saving nevada’s lakes

Conserving these four major waterways will take great environmental, individual, and political strides.

By CHARLIE JOHNSTON | July/August 2010

Growing up in the shadow of Northern Nevada’s Carson Range, some of my fondest memories include outings to Lake Tahoe, practically in our backyard. I don’t recall exactly what my initial impression of the lake was—cut me some slack, I was only two or three—but, as I grew older, my observation of the famous body of water echoed the sentiment expressed by Mark Twain upon first seeing it in 1861. “I thought it must surely be the fairest picture the whole world affords,” he said.

Though few lakes can compare with the sheer beauty of Tahoe, Nevada’s vast desert expanses contribute to similar admiration for all of its lakes and the precious, life-supporting water they hold. Sadly, the beauty of these oases does not ensure their survival, and Nevada’s four major lakes—Mead, Pyramid, Tahoe, and Walker—face serious challenges. If future generations are to relate to Twain’s assessment and appreciate these lakes as so many before them have, we must address these challenges and come to acceptable solutions—before it’s too late.

LAKE MEAD

Standing at Saint Thomas Point and Historical Site in Southern Nevada, editor Matthew B. Brown and I are awash with disbelief at the scene before us. A sea of green stretches for miles across the shallow basin to the east and south until it is lost beneath the craggy desert ridges of Lake Mead National Recreation Area. Our shock stems not from the presence of the lush field of vegetation in this, one of the driest places in North America, but from the lack of something even more unlikely in such an environment: water.

Ten years ago, the waters of Lake Mead’s Overton Arm would have been lapping at our feet. Today, no water can be seen from this vantage. It is the nature of any desert lake—especially a reservoir such as Mead—to vary in depth from year to year, tied to snowmelt from upstream mountains. Mead’s “bathtub ring” (see photo above) is evidence of its manically shifting shoreline. More than 120 feet of previously submerged land above the shore is painted white by mineral deposits—a sharp contrast to the original hues of brown and red. The ring, towering above the shoreline, tells an ominous tale. While the lake’s 70-year-plus history is punctuated by periods of drought, the latest has many concerned. As the result of this decade-long drought, Mead is at its lowest point since 1965, when the Colorado River was diverted to fill the newly constructed Lake Powell, upstream in Arizona.

To put this into better perspective, consider that in 1983 Lake Mead’s surface elevation reached 1,225 feet above sea level. Its average elevation is 1,173 feet. Anything below 1,125 feet is considered a drought. As of June 7, 2010, Lake Mead was at 1,093 feet, already tied with 2009’s low-water mark months before the lake’s traditional low season. If the lake’s level dips to 1,050 feet, Hoover Dam’s hydroelectric power plant will shut off. Although it is hard to predict when the water will reach this impasse, many scientists agree that the region is growing drier, an indication that such a day is on the horizon. To compound the climatic issues contributing to the lake’s dwindling level, the number of people who depend on water from the Colorado River has increased exponentially since the 1936 construction of Hoover Dam and corresponding creation of Lake Mead. Las Vegas, a short drive west of Lake Mead, has exploded from fewer than 9,000 residents to a metropolitan area of nearly 2 million people.

In Las Vegas—a city that relies on Lake Mead for power and water and receives just 4.5 inches of rain a year—the Southern Nevada Water Authority is taking steps to conserve the dwindling water supply. A rebate program offers SNWA customers money to replace grass with desert landscaping, and strictly enforced restrictions prohibit landscape watering during the hottest hours of the day in the summer. Some of SNWA’s more aggressive solutions include the construction of an intake pipe that would allow the utility to access Mead’s water to elevations lower than 1,000 feet and a controversial proposed pipeline to transport groundwater from eastern Nevada.

Though drought and seemingly insatiable demand for water combine to deal Lake Mead a hard hand, the lake is also being attacked from within by invasive species. While the issue doesn’t receive as much attention as drought and water use, it is also cause for concern. Dr. Sudeep Chandra is a limnologist (limnology is the study of biological, chemical, physical, geological, and other attributes of inland waters, especially lakes) at the University of Nevada, Reno and an expert on the impact of nonnative species. He says that introduced species, such as Lake Mead’s quagga mussel, have numerous negative effects on the water quality and ecology of lakes.

The mussels in Lake Mead are of particular concern because of the correlation between rising quagga populations and increases in dangerous toxins. They absorb toxins and heavy metals such as mercury and excrete them in concentrated pellets that sink to the lake floor, where many are eaten by bottom-feeding fish. Eventually the toxins concentrate in the fishes’ tissues. This process works its way up the food chain all the way to birds and fishermen. Additionally, the presence of the mussels and their affect on the food chain results in a lower ratio of nitrogen-to-phosphorus in the water, creating ideal conditions for the growth of cyanobacteria, a dangerous type of algae associated with creating dead zones in lakes. Researchers at UNR and the University of Nevada, Las Vegas are working diligently to solve these problems.

PYRAMID LAKE

“I once caught a fish this big!” Anyone reading this can practically see my hands spreading further and further apart as the tale grows taller—another big fish story. But, if I were referencing a Lahontan Cutthroat Trout caught at Pyramid Lake in the early 1900s, the account would doubtfully be a fable. The largest Lahontan Cutthroat ever caught—and recorded—was at Pyramid Lake in 1925. The monster tipped the scales at 41 pounds. Photos and more stories suggest that as recently as the late 1800s, the lake produced fish of 60 pounds and larger.

It is unlikely that Pyramid will ever know a fish of these proportions again. Severe overfishing in the 1800s removed many such fish, and the lake’s receding shoreline has played a substantial role in the continued drought of record-setting catches. Being a terminal lake—having no outlet—the survival of Pyramid and its unique inhabitants depends on a crucial inflow of fresh water. In 1905, as part of the Newlands Project, the Derby Dam was constructed on the Truckee River to divert water for irrigation use in Churchill County. The water diverted by the dam supports 57,000 acres of farmland—among the region’s most important and productive agricultural assets—and 6,000 acres of wetlands, making the debate over water diversion and use all the more complex and heated.

In the following 60 years, Pyramid’s water level dropped more than 80 feet, pushing the Lake’s salinity, alkalinity, and overall level of total dissolved solids, or TDS (the combined content of all inorganic and organic substances found in freshwater), to levels that put many of the fish in danger of dwindling to unsustainable numbers. Among those fish are the Lahontan Cutthroat Trout, a species found in certain rivers and lakes in the Great Basin, and the Cui-ui, a suckerfish found only in Pyramid Lake. To preserve these species and the lake, the Pyramid Lake Paiute Tribe, to which the lake belongs, fought to have the fish protected under the 1973 Endangered Species Act, effectively making Pyramid the top priority for water rights on the Truckee River and ensuring a future for the Cutthroat and Cui-ui in the lake. The Pyramid Lake Paiute Tribal Chairman, Mervin Wright Jr., says fishermen who use the lake often practice catch and release, also helping ensure survival of Cutthroat.

Even with these steps, Pyramid still faces an uncertain future. Runoff from Reno and Sparks is a constant challenge to the lake’s water quality—treated water from those upstream cities entering the lake causes further eutrophication (the “greening” of lakes through excessive nutrient loading), and in severe droughts the Truckee River can be diminished to a trickle. While stopping the inflow of treated water would curb eutrophication and aid water quality, Wright says the lack of that extra water in severe drought years would be devastating for the lake.

LAKE TAHOE

A few years ago, my friends and I lost our portable CD player to the icy blue waters of Lake Tahoe. A passing boat’s wake and resulting stumble of one of our passengers sent it overboard, and by the time we clamored to the edge it was too late. Leaning over the side of the boat, we watched the shimmering object slip further and further into the cerulean abyss. We guessed that it reached nearly 100 feet before falling out of view forever.

A few decades ago, our approximation would have easily been correct, but not so today. From the time researchers at the University of California, Davis started recording the clarity of Lake Tahoe in the early 1960s, a concerning trend has emerged. The clear crystalline waters were growing less and less pristine with each passing year. The first annual average clarity measurement taken by UC Davis in 1968 was measured at more than 102 feet. By 2000, that number had plummeted to about 67 feet and has remained in the range of 70 feet since.

Dr. Charles Goldman, a limnologist at UC Davis, has dedicated more than 50 years of his life to studying and protecting Lake Tahoe. “The value of Lake Tahoe is almost incalculable,” he says. Goldman’s primary area of focus is eutrophication, one of the major contributors to Lake Tahoe’s declining clarity over the last four decades. Nutrient loading, especially the ratio of nitrogen to phosphorous, feeds and encourages growth of algae, which in turn worsens water clarity.

The progressive greening of Lake Tahoe is the result of a number of factors, one of the most prevalent being population growth in the Tahoe Basin. Since clarity measurements began, the number of people living on the lake’s shores has increased from 10,000 to 60,000. Goldman says such environmentally irresponsible building as the construction of the Tahoe Keys—which dug out Pope Marsh, formerly the largest wetland in the Sierra Nevada and a vital filter for the lake’s water—sped eutrophication drastically. Runoff from Tahoe communities further speeds the lake’s declining clarity. More environmentally responsible building, diverting treated sewage water out of the Tahoe Basin, and what Goldman calls some of the strictest building codes in the world have helped in the struggle to slow loss of clarity. Millions of people visit Lake Tahoe each year to admire its unsurpassed beauty and partake in myriad activities from skiing and boating to hiking and sightseeing. Without its legendary clear waters, Goldman says, the lake would fail to draw such attention, a potentially devastating scenario for the region’s tourism-based economy.

Introduced species in Lake Tahoe not only contribute substantially to eutrophication of the lake, but also disrupt the food chain and compete with native species for limited resources. According to Chandra, the introduction of such fish as Rainbow, Brook, Brown, and Lake trout, crayfish, Kokanee salmon, and Mysis shrimp during the late-19th through mid-20th century directly caused a decline in such native species as Lahontan Cutthroat Trout, Lahontan redside shiners, and speckled dace. The detriment caused by such invasive species is extensive, and some of the harm is only just beginning.

Dr. Marion Wittmann of UC Davis specializes in one of Tahoe’s most threatening invasive species, the Asian clam. The clams were first observed in the lake in 2002 and since have grown to densities as high as 3,000 per square meter in the southeast part of the lake. According to Wittmann, Asian clams are known for their ability to aggressively outcompete native invertebrate species thanks to their high rates of filtration, metabolism, reproduction, and tolerance to a wide range of habitats. The heightened filtration and shift in natural cycles of food availability and waste production brought by the clams also encourages growth of algae.

Wittmann says experiments aimed at reducing Asian clam populations in Tahoe have mixed results. Bottom barriers—rubber mats similar to pond liners—can be laid on top of clam beds to reduce oxygen and kill up to 100 percent of the clams.

Unfortunately, the barriers also kill native species. Diver-assisted suction, in which the clams are removed with underwater vacuums, is effective but labor intensive and very costly.

Ambitious efforts to preserve water quality and keep more invasive species such as quagga and zebra mussels from entering the lake are gaining momentum and appear to be working. The Tahoe Regional Planning Agency’s Blue Boating program requires that all boats entering the lake be inspected to ensure they aren’t carrying invasive species and that they meet clean boating standards. Annual Blue Boating certification costs from $20-$60 for boats that use only Lake Tahoe and from $70-$125 for boats that use other waters.

WALKER LAKE

As I descend the road to the boat ramp at Walker Lake’s Sportsman’s Beach, a series of small brown signs catches my eye. “Lake Level 1882”…1908…1927… 1933…1935…and so on at intervals ranging from two to 10 years. When I reach the final sign—“Lake Level 1969”—just above the boat dock, I am still more than 20 vertical feet from the shore and to the best of my estimation, no less than 100 vertical feet from where the signs started. The end of the boat ramp trails off into the rocky shore a fair distance from the water’s edge, rendering it useless.

A large yellow caution sign makes the hollow promise that the ramp is scheduled for repair and tells visitors to use it at their own risk. Not long after the water fell below the ramp, the catalyst for the ramp’s existence—Lahontan Cutthroat Trout—started disappearing from Walker Lake. And without the fish, the droves of anglers who once plied the lake’s waters and frequented the ramp have vacated as well.

Glenn Bunch is the chairman of the Walker Lake Working Group, an organization dedicated to saving Walker Lake. Since the 1990s, Bunch, the Working Group, and a number of Nevada politicians—namely U.S. Senator Harry Reid—have been entrenched in the battle to save Walker Lake. It hasn’t been going so well. Quoting a scientific survey conducted on levels of total dissolved solids in the lake, Bunch says Lahontan Cutthroat cannot survive at levels above about 16,000. Walker Lake is at 17,000 and climbing. When the boat ramp at Sportsman’s Beach was built in the late 1980s, the TDS level was 12,000. The bottom of the now dry ramp indicates the lake level at 16,000 TDS, the point at which the lake ceased to be a viable fishery. While a few hardy fish remain, it is likely they are among the lake’s last Lahontan Cutthroat unless drastic steps are taken to get more water into the lake and thereby improve its water quality.

According to Bunch, studies conducted by UNR and UC Davis have concluded that without diversions of the Walker River such as irrigation, the lake would still be as full as it was more than 100 years ago. Stopping upstream diversions would cripple agriculture in the Mason Valley and is not a feasible option, but the Working Group hopes to collaborate with upstream farmers to lease unused water rights and encourage the cultivation of crops that require less water. Bunch says some farmers have made their unused water rights available to help feed the lake, and organizations such The Nature Conservancy purchase upstream irrigation rights to free up more water.

According to Bunch, the lake would need an influx of roughly 100,000 acre-feet (almost 33 billion gallons) of water to bring it to desired levels—an unimaginably large and unrealistic amount of water to acquire over the short term. Longer-term goals to bring the lake to what the Working Group and other conservationists consider an acceptable level, Bunch says, are more attainable: “We are looking for 25,000 to 50,000 acre feet [annually] to bring the lake back and maintain it.”

THE FUTURE OF OUR LAKES

While the picture painted by the issues facing Nevada’s major lakes may look like a bleak one, it doesn’t have to be. Through learning from the mistakes of previous generations we are in a unique position to make steps toward correcting many of them. Fifty years ago, treated sewage from communities surrounding Lake Tahoe was put back into the lake. Through the efforts of Goldman and other conservation-minded individuals, that practice was brought to a halt decades ago, a major step in preserving the water quality and clarity of Lake Tahoe.

Some of the steps necessary to preserve our lakes are substantial state, national, and global issues and require continued action on the part of our leaders in Carson City and Washington D.C. But there are simple steps we can all take to reduce our impact on the natural gems we cherish and enjoy so much. As desert dwellers, Nevadans must be constantly mindful of our water use and in so doing, can preserve our lakes in the process. Watering lawns only on assigned days and using professional car washes instead of washing our own vehicles reduces water waste and runoff. Replacing old faucets, showers, and toilets with more water-efficient models can save water and money. Opting for a xeriscaped yard instead of a lawn can save 10,000 gallons of water annually at a typical suburban home.

While enjoying the lakes, simple steps such as properly disposing of waste water and opting for watercraft with newer, more environmentally friendly four-stroke engines, instead of two-strokes, can directly help in the struggle to protect the water clarity and quality of the lakes. Utilizing human-powered watercraft whenever possible reduces pollution even further.

Ensuring the survival of Mead, Pyramid, Tahoe, and Walker will not be an easy task. It will require many years of hard work, cooperation, and sacrifice. But as I reminisce on my first impressions of these unique, awe-inspiring places, it seems like a small price to see that future generations of Nevadans and visitors can experience our amazing lakes as so many of us have.