City Creek Nature Notes – Salt Lake City

May 28, 2017

May 26th (Revised)

Filed under: People — canopus56 @ 9:08 pm

Will the Great Salt Lake Disappear? – Part I

11:00 p.m. I am bedridden and despite repeated attempts, I am unable to rise for my daily canyon jog. It is a rest day. I fall in and out of sleep and awaken late in the evening, my head unable to focus from dreams of running in the Sun and of the sound of moving water. It is the start of a long federal holiday weekend. In six days, the canyon will reopen to public automobile traffic on alternate days, and the canyon’s solitude will lessen. I am conflicted by the coming change. For the two previous years, I was able to run to milepost 4.0 at at least every other day. My abilities have declined, and now I run either to milepost 2.0 or milepost 1.0. The opening of the road will allow me to fit runs in the upper canyon back into my schedule, but bringing an automobile in the canyon runs counter to my love this place.

* * * *

Whether or not northern Utah bird populations continue to be sustained depends on the continued viability of Great Salt Lake, and continuance of the lake now depends on the human will to preserve it. The lake sits on a eastern branch of the Pacific Flyway, and as such the lake is recognized as a migratory resource of international significance. Study of the bird ecology of the lake has focused on migratory water fowl and shorebirds, and estimates of shorebirds using the lake are about 3.2 million (Don 2002 at 6) and of migrating waterfowl about 5 million (Utah Department of Natural Resources 2013 at p. 2-109). Of migrating waterfowl, about 750,000 breed in the marshes along its shores (id). It is one of a series of inland lakes upon which migratory birds in the flyway’s eastern branch depend upon. The lake’s ability to sustain these numbers comes primarily from the March through July explosion of brine shrimp and brine flies. Densities of brine shrimp can reach 3,000 per cubic meter of water in June and brine fly larvae reach about 40 per cubic meter of water in August (Don 2010, pp. 24-25). Given that there are about 570 square kilometers or 570 million square meters (141,000 acres) of seasonal and permanent wetlands (Don 7-12), the top meter of lake during the peak summer season may contain 1.7 trillion brine shrimp and 22.8 billion fly larvae.

It is a reasonable supposition that the future population of birds in the canyon also depends on the health of the lake’s eastern marshes. Most research on the lake’s bird ecology has focused on shorebirds and waterfowl, and it is less clear on how other neotropical birds such as those found in the canyon utilize the lake during their migrations. Do they canyon hop up the western slope of the Rocky Mountain’s spine in central Utah or do they, like waterfowl, fly between inland lakes along Utah’s western and central deserts? The Cornell Laboratory Ebird checklist of the closest marsh to the canyon, the eight mile distant Farmington Bay Waterfowl Management Area, shows 254 species and this includes almost all of the birds seen in the nearby canyon.

The forty by sixty mile Great Salt Lake is showing signs of disappearing as northern Utah’s population, which is projected to double by 2050, due to excessive upstream water withdrawals. At first impression, that this large inland sea of about 1,700 square miles with no outlet to the ocean might evaporate within thirty years seems an outrageous proposition, but there is ample precedent. A similar shallow inland sea about fifteen times the size of the Great Salt Lake, the 26,000 square mile Aral Sea in Kazakhstan, reduced to 10 percent of its original area from 1960 through 2007. The Aral lake’s demise was by design: Soviet era planners diverted most of its inflow to support agriculture and they knew the lake would disappear. A similar fate fell upon California’s Tulare Lake. Utah’s Great Salt Lake is currently the largest lake in the United States outside of the northeast’s Great Lakes, but this was not always the case. The Tulare Lake was a freshwater endroheic playa lake: a shallow lake with no outlet to the sea that has large dry pan areas. It had a maximum area in 1879 of about 1,800 square miles. Historically, Tulare Lake supported a pre-Euro-American population of 70,000 First Peoples. Withdraw of its source waters to support agriculture in California’s central valley, that grows one-third of the nation’s fruit and vegetable produce, resulted in the complete evaporation of the lake. While the Aral Sea is and California’s Tulare Lake was larger than the Great Salt Lake, the 188 square mile Sevier Lake in central Utah is smaller, and like the Great Salt Lake, it is an endroheic playa lake. The Sevier Lake, that had a maximum historic depth of 15 feet, naturally evaporated in the nineteenth century, but after Utah’s peak flooding of 1985 to 1987, the lake refilled to its historic high. Since then, agriculture withdrawals have again almost entirely evaporated the lake.

Utah’s population has reached levels such that about 40 percent of water in rivers that feed the Great Salt Lake have been withdrawn for human use or reserved for wildlife protection, and their use, along with an extended drought, has reduced the lake’s level by 11 feet, its volume by one-half and its area by about one-half since the arrival of the Euro-American colonists in 1847 (Wurtsbaugh et al 2016). The lake’s surface area declined from about 1,600 square miles to 1,050 square miles in 2015, and this exposed 550 square miles of new dry lake bottom. In 2016, the lake reached a new historic low level, resulting in much of the southeastern lake bed, next to Farmington Bay and the canyon, turning into a dry pan.

Another sign of high upstream water withdrawals is Utah Lake, that is about thirty miles south of the Great Salt Lake and which drains into the Great Salt Lake to the north via the Jordan River. In recent drought years, the level of Utah Lake has also declined, and one consequence is that from 2014 through 2016, the lake now experiences an annual July toxic algae blooms containing sufficient levels of toxins to be hazardous to human health that require closing parts of the lake to boating and its shores to swimming (Salt Lake Tribune, July 15, 2016; Utah Department of Environmental Quality 2017b). The toxic Utah Lake algae flush from Utah Lake, down the Jordan River through the populated center of Salt Lake Valley, and out in to the Great Salt Lake (Utah Department of Environmental Quality 2017, Maps of toxic level sites). The shallow Great Salt Lake naturally contains high, but not toxic levels, of green and red algae, and due to the 1959 construction of an earthen railroad causeway across the northern third of the lake, differences in the two populations of algae can be seen from low earth orbit (NASA 2017)

Researchers’ ability to model the level of the Great Salt Lake has improved and significantly changed in the last ten years with the addition of historical tree ring studies. In 1997, Wold and colleagues built an early dynamic model of the hydrology of the Great Salt Lake and its salt content in its northern and southern arms that are divided by the causeway. In response to climate change concerns in 2012, Mohammod and Tarboton and in 2015, Gillies and colleagues prepared updated models using improved climate records based on an expanded climate record from 576 years of tree ring measurements. In 2015, Shope and Angeroth expanded Wold’s model of salt loading. Finally, in 2016, Huybers, Rupper and Roe worked on a dynamical model of the delayed response time of the Great Salt Lake’s lake level to prior year’s precipitation.

In a 2016 white paper, Wurtsbaugh et al of Utah State University raised the concern that if further water withdrawals are taken from the lake’s upstream water sources, such as another 250,000 acre feet from the proposed Bear River Project, then the lake will decline between another 8.5 and 14 inches and will expose and dry out between another 30 to 45 square miles (Wurtsbaugh et al 2016; Utah Division of Water Resources 2004). (1.2 million acre feet is currently reserved to flow to the Bear River Migratory Refugee, but in recent drought years, less than that amount has reached those marshes.) Although Wurtsbaugh and colleagues did not discuss the impact the proposed withdrawal would have on Great Salt Lake migratory bird populations, they noted that declining lake levels currently impact human health in the form of increased dust particles.

The dust particles referred to by Wurtsbaugh and colleagues come from dust storms. The ancient Lake Bonneville, including the dry Sevier Lake bed and the expanded dry pans of the newly exposed Great Salt Lake bottom generate large dust storms, called haboobs in Arabian desert, that floods the Salt Lake valley and the canyon with fine particles. These storms aggravate urban asthma. (One such wind storm most recently occurred on May 24th and it covered my car in a thick light brown layer.) The largest man-made source of dust in the United States is the Owens Valley lake bed – an artificially created dry lake in central California generated by Los Angeles withdrawing water from the lake to supply Los Angeles municipal drinking water. Los Angeles has spent 1.2 billion USD on dust suppression in Owens Valley (Iovenko 2015).

Another human health risk of a drying lake that has yet to be analyzed by governmental or academic research is lake purification. Salt Lake City residents are familiar with summer lake stench. One or two times during each summer, clouds of stench from organic matter dying in the lake invade the city. In Utah, these are a minor aesthetic inconvenience, but California’s evaporating 340 square mile Salton Sea provides precedent for larger impacts. The 45 foot deep Salton Sea was created in 1905 by an engineering accident that diverted the Colorado River into an ancient dry lake bed. In 2015, the Coachella valley surrounding the Salton Sea had at least five air quality alerts from rotting-egg smell emanating from the sea (Iovenko 2015).

An unknown risk in the Huybers et al’s model of the Great Salt Lake water levels is the potential for dynamic chaotic responses. Huybers and colleagues used ordinary differential equations for their model. Mathematicians and physical sciences well now that such equations contain chaotic boundaries in which the system responds in new and unlikely directions once certain break points are reached. However, the state-of-the-art expert opinion, summarized in Wurtsbaugh et al, is that increases in the decline of Great Salt Lake levels will be incremental and not chaotic. The lake, and its life-giving marshes that support northern Utah bird life in the canyon, should continue for the near future. Notwithstanding present model studies, that the Great Salt Lake might disappear completely in the next thirty years is still be within the scope of probable scenarios.

* * * *

On May 26, 1983, City officials proclaimed a flood emergency in Salt Lake City after a winter of heavy snowfall followed by a late warming (Salt Lake Tribune). In a April 29, 2011 retrospective article, Salt Lake Councilperson Grant Mabey recalled how he had witnessed the 1952 flooding of downtown by City Creek Canyon, and in 1983 he feared a repeat of that event (Salt Lake Tribune). The city pre-ordered 250,000 sandbags (id). Sandbagging State Street kept City Creek from flooding underground parking at ZCMI Mall (id). On May 28th, Mayor Ted Wilson learned that rock and tree debris from City Creek Canyon were clogging up the 1910 underground culvert down State Street and a second pipe system along North Temple (id). The flood waters receded by June 11, 1983. On May 26th, 2003, the Salt Lake Tribune reviews the history of the establishment of Memory Grove Park (Salt Lake Tribune).

On May 26th, 1933, a letter to the Salt Lake Telegram editor stated that City Creek Canyon Road had deteriorated into a “deplorable condition.” On May 26th, 1906, the Commercial Club inspected construction work on road improvements up City Creek Canyon Road to 11th Avenue (Salt Lake Tribune).


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