Researcher: Ring of fire around Lake Tahoe “Not going to happen”

Friday, Aug. 13, 1999 | 8:24 a.m.

"The idea of a fire burning a ring around the lake - that's not going to happen," said Dennis Murphy, a University of Nevada-Reno scientist.

"The risk of fire is high, as high as you can imagine. But the risk of a massive conflagration that's going to burn much of Tahoe is less than many people have feared," he said.

Murphy led the Lake Tahoe Watershed Assessment Team, which conducted the $2.6 million study authorized by President Clinton at an environmental summit at the lake in 1997.

A federal panel is reviewing the full 800-page report and is expected to release it soon.

A draft copy obtained by the Reno Gazette-Journal suggests a number of factors would help diminish the chances of a disastrous fire.

The area's topography and wind conditions likely would limit a fire to one or two of the basin's more than 60 watersheds. The large number of fire-fighting agencies in the region also would help to limit the size of a fire, the report said.

Fire threats generally remain high because as much as one-third of the forest surrounding the lake it estimated to be dead, diseased or dying.

Massive clear cuts a century ago disrupted the natural forest cycles as did a widespread drought in the winter of 1994-95.

The pending report is a first-of-its kind look at the entire Tahoe Basin watershed and is designed to aid land-use managers with decisions needed to save an endangered national treasure.

Murphy said it bolsters what has been a disappointing shortage of research on the condition of Tahoe Basin forests.

While not recommending specific courses of action, the watershed assessment examines such issues as how sediment is eroding from the banks of Lake Tahoe tributaries, entering the lake and fueling algae growth that robs the lake's famed clarity.

As foresters have insisted for some time, the use of controlled burning to remove brush and smaller trees is the best way to reduce danger of wildfire at the lake, the report said. But it suggests that the traditional period for starting those fires, in the fall, may not be the best time to do so.

That's because in the fall the winds that flush smoke out of the basin are weaker than in summer, said Tom Cahill, the University of California, Davis researcher who compiled the report's air-quality data.

In the fall, the atmospheric inversion layer that acts as a lid over smoke is stronger.

Fires set in the summer would result in smoke settling near the lake in the morning, but it wouldn't stay there.

"When the wind comes up, as it always does every summer, the smoke disperses rather rapidly," Cahill said. In the fall, "the smoke tends to stay in the basin."

Controlled fires during fall are far more likely to result in violation of health and visibility standards than fires set in the summer, the report said.