The Onset of the California Mega Drought

Water is quickly becoming the “blue gold” of the American southwest. Every day, new groundwater wells are being drilled, some to depths of over 1,000 feet and costing over $300,000 each, to access an ever-decreasing supply of water. Nowhere is this more apparent than California which is experiencing one of the worst multiple year droughts in its history.

NOAA

There are two sources of water for California – surface water in rivers and streams and groundwater pumped from aquifers. The majority of Californians water (over 80%) comes from surface water sources, which originates as spring snow melts in the inland mountain ranges. However, for the past several years, snowfall amounts have been considerably below average for the mountain ranges nearest to California.

The aquifers under California do not have the reserves to compensate for long periods of drought. Furthermore, the use of water from aquifers may only provide a temporary solution. This is because, unlike groundwater, aquifers take a long time to recharge. While some aquifers lie close to the surface, and may be partially regenerated by groundwater over time, the aquifers in California are deep underground, and may take thousands, or even millions of years, to replenish.

What worries scientists more are computer models which suggest that the worse is yet to come. While droughts, which are characterized as a prolonger period of low rainfall, have occurred in 11 of the past 14 years in the southwest, the worst is probably yet to come. When predictions of the current levels of climate change are factored into the models, the data suggest that there is an 80% chance that California and the remainder of the southwest may experience a “megadrought” (an event lasting more than 35 years) before 2080. Scientists believe that an event such as this may have led to the decline of the Pueblo people over 1,400 years ago.

There are only two solutions – decrease water demand or increase the water supply. The population of California has increased by almost 20 million people in the past 40 years, and is predicted to continue to grow in the future. Mandatory water restrictions often help, but these measures often specifically target residential use. As is the case in many parts of the country, most of the water is used by agricultural and industry. In California, the major user is agriculture. California grows the majority of the United State’s fruits and vegetables, and thus any disruption has a ripple effect in the food supply.

Increasing the water supply is also difficult. Aquaducts, canals and pipelines are expensive, and take a considerable time to build. Desalination plants, which the remove the salt from ocean water, require a significant amount of energy, and often only supply water for a small percent of the population. For example, the new desalination plant in San Diego, the largest in the world, will only supply around 10% of the local population with water.

640px-Carlsbad_desalination_plant3

So what then is the solution? Most would agree that it is a complex problem, and that a single solution will not adequately address the entire problem. New technologies in the areas of water desalinization may help, as will more research in how reservoirs are recharged in the water cycle. However, most scientists agree that the lessons learned from the California crisis may help us better address some of the global challenges that we will face as our climate changes.

 

Additional Resources

Images

  • California Drought –  The National Drought Mitigation Center (May 2015)
  • Carlsbad desalination plant – By Bovlb (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Michael Windelspecht is an author, instructor of introductory biology and CEO of Ricochet Creative Productions

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