Imagine the snow in the Sierra Nevada mountains as a giant reservoir providing water for 23 million people throughout California. During droughts, this snow reserve shrinks, affecting water availability in the state.
Researchers fear global warming will cause the Sierra Nevada snowpack to lose much of its freshwater by the end of the century, spelling trouble for water management throughout the state.
The California Department of Water Resources found last month that the water content in the Sierra snowpack was about half its historical average for the beginning of April despite late winter storms. One year before, the water content had been measured at over 160 percent of the historical average. This swing is not new and continues California’s recent trend of climate shifts, following the 2011-2015 drought.
Scientists from the University of California, Los Angeles (UCLA) expect to see an increase in ‘precipitation whiplash’ events in the region, with rapid transitions between extreme wet and extreme dry periods.
These extreme precipitation events pose a risk to dams, levees and canals, few of which have been tested against intense storms such as those that caused the Great Flood of 1862. By the end of the 21st century, the frequency of floods of this magnitude across the state is expected to increase by 300 to 400 percent.