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About this Article
Written by: Hannah Gray
Written on: October 1st, 2009
Tags: civil engineering, energy & sustainability, environmental engineering
Thumbnail by: Ikluft/Wikimedia Commons
About the Author
In Fall 2009, Hannah Gray was a sophomore at the University of Southern California with hopes of earning a bachelor’s degree in Environmental Engineering. Currently, she is performing research through the Sonny Astani Environmental Engineering Department concerning methods of water filtration for third world countries.
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Volume XI Issue II > California's Water Crisis
With its naturally arid landscape, Southern California has always relied on water piped in from other locations in order to meets its demand. However, a growing population and dwindling supplies are creating a huge water deficiency. Traditional methods of tapping into new surface or groundwater sources have proven to be very detrimental to the environment, leading engineers to search for new sources freshwater. Desalination is a popular option, but it too comes with its own environmental impact. To truly create a sustainable future for Southern California, new conservation technologies and practices must be designed by engineers and adopted by the general public.

Southern California: Land in Crisis

Imagine Los Angeles 100 years from now. Southern Californians would like to picture a futuristic and thriving center of the West Coast. Yet, in current times, a more realistic vision is a barren land, with crumbling buildings and sparsely scattered plants. This bleak outlook on Southern California’s future is a result of excessive water usage and rapidly shrinking water supplies. The average Californian household uses about one acre-foot, or 325,851 gallons, of water per year. While most of this water helps produce crops, factories and power plants utilize some and over forty million thirsty residents consume the rest. Forty million people each using at least 100,000 gallons of water a year require a massive quantity of water. Because this water cannot be found in the region, some is diverted from the Colorado River and some is piped from Northern California through a lengthy aqueduct. Even with these outside water sources, Southern California’s needs are not quenched and water consumption rises every year. As this ever-increasing demand for water continues, engineers attempt to tap into new sources of water for residents. However, due to the detrimental environmental impact that the new water solutions can bring, the only way Southern California will truly survive another century is by adopting a variety of water conservation practices.
Eric Polk/Wikimedia Commons
Figure 1: The Bristol Mountain Range in the Mojave Desert. Southern California’s natural landscape consists of dry brush rather than expensive lawns.
Few know the true extent of the California water crisis because the Southern California region is replete with green lawns, decorative fountains, and gigantic swimming pools. Driving south of Orange County, one can observe the true natural landscape of the region. Between Camp Pendleton and San Diego lie 50 miles of chaparral - barren, dry land covered in sparse shrubs (see Fig. 1). In their attempts to turn this naturally arid land into a green paradise, Californians use an average of 50% more water than people in the Eastern regions of the United States [1]. Because it rains less than 10 inches a year in most southern areas of the state, this water must be taken from elsewhere, particularly the other desert states surrounding California, and Northern California. In fact, while Northern California provides 75% of the state’s water supply, Southern California uses approximately 75% of California’s water resources [2]. This discrepancy points towards Southern California’s water problem: too much use with very little inflow.
The mindset of Southern Californians only contributes to the dire situation. This summer, even though many counties in Southern California issued warnings to take more caution with water consumption, few residents paid heed to these caveats and even fewer areas enforced the imposed water regulations. Although few individuals are aware of the precarious position of this precious resource, estimates by the U.N. suggest that by 2025, humans will use 90% of the available fresh water, and in an area as arid as California, this number could be even higher [3]. If all available fresh water goes to human needs, natural environments and habitats will suffer.
Climate change and outdated infrastructure also pose a threat to California’s water sources. As snow caps and glaciers in the surrounding mountains begin to melt earlier in the year, water quantities from these natural resources will become extremely sparse by mid-spring. By summer and early fall, water needed for crops, pools, and gardens will no longer be available. Evaporation from exposed aqueducts due to an increase in temperature and less frequent rainfall also place greater stress on the region. Furthermore, leaks and disrepair cause aqueducts to lose large quantities of water. With all these contributions to Southern California’s decreasing supply of water, imagining a solution is intimidating. In order to prevent Southern California from turning into an empty desert, both the government and citizens are attempting to discover ways to access more water.

Tapping New Water Sources

Many believe that diverting more water to Southern California will satiate its need for water. There are small lakes and rivers throughout the state and surrounding states that are untapped and filled with fresh, potable water. Diverting water from these small bodies of water could certainly add hundreds of thousands of gallons to the water supply without taking too much from rural areas dependent upon the source. Although this solution seems feasible and has been attempted many times, the story of Mono Lake testifies as to why this is not a viable solution. Mono Lake, which lies 190 miles east of San Francisco, was one of the first locations affected by Los Angeles’ water needs. Streams feeding into Mono Lake were initially diverted toward Los Angeles in the 1940s. Twenty years later, the lake had dropped over thirty feet in depth, increasing the salinity from 50 to 100 grams per liter and reducing the volume of water from 4.5 to 2.2 million acre-feet [4]. This lake was reduced to half its size in a fraction of a human lifetime. The growth of green algae and shrimp, the main food sources for lake life, was greatly reduced, thereby altering the fish and bird populations drastically. As a result of the ecological damage once wreaked upon this area, Mono Lake now serves as a warning against human greed for water. Although Mono Lake has recovered significantly due to increased water regulations, diverting water continues to cause major tensions between various regions both in and out of the state (see Fig. 2). Diverting water to save Southern California will only create further problems somewhere else.
Mila Zinkova/Wikimedia Commons
Figure 2: Mono Lake, California. Tufa, or salt formations, show how far the water level has decreased.
A lesser-known freshwater source that could also be considered a solution to the water shortage is groundwater. Groundwater often seems to be a more reliable and less precarious water source because no ecological systems depend directly on groundwater, it self-filters, and it can be accessed in most areas, even deserts. Accessing this resource once was as simple as digging a hole in the ground. However, California already uses groundwater faster than it can recharge. After all, the water that recharges underground aquifers can only move a few feet a month, unlike an open body of water, because groundwater passes through layers of porous soil and sand as it flows [5]. California once contained over 50% of the nations’ groundwater aquifers but now contains less than 20% [6]. If these groundwater aquifers empty much further, the gap left behind can cause cave-ins, devastation to lakes and streams, and increased salinity of new groundwater [1]. In some areas of California, the ground itself has dropped over 50 feet due to the excessive removal of groundwater [6]. In a community perched atop this land, using this natural resource is not an effective solution.

Desalination - A Viable Option?

Fortunately, most progressive Californian decision makers are aware of the futility of attempting to depend on decreasing fresh water sources. Instead, to provide an increasing population with desired amounts of fresh water, scientists and engineers are focused on producing it from new sources. Although Southern California lacks potable fresh water, she has an advantageous proximity to the ocean, which holds over 97% of the earth’s water [7].
Infigen Energy/Green Diary
Figure 3: Proposed desalination plant in Australia. Similar plants that are already operational have relieved water demand, but environmental hazards may become visible.
Through the method of reverse osmosis, salt water can be pushed through a membrane at high pressure with microscopic pores that allows pure water to pass through but not salt. In fact, the Water 2025, a national water information guide released by the National Bureau of Reclamation concerning the worsening water shortages in the West, describes desalination through reverse osmosis as the treatment of the future for providing the West with water (see Fig. 3). The fault in this method lies in the waste left behind: salty brine water [5]. Once the water is filtered, the waste drained back into the sea has a salinity level many times more than the natural levels. This increase in salinity kills an abundance of marine life, especially next to the drain, where the brine has not had a chance to be diluted. The closest accessible ocean water can only be filtered so many times before it not only contains very little marine life but also becomes too briny to filter. Diluting this brine with wastewater run off still lacks long-term viability as this process cannot be repeated indefinitely. The high pressures and complex technologies involved make the desalination process very expensive, to the point where the US would potentially need to invest one billion dollars a year even before being able to provide water to a majority of the citizens [8]. Because of the significant costs and risks; desalination cannot act as a truly sustainable solution to the water crisis.

Water Conservation Practices

The answer to our dwindling water resources lies in the hands of engineers, but not for creating more fresh water. Instead, new and inventive designs for conserving water must be implemented in order to maintain a comfortable lifestyle in Southern California. Water conservation can be most immediately applied to methods of water transportation. Evaporation from dams, canals, and aqueducts affects millions of acre-feet of water per year (see Fig. 4) [1].
Ikluft/Wikimedia Commons
Figure 4: California’s uncovered aqueducts snaking through brown, dry farmland are subject to a lot of evaporative losses.
Covering these water stores and sealing their leaks would contribute to California’s water recovery in a significant way. A better-designed, possibly underground, series of aqueducts could better protect the water that is already diverted to Southern California. This new infrastructure could be built in conjunction with new rainwater harvesting systems. In both cities and suburbs, roofs cover a large land area, which means that rainwater falls not onto soil where it can pass through to recharge groundwater sources, but goes directly down storm drains and into the ocean. Because a rainstorm can yield over 50,000 liters in an area smaller than a home, applying rainwater harvesting on a large scale could contribute millions of liters of water to the water system [9]. Collected rainwater could be used without further processing for irrigation or other applications where humans do not ingest it.
While protecting and collecting the water that is readily available can go a long way to assisting in the water shortage, a complete solution will ultimately require decreased water consumption, especially in agriculture. California produces more than half of the nation’s fruits, vegetables and nuts, and consumes about 80% of the water from state water projects to do so [10]. Sustainable water usage, including irrigation methods such as drip irrigation and terraced ground, would ensure that no water is wasted as run-off. With drip irrigation, water would seep directly to the plant roots and in a terraced system, any existing run-off would trickle down to other crops, unlike spray watering, the current most commonly used method (see Fig. 5) [5]. Planting fewer water-dependent crops in arid areas also would greatly assist California’s water solutions. Switching from rice, alfalfa, and peppers, to less water intensive plants, such as fruit trees or wheat, would decrease the water demand while still providing economic value to the region [11]. Genetic engineers also hope to design drought-resistant crops, which would use significantly less water than other crops. Since more than a quarter of all U.S. crop acreage contains genetically engineered crops, drought-resistant crops certainly seem possible in the near future [12].
Goldlocki/Green Fudge
Figure 5: Tomatoes grown with drip irrigation. Each plant receives water directly and virtually none runs off.
Nonetheless, agricultural changes alone do not have the power to save California. Individual effort to be progressive and conscious of water usage plays an enormous role in conserving water. In the 1990s, aggressive water conservation programs in urban areas of California led to a decrease of up to 28% of water usage, so the potential to create similar change exists [11]. Simple measures can be taken to reduce water usage each day, even without fancy new technologies. For example, using the toilet more than once before flushing saves over 15 gallons a day; turning off the shower while shampooing or shaving can save over 20 gallons per shower; and laundering only full loads of clothes can save anywhere from 30 to 60 gallons each load [13]. Engineers are also designing low-water usage toilets, washing machines, and dishwashers in order to reduce water consumption while still maintaining a comfortable lifestyle. Other methods of individual conservation include sweeping a driveway instead of hosing it, or going to a car wash, where water is often recycled, instead of washing the car at home. Planting native plants that require less water instead of a water intensive lawn also significantly reduces individual water use. The water-saving possibilities continue – engineering concepts can be applied to almost every human procedure to promote conservation. Industrial refining processes, construction, and transportation can all be reformed by engineers seeking to save water and save California.

Conclusion

As of now, the future of water supplies for Southern California remains uncertain. The techniques used to meet water needs in the past are not a sustainable option, and while desalination opens up new potential water sources, the environmental and economic costs of that technology need to be further addressed. Nevertheless, hope for a wetter future persists as long as engineers are working on conservation technologies that will lower current consumption and consumers learn to embrace them. Careful water conservation practices will make it possible to imagine another century in sunny Southern California.

References