| T-Mobile Fixed Wireless | 100 / 20 |
| AT&T Fixed Wireless · DSL · Fiber in parts of the area | 100 / 20 |
May also be available: Unwired.
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