Watching clarity emerge from its drivers, in real time.

Live readings from the Tahoe Environmental Observatory Network — lake sondes sampling water quality every fifteen minutes, and forest stations tracking the soil, air and trees of the watersheds that feed the lake.

The network

Every instrument in the basin with a coordinate — TEON's lake sondes, forest loggers, stream gauge and cameras, plus the USGS creek gauges. One marker per physical location rather than per endpoint, because a single forest tripod reports under three or four different sensor names. The dashed line is the transect: two stations 64 metres apart in latitude on opposite shores.

Shade the 60 stream catchments by any of the climate and landscape variables below. Annual precipitation is the one to start with: it runs from about 1,460 mm on the northwest shore down to 480 mm on the east, and that threefold gradient is the rain shadow the transect exists to measure.

Same weather, two watersheds

Homewood and Glenbrook 5 sit 64 metres apart in latitude on opposite shores of the lake — the same line across the map, one side facing the Pacific storms and one side in the Sierra rain shadow. Both are upland hillslope stations, and both readings below are taken at the same instant, because air temperature and humidity swing far too much across a day for "latest at each site" to mean anything.

Three anchors on the lake

The lake and its outlet

Lake Tahoe's surface elevation, and the single channel every drop leaving it passes through. Daily mean outflow at the outlet has been measured since 1895 — 131 years, a baseline no new sensor network can manufacture.

Tributaries

USGS gauges on the creeks feeding the lake, monitored for discharge, sediment and water quality since the late 1980s. Five carry real-time turbidity — the same measure as TEON's in-lake sondes, from independent instruments, which makes them the cross-check on readings like Sunnyside's faulty turbidity channel.

Forest stations

Each station is a Campbell logger reading soil moisture and temperature at two depths, air temperature and humidity, and at three Glenbrook sites a set of eight band dendrometers measuring stem diameter — which both grows through the season and swells and shrinks daily with the tree's water content.

Field cameras

Five stations carry cameras logging into TEON's LoggerNet bucket.

Wildfire in the water

Smoke deposition delivers nutrients to the lake; nutrients feed algae; algae erode clarity. Overlaying NASA FIRMS active-fire detections and HRRR-Smoke plume forecasts on the chlorophyll and turbidity signals above lets us watch a fire's fingerprint arrive in the lake.

Observatory inventory

TEON launched publicly on Sept 15, 2026 and is still building out. Below is every sensor in the current inventory. Green dots are reporting within the last day; amber have been quiet longer; grey have been dormant a while — often seasonal, since many lake sondes get pulled over the summer for maintenance.