USGS Water Services · Rate Limits

Usgs Water Rate Limits

USGS Water Services (both legacy WaterServices and next-generation api.waterdata.usgs.gov) implement rate limiting to prevent any single user from degrading service availability for others. Anonymous (unauthenticated) users face a more conservative request ceiling; registering for a free API key at api.waterdata.usgs.gov/signup/ raises that ceiling. Exact numeric thresholds are not publicly published. Enforcement is via IP-level blocking (HTTP 403) for excessive anonymous use. API-key users receive HTTP 429 on throttle. The Water Quality Portal (waterqualitydata.us) does not publish specific limits but supports POST for large queries and gzip compression to reduce round-trip load.

Usgs Water Rate Limits is the machine-readable rate-limit profile for USGS Water Services on the APIs.io network, conforming to the API Commons Rate Limits specification.

It captures 2 rate-limit definitions, across the anonymous and api-key tiers, measuring requests.

The profile also includes 6 backoff/retry policies defined and response codes documented for throttled, quotaExceeded, and serviceUnavailable.

Tagged areas include Water, Hydrology, Environmental, Government, and Rate Limiting.

2 Limits Throttle: 429 Quota: 403
WaterHydrologyEnvironmentalGovernmentRate LimitingIP BlockingAPI Key

Limits

Anonymous IP Limit ip-address
requests · hour
unspecified
API Key Higher Limit api-key
requests · hour
unspecified

Policies

Minimal Footprint
Always specify the minimum amount of data needed in each request using built-in filters (site codes, parameter codes, date ranges, bounding boxes). Never attempt to retrieve all available data in a single call.
Gzip Compression
Send Accept-Encoding: gzip header to compress responses and reduce bandwidth. Strongly recommended for any bulk or time-series queries.
Exponential Backoff on 403/429
On HTTP 403 (IP blocked) or HTTP 429 (throttled), wait before retrying. Use exponential backoff with jitter; start at 30 seconds for 403 responses, which indicate IP-level blocking that may persist for several minutes.
API Key for Bulk Work
Register for a free API key at api.waterdata.usgs.gov/signup/ before running bulk or automated workflows to access the higher rate limit tier.
Use POST for Large WQP Queries
When Water Quality Portal query parameters exceed URL length limits, use HTTP POST with a JSON body instead of GET to avoid truncation errors.
Contact for High Volume
Contact wdfn@usgs.gov to discuss data needs that require sustained high request rates or bulk data downloads beyond what the standard API supports.

Sources