Blue Lake Tahoe faces permanent loss of clarity
by Teresa Crawford, Outpost staff
When Mark Twain marveled at the turquoise oval of Lake Tahoe, it was 10 years into the intense logging to build the Comstock mines that by 1900 denuded its shores. Tons of silt washed from the bare slopes into the lake. But the lake recovered most of its clarity after the silver mines closed. Until the 1950s, the Tahoe Basin lay in near-primeval peace, new forests grew, though not so fine as the original and the sediment gradually settled.
Mark Twain
described a vista like this one when he traveled to
LakeTahoe from Carson City, Nevada. Photo by Teresa
Crawford
Lake Tahoe is startlingly clear and shimmers in
ever-changing shades of blue because the water is nearly
free of organic matter and suspended sediment and reflects
most of the light falling on it. Twain was so impressed that
in "Innocents Abroad," he said Lake Como, the alpine jewel
of Northern Italy, was inferior to Tahoe.
A population and building boom that started when the basin's largest wetland was destroyed for a subdivision and marina in the late1950s continues today. The soil tonnage washing into the lake rivals the Comstock era and may be causing irreversible changes say water quality scientists from the University of Nevada, Reno and The Tahoe Research Group. Now the gradually clouding waters reflect soil erosion and air pollution as much as the mountain skies.
But wouldn't the tourists and their millions come even if human disturbance turned the lake an ordinary green?
Some people say the real reason to save the lake's clarity and preserve its forests has to do with values.
"It is one of the deepest, clearest lakes in the world," said Dennis Machida, director of the California Tahoe Conservancy in a "Sacramento Bee" interview last summer. "It has value just because it is that."
UNR environmental chemist Glenn Miller said the gas dumped by jet-ski engines into the lake evaporates out, but that's no reason to tolerate it.
"It's a values issue," he said. "How much gas do you want in there?"
Charles Goldman, director of the TRG, said the lake's defenders have 10 years before the changes are irreversible and the lake is eutrophic, or as rich in nutrients, low in oxygen and murky as a farmyard pond. Goldman named the tons of soil that wash into the lake as the biggest culprit. What scientists call nutrients, nitrogen and phosphorus are attached to the soil particles and dissolve into the water to feed microscopic bits of vegetable matter called algae. The soil itself absorbs rather than reflects light.
In July 1997, a presidential summit at Lake Tahoe convened by the governments of Nevada and California and attended by President Bill Clinton and Vice-President Al Gore focused national attention on preserving the region.
The meetings generated only $26 million in new federal funding against the $900 million that the Tahoe Regional Planning Agency says is needed to heal environmental damage. But they did cause the dozens of agencies involved in the region to connect with each other.
At a symposium in October 1998 that was an outgrowth of the presidential summit, about 200 scientists and land managers met to share research findings and develop plans for a last-ditch effort to beat Goldman's 10-year deadline and keep the lake pure enough for Twain to brag on forever.
This collection of stories includes a close-up look at that meeting and the difficult work of bringing balance to the relationship of humans and nature.
Posted Dec.
7, 1998
Copyright 1998 Nevada Outpost
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