GageLog documentation
GageLog collects 15-minute streamflow readings from 9,100+ USGS and state streamgages, normalizes them to one schema, and layers analytics, alerting, and reporting on top. These pages explain each part of the site and how the numbers behind it are computed.
If you're new, start with Getting started. If you're evaluating whether the data fits your use, read Data sources & methodology first — it covers where readings come from, how often they update, and what the quality flags mean.
Getting started
Accounts, what's free, and a first tour of the site.
Finding gages
The Explore map, search, and locating gages near you.
The gage detail page
What each tab shows, from Today through Archive.
Charts & statistics
How every chart and statistic is computed, and the conventions behind them.
Tracked gages
Your dashboard: overview, side-by-side comparison, and reporting.
Monitors & alerts
Threshold and anomaly monitors, delivery, and alert behavior.
Exports & the API
Workbooks, the flow-conditions PDF, and programmatic access.
Data sources & methodology
Where readings come from and how they're processed.
Plans
What each tier includes and how limits apply.