521 D St, Martinez, CA 94553 Property Records

Contra Costa County property record for 521 D St, Martinez, CA 94553

Property Summary

Property Type	Single Family Home
Details	3 bd · 1.5 ba · 1,365 sqft · built 1929
Lot Size	0.161 acres (7,020 sqft)
Owner	Individual Name on File
Last Sale	$67,500 (Nov 1994)
Tax Bill	$2,301 (2025)
Flood Zone	Zone AO (high risk)
APN	`370-230-009`

Property Details

APN / Parcel Number

Primary APN	`370-230-009`
Alternative APN	`370-230-009-0`

Interior

Bedrooms	3 Beds
Full Baths	1.5 Baths
Half Baths	1 Half Bath
Total Rooms	9 Rooms
Stories	1 Story
Building Area	1,365 sqft Living Area
1st Floor Area	1,365 sqft

Exterior

Year Built	Built 1929
Effective Year Built	Effective 1929
Lot Area	7,020 sqft (0.161 acres)
Garage Type	Attached
Garage Area	248 sqft
Parking Spaces	1 Parking Space

Location & Zoning

Street Address	521 D ST
City	MARTINEZ
State	CA
Zip	94553-3203
Property Category	Residential
Property Type	Residential > Single Family > Home
Local Zoning Code	R3
Legal Description	CASTRO ST EXT POR LOTS 7,8 & 9 BLK 97
Legal Subdivision	CASTRO ST EXT
Legal Block	97
Legal Lot Number	7,8,9
Jurisdiction	CONTRA COSTA CA
Township / Civil Division	CENTRAL CONTRA COSTA
Census Block Group	3
Census Block	3006
Census Tract	318000

Owner

Source: Contra Costa County records · APN 370-230-009

Assessment roll updated July 14, 2026 · Last verified July 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 File
Mailing Address	521 D ST, MARTINEZ, CA 94553-3203
Occupancy	Owner Occupied
Owner Type	Individual
Vesting	Single Person

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	Verified Name on Deed
Last Sale	Nov 23, 1994 · Amount on Record
Deed Sale	Nov 23, 1994 · Amount on Record
Deed Document Number	1994282947
Record Updated	Sep 20, 2026

Tax Assessment & Valuation

Source: Contra Costa County records · Assessment roll updated July 14, 2026 · Last verified July 2026

Property Jurisdictions

Type	Name
State	California
County	Contra Costa County
Municipality	Martinez City
Unified School District	Martinez Unified School District (KG - 12)

Tax Bill & Assessment History

Assessed value is set for property tax purposes and is not a market price estimate.

Year	Tax Bill	Assessed Value
2026		$115,610 (+2%) Land $102,780 Building $12,830
2025	$2,301.00 (+6.38%)	$113,344 (+4.04%) Land $100,765 Building $12,579
2023	$2,163.00 (+1.36%)	$108,945 Land $96,853 Building $12,092
2022	$2,134.00

Flood & Wildfire

Source: FEMA National Flood Hazard Layer as of October 12, 2026 · FEMA NFIP claims and policies as of September 2026 · USDA Forest Service Wildfire Risk to Communities as of 2024 · Last verified October 2026

Flood

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	Severe Storms, Flooding, Mudslides, And Landslides, Jan 2006 · 12 claims Severe Storms, Flooding, Mud And Landslides, Jan 1997 · 5 claims Severe Storms, Flood, Mudslides & High Tide, Jan 1982 · 6 claims

Wildfire

Wildfire Risk	Moderate above 47% of the US · lower than 72% of California
Wildfire Likelihood	0.08% annual chance
Exposure	Direct burnable vegetation at the parcel

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.

Internet Providers

Source: FCC Broadband Data Collection as of December 31, 2025 · Last verified October 2026

Provider	Max Down / Up (Mbps)
Xfinity Cable	2,000 / 250
Radiate Holdings Fiber · Cable in parts of the area	1,500 / 1,500
Verizon Fixed Wireless	300 / 20
T-Mobile USA Fixed Wireless	100 / 20
AT&T Fixed Wireless · DSL · Fiber in parts of the area	100 / 20

May also be available: Unwired.

Based on FCC filings for 358 locations within half a mile of this property.

Drinking Water

Source: EPA Safe Drinking Water Information System as of 2026 Q3 · EPA water system boundaries as of March 2026 · Last verified October 2026

Water System	CITY OF MARTINEZ serves 31,015 people
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

Violations Reported to EPA

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 as reported to EPA, not water tested at this address; lead at the tap also depends on the building's own pipes. The full violation and enforcement history is in the system's EPA record.