Air Date: Week of February 21, 1997

Last year, Lake Tahoe was visited by five times as many people as Yosemite. Yet it does not enjoy the same protections as a Naitonal Park. As a result, Tahoe has lost a third of its renowned transparency in the past three decades, and water quality continues to decline. William Albright reports from Nevada.

Transcript

CURWOOD: Visiting Lake Tahoe in 1861, Mark Twain wrote, "The water is clearer than the air, and the air is the air the angels breathed." But Lake Tahoe's famous crystalline purity has been declining since Twain's day, largely due to human activity. Every year the lake is visited by millions of people from around the world who come to gamble, ski, and admire the clarity of its water. Situated in the High Sierra on the California/Nevada border, Lake Tahoe is widely regarded as one of the most beautiful Alpine lakes in the world. It is also one of the deepest in North America. And as Willy Albright reports, concerns about Lake Tahoe are growing.

(Clinking sounds)

ALBRIGHT: Dense forests and high mountain peaks surround Lake Tahoe. Ski resorts, expensive homes, and casinos like this one compete for space along its shores. Last year Lake Tahoe was visited by 5 times as many tourists as visited Yosemite National Park. Although 75% of all land here is Federally owned, Tahoe does not enjoy the same protections as Yosemite.

(Boat motor)

ALBRIGHT: As a result, many people say the lake is on the verge of environmental collapse. The research vessel John LeConte, with its distinctive array of cranes and winches, has been a familiar sight on Lake Tahoe for over 20 years. The unpainted aluminum trawler is used by the Tahoe research group to study algae, the primary cause of the lake's declining clarity.

(The motor revs up)

ALBRIGHT: Today the John LeConte is headed out to the 1800-foot deep water in the middle of the lake. The goal is to measure the lake's clarity using a circular piece of white plastic called a secchi disk. The disk is lowered to the point where it just disappears, and then raised to the point where it just becomes visible again. The 2 depths are averaged, yielding what Dr. Charles Goldman, the founder and director of the Tahoe research group, calls secchi depth. Today's secchi depth is 20 meters.

GOLDMAN: When I began my studies in the late 50s at Tahoe, the average reading was 30 meters. So in effect, we've lost about a third of the transparency in a little over 3 decades.

ALBRIGHT: In fact, Lake Tahoe is losing its clarity at an average rate of a foot and a half each year. Back in his lakeside laboratory, Dr. Goldman says the explosive growth of algae is fueled by nitrates that pour into the lake from fertilizers and car exhaust.

GOLDMAN: In the early days lots of flatland technology was applied to construction activities of both roads and buildings in the Tahoe basin. And also, there's been a steady increase in air pollution with more automobile traffic around the lake as well as pollutants wafted up by the prevailing winds from the valley.

ALBRIGHT: As a result of Dr. Goldman's research, Congress created the Tahoe Regional Planning Agency, or TRPA, in 1969 to regulate development through rigorous permitting and enforcement procedures. The bi-state agency is supposed to enforce conservation measures while encouraging economic growth. But this twin mission has often plunged TRPA into controversy. The agency has drawn criticism from environmental groups who say it bows to local business interests, while many property owners and businessmen say TRPA regulations make it too difficult to develop their own land. But TRPA spokesman Pam Drum says the need for regulation is real.

DRUM: To some extent, yes. We do do business differently at Lake Tahoe. It is more expensive to build at Tahoe than perhaps other places. But there is a reason for that. We're trying to protect a natural resource that is unique, and that is our charge from the state of California as well as the Federal Government.

ALBRIGHT: Many of TRPA's harshest critics belong to the Tahoe Preservation Council, which is suing TRPA and several other agencies for $27 million. This week the US Supreme Court will hear arguments related to one case in that suit. Mary Gillanfar is a realtor and director of the Council. On a golf course outside her Tahoe city office, she says the lawsuit is an effort to get compensation for landowners who are effectively barred from developing their property because of what she describes as questionable concerns over water clarity.

GILLANFAR: It hurts me to read in the media and other places that when we say the lake clarity is declining we mean that we've lost a few feet of visibility, and they think we mean it's all green and full of algae. The lake is absolutely beautiful: pristine, crystal clear, absolutely wonderful. The air is incredibly pure, and this is what draws people here.

ALBRIGHT: But Dr. Goldman says there is more at stake than just clarity. He says he has noticed a sharp decline in the oxygen layer that holds the sediments at the bottom of the lake in place. Once this layer is gone, the lake's ecology will be changed forever.

GOLDMAN: I'd say that the next 10 to 20 years are extremely crucial. And if we don't turn around the process, the game will have been lost.

ALBRIGHT: A recent TRPA report says algae production in the lake has more than tripled since the agency began regulating development 27 years ago. Nearly everyone agrees that something must be done to save the lake and the community is struggling to work together. They have even called on the Clinton Administration to convene a summit here to address the problems facing the lake.

(A boat cutting through water)

ALBRIGHT: For Living on Earth, I'm Willy Albright at Lake Tahoe.