openapi: 3.0.3
info:
  title: USACE Corps Water Management System Data Catalog Measurements API
  description: The Corps Water Management System Data API (CDA) is a REST service providing programmatic access to USACE water management data. It supports retrieval of time series measurements, monitoring locations, rating curves, reservoir pool levels, lock data, and operational information across Army Corps of Engineers projects. Public data is accessible without authentication; write operations require an API key.
  version: latest
  contact:
    url: https://cwms-data.usace.army.mil/cwms-data/
  license:
    name: US Government Work
    url: https://www.usa.gov/government-works
servers:
- url: https://cwms-data.usace.army.mil/cwms-data/api/latest
  description: National CWMS Data API Production Server
- url: https://water.usace.army.mil/cwms-data/api/latest
  description: USACE Water Data Production Server
tags:
- name: Measurements
  description: Field measurements and observations
paths:
  /measurements:
    get:
      operationId: getMeasurements
      summary: Get Field Measurements
      description: Returns field measurement data collected at CWMS locations including streamflow discharge measurements used for rating curve development.
      tags:
      - Measurements
      parameters:
      - name: office
        in: query
        description: USACE district office ID
        required: false
        schema:
          type: string
      - name: location-id
        in: query
        description: CWMS location identifier
        required: false
        schema:
          type: string
      - name: unit-system
        in: query
        description: Unit system for output values (EN or SI)
        required: false
        schema:
          type: string
      - name: begin
        in: query
        description: Start of time window
        required: false
        schema:
          type: string
      - name: end
        in: query
        description: End of time window
        required: false
        schema:
          type: string
      responses:
        '200':
          description: Field measurements
          content:
            application/json:
              schema:
                type: object