Drought in California – Possible solutions
The west of the United States is literally being dried out by a hundred-year drought. California has been hit particularly badly. The precipitation and temperature measurements suggest that it is the most extreme phase of drought on record. The US weather agency, NOAA, is even speaking of the worst dry period in 1,200 years. What solutions are in sight?
Expert meeting in California
In October 2015, the alumni of our 2013 and 2014 Resilience Academies came together for a meeting. They held a "spin-off Resilience Academy" at the Cal Poly University in San Luis Obispo northwest of Los Angeles. The symposium programme was developed in cooperation with our partner, UNU-EHS. This time the focus was not on development cooperation but rather on a problem now affecting one of the richest countries in the world: the drought in California. The dryness here has reached an historic level. The Academy participants discussed how drought can be combatted and which solutions can also be applied to other locations. The challenges in California are complex.
The situation at present
California is important for the United States in many different ways. No other state produces more agricultural products. The agricultural industry generates an annual turnover of 45 billion US dollars. In regard to fruit and vegetables especially, the United States are largely dependent on the "Golden State". For almonds and other nuts, California is indispensable. The drought consequently not only affects the people living there but also poses a potential risk to supply reliability in the United States.
Eighty per cent of the water available is used by agriculture, for which the consequences are particularly severe. Because of the low precipitation rates, the farmers are increasingly reverting to wells. In California, there are no regulations governing how much water can be taken from underground springs, as long as the well is on private property. There are also no statistics regarding the number of private wells in existence. What can be measured, however, is the falling groundwater table. Residents must go to ever greater lengths to be able to access water at all. The wells are being drilled deeper. This leads to another problem near the coast: saltwater from the sea is gradually leaching into the groundwater and the soil. This salination is weakening the soil and encumbering agriculture even further.
When approached about this, the people concerned often reply: "El Niño will come and bring us rain again." The recurring occean currents in the equatorial Pacific generally lead to massive rainfall in the western parts of North and South America. It is uncertain whether this can improve the situation in the long term. The first indications of an incipient El Niño can currently be observed: torrential rains transformed the north of Los Angeles into a landscape of mud on 16 October 2015. For nature, this initially brings relief, but the rain has come at the wrong time. The growth phase of the crops is long past, the farmers are already having to deal with a poor harvest. It is therefore not only significant how much rain falls, but also when it falls.
The effects of global warming
Global climate change is causing increased warming in numerous regions of the world. California, in particular the Sierra Nevada, is one of them. For years, the temperatures have been rising, the amount of snow is decreasing and precipitation increasingly falls in the form of rain. In a normal winter, the Sierra Nevada stores immense masses of water in the form of snow. This means that when the snow melts in the spring, the farmers are provided with valuable water right on time for sowing the crops. Due to the comparatively warm winters in recent years, the amount of snow has decreased; in the winter the rain already flows as unused water towards the sea. In the drier spring months, the meltwater is missing, thus exacerbating the drought.
The springs that are suitable for use have already been tapped. The three major river systems, Colorado River, Sacramento and San Joaquin, are being intensively exploited. The reservoirs often hold only 20 percent of the normal water levels. Wells are being drilled, but lead to further conflicts – as described above.
The most obvious solution is to save water. Governor Jerry Brown for this reason declared a "drought State of Emergency" in January 2015. Since this date, the government is empowered to order cuts. On 5 May, for example, it ordered all cities to reduce their water consumption by 25%. Many municipalities succeeded in doing this. The irrigation of road verges was stopped, front gardens stocked with drought-resistant plants, courses on how to save water offered in public institutions, and much more. It must be kept in mind, however, that cities and towns do not consume even 20 per cent of the water available. The water-saving measures are good on the whole, and important as a signal, but probably not enough.
The call for technical solutions is becoming increasingly louder. For several years now, large water treatment plants have been in operation throughout the country. Although the reprocessed wastewater is not drinkable, it can be used for irrigation or flushing toilets. The high costs are not necessarily caused by the elaborate recycling processes, but rather the infrastructure changes that go hand in hand with them. For so-called grey water, conventional pipelines cannot be used, as these are reserved for drinking water. For this reason, a new pipeline system must be installed and measures taken to ensure that the different types of water do not mix. In California, the new utility lines are painted in lurid purple (Purple Pipes). Another possible approach lies in seawater desalination plants. The larger cities often cooperate with universities to create new concepts. The outlay is enormous: the transformation of salt water into good quality drinking water requires huge amounts of energy.
The drought in California is confronting the government, cities and people with major challenges. There are no easy solutions. Immense hope is being placed in El Niño. However, it must come at the right time and bring heavy rainfalls at the same time. California's plight can only be alleviated in this way. If the rain does not come, there is a great danger of the "Golden State" becoming a "Brown State".