Mono Lake, salty and alkaline and California’s second-largest lake, became the center of controversy in the 1970s. It supported the world’s second-largest breeding colony of California gulls and was habitat to other bird species. Mono Lake was also beautiful, a large open body of water in desert landscape below the east slope of the Sierra Nevada, its shores lined in place with tufa towers, an unusual and curious geological feature. The streams that flowed into it were famous for some of the best recreational fishing in the U.S.
Since the 1940s, the city of Los Angeles had diverted all the stream water that had previously flowed into the lake. By the 1980s that water, the best quality the city had access to, provided 17% of Los Angeles’s water supply. But as a result of the stream water diversion, the lake level was dropping and the salinity and alkalinity of the lake increasing.
Mono lake's unusual chemistry supported a huge annual production of brine flies and brine shrimp, providing food for the more than 1.3 million birds that stopped at the lake to molt and feed during migration or to nest and breed. Many people feared that as the lake’s salinity and alkalinity increased, these would exceed the tolerance of the shrimp and flies, destroying the food base of the birds. The fear extended to concern that the lake would eventually dry to the point that all life in it would die, including the algae that were food for the shrimp and fly. The lowering lake level also caused several islands used by California gulls as nesting and breeding sites to become bridged to the mainland. Coyotes crossed the bridges, preying on gull chicks and disrupting breeding. Reproductive success plummeted. Even after the lake level rose during wet years and made the sites islands again, the gulls seemed reluctant to reoccupy them for several years.
For all these reasons, bumper stickers saying “Save Mono Lake,” became common and an environmental group, the Mono Lake Committee, led an effort to stop the water diversion to Los Angeles. The city in turn claimed that the lake’s life would not die, because the lake received ground water and direct rainwater that would keep it at a sustainable level.
Direct environmentalist action failed to stop the water diversions, so in the 1980s the Mono Lake Committee lobbied the California legislature, which passed a bill funding a scientific study to determine whether the lake would dry out to the point that the invertebrates and algae in the lake would become die out and the migrating and nesting birds would no longer be able to use the lake. I was asked by the State Department of Fish and Game to direct that scientific study, and formed a small scientific committee of scientists, interested in the lake, but who had no stated political bias about the water diversion issue. In addition to myself, members included: the famous geochemist Wallace S. Broecker, hydrologist Lorne G. Everett, limnologist Joseph Shapiro, and ecologist John A. Wiens, who was an expert on birds and their environments.
Our approach differed that of most large scientific analyses of major environmental problems. Typically, a large committee of well-known scientists would have a few meetings to discuss the problem and then write a report based on existing information. It was the scientific-consensus approach.
Our scientific committee, in contrast, was small enough to have direct discussions (that is arguments), met for longer periods, and maintained frequent communication among its members. It also had funds to support work by scientists already doing research at Mono Lake. But the work it funded first was not to be new research, but the integration and summarization of existing research. Surprisingly, such integration and summarization had not been done. The committee also retained sufficient funds to support some new research if that became necessary, which it did.
The key to whether the lake would continue to support brine flies, brine shrimp, and various species of algae was whether it would dry out to the point where it became so salty and alkaline that none of these species could complete their life cycles. Existing studies showed what levels of salinity and alkalinity would be lethal, but two things were missing to determine whether and when this would happen: a mathematical model was necessary to forecast the rate of water evaporation from the lake, and the total volume of water in the lake had to be known. Without these two kinds of analysis, the argument between the environmentalists and the city of Los Angeles could have gone on indefinitely with no way to resolve it.
To determine the water volume of the lake, we needed a map of the lake’s basin. But, surprisingly, nobody had ever done such a map. We hired an oceanographic mapping company to make that map, and consulted with a scientist who developed a computer model of rates of evaporation from the lake .
Ironically, more than a century earlier, Henry David Thoreau had run into the same problem. When he lived at Walden Pond, he complained that “There have been many stories about the bottom, or rather no bottom, of this pond, which certainly had no foundation for themselves. It is remarkable how long men will believe in the bottomlessness of a pond without taking the trouble to sound it,” Thoreau wrote during his sojourn there. “Many have believed that Walden reached quite through to the other side of the globe,” he continued.
Thoreau took a simple and direct approach to determining the depth of the pond: He measured it. He had the skill to do this because he worked now and again as a surveyor. "As I was desirous to recover the long lost bottom of Walden Pond,” he wrote, “I surveyed it carefully, before the ice broke up early in '46 with compass and chain and sounding line. I fathomed it easily with a cod-line and a stone weighing about a pound and a half, and could tell accurately when the stone left the bottom, by having to pull so much harder before the water got underneath to help me.”
With the evaporation forecasting model and the volume of water in Mono Lake known, we were able to calculate how small the lake needed to be to kill off its life. This could be measured as the surface’s elevation above sea level, and we could calculate when this level was likely to be reached.
This study had two more unusual qualities to this study. First, rather than having our group of scientific experts tell the state and its citizens what to do, we presented options that, in our democracy, could be selected by the public or their representatives. We had learned from our study that the lake told a story of three crucial levels, which we showed as options to the public: the highest lake level that retained all the benefits of the lake; a lower level that kept the aquatic species going but sacrificed a fair amount of bird nesting habitat and scenic qualities; and a third level, which would cause the death of all the lake’s life. That level was just 28 feet below the then current level, and we forecast that it could be reached by this year---2012.
The second unusual quality of the study was that, in our description of the three options, we accepted that the climate was always changing, and that the lake and its surroundings experienced droughts and periods of high rainfall. We had information about the seriousness of the 50-year drought — the worst drought in recorded history--- that occurred on average at least once in 50 years. We explained to the public that to prevent the lake from falling below any of the crucial levels — whichever was chosen — the lake had to be managed to maintain in an average rainfall year a much higher level. This meant that when the 50-year drought happened, the lake would decline to, but not below, that crucial level.
Our report was taken up by the courts. Before our study, the courts had decided that unless any environmental damage could be demonstrated, the city of Los Angeles could continue to withdraw 100% of the stream flow that used to go into the lake. With our study in hand, the courts reversed that decision, and told the city that it could divert none of that water until the lake reached the highest of the three crucial levels. After several years of negotiations, the city gave up all rights to the waters that had fed Mono Lake.
In my years of trying to help solve environmental problems, this was one of the few successes. I attributed much of the success to the unusual methods we applied throughout the project. Interestingly, our study was made public in 1988. Today, 24 years later, the lake has still not reached that legally required level.
In sum, it is possible to find solutions to complex environmental problems when scientific analysis is applied appropriately. The unusual features of the Mono Lake study suggest several ways that success can be attained.
If you are interested in finding out more about Mono Lake and this study, you can refer to:
Botkin, D. B. , 2001, No Man’s Garden: Thoreau and a New Vision for Civilization and Nature, Island Press. (Soon to appear as an ebook in all ebook formats)
Botkin, D.B., W.S.Broecker, L. G. Everett, J. Shapiro, and J. A. Wiens, 1988, The Future of Mono Lake, California Water Resources Center, University of California, Riverside, Report #68.
Botkin, D. B. And J. A. Wiens, 1988, “Mono Lake: Solving an Environmental Dilemma,” The World and I, Washington Times Corp. Vol. 3 No. 5: 198-205. (copies of which can be obtained from D. B. Botkin)
Wiens, J. A., D. T. Pattern, D. B. Botkin, 1993, Assessing Ecological Impact Assessment: Lessons from Mono Lake, California, Ecological Applications 3(4): 595-609.