Drought conditions have returned to California's San Joaquin Valley and the central coastal region where three-quarters of its fruit, nuts and vegetables are grown. These areas are irrigated using underground aquifers so droughts have not affected agricultural output, which has in fact continued to rise.
Recently published tree ring analysis reveals that California's 2012-2014 drought was its worst in 1,200 years. Lakes and rivers shrank and record high temperatures sizzled the landscape. Yet California somehow produced 51% of US food and accounted for 71% of farm value in 2015. According to the USDA, lemons, tangerines, mandarins, nectarines, blueberries, raspberries, strawberries, honeydew melons, pistachios and walnuts “exceeded the previous 3-year average volumes, despite continued drought conditions.”
Yet this plundering of aquifers has many worried. 60% of California's water needs are now met by its subterranean aquifers. With no restrictions on how much can be pumped and very little winter replenishment of late, there's a real danger that California might one day run out of water.
High in the Sierra Nevada mountains lies the snowpack that provides one third of California's surface water. Last winter just 5% of normal snowfall accumulated in the mountains. Now scientists have found that snow pack is at its lowest level in five centuries. Winter snowfall is vital as its spring melt feeds the state's rivers and reservoirs.
Lakes reliant on incomes from tourists and fishing enthusiasts have been affected badly. Eagle Lake has seen a 15 foot drop in water level, so what was once one of the largest and busiest lakes in California, now has only one working marina. The rest have dried up. Boat mechanic James Watts said: “We watched the water level go and every year it was like, don’t worry, it’ll come back, it’ll come back. And three years ago was when it actually turned and went to nothing.”
Annual droughts have implications for wildfires too. This year over 102 million trees are thought to have died from drought, which leaves them prone to bark beetle attacks. The resulting forests of tinder-dry deadwood are a serious danger should fires break out. There is some disagreement about how to deal with them with officials wanting them processed as lumber, while others want them cut down to decompose on the forest floor.
Fire ecologists are not worried by the die-off which they say is part of the process of forest regeneration. Fire suppression allowed too much green forest to grow, which meant that the next fires to come were more devastating than previous ones.
California's ability to produce food during drought is now legendary. According to US Drought Monitor, 44.7 million people are currently living under “exceptional drought” conditions. For some of them the biggest question is whether or not to keep a grass lawn, something that can be frowned upon by neighbours, as it requires daily watering. But by continuing to rely on aquifers when rainfall patterns are no longer replenishing water stocks, some fear that California is taking out loans it might not be able to repay in future.
Check out the graph below:
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration. Map courtesy of NDMC-UNL.