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February 13, 2013

The Sierra Snowpack: Losing Snow, Losing Species

The Sierra Nevada Mountains, a spectacular mountain range located in California and Nevada, is not only a major source of California’s water supply, but is also home to hundreds of endemic species. During the fall and winter, a snowpack accumulates on the mountaintops and naturally melts during the spring, providing plants, animals, and people with a fresh source of water. In the past, the annual snowpack was enough to support these species as well as California’s water supply, however due to climate change and anthropogenic causes, precipitation has decreased and the snowpack is not able to accumulate the proper amount of snow like it has in past years. While the Sierra snowpack provides the majority of California’s water supply, it also is vital to the survival of the plants and animals in the Sierras. The snowmelt that supports these now endangered and at risk species are suffering. Higher temperatures, invasive species, and human influence are some of the causes that pose major threats to this ecosystem.


Some of these species include the bighorn sheep, yellow-legged frog, American pika, and Delta smelt. The bighorn sheep are one species who are severely impacted from the loss of snowpack because their natural habitat is being depleted. The bighorn, who has already had to recover from the brink of extinction in the 20th century, is an animal that utilizes the elevation to escape from predators. The warming temperatures has allowed the tree lines to move to higher elevations which encroaches on the bighorn’s living space and makes it more difficult for the bighorns to evade predators. The yellow-legged frog is also affected by the lack of snow because it depends on the snowpack to melt during certain times of the year to assure proper living conditions (doesn’t freeze in the winter, but has enough water in the summer to lay eggs). Additionally, they are at risk because of the numerous invasive species that are preying on the frogs during their tadpole stages. Another species that has been severely impacted by the decline of snowpack is the American pika. The pika is a small hamster-like creature that has a minuscule temperature window and relies on the snowpack for insulation in the winter and moderate temperatures in the summer. In response to the unbearable temperatures, the pika have been forced to move upslope, an unsafe habitat for the vulnerable animal, which has already become extinct in some low-lying areas. Lastly, the Delta smelt, like salmon, is an upstream swimming species of fish that is reliant on the cold downstream that the snowmelt usually provides. “As the headwaters decrease and temperatures rise, endangered fish species such as the Delta smelt will suffer.” (Merry) Not only are animals suffering as a result of decreased snowpack and higher temperatures, but plants are also feeling the effects.

Conifer trees are surprising less resistant to the hotter temperatures and decrease in precipitation. The trees are dying much more often than in previous years because of warmer temperatures and evaporated moisture in the soil. In addition, the conifers are also being infested by fungi and insects that thrive in the warmer climates. Both drier conditions and increased temperatures have led to an increase in wildfires. A positive feedback loop is created when trees that catch fire release carbon dioxide stored in their trunks, which is in turn absorbed into the atmosphere, further advancing global climate change.

The Sierra snowpack is a crucial part of this environment that requires mitigation in order to protect the vulnerable species that rely on its abundance. The Sierra Club proposes a great strategy as to how to protect these animals and is a decent step towards finding a solution that solves the issue at hand. They propose that a core area and a buffer zone are necessary so that species are able to withstand the changes that are occurring within their habitats. Although some steps that will help alleviate the issue are in action, state legislature would be a strong supplement that may drastically increase the revitalization of species in the Sierra Nevada ecosystem.

This post was authored by Dana Handy, a sophomore majoring in Environmental Studies, and Angel Marquez, a sophomore double majoring in Economics/ Mathematics, and Business Administration.

Works Cited:

Sierra Nevada Snowpack—There’s Plenty!!

Filed under: California Drought — lecollin @ 11:43 am

The Sierra Nevada mountain range is one of the prized natural wonders of the West Coast, as well as a hotbed of countless types of outdoor activities. Many environmentalists fear that changes in the snowpack (accumulation of snow) of these mountains reflect a permanent decline, stirring much alarm. As environmental enthusiasts, one does not disagree with the consciousness certain activists are attempting to bring to the issue. However, historic trends as well as present-day measurements—while low at cer

tain points—do not indicate any alarming decrease in snow content in the region. There’s plenty!

This graph from a Sacramento newspaper illustrates some trends among the snowpack content over the years. As you can see, very wet years like 82-83 happen just as easily as do dry years like 66-67.

This graph from a Sacramento newspaper illustrates some trends among the snowpack content over the years. As you can see, very wet years like 82-83 happen just as easily as do dry years like 66-67.

From 2012’s Western Snow Conference, researchers Maruice Roos and Sunny Sahota find Northern Sierra Nevada snowpack to be decreasing the last 60 years–Southern Sierras have shown an increase, however. While the North Sierra Snowpack (Water Content) is at 18 degrees below average, South Sierra is at 20 percent above average, some places nearly 22 percent (Roos, Sahota 21).  This bodes well for us in Southern California—but also more seriously for the fate of the range in general. Further evidence can attest to this variability. That same study finds ENSO variability to produce patterns, sometimes with serious anomalies, though a periodic oscillation. 1950-1994 saw almost 45 years in an overall (while oscillating) decrease from maximum snow water equivalent, until a large spike in 1997 reached the highest point in 50 years. The variability is immense in its timescale.

Even within a year or a season, measurements can be sporadic. Typically measurements are gathered intermittently throughout the winter months.  This year’s initial measurements taken December 31st, 2012 showed that precipitation, runoff and reservoir storage all measured significantly above the average and well above the previous 2011 measurements. Currently, measurements show that we are on track to receive 155% of the average this year versus 49% last year (Ca. Dept Water Resources 2013). This can be seen by the graph below

*;  although the Mammoth Snow Pass Snowpack is not much higher than the annual average it has exceed far above where it was last year at the same time. However, as we have learned, this does not indicate that the entire year or season will necessarily remain this truly optimistic. Take Lake Tahoe’s 2000 season in which snowpack went from a dismal 22% low to over 100% of its usual rate in just a matter of a week-long storm.

So what does this mean?  First of all the snowpack is not only important for water supply as much of California’s water resources come from the Sierra Nevada region, but also the annual snowpack largely determines how well tourism and snow sports will be on the local mountains -particularly Mammoth and Big Bear. Thus, media outlets will be touting the success of the current seasons’ snowpack to market to visitors, whether or not it is slightly below average. However, a good year of snow does carry huge economic benefits for the region– in 2010 California’s ski resorts had an increase of almost 1 million tourists during the annul ski year because of a snowpack 143% of their usual illustrating the importance of maintaining this regions snowpack levels not only for environmental but for economic and social reasons (Martin, H , 2010).

However, there will never be a completely predictable or (yet) fully understandable pattern of snowfall and thus snowpack in this region. Even areas where April 1 snowpack measurements are optimistic, those same regions often see the season end sooner as snow accumulation decreases and melts more quickly (Harpold).  As far as 2013 goes, it is still too soon to tell where the seasons’ end will fall in terms of shortcomings or exceeding expectations of snowfall and snowpack. Many, though, are impressed by its immensity so early in the season. Statements released by both the California Department of Water Resources and the Los Angeles Department of Water and Power (LADWP) show little concern for the upcoming snow year (LADWP 2013). Already the region shows levels of precipitation well above average from previous years. Media particularly newspapers such as the Los Angeles Times and the San Francisco Tribune were quick to relay this information promising their readers a good snow season and a plentiful water supply predicted for the upcoming months.

Snowpack plays a leading role by supplying water to more than 25 million people and almost one million acres of farmland

Snowpack plays a leading role by supplying water to more than 25 million people and almost one million acres of farmland

This post was authored by Meghan Hennegan, a junior double majoring in Environmental Studies and International Relations, and Jennica Wragg a sophomore double majoring in Environmental Studies and Cinematic Arts Critical Studies.

Works Cited:

Harpold, A., P.Brooks, S.Rajagopal, I.Heidbuchel, A.Jardine, and C.Stielstra (2012), Changes in snowpack accumulation and ablation in the intermountain west, Water Resour. Res., 48, W11501, doi:10.1029/2012WR011949

Roos M, Sahota S. Contrasting Snowpack Trends in the Sierra Nevada of California. 80th Annual Western Snow Conference [Internet]. 2012. Available from: sites/

SHAW, G. (1979, May 27). Rise in sierra snowpack possible. Los Angeles Times (1923-Current File). Retrieved from

How are California’s reservoirs – How are California’s reservoirs? (1993, Sunset, 190, 28-28. Retrieved from

Abundant snowfall a big lift for state’s ski resorts- Martin, H. (2010, May 15). Abundant snowfall a big lift for state’s ski resorts. Los Angeles Times. Retrieved from

From mountaintop to tap HOW MELTED SIERRA SNOWPACK BOOSTS VALLEY WATER SUPPLY. (1995, May 07). Los Angeles Times (Pre-1997 Fulltext). Retrieved from

Los Angeles Department of Water and Power, (2013). Eastern sierra precipitation conditions. Retrieved from website:;jsessionid=mcv7RTfpTyGrZyTCrtFWhGd9Q4217Lnv5hkBcyGGspd656ZjKfXS!-1241156102?_adf.ctrl-state=1dud0gky71_63&_afrLoop=305873035374000&_afrWindowMode=0&_afrWindowId=null

California Department of Water Resources, (2013). First snow survey of 2013 shows wet conditions. Retrieved from website:



California Drought, Should We Be Worried?

Filed under: California Drought — lecollin @ 11:26 am

Picture a place of rolling agricultural landscapes and expansive megacities, endless deserts and snow capped mountains, California; a land bound together by a struggle for water.  Some regions, such as Northern California are blessed with ample water supplies; while California’s largest city in the south, Los Angeles, stretches ever further to meet its growing parchedness.

Now imagine desolation. Arid croplands replace once lush fields, rivers run dry, reservoirs emptied to the last drop, imagine drought. This is the image that is painted regularly across the Californian landscape. We Californians are resilient though, we adapt and ration, as thus we have endured. There is not much to fear as after every drought comes a flourish of rain to revive the sunken land. One must ask then how concerned should Californians be of droughts of the present and future. Droughts of course have different severities and to foresee what the future may hold we must look back at what the past has already told. In concurrence with climate change droughts are expected to increase in persistence and severity in the coming years.

Kerns River, Bakersfield, California. Photograph Credit David McNew

Kerns River, Bakersfield, California. Photograph Credit David McNew

Current Conditions

California has just experienced a drought such as the one described in this past year, but on milder terms.  The state’s water reservoirs have been gradually filling since the start of the wet season and now most of them are at normal levels according to the California Department of Water Resources. Precipitation levels have also increased to date, about 135% of average rainfall. Presently it seems as if California is in the clear and has no need to worry about a drought.

Historical Drought Patterns

The most recent drought in California occurred from October 2011 to April 2012, but there have been many similar events before. Looking back to when scientists first started keeping rainfall records, we can see that there are numerous years where rainfall did not meet its expected totals. Additionally, we can see that there has been four times where the amount of rainfall failed to meet its average over a ten year span. Episodes like these cause for much alarm because it cripples the local economy, which depends on the growth of agriculture. However, the drought eventually ends as it is succeeded by some years of plentiful precipitation.

: Historical Precipitation Rates (Precipitation and Its Effect On Groundwater Supply In WRD's Region, Tony Kirk)

: Historical Precipitation Rates (Precipitation and Its Effect On Groundwater Supply In WRD’s Region, Tony Kirk)

Some of this abundant water is stored in groundwater, snowpack, and reservoirs so that it can be used in times of crisis. Starting in the 1950s, California began building infrastructure that would be able to transport large quantities of water from the Sierras, through the Central Valley, and eventually to Southern California. Since then, the California State Water Project has become the world’s largest water and power development system that can provide water to more than 25 million people. From 1987-1991, this system was challenged for the first time when the decline in precipitation led to four out of the five years having less than 50% of normal runoff. Although the system was receiving less water input annually, “it still enabled its agriculture to survive three years of drought with minimal impact” (Zilberman 2011). In the years following, farmers and water districts worked to cut back their use of water and provided people with incentives to conserve it. Thus California has been able to adjust to fairly regular drought patterns and effectively manage water resources in times of drought.

What Future Droughts May Look Like

One of the most pressing concerns for water planners of today is the hydrologic needs of tomorrow.  The population of California is expected to grow from 34 million people in 2010 to 51 million in 2050 (California Department of Finance). Population growth brings a concurrent growth of water needs and conflicts among stakeholders. Drought will continue to be a part of the Californian experience in the future and planners must account for this in hydrologic projections. In order to get a more thorough look at what future droughts may encompass we must take a look into the past.

Among the multitude of droughts that have been observed in California one case study is particularly important in the forecast of forthcoming droughts. The Medieval Warm Epoch (900 A.D to 1300 A.D) is characterized by a high frequency of volcanism, increased solar irradiance, and hydrologic anomalies. The hydrologic anomalies mostly encompassed high precipitation rates in some parts of the world and extreme drought conditions in places such as the western United States, particularly California. These anomalies were driven by changing El Nino and La Nina oscillation patterns, which are wet and dry climate patterns respectively. Both of these patterns are driven by temperature, especially warming. This indicates that increased warming in the present day may give birth again to the hydrologic anomalies experienced in the Medieval Warm Epoch; drought conditions similar to those that occurred in the Medieval Warm Epoch would also re-emerge along with the anomalies.


Professor Scott Steine asserts in his publication on persistent droughts that if medieval warming caused persistent droughts in California previously then “future natural or anthropogenically induced warming may cause a recurrence of the extreme drought conditions” (Steine 546). The Intergovernmental Panel on Climate Change also came to the same conclusions on anthropogenically caused warming in its 2007 Climate Change Synthesis Report, to quote “There is also high confidence that many semi-arid areas (e.g. the Mediterranean Basin, western United States, southern Africa and north-eastern Brazil) will suffer a decrease in water resources due to climate change. Drought-affected areas are projected to increase in extent” (IPCC 2007, pg. 49). Based on these reports it is more than likely that droughts will increase in severity if warming continues at the pace it is going. Upon examination of figure 2 one can clearly see that the Western United States projected to be a much drier zone by the end of this century. Future droughts will entail a longer residence time up to several decades and result in greater water shortages, especially in combination with population growth.


California is perfectly capable of handling drought under current climatic conditions using its extensive water management system. In the future climate change will most likely reduce this capability as droughts become more severe and persistent. Couple this with a growing population and we now have a synergistic problem. Californians should prioritize future droughts as one of the biggest challenges to face in the coming years and in turn should address the one of the causes of potentially catastrophic droughts, anthropogenically induced climate change.

 This post was authored by Kieran Bartholow, a junior majoring in Environmental Studies, and Minh Ngo, a junior double majoring in Environmental Studies and Earth Science.

Works Cited

Core Writing Team, Pachauri, R.K. and Reisinger, A. (Eds.) “Climate Change 2007 Synthesis Report” IPCC, Geneva, Switzerland. pp 104

“Executive Summary of Hydrologic Conditions in California.” California Department of Water Resources. California Department of Water Resources, 01 Jan. 2013. Web. 01 Feb. 2013.

“Interim Population Projections for California and Its Counties 2010-2050.” California Department of Finance. California Department of Finance, May 2012. Web. 01 Feb. 2013.

Kirk, Tony. “Precipitation And Its Effect On Groundwater Supply In WRD’s Region.” Precipitation And Its Effect On Groundwater Supply In WRD’s Region. Water Replenishment District of Southern California, 2007. Web. 01 Feb. 2013.

Stine, Scott, et al. “Extreme and Persistent Drought in California and Patagonia during Mediaeval Time.” Nature Publishing Group Vol 369 (1994): 546.

Zilberman, David, et al. “Individual and institutional responses to the drought: the case of California agriculture.” Journal of Contemporary Water Research and Education 121.1 (2011): 3.