Tahoe's water gets a shot of blue
by Rebecca Romaggi, Outpost contributor
The passage of the $20 million Lake Tahoe preservation bond in November 1996 was a victory for the environment. The problem is deciding how the money should be used among the scientists, forest service and environmental groups who each have different ideas. Meanwhile, the blue lake turns greener every day.
Along with a $10 million bill from California, the two states will use the money to fund erosion-control projects around the lake. But this money is nowhere near enough to Jeffry Cutler, assistant executive director of the League to Save Lake Tahoe.
"Although $30 million is a good chunk, it is less than what we need," Cutler said. "(Tahoe Regional Planning Agency) has identified a whole list of projects -- $500 million worth of work."
The good news is that every little bit counts, he said. The
The crystal-blue water of Lake Tahoe could be in trouble due to outside factors. Photo by Jennifer Greer. |
"There is a real recognition amongst the league that we've got to hit the big ticket items: the wetland and watershed restoration," Cutler said.The crystal blue water Lake Tahoe is famous for is becoming about a foot and a half cloudier with each passing year. Clarity is measured by the depth at which the human eye can see a white plate-like object called a secchi disc. Thirty years ago, the disc could be seen at a depth of about 100 feet. Today, the average visible depth is about 70 feet.
This loss of clarity is due to increased algae growth nourished by nitrogen and phosphorous. As the algae flourish, the lake loses clarity. However, people disagree about where the excess nitrogen and phosphorous is coming from.
Scott Tyler, a scientist at Desert Research Institute is conducting a four-year study to determine if nitrogen could be seeping into the lake through the ground water.
"The reason we study this is ... a lot of money is spent on pollution control, and hopefully our work will prioritize," Tyler said. "It's a low cost study that can answer basic questions."
Sixty percent of the water added to the lake comes from precipitation, which typically contains very little nutrients, Tyler said. Turning up the ground around the lake allows rain and snow to pick up nutrients when draining down into the lake. He said the bond passage was positive because people are now aware of problems like these at Tahoe.
"Basically, we're speeding up the biological aging of the lake," Tyler said.
About 80 percent of the land around the lake is federally owned. Through the forest service, the land is controlled by the Lake Tahoe Basin Management Unit, with an annual budget averaging $500,000. Mike Derrig, a hydrologist for the Management Unit, said the main problem is erosion.
"The algae blooms are the result of phosphorous, which is sediment related," Derrig said.
One of the ways soil displacement occurs is mountain biking, he said. Rain washes nutrients from the exposed land and feeds the algae in the lake. Projects for the Management Unit over the past decade have focused on restoring disturbed land.
"I'm firmly convinced that we are seeing impact from mountain bikes," Derrig said. "The problem is a lot of these trails have turned into spaghetti bowls in the mountains."
However, the League to Save Lake Tahoe sees jet skis as a big problem. Cutler said the group supports an outright ban on the water craft until the industry will produce machines that meet EPA standards. The TRPA has recommended that Jet Skis be banned at Lake Tahoe by June, 1999. Personal watercraft business owners around Lake Tahoe have filed suit against TRPA to stop the proposed ban. The matter is still pending.
"Jet skis dump 25 to 40 percent of their fuel directly into the lake," Cutler said.
Derrig said any objections he has toward jet skis are not based upon evidence of environmental damage, but his own personal feelings.
"I hate the noise more than anything -- they remind me of a pack of hornets," Derrig said. "Every year there seems to be more of them."
Tyler said that water craft introduce "oil and gasoline into the lake." He said additional chemicals and nutrients introduced by man into the lake will help the algae grow.
Cutler said regulations placed on jet skis instead of a ban by the TRPA would not be satisfactory to the league, because there is no money for enforcement.
"We think a ban would pass legal muster here," Cutler said.
Posted Dec. 16, 1997
Copyright 1997 Nevada Outpost
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