Lake Tahoe’s water quality and clarity are in good condition following this summer’s devastating Caldor Fire, new research showed.
According to the League to Save Lake Tahoe, citizen volunteers from its Pipe Keepers program collected stormwater samples during an atmospheric river storm on Oct. 24. The samples came from 25 sites on Tahoe’s south shore, including 16 storm water pipes and eight stream sites that drain the areas burned by the Caldor Fire.
The results of the water samples showed that overall turbidity — a measure of particles suspended in water — ”was not out of the ordinary for an intense storm,” the league said.
The contaminants to the lake could have been much higher, the league said, but the results show that the stormwater infrastructure and natural filtration function of Tahoe’s rivers, marshes, meadows and wetlands were effective in removing debris and particles from the streams that flow into the lake.
“In the context of an intense rain and snow event hitting huge swaths of scorched slopes from the Caldor Fire, these results were good news,” the league added.
The fire hit Meyers and the Christmas Valley areas the hardest. In these areas, volunteers recorded some of the highest turbidity levels. But the cloudiness of the water declined as the Upper Truckee River winded through meadows toward the lake. Data shows that the turbidity readings were 41.7 Nephelometric Turbidity Units, or NTUs, at Christmas Valley, but dropped to 4.4 NTUs by the time river flowed past the South Tahoe airport, the league said.
The standard for the lake set by the Lahontan Water Quality Control Board is 3 NTUs.
The sampling program will continue monthly through the winter, but the league said preliminary readings were encouraging.
The Caldor Fire began Aug. 14 and burned through much of Eastern El Dorado County from Grizzly Flats to the outskirts of South Lake Tahoe, jumping across Highway 50 at one point. The blaze charred 221,505 acres, or about 346 square miles, according to the U.S. Forest Service, before it was fully contained Oct. 21.
This story was originally published November 17, 2021 5:00 AM.