Alameda County property record for 18509 Greenridge Ct, Castro Valley, CA 94552
| Property Type | Single Family Home |
|---|---|
| Details | 2,344 sqft · built 1976 |
| Lot Size | 0.535 acres (23,289 sqft) |
| Owner | 2 Individual Names on File |
| Last Sale | $1,435,000 (Aug 2025) |
| Tax Bill | $3,809 (2025) |
| Deeds & Mortgages | Dec 2018 Transfer |
| Flood Zone | Zone X (minimal risk) |
| APN | 85-1613-7 |
| Primary APN | 85-1613-7 |
|---|---|
| Alternative APN |
|
| Building Area | 2,344 sqft Living Area |
|---|
| Year Built | Built 1976 |
|---|---|
| Effective Year Built | Effective 1978 |
| Architectural Style | Custom Design |
| Construction Type | Wood |
| Lot Area | 23,289 sqft (0.535 acres) |
| Street Address | 18509 GREENRIDGE CT |
|---|---|
| City | CASTRO VALLEY |
| State | CA |
| Zip | 94552-1809 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Legal Description | LOT: 00026 BLK: TR: 3611 |
| Legal Subdivision | M92 1 |
| Legal Tract | 3611 |
| Jurisdiction | ALAMEDA CA |
| Township / Civil Division | HAYWARD |
| Census Block Group | 1 |
| Census Block | 1009 |
| Census Tract | 430102 |
18509 Greenridge Ct is owned and occupied by two individuals who bought it in August 2025.
Source: Alameda County records, as of August 5, 2026
| Owner of Record | 2 Individual Names on File |
|---|---|
| Mailing Address | 18509 GREENRIDGE CT, CASTRO VALLEY, CA 94552-1809 |
| Occupancy | Owner Occupied |
| Owner Type | Individual |
| Vesting | Joint Tenants |
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 | 2 Names on Deed |
|---|---|
| Last Sale | Aug 1, 2025 · Amount on File |
| Deed Sale | Aug 1, 2025 · Amount on File |
| Deed Document Number | 202597292 |
| Prior Transfer Date | Nov 6, 2018 |
| Prior Transfer Doc | 0000235966 |
| Record Updated | Oct 29, 2026 |
| Document Type | Quit Claim Deed |
|---|---|
| Jurisdiction | ALAMEDA CA |
| Recording Date | Dec 12, 2018 |
| Property Address | 18509 GREENRIDGE CT, CASTRO VALLEY, CA 94552-1809 |
| Document Number | 0000235966 |
| Instrument Date | Nov 6, 2018 |
| Instrument | 235966 |
| Record Updated | Dec 28, 2018 |
| Title Company | ATTORNEY ONLY |
| Tax | $0.00 |
|---|---|
| Additional |
|
| Name | Verified Name |
|---|
| Name | Verified Name |
|---|---|
| Relationship | Personal Trust |
| Address | 18509 GREENRIDGE CT CASTRO VALLEY CA 945521809, CASTRO VALLEY, CA 94552-1809 |
The 2025 property tax bill for 18509 Greenridge Ct was $3,809.
Source: Alameda County assessment roll, as of August 5, 2026
| Type | Name |
|---|---|
| State | California |
| County | Alameda County |
| Unified School District | Castro Valley Unified School District (KG - 12) |
| Year | Tax Bill | Assessed Value | Assessed Market Value |
|---|---|---|---|
| 2026 | $1,428,000 (+457.59%) Land $430,500 Building $1,004,500 | ||
| 2025 | $3,809.00 Homeowner's exemption | $256,101 Land $93,995 Building $162,106 | |
| 2023 | $3,634.00 Homeowner's exemption | $246,157 Land $90,345 Building $155,812 | $1,777,050 |
Assessed value and assessed market value are set for property tax purposes, not market price estimates; both are a fraction of this property's market value.
FEMA maps place 18509 Greenridge Ct in Zone X, an area of minimal flood risk.
Source: FEMA National Flood Hazard Layer, effective May 25, 2026
| FEMA Flood Zone | Zone X minimal risk |
|---|---|
| Flood Insurance Requirement | Not required lenders may require it |
Values are read at the parcel center point; lenders make the official flood determination.
Wildfire risk around 18509 Greenridge Ct is high, ranking above 79% of the US, with a 0.5% annual chance of wildfire.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | High above 79% of the US · above 57% of California |
|---|---|
| Wildfire Likelihood | 0.5% 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 | EAST BAY MUD serves 1,468,000 people · EPA ID CA0110005 |
|---|---|
| Water Source | Surface water |
| Last State Inspection | Dec 2021 |
| Lead | Under 1 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. This system sells water to local utilities; the supplier billing this address may be one of them.
Source: FCC Broadband Data Collection, based on 15 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| AT&T Fiber | 5,000 / 5,000 |
| Xfinity Cable | 2,000 / 250 |
| Etheric Networks Fixed Wireless | 250 / 100 |
| T-Mobile Fixed Wireless | 100 / 20 |
May also be available: Unwired.
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