When Stuart Roll moved to Tahoe around two decades ago he took the gondola up the mountain in South Lake Tahoe. What he saw concerned him.
“I remember riding up the gondola and looking out over the lake and seeing what appeared to be a giant brown plume coming out of the river,” said Roll, a watershed supervisor for the California Tahoe Conservancy. That plume is fine sediment from the Upper Truckee River that pours into the lake.