California Weather Whiplash: Flood to Drought to Flood

whiplashCalifornia has a reputation in the United States of being the Garden of Eden when it comes to weather. Sunny beaches (“It Never Rains in Southern California”) and the romantic mists of “walking with my baby down by the San Francisco Bay” are what come to mind when thinking about California. Unfortunately, the reality has been much harsher over the past few years, creating a phenomenon known as weather whiplash.

From 2013 to 2016 California experienced its worst drought ever. At the end of 2016, the skies opened and record amounts of precipitation caused flooding and mudslides, collapsed a bridge and damaged the Oroville Dam, forcing 250,000 to evacuate their homes. Just a couple of months later California suffered its worse fires ever, causing serious damage across 280,000 acres. The fires were followed by further flooding and mudslides. [1]

The Whiplash Effect—No Relief in the Future

Although it’s not unusual for the first rains after a drought to cause some flooding, the intensity of the whiplash effect in California was remarkable.

Over the last two centuries, weather whiplash has been recorded about four times a century. In the 21st and 22nd centuries it is expected to occur twice as often. [2] One explanation for these extreme weather conditions points the finger at global warming. As temperatures rise, clouds are heavier with rain water, creating what is known as atmospheric rivers. Depending on winds and atmospheric pressures, these rivers, which hold 50% more water than normal clouds, can open up at any time, causing flooding—or blow right past, causing droughts. [3]

The Whiplash Effect—Water Management

There have been a number of studies about what causes precipitation whiplash and what steps can be taken to manage water during this kind of crisis.

In April 2018 a major study was released by UCLA’s Institute of Environment and Sustainability. Daniel Swain, the study’s lead author, wrote about California’s past weather history, its current problems, and the challenges in managing water in the face of the problems that we know will occur during the next one hundred years.

Knowing that floods cause many more deaths than drought, Swain and his colleagues studied in depth the flood of 1862. Forty three days of continuous rain after a four-year drought created rivers that were 300 miles long and 60 miles wide. At that time there were only 500,000 people living in California. Today the state is home to more than 40 million inhabitants. UCLA’s study shows that drastic flooding such as what took place in 1862 takes place about once every 200 years and argues that now is the time to prepare for the next major event. [4]

The study showed that instead of preparing for average rainfall, as in the past, we need to plan for extremes. The potential damage from a major flood is expected to be close to one trillion dollars and many lives lost. The scientists are saying that we have to plan the same way as we plan for earthquakes—by looking at the worst-case scenario and being prepared if and when it happens. One example of the measures they are suggesting is a law that was passed in California in 2016 with much stricter infrastructure requirements on all new buildings. [5]

The Final Note

Ellen Hanak, water policy director of the Public Policy Institute of California summed it up perfectly when she said that the secret is simply to store water for the dry seasons and keep water out of harm’s way during the wet seasons. Of course implementing this kind of policy requires foresight, planning and allocation of resources. Let’s hope that the powers-that-be in California and other parts of the world will hear and understand this message so that we will all be better prepared to face the weather extremes of the coming century.

References

[1] Megan Multeni, California’s Water Whiplash is only going to get worse, April 23, 2018
[2] Doyle Rice, , California’s wild extremes of droughts and floods to worsen as climate warms, April 23, 2018
[3] Umair Ufun, California’s droughts and deluges are a sign of the weather whiplash to come, April 24, 2018
[4] Dave Colgan, Study predicts a severe climate future for California, April 23, 2018
[5] Tara Lohan, Report: Climate change is driving precipitation whiplash in California, April 23, 2018

×

Comments are closed.