Methodology

Where readings come from

Every number on a lake page comes from a specific official measurement series that an editor has matched to that lake: a provider (such as USGS or LCRA), a station or location identifier, and a parameter. The source is named and linked on every page.

How often we check

Our servers request new data on a schedule that follows each source’s reporting cadence — typically every 15–60 minutes for gauges that report continuously, and a few times a day for sources that publish daily values. If a source is unavailable we keep showing the last verified reading with its original timestamp and a notice that it is not current.

Quality checks

• Non-numeric values, provider “no data” codes and impossible timestamps are rejected; a missing value is never shown as zero.
• Units are converted only between compatible quantities (for example feet to meters), and the vertical datum is preserved.
• Readings outside a plausible range for that lake, or sudden jumps, are held back for review instead of being published.
• Repeat downloads are de-duplicated, and provisional readings are updated when the agency revises them.

Changes over time

A “24-hour change” compares the latest reading with the reading closest to 24 hours earlier from the same series. If no reading exists close enough to that time, we show that the change cannot be calculated instead of guessing. Long-range charts use the last reading of each calendar day (UTC).

Freshness labels

“Up to date”, “Delayed” and “Stale” are based on the age of the latest observation relative to how often that particular source normally reports.

Limitations

This site is for general information and is not a flood-warning or navigation service. Always follow instructions from the lake operator, the National Weather Service and local authorities.