King County, WA parcel and infrastructure data API
Korzy has about 630,000 parcel records for King County, Washington, with source updates through October 2026. Nearly every record carries land use; 40% include year built and 40% include building size. In and around the county the API also maps about 15 data-center projects (15 operating); about 450 miles of active rail; and 2 ports with reported cargo. Look up any parcel by address or coordinates, then check nearby data-center projects, utilities and grid context at the same point.
Parcel coverage in King County
About 630,000 parcel records with boundaries, situs addresses and parcel numbers, with the latest source update from October 2026. Each record has a stable korzy_id you can store and look up again with /v1/records/{id}. Share of records with each field:
| Field | Coverage | Share |
|---|---|---|
| Situs address | Nearly all · 98% | |
| Owner name | Some · 3% | |
| Assessed or market value | Some · 13% | |
| Year built | Many · 40% | |
| Building size | Many · 40% | |
| Last sale | Some · 13% | |
| Land use | Nearly all · 97% | |
| Zoning | Not published |
Owner name and mailing address are returned by /v1/enrich with the owner group, at 2 credits per parcel instead of 1 credit. 3% of King County records carry an owner name.
Infrastructure in and around King County
Power plants
About 10 operable plants with about 160 MW of nameplate capacity; largest by capacity: hydro, oil, other fuels.
Within 50 km: /v1/lookup section power; details: /v1/records/{id}
Substations and transmission
About 240 in-service substations, about 20 rated 230 kV or higher.
About 1,500 miles of transmission lines: about 35 mi at under 100 kV; about 660 mi at 100–161 kV; about 410 mi at 220–287 kV; about 80 mi at 345 kV; about 290 mi at 500 kV.
Water and sewer service
Service areas of about 130 community water systems cover about 37% of the county.
Sewer service areas of about 15 systems cover about 24%.
At an address or point: /v1/lookup section utilities
Data-center projects
About 15 tracked projects: 15 operating, 3 status not reported.
Within 10 km: /v1/lookup section datacenters
Flood zones and wetlands
Special flood hazard areas cover about 4% of the county on the current federal flood maps, published September 2026.
Mapped wetlands cover about 2%.
At an address or point: /v1/lookup section environment
Rail, ports and freight
- About 450 miles of active rail, about 150 of it main line
- About 140 miles of national freight network highway
- 2 port areas with reported cargo tonnage
- 7 intermodal rail terminals
Within 25 km: /v1/lookup section logistics
Example requests for King County
The lookup response is a real production response, trimmed to the main fields. Every request needs an API key with api:read; see authentication and credits and limits.
1. Find a parcel and nearby data-center projects
/v1/lookup matches 5017 90TH AVE SE, MERCER ISLAND, WA and returns the parcel's korzy_id and record, plus the data-center projects within 10 km, nearest first. 2 credits.
curl --fail-with-body -sS \
-H "Authorization: Bearer $KORZY_API_KEY" \
-H "Content-Type: application/json" \
-d '{"address":"5017 90TH AVE SE, MERCER ISLAND, WA","sections":["datacenters"]}' \
https://api.korzy.co/v1/lookupPython
import os
import requests
response = requests.post(
"https://api.korzy.co/v1/lookup",
json={"address": "5017 90TH AVE SE, MERCER ISLAND, WA", "sections": ["datacenters"]},
headers={"Authorization": f"Bearer {os.environ['KORZY_API_KEY']}"},
timeout=60,
)
response.raise_for_status()
body = response.json()
parcel = body["parcels"]["records"][0]
print(parcel["korzy_id"], body["sections"]["datacenters"]["status"])Production response (trimmed)
{
"location": {
"longitude": -122.22000419151124,
"latitude": 47.557410399999995,
"address": "5017 90TH AVE SE, MERCER ISLAND",
"match_type": "exact"
},
"parcels": {
"records": [
{
"id": "53033-0d68a6e3057f0566c32f",
"korzy_id": "53033-0d68a6e3057f0566c32f",
"parcelid": "033-4351300740",
"parceladdr": "5017 90TH AVE SE",
"parcelcity": "MERCER ISLAND",
"situs_zip": "98040-4709",
"statefp": "53",
"geoid": "53033",
"longitude": -122.22000419151124,
"latitude": 47.557410399999995,
"usedesc": "School(Private)",
"land_use_code": "68",
"yearbuilt": 1965,
"bldgsqft": 12850,
"totalvalue": 4743500,
"land_value_usd": 3540100,
"improvement_value_usd": 1203400,
"saledate": "1992-07-09",
"saleamt": 687500,
"updated": "2026-10-28"
}
],
"truncated": false
},
"sections": {
"datacenters": {
"status": "ok",
"data": {
"radius_km": 10,
"projects": [
{
"id": "datacenter:dc_059f411dc6327a0c7a91",
"project_id": "dc_059f411dc6327a0c7a91",
"name": "Sabey Intergate.East Building 1",
"operator": "Sabey Data Centers",
"status": "operating",
"state": "WA",
"city": "Tukwila",
"longitude": -122.28819430066527,
"latitude": 47.4948596,
"location_precision": "footprint",
"source_count": 3,
"source_date": "2026-07-23",
"mapped": true,
"distance_km": 8.636645622867036
},
{
"id": "datacenter:dc_0f114c9bf38ea5b9c0bc",
"project_id": "dc_0f114c9bf38ea5b9c0bc",
"name": "Intergate Seattle East Building 2",
"status": "unknown",
"state": "WA",
"city": "Tukwila",
"address": "3311 South 120th Place",
"longitude": -122.29056965,
"latitude": 47.4950309,
"location_precision": "footprint",
"source_count": 2,
"source_date": "2026-02-09",
"mapped": true,
"distance_km": 8.728408288713057
},
{
"id": "datacenter:dc_a41c0852f552e915b7f8",
"project_id": "dc_a41c0852f552e915b7f8",
"name": "Digital Realty SEA1 (Intergate Seattle-East, Bldg 4)",
"operator": "Digital Realty",
"status": "operating",
"state": "WA",
"city": "Tukwila",
"address": "3433 South 120th Place",
"longitude": -122.28886403470332,
"latitude": 47.493320600000004,
"location_precision": "footprint",
"source_count": 3,
"source_date": "2026-07-23",
"mapped": true,
"distance_km": 8.804527937947649
}
],
"truncated": true,
"note": "Straight-line distance to the reported project point; inspect location_precision. Projects merge supported source matches, not every nearby building. Approximate locations do not identify a parcel. Reported IT load, facility power, planned capacity and estimates remain separate source claims. No record or unknown status does not establish absence or inactivity."
},
"provenance": [
{
"dataset": "datacenters",
"as_of": "2026-11-02",
"data_version": "20261102T123021962884Z"
}
]
}
},
"credits": {
"charged": 2,
"refunded": 0
}
}2. Add owner and sale fields
/v1/enrich returns the fields you choose for up to 25 parcels per request; here the parcel 53033-0d68a6e3057f0566c32f, with the owner group. 2 credits.
curl --fail-with-body -sS \
-H "Authorization: Bearer $KORZY_API_KEY" \
-H "Content-Type: application/json" \
-d '{"items":[{"korzy_id":"53033-0d68a6e3057f0566c32f"}],"fields":["identity","sale","owner"]}' \
https://api.korzy.co/v1/enrich3. Fetch the record again by ID
/v1/records/{id} returns the stored parcel's full record, without owner fields. 1 credit.
curl --fail-with-body -sS \
-H "Authorization: Bearer $KORZY_API_KEY" \
https://api.korzy.co/v1/records/53033-0d68a6e3057f0566c32fJavaScript
const response = await fetch(`https://api.korzy.co/v1/records/${encodeURIComponent("53033-0d68a6e3057f0566c32f")}`, {
headers: { Authorization: `Bearer ${process.env.KORZY_API_KEY}` },
});
if (!response.ok) throw new Error(`Korzy API ${response.status}`);
const { record } = await response.json();
console.log(record.parceladdr, record.usedesc);King County data questions
- How many parcels in King County include year built?
- About 250,000 of about 630,000 parcel records (40%) include year built.
- Does the Korzy API return owner names for King County parcels?
- Yes. 3% of King County parcel records carry an owner name. Ask /v1/enrich for the owner group; each parcel then costs 2 credits instead of 1 credit. Lookups and records never include owner fields.
- How many data-center projects are in King County?
- Korzy tracks about 15 data-center projects in King County: 15 operating and 3 status not reported. A /v1/lookup with the datacenters section lists projects within 10 km of any address or point.
- How much power generation is in King County?
- About 10 operable power plants in King County total about 160 MW of nameplate capacity, mainly hydro, oil and other fuels.
- Which water systems serve King County?
- Service areas of about 130 community water systems cover about 37% of King County, and sewer service areas cover about 24%. A /v1/lookup with the utilities section returns the water and sewer matches at an address or point.
More featured counties
- Snohomish County, WABorders King County · about 310,000 parcels
Build on King County parcel data
Lookups, enrichment and records work the same in every county Korzy covers. Credits are shared across parcels, utilities, environment, logistics, power, grid, data-center and terrain sections.