---
title: "Instantaneous values (live sensor feed)"
method: GET
path: "/api/v1/environment/usgs-water/iv"
tags: ["Environment"]
---

# Instantaneous values (live sensor feed)

`GET /api/v1/environment/usgs-water/iv`

Live sensor readings from automated USGS gages, typically 5-15 minute cadence. Default window is last 1 day when no date range is given. Values marked with qualifier 'P' are provisional and may be revised. Dual-path: legacy WaterServices primary, OGC `continuous` collection fallback.

## Query parameters

- `site` string, required — USGS site number(s), comma-separated.
- `parameter` string — Parameter code(s), comma-separated (e.g. 00060=discharge, 00065=gage height, 00010=water temperature).
- `start_date` string — Start date/datetime ISO 8601.
- `end_date` string — End date/datetime ISO 8601.
- `period` string — ISO 8601 duration shortcut (P1D, P7D, PT1H). Ignored if start_date/end_date supplied.

## Response `200`

Flattened instantaneous-value time series with per-observation qualifiers.

- EnvelopeUSGSWaterTimeSeriesData
  - `data` USGSWaterTimeSeriesData, required — Response for GET /iv, /dv, /latest.
    - `series` USGSWaterSeries[]
      - `site_id` string, nullable
      - `site_name` string, nullable
      - `parameter_code` string, nullable
      - `parameter_name` string, nullable
      - `unit` string, nullable
      - `statistic_code` string, nullable
      - `statistic_name` string, nullable
      - `value_count` integer
      - `values` USGSWaterValue[]
        - `time` string, nullable — ISO 8601 UTC timestamp.
        - `value` number, nullable
        - `qualifiers` string[], nullable
    - `series_count` integer
    - `api_version` string, required
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

[API](https://skmtc.net/sugra/apis/sugra-api.md) · [All operations](https://skmtc.net/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sugra/sugra-api/versions/4e2740743eb4/schema)