Contra Costa County property record for 3527 Keystone Loop, Discovery Bay, CA 94505
| Property Type | Single Family Home |
|---|---|
| Details | 5 bd · 4 ba · 4,011 sqft · built 2003 |
| Lot Size | 0.156 acres (6,800 sqft) |
| Owner | Individual Name on File |
| Tax Bill | $10,484 (2025) |
| Flood Zone | Zone X (moderate risk) |
| APN | 011-421-021-4 |
| Primary APN | 011-421-021-4 |
|---|---|
| Alternative APN |
|
| Bedrooms | 5 Beds |
|---|---|
| Full Baths | 4 Baths |
| Total Rooms | 12 Rooms |
| Stories | 2 Stories |
| Building Area | 4,011 sqft Living Area |
| 1st Floor Area | 1,984 sqft |
| 2nd Floor Area | 2,027 sqft |
| Year Built | Built 2003 |
|---|---|
| Effective Year Built | Effective 2004 |
| Architectural Style | Cluster |
| Lot Area | 6,800 sqft (0.156 acres) |
| View / Lot | Lake |
| Garage Type | Attached |
| Garage Area | 438 sqft |
| Parking Spaces | 2 Parking Spaces |
| Cooling System | Central |
|---|
| Street Address | 3527 KEYSTONE LOOP |
|---|---|
| City | DISCOVERY BAY |
| State | CA |
| Zip | 94505-2322 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Local Zoning Code | P1 |
| Legal Description | T8430 POR LOTS 21 & 20 |
| Legal Subdivision | SUBDIVISION 8430 |
| Legal Tract | 8430 |
| Legal Lot Number | 21,20 |
| Jurisdiction | CONTRA COSTA CA |
| Township / Civil Division | EAST CONTRA COSTA |
| Census Block Group | 3 |
| Census Block | 3001 |
| Census Tract | 304007 |
3527 Keystone Loop is owned and occupied by an individual who acquired it in June 2025.
Source: Contra Costa County records, as of July 14, 2026
| Owner of Record | Individual Name on File |
|---|---|
| Mailing Address | 3527 KEYSTONE LOOP, DISCOVERY BAY, CA 94505-2322 |
| Occupancy | Owner Occupied |
| Owner Type | Individual |
| Vesting | Sole Owner |
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 | Jun 13, 2025 |
| Deed Sale | Jun 13, 2025 |
| Deed Document Number | 202559890 |
| Prior Transfer Date | May 27, 2025 |
| Prior Transfer Doc | 0000059891 |
| Record Updated | Oct 29, 2026 |
The 2025 property tax bill for 3527 Keystone Loop was $10,484.
Source: Contra Costa County assessment roll, as of July 14, 2026
| Type | Name |
|---|---|
| State | California |
| County | Contra Costa County |
| Elementary School District | Byron Union Elementary School District (KG - 08) |
| Secondary School District | Liberty Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $834,914 (+10.28%) Land $161,357 Building $673,557 | |
| 2025 | $10,484.00 | $757,087 Land $156,388 Building $600,699 |
| 2023 | $9,848.00 (+1.65%) | $727,690 Land $150,316 Building $577,374 |
| 2022 | $9,688.00 |
Assessed value is set for property tax purposes and is not a market price estimate.
FEMA maps place 3527 Keystone Loop in Zone X, an area of moderate flood risk, within 500 ft of a high-risk flood zone.
Source: FEMA National Flood Hazard Layer, effective October 12, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone X moderate risk |
|---|---|
| 500-Year Floodplain | Yes 0.2% annual chance |
| Nearest Special Flood Hazard Area | Zone A, within 500 ft |
| Flood Insurance Requirement | Not required lenders may require it |
| Community Rating System | Class 6 (20% premium discount) |
| Nearby Flood Policies | 2 in force |
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.
Wildfire risk around 3527 Keystone Loop is low, with a 0.01% annual chance of wildfire.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Low lower than 80% of the US · lower than 88% of California |
|---|---|
| Wildfire Likelihood | 0.01% annual chance |
| Exposure | None beyond 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 | TOWN OF DISCOVERY BAY serves 16,790 people · EPA ID CA0710009 |
|---|---|
| Water Source | Groundwater |
| Last State Inspection | Mar 2023 |
| 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.
Source: FCC Broadband Data Collection, based on 226 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Xfinity Cable | 2,000 / 250 |
| Unwired Fixed Wireless | 300 / 25 |
| Verizon Fixed Wireless | 300 / 20 |
May also be available: AT&T, T-Mobile.
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