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Contra Costa County, CA parcel and infrastructure data API

Korzy has about 410,000 parcel records for Contra Costa County, California, with source updates through October 2026. 93% include building size and 90% include last sale. In and around the county the API also maps about 40 power plants with about 4,200 MW of capacity, led by natural gas; 2 data-center projects; and 1 port with reported cargo. Look up any parcel by address or coordinates, then check water, sewer and infrastructure context at the same point.

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Parcel coverage in Contra Costa County

About 410,000 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:

FieldCoverageShare
Situs addressNearly all · 99%
Owner nameNot published
Assessed or market valueMost · 89%
Year builtMost · 85%
Building sizeMost · 93%
Last saleMost · 90%
Land useMost · 90%
ZoningNot published

Contra Costa County records do not include owner names. See pricing for credit costs.

Infrastructure in and around Contra Costa County

Power plants

About 40 operable plants with about 4,200 MW of nameplate capacity; largest by capacity: natural gas, battery and pumped storage, wind. Proposed generators add 7 MW.

Within 50 km: /v1/lookup section power; details: /v1/records/{id}

Substations and transmission

About 100 in-service substations, about 20 rated 230 kV or higher.

About 890 miles of transmission lines: about 130 mi at under 100 kV; about 270 mi at 100–161 kV; about 420 mi at 220–287 kV; about 55 mi at 500 kV; 5 mi at DC.

Water and sewer service

Service areas of about 40 community water systems cover about 58% of the county.

Sewer service areas of about 15 systems cover about 46%.

At an address or point: /v1/lookup section utilities

Data-center projects

2 tracked projects: 1 permitted, 1 status not reported. Reported planned capacity: about 100 MW.

Within 10 km: /v1/lookup section datacenters

Grid capacity data

13 utility-published grid capacity layers cover parts of Contra Costa County, including load headroom, loading forecasts, substation inventory, planned grid projects, grid needs, large-load requests.

Nearby records: /v1/lookup section grid

Flood zones and wetlands

Special flood hazard areas cover about 17% of the county on the current federal flood maps, published October 2026.

Mapped wetlands cover about 4%.

At an address or point: /v1/lookup section environment

Rail, ports and freight

  • About 300 miles of active rail, about 100 of it main line
  • About 50 miles of national freight network highway
  • 1 port area with reported cargo tonnage

Within 25 km: /v1/lookup section logistics

Example requests for Contra Costa 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 its water and sewer service

/v1/lookup matches 4180 TREAT BLVD, CONCORD, CA and returns the parcel's korzy_id and record, plus the water and sewer service areas at the parcel and the nearest treatment plants. 2 credits.

curl --fail-with-body -sS \
  -H "Authorization: Bearer $KORZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"address":"4180 TREAT BLVD, CONCORD, CA","sections":["utilities"]}' \
  https://api.korzy.co/v1/lookup
Python
import os
import requests

response = requests.post(
    "https://api.korzy.co/v1/lookup",
    json={"address": "4180 TREAT BLVD, CONCORD, CA", "sections": ["utilities"]},
    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"]["utilities"]["status"])
Production response (trimmed)
{
  "location": {
    "longitude": -122.00202961400032,
    "latitude": 37.954574,
    "address": "4180 TREAT BLVD, CONCORD",
    "match_type": "exact"
  },
  "parcels": {
    "records": [
      {
        "id": "06013-0ccfdec3454e77baad1a",
        "korzy_id": "06013-0ccfdec3454e77baad1a",
        "parcelid": "134062022",
        "parceladdr": "4180 TREAT BLVD",
        "parcelcity": "CONCORD",
        "situs_zip": "94518",
        "statefp": "06",
        "geoid": "06013",
        "longitude": -122.00202961400032,
        "latitude": 37.954574,
        "usedesc": "Office Buildings",
        "yearbuilt": 1978,
        "bldgsqft": 18100,
        "totalvalue": 3446150,
        "saledate": "1993-06-16",
        "updated": "2026-10-13"
      }
    ],
    "truncated": false
  },
  "sections": {
    "utilities": {
      "status": "ok",
      "data": {
        "water": [
          {
            "id": "utility:water:573",
            "feature_id": "water:573",
            "name": "CONTRA COSTA WATER DISTRICT",
            "boundary_basis": "System Sourced"
          }
        ],
        "sewer": [
          {
            "id": "utility:sewer:4341",
            "feature_id": "sewer:4341",
            "name": "Central Contra Costa WWTF",
            "boundary_basis": "Modeled"
          }
        ],
        "treatment_plants": [
          {
            "id": "utility:treatment:9334",
            "feature_id": "treatment:9334",
            "name": "Central Contra Costa WWTF",
            "distance_km": 7.586902297724021
          },
          {
            "id": "utility:treatment:9333",
            "feature_id": "treatment:9333",
            "name": "MOUNTAIN VIEW WWTF",
            "distance_km": 11.041343810539505
          },
          {
            "id": "utility:treatment:9332",
            "feature_id": "treatment:9332",
            "name": "Delta Diablo Wastewater Treatment Plant",
            "distance_km": 16.061992024409527
          }
        ],
        "truncated": {
          "water": false,
          "sewer": false
        }
      },
      "provenance": [
        {
          "dataset": "water",
          "data_version": "63b7c1c3-9661-4fed-a59f-ddbfff80c2e4"
        },
        {
          "dataset": "sewer",
          "data_version": "63b7c1c3-9661-4fed-a59f-ddbfff80c2e4"
        },
        {
          "dataset": "treatment",
          "data_version": "63b7c1c3-9661-4fed-a59f-ddbfff80c2e4"
        }
      ]
    }
  },
  "credits": {
    "charged": 2,
    "refunded": 0
  }
}

2. Add value and sale fields

/v1/enrich returns the fields you choose for up to 25 parcels per request; here the parcel 06013-0ccfdec3454e77baad1a. 1 credit.

curl --fail-with-body -sS \
  -H "Authorization: Bearer $KORZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"items":[{"korzy_id":"06013-0ccfdec3454e77baad1a"}],"fields":["identity","value","sale"]}' \
  https://api.korzy.co/v1/enrich

3. 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 $KORZY_API_KEY" \
  https://api.korzy.co/v1/records/06013-0ccfdec3454e77baad1a
JavaScript
const response = await fetch(`https://api.korzy.co/v1/records/${encodeURIComponent("06013-0ccfdec3454e77baad1a")}`, {
  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);

Contra Costa County data questions

How many parcels in Contra Costa County include year built?
About 350,000 of about 410,000 parcel records (85%) include year built.
Does the Korzy API return owner names for Contra Costa County parcels?
Contra Costa County parcel records do not include owner names. Values, land use and building facts are returned where the county publishes them.
How many data-center projects are in Contra Costa County?
Korzy tracks 2 data-center projects in Contra Costa County: 1 permitted and 1 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 Contra Costa County?
About 40 operable power plants in Contra Costa County total about 4,200 MW of nameplate capacity, mainly natural gas, battery and pumped storage and wind.
Which water systems serve Contra Costa County?
Service areas of about 40 community water systems cover about 58% of Contra Costa County, and sewer service areas cover about 46%. A /v1/lookup with the utilities section returns the water and sewer matches at an address or point.

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Build on Contra Costa 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.

Get an API keySee pricingAPI referenceUse cases for parcel and infrastructure data