How we measure

LakeSonar shows freshwater conditions from public gauges and state stocking reports. Every value on a water page shows its source and how old it is. Age is the observation time, or the issued time for a forecast. Where no sensor exists, the page says "Not measured". Missing values are left blank. They are not stored as a number.

Gauges

USGS Instantaneous Values supply the gauges named on each water. USACE CWMS supplies the Dale Hollow pool elevation, tailwater temperature, and outflow. Those series are observed values. Forecast series are not used.

Weather

The National Weather Service forecast supplies wind and the other weather values on a water. The EPA UV index is read for the ZIP on that water, when one is set. The age of a forecast is its issued time.

Stocking

Georgia DNR publishes a weekly trout stocking PDF. A row is a report for that date. The report does not publish a fish count, so the page does not show one.

TPWD publishes a trout stocking schedule. A date is labeled scheduled. It is not labeled stocked. A date before today is hidden. When every listed date is already past, the page says TPWD has not posted this season's schedule yet. A season total is shown only from upcoming dates, and only when that total does not have to be split across dates that already passed.

Bite times

Bite times are sun and moon times at the water's coordinates. There is no score.

Depth

Canyon Lake contours come from the Texas Water Development Board volumetric survey of November 2001, recalculated in October 2016. Depth is feet below the survey conservation pool of 909 ft. Contours: Texas Water Development Board survey. Not for navigation.

Lake Lanier and Dale Hollow Lake do not have a depth layer yet. Those maps say "Depth map coming". Where contours exist, the teaser says "Depth map" and the survey credit stays on the depth tab. A river has no depth pill. Its depth tab notes that the river has no depth map. Flow and temperature stay on the Conditions tab.

The scene behind the page is an illustration. It is not a measurement.

Full pool comparisons appear only where a published reference is cited on the same datum as the reading. Cited figures include 1,071 ft for Lake Lanier and 909 ft for Canyon Lake.

Sources

USGS Instantaneous Values

https://waterservices.usgs.gov/nwis/iv/

USACE CWMS

https://cwms-data.usace.army.mil/cwms-data

National Weather Service

https://api.weather.gov

EPA UV index

https://data.epa.gov/efservice/getEnvirofactsUVDAILY/ZIP

Georgia DNR weekly trout stocking report

https://georgiawildlife.com/sites/default/files/wrd/pdf/trout/Weekly_Stocking_Report.pdf

TPWD trout stocking schedule

https://tpwd.texas.gov/fishboat/fish/management/stocking/trout_stocking.phtml

Texas Water Development Board survey

https://www.twdb.texas.gov/surfacewater/surveys/completed/index.asp#canyon

U.S. Census Bureau Gazetteer Files

https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.html