San Mateo County property record for 409 Walnut St, San Carlos, CA 94070
| Property Type | Quadplex |
|---|---|
| Details | 7 bd · 6 ba · 5,570 sqft · built 1937 |
| Lot Size | 0.178 acres (7,750 sqft) |
| Owner | Company Name on File |
| Tax Bill | $27,801 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 050-071-160 |
| Primary APN | 050-071-160 |
|---|
| Bedrooms | 7 Beds |
|---|---|
| Full Baths | 6 Baths |
| Total Rooms | 15 Rooms |
| Units | 4 Units |
| Stories | 2 Stories |
| Building Area | 5,570 sqft Living Area |
| 1st Floor Area | 780 sqft |
| 2nd Floor Area | 780 sqft |
| Fireplaces | 1 Fireplace |
| Fireplace | Fireplace |
| Year Built | Built 1937 |
|---|---|
| Effective Year Built | Effective 1937 |
| Architectural Style | Ranch |
| Roof Material | Other |
| Lot Area | 7,750 sqft (0.178 acres) |
| Lot Dimensions | 155 ft deep x 50 ft wide |
| Garage Type | Attached |
| Garage Area | 250 sqft |
| Parking Spaces | 1 Parking Space |
| Cooling System | Central |
|---|---|
| Heating System | Central |
| Sewer | Municipal |
| Water Source | Commercial |
| Street Address | 409 WALNUT ST |
|---|---|
| City | SAN CARLOS |
| State | CA |
| Zip | 94070-2319 |
| Property Category | Residential |
| Property Type | Residential > Multi-Unit > Quadplex |
| Local Zoning Code | RM0000 |
| Legal Description | SELY 50 FT OF LOT 5 BLOCK 19 AMEND MAP TOWN OF SAN CARLOS |
| Legal Subdivision | TOWN OF SAN CARLOS |
| Legal Block | 19 |
| Legal Lot Number | 5 |
| Jurisdiction | SAN MATEO CA |
| Township / Civil Division | SAN MATEO |
| Census Block Group | 3 |
| Census Block | 3004 |
| Census Tract | 609202 |
409 Walnut St, a quadplex, is owned by a company that acquired it in July 2013.
Source: San Mateo County records, as of July 15, 2026
| Owner of Record | Company Name on File |
|---|---|
| Mailing Address | 895 LATHROP DR, STANFORD, CA 94305-1054 |
| Owner Type | Company |
| Vesting | Company |
Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.
| Deed Names | Name on Deed |
|---|---|
| Last Sale | Jul 2, 2013 |
| Deed Sale | Jul 2, 2013 |
| Prior Sale | Nov 24, 2009 · Amount on File |
| Deed Document Number | 201398663 |
| Prior Transfer Date | Nov 3, 1997 |
| Prior Transfer Doc | 0000145236 |
| Record Updated | Oct 29, 2026 |
The 2025 property tax bill for 409 Walnut St was $27,801.
Source: San Mateo County assessment roll, as of July 15, 2026
| Type | Name |
|---|---|
| State | California |
| County | San Mateo County |
| Municipality | San Carlos City |
| Elementary School District | San Carlos Elementary School District (KG - 08) |
| Secondary School District | Sequoia Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $2,035,779 (+2%) Land $961,140 Building $1,074,639 | |
| 2025 | $27,801.00 | $1,995,864 Land $942,295 Building $1,053,569 |
| 2023 | $26,470.00 (+2.11%) | $1,918,364 Land $905,705 Building $1,012,659 |
| 2022 | $25,924.00 |
Assessed value is set for property tax purposes and is not a market price estimate.
FEMA maps place 409 Walnut St in Zone X, an area of minimal flood risk, though there have been 1 flood claim nearby since 2023.
Source: FEMA National Flood Hazard Layer, effective September 10, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone X minimal risk |
|---|---|
| Flood Insurance Requirement | Not required lenders may require it |
| Community Rating System | Class 9 (5% premium discount) |
| Nearby Flood Policies | 15 units insured incl. 15 condo units |
| Nearby Flood Claims | 1 (2023) |
| Claims Outside the SFHA | 1 of 1 |
| 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.
The area around 409 Walnut St has no burnable land within ember reach, so its wildfire risk is not rated.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Not rated no burnable land 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 | CALIFORNIA WATER SERVICE - SAN CARLOS private · serves 34,801 people · EPA ID CA4110007 |
|---|---|
| Water Source | Purchased surface water from several systems |
| Last State Inspection | Sep 2024 |
| Lead | 6 ppb (2022–2024) 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 809 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| AT&T Fiber · DSL in parts of the area | 5,000 / 5,000 |
| Xfinity Cable | 2,000 / 250 |
| Sonic Telecom Fiber | 1,000 / 1,000 |
| Verizon Fixed Wireless | 300 / 20 |
| T-Mobile Fixed Wireless | 100 / 20 |
May also be available: Etheric Networks, GeoLinks.
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