Query official Colorado, New Mexico, Montana, Idaho and Oregon water rights records over HTTP: 1,532,260 records in all. Responses are JSON; every record links back to its official source page.
Requests are authenticated with an API key sent in the X-API-Key header. Your key and the base URL are issued together when your account is set up. Email erik@westernwaterdata.com to request one.
If you'd rather not work with an API at all, that's fine: send the county, stream or basin you care about and you'll get the results back as a spreadsheet.
| Method & path | Auth | Returns |
|---|---|---|
GET /v1/health | none | Record counts by state and the last successful data load |
GET /v1/water-rights | API key | Filtered, paginated list of records |
GET /v1/water-rights/{id} | API key | A single record, including the original source record |
curl -H "X-API-Key: YOUR_KEY" \
"https://YOUR_BASE_URL/v1/water-rights?state=CO&county=BOULDER&priority_before=1880-01-01&limit=10"All filters are optional and combine with AND: each one you add narrows the result. With no filters you get the first page of everything.
| Parameter | Matching | Example |
|---|---|---|
state | exact | CO, NM, MT, ID or OR |
county | exact, uppercase | BOULDER, DONA ANA, YELLOWSTONE |
water_source | partial (contains) | RIO GRANDE |
owner | partial (contains) | SMITH (New Mexico, Montana and Idaho records) |
q | partial; structure name, source or identifier | DITCH |
status | exact, source status code | ADJ, PMT (New Mexico); ACTV (Montana); Active (Idaho) |
right_type | partial (contains) | STATEMENT OF CLAIM (Montana); Decreed, License, Permit (Idaho); Cert, Permit, Inchoate, Claim (Oregon) |
priority_after | date ≥ | 1900-01-01 |
priority_before | date ≤ | 1880-01-01 |
min_amount | number ≥ | 100 |
units | exact | CFS (flow) or AF (volume) |
limit | 1–500, default 50 | 100 |
offset | pagination offset | 50 |
include_raw | boolean | true adds the original source record |
total (how many records match your filters in the whole database) and results (the ones returned on this page, limited by limit).| Field | Description |
|---|---|
id | Stable identifier in this database |
source_state / source_agency | Originating state and agency |
source_record_id | The agency's own record identifier |
right_identifier | WDID (Colorado), file number such as RG-13267 (New Mexico), water right number (Montana, Idaho) |
structure_name / structure_type | Ditch, well, reservoir, etc. |
water_source | Stream, river or declared basin |
county | County name |
latitude / longitude | Decimal degrees (NAD83) |
location_accuracy | How the coordinates were derived |
appropriation_date | Colorado: date the appropriation was initiated |
adjudication_date | Colorado: date confirmed by the water court |
priority_date | Effective seniority date in that state's own semantics |
priority_rank | Numeric rank within the state (Colorado administration number). Not comparable across states. |
amount_absolute / amount_conditional | Decreed amounts |
amount_units | CFS or AF |
uses | Decreed or permitted uses, as coded by the agency |
right_type | Type of right as the agency classifies it: statement of claim, provisional permit or certificate (Montana); decreed, licensed, permitted or statutory claim (Idaho) |
status | Agency status code (New Mexico, Montana, Idaho) |
owner | Owner of record (New Mexico, Montana, Idaho) |
case_numbers | Associated case or sub-file numbers |
source_url | Link to the official record at the agency |
source_modified_at | Last change reported by the source |
last_seen_at | When this record was last confirmed present at the source |
raw | The complete original source record (only with include_raw=true) |
Colorado: 174,440 records from the Division of Water Resources (CDSS/HydroBase), updated daily at the source. Priority dates are present on every record. Owner names are not part of the state's net amounts dataset.
New Mexico: 283,493 points of diversion from the Office of the State Engineer (WATERS), with owner names and coordinates on every record. Priority dates are not available in bulk: the OSE has confirmed in writing that no downloadable priority-date dataset exists. For the 17,151 adjudicated records, source_url links directly to the official water right summary where the priority date is shown.
Montana: 603,569 points of diversion from the DNRC Water Resources Division, with the owner of record, the enforceable priority date on 581,147 of them, and the type of right on every one. A single right can have several points of diversion, so count distinct right_identifier values, not rows. Each record links to the state's official abstract.
Oregon: 196,567 points of diversion from the Water Resources Department, covering 85,898 distinct water rights, each with its owner of record, priority date and stage (certificated, permit, inchoate or claim). The OWRD's mapped data leaves out pending applications, irrigation district rights, temporary transfers, instream leases and limited licenses, so it is not every drop of water in the state. County is assigned here by point-in-polygon against the Census county boundaries.
Idaho: 274,191 points of diversion from the Department of Water Resources, with owner, priority date on 273,640 of them, and the legal basis of each right (decreed, licensed, permitted or statutory claim). County is not published by the agency: it is assigned here by point-in-polygon against the Census county boundaries, so a point within roughly 100 m of a county line may fall in the neighbouring county.
All records come from official state open-data channels: the Colorado Division of Water Resources, the New Mexico Office of the State Engineer, the Montana DNRC Water Resources Division, the Idaho Department of Water Resources and the Oregon Water Resources Department. License terms for each source were reviewed before ingestion, and the original record is preserved alongside the normalized one. Data is informational only and not suitable for legal, engineering or survey purposes.
Data is provided as-is, without warranty of any kind, and is not an official record of any agency. For legal purposes, verify at the source using the source_url on each record.